U.S. patent application number 15/924703 was filed with the patent office on 2018-07-26 for antibodies against clostridium difficile toxins and uses thereof.
The applicant listed for this patent is E. R. Squibb & Sons, L.L.C., UNIVERSITY OF MASSACHUSETTS. Invention is credited to Donna M. AMBROSINO, Gregory J. BABCOCK, Teresa BROERING, Robert GRAZIANO, Hector Javier HERNANDEZ, Israel LOWY, Robert MANDELL, Deborah MOLRINE, William D. THOMAS, Jr., Hui-Fen ZHANG.
Application Number | 20180208643 15/924703 |
Document ID | / |
Family ID | 36928722 |
Filed Date | 2018-07-26 |
United States Patent
Application |
20180208643 |
Kind Code |
A1 |
AMBROSINO; Donna M. ; et
al. |
July 26, 2018 |
ANTIBODIES AGAINST CLOSTRIDIUM DIFFICILE TOXINS AND USES
THEREOF
Abstract
Antibodies that specifically bind to toxins of C. difficile,
antigen binding portions thereof, and methods of making and using
the antibodies and antigen binding portions thereof are provided
herein.
Inventors: |
AMBROSINO; Donna M.;
(Jamaica Plain, MA) ; BABCOCK; Gregory J.;
(Marlborough, MA) ; BROERING; Teresa; (Brookline,
MA) ; GRAZIANO; Robert; (Frenchtown, NJ) ;
HERNANDEZ; Hector Javier; (Canton, MA) ; LOWY;
Israel; (Dobbs Ferry, NY) ; MANDELL; Robert;
(Collins, IA) ; MOLRINE; Deborah; (Newton, MA)
; THOMAS, Jr.; William D.; (Dedham, MA) ; ZHANG;
Hui-Fen; (Pennington, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
UNIVERSITY OF MASSACHUSETTS
E. R. Squibb & Sons, L.L.C. |
Boston
Princeton |
MA
NJ |
US
US |
|
|
Family ID: |
36928722 |
Appl. No.: |
15/924703 |
Filed: |
March 19, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14926706 |
Oct 29, 2015 |
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15924703 |
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14080598 |
Nov 14, 2013 |
9217029 |
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14926706 |
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13490757 |
Jun 7, 2012 |
8609111 |
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14080598 |
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12533501 |
Jul 31, 2009 |
8236311 |
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13490757 |
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11051453 |
Feb 4, 2005 |
7625559 |
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12533501 |
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60613854 |
Sep 28, 2004 |
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60542357 |
Feb 6, 2004 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61P 31/00 20180101;
C07K 2317/56 20130101; A61K 39/08 20130101; C12N 15/86 20130101;
A61P 43/00 20180101; Y10S 424/809 20130101; C07K 2317/92 20130101;
G01N 33/56911 20130101; A61K 2039/505 20130101; A61P 1/12 20180101;
A61P 31/04 20180101; A61K 48/00 20130101; A61P 1/04 20180101; A61K
2039/507 20130101; C07K 2317/21 20130101; C07K 2317/565 20130101;
C07K 2317/76 20130101; C07K 2317/24 20130101; G01N 2333/33
20130101; C07K 16/1282 20130101; A61P 1/00 20180101; A61P 37/04
20180101; A61K 39/08 20130101; A61K 2300/00 20130101 |
International
Class: |
C07K 16/12 20060101
C07K016/12; A61K 39/08 20060101 A61K039/08; G01N 33/569 20060101
G01N033/569 |
Claims
1. An isolated monoclonal antibody that binds to Clostridium
difficile (C. difficile) toxin A, or an antigen binding portion
thereof, wherein the antibody, or antigen binding portion thereof,
comprises: (i) a heavy chain variable region CDR1 comprising SEQ ID
NO: 7; a heavy chain variable region CDR2 comprising SEQ ID NO: 8;
a heavy chain variable region CDR3 comprising SEQ ID NO: 9; a light
chain variable region CDR1 comprising SEQ ID NO: 16; a light chain
variable region CDR2 comprising SEQ ID NO: 17; and a light chain
variable region CDR3 comprising SEQ ID NO: 18; (ii) a heavy chain
variable region CDR1 comprising SEQ ID NO: 10; a heavy chain
variable region CDR2 comprising SEQ ID NO: 11; a heavy chain
variable region CDR3 comprising SEQ ID NO: 12; a light chain
variable region CDR1 comprising SEQ ID NO: 19; a light chain
variable region CDR2 comprising SEQ ID NO: 20; and a light chain
variable region CDR3 comprising SEQ ID NO: 21; or (iii) a heavy
chain variable region CDR1 comprising SEQ ID NO: 13; a heavy chain
variable region CDR2 comprising SEQ ID NO: 14; a heavy chain
variable region CDR3 comprising SEQ ID NO: 15; a light chain
variable region CDR1 comprising SEQ ID NO: 22; a light chain
variable region CDR2 comprising SEQ ID NO: 23; and a light chain
variable region CDR3 comprising SEQ ID NO: 24.
2. The isolated monoclonal antibody, or an antigen binding portion
thereof, of claim 1, wherein the antibody, or antigen binding
portion thereof, comprises a heavy chain variable region CDR1
comprising SEQ ID NO: 7, a heavy chain variable region CDR2
comprising SEQ ID NO: 8, a heavy chain variable region CDR3
comprising SEQ ID NO: 9, a light chain variable region CDR1
comprising SEQ ID NO: 16, a light chain variable region CDR2
comprising SEQ ID NO: 17, and a light chain variable region CDR3
comprising SEQ ID NO: 18.
3. The isolated monoclonal antibody, or an antigen binding portion
thereof, of claim 1, wherein the antibody, or antigen binding
portion thereof, comprises a heavy chain variable region CDR1
comprising SEQ ID NO: 10, a heavy chain variable region CDR2
comprising SEQ ID NO: 11, a heavy chain variable region CDR3
comprising SEQ ID NO: 12, a light chain variable region CDR1
comprising SEQ ID NO: 19, a light chain variable region CDR2
comprising SEQ ID NO: 20, and a light chain variable region CDR3
comprising SEQ ID NO: 21.
4. The isolated monoclonal antibody, or an antigen binding portion
thereof, of claim 1, wherein the antibody, or antigen binding
portion thereof, comprises a heavy chain variable region CDR1
comprising SEQ ID NO: 13, a heavy chain variable region CDR2
comprising SEQ ID NO: 14, a heavy chain variable region CDR3
comprising SEQ ID NO: 15, a light chain variable region CDR1
comprising SEQ ID NO: 22, a light chain variable region CDR2
comprising SEQ ID NO: 23, and a light chain variable region CDR3
comprising SEQ ID NO: 24.
5. An isolated monoclonal antibody that binds to Clostridium
difficile (C. difficile) toxin A, or an antigen binding portion
thereof, wherein the antibody, or antigen binding portion thereof,
comprises a heavy chain variable region having an amino acid
sequence at least 95% identical to the amino acid sequence set
forth in SEQ ID NO: 1, SEQ ID NO: 2, or SEQ ID NO: 3 and/or a light
chain variable region having an amino acid sequence at least 95%
identical to the amino acid sequence set forth in SEQ ID NO: 4, SEQ
ID NO: 5, or SEQ ID NO: 6.
6. The isolated monoclonal antibody, or an antigen binding portion
thereof, of claim 5, wherein the antibody, or antigen binding
portion thereof, comprises a heavy chain variable region having an
amino acid sequence at least 95% identical to the amino acid
sequence set forth in SEQ ID NO: 1.
7. The isolated monoclonal antibody, or an antigen binding portion
thereof, of claim 5, wherein the antibody, or antigen binding
portion thereof, comprises a heavy chain variable region having an
amino acid sequence at least 95% identical to the amino acid
sequence set forth in SEQ ID NO: 2.
8. The isolated monoclonal antibody, or an antigen binding portion
thereof, of claim 5, wherein the antibody, or antigen binding
portion thereof, comprises a heavy chain variable region having an
amino acid sequence at least 95% identical to the amino acid
sequence set forth in SEQ ID NO: 3.
9. The isolated monoclonal antibody, or an antigen binding portion
thereof, of claim 5, wherein the antibody, or antigen binding
portion thereof, comprises a light chain variable region having an
amino acid sequence at least 95% identical to the amino acid
sequence set forth in SEQ ID NO: 4.
10. The isolated monoclonal antibody, or an antigen binding portion
thereof, of claim 5, wherein the antibody, or antigen binding
portion thereof, comprises a light chain variable region having an
amino acid sequence at least 95% identical to the amino acid
sequence set forth in SEQ ID NO: 5.
11. The isolated monoclonal antibody, or an antigen binding portion
thereof, of claim 5, wherein the antibody, or antigen binding
portion thereof, comprises a light chain variable region having an
amino acid sequence at least 95% identical to the amino acid
sequence set forth in SEQ ID NO: 6.
12. The isolated monoclonal antibody, or an antigen binding portion
thereof, of claim 5, wherein the antibody, or antigen binding
portion thereof, comprises heavy and light chain variable regions
comprising amino acid sequences at least 95% identical to the amino
acid sequences set forth in SEQ ID NOs: 1 and 4, respectively.
13. The isolated monoclonal antibody, or an antigen binding portion
thereof, of claim 5, wherein the antibody, or antigen binding
portion thereof, comprises heavy and light chain variable regions
comprising amino acid sequences at least 95% identical to the amino
acid sequences set forth in SEQ ID NOs: 2 and 5, respectively.
14. The isolated monoclonal antibody, or an antigen binding portion
thereof, of claim 5, wherein the antibody, or antigen binding
portion thereof, comprises heavy and light chain variable regions
comprising amino acid sequences at least 95% identical to the amino
acid sequences set forth in SEQ ID NOs: 3 and 6, respectively.
15. The isolated monoclonal antibody, or antigen binding portion
thereof, of claim 1, wherein the antibody is a human antibody, a
humanized antibody or a chimeric antibody.
16. The antigen binding portion of claim 1, wherein the antigen
binding portion is a Fab, Fab'2, ScFv, Fd, Fv or dAb.
17. The isolated monoclonal antibody of claim 1, wherein the
antibody is an IgG1 or IgG3 isotype.
18. The isolated monoclonal antibody, or antigen binding portion
thereof, of claim 1, wherein the K.sub.D of the antibody, or
antigen binding portion thereof, is less than 20.times.10.sup.-6
M.
19. The isolated monoclonal antibody, or antigen binding portion
thereof, of claim 1, wherein the antibody, or antigen binding
portion thereof, neutralizes toxin A in vitro or in vivo.
Description
RELATED INFORMATION
[0001] The application is a continuation of U.S. patent application
Ser. No. 14/926,706, filed on Oct. 29, 2015, which is a
continuation of U.S. patent application Ser. No. 14/080,598, filed
on Nov. 14, 2013, now U.S. Pat. No. 9,217,029, which is a
divisional application of U.S. patent application Ser. No.
13/490,757, filed on Jun. 7, 2012, now U.S. Pat. No. 8,609,111,
which is a continuation of U.S. patent application Ser. No.
12/533,501, filed on Jul. 31, 2009, now U.S. Pat. No. 8,236,311,
which is a divisional application of U.S. patent application Ser.
No. 11/051,453, filed on Feb. 4, 2005, now U.S. Pat. No. 7,625,559,
which claims priority to U.S. provisional patent application No.
60/542,357, filed on Feb. 6, 2004, and U.S. provisional patent
application No. 60/613,854, filed on Sep. 28, 2004, the entire
contents both of which are hereby incorporated by reference.
[0002] The contents of any patents, patent applications, and
references cited throughout this specification are hereby
incorporated by reference in their entireties.
BACKGROUND OF THE INVENTION
[0003] Clostridium difficile (C. difficile) is a gram-positive
bacterium that causes gastrointestinal disease in humans. C.
difficile is the most common cause of infectious diarrhea in
hospital patients, and is one of the most common nosocomial
infections overall (Kelly et al., New Eng. J. Med., 330:257-62,
1994). In fact, disease associated with this pathogen may afflict
as many as three million hospitalized patients per year in the
United States (McFarland et al., New Eng. J. Med., 320:204-10,
1989; Johnson et al., Lancet, 336:97-100, 1990).
[0004] Treatment with antibiotics such as ampicillin, amoxicillin,
cephalosporins, and clindamycin that disrupt normal intestinal
flora can allow colonization of the gut with C. difficile and lead
to C. difficile disease (Kelly and Lamont, Annu. Rev. Med.,
49:375-90, 1998). The onset of C. difficile disease typically
occurs four to nine days after antibiotic treatment begins, but can
also occur after discontinuation of antibiotic therapy. C.
difficile can produce symptoms ranging from mild to severe diarrhea
and colitis, including pseudomembranous colitis (PMC), a severe
form of colitis characterized by abdominal pain, watery diarrhea,
and systemic illness (e.g., fever, nausea). Relapsing disease can
occur in up to 20% of patients treated for a first episode of
disease, and those who relapse are at a greater risk for additional
relapses (Kelly and Lamont, Annu. Rev. Med., 49:375-90, 1998).
[0005] C. difficile disease is believed to be caused by the actions
of two exotoxins, toxin A and toxin B, on gut epithelium. Both
toxins are high molecular weight proteins (280-300 kDa) that
catalyze covalent modification of Rho proteins, small GTP-binding
proteins involved in actin polymerization, in host cells.
Modification of Rho proteins by the toxins inactivates them,
leading to depolymerization of actin filaments and cell death. Both
toxins are lethal to mice when injected parenterally (Kelly and
Lamont, Annu. Rev. Med., 49:375-90, 1998).
[0006] C. difficile disease can be diagnosed by assays that detect
the presence or activity of toxin A or toxin B in stool samples,
e.g., enzyme immunoassays. Cytotoxin assays can be used to detect
toxin activity. To perform a cytotoxin assay, stool is filtered to
remove bacteria, and the cytopathic effects of toxins on cultured
cells are determined (Merz et al., J. Clin. Microbiol., 32:1142-47,
1994).
[0007] C. difficile treatment is complicated by the fact that
antibiotics trigger C. difficile associated disease. Nevertheless,
antibiotics are the primary treatment option at present.
Antibiotics least likely to cause C. difficile associated disease
such as vancomycin and metronidazole are frequently used.
Vancomycin resistance evolving in other microorganisms is a cause
for concern in using this antibiotic for treatment, as it is the
only effective treatment for infection with other microorganisms
(Gerding, Curr. Top. Microbiol. Immunol., 250:127-39, 2000).
Probiotic approaches, in which a subject is administered
non-pathogenic microorganisms that presumably compete for niches
with the pathogenic bacteria, are also used. For example, treatment
with a combination of vancomycin and Saccharomyces boulardii has
been reported (McFarland et al., JAMA., 271(24):1913-8, 1994.
Erratum in: JAMA, 272(7):518, 1994).
[0008] Vaccines have been developed that protect animals from
lethal challenge in infectious models of disease (Torres et al.,
Infect. Immun. 63(12):4619-27, 1995). In addition, polyclonal
antibodies have been shown to protect hamsters from disease when
administered by injection or feeding (Giannasca et al., Infect.
Immun. 67(2):527-38, 1999; Kink and Williams, Infect. Immun.,
66(5):2018-25, 1998). Murine monoclonal antibodies have been
isolated that bind to C. difficile toxins and neutralize their
activities in vivo and in vitro (Corthier et al., Infect. Immun.,
59(3):1192-5, 1991). There are some reports that human polyclonal
antibodies containing toxin neutralizing antibodies can prevent C.
difficile relapse (Salcedo et al., Gut., 41(3):366-70, 1997).
Antibody response against toxin A has been correlated with disease
outcome, indicating the efficacy of humoral responses in
controlling infection. Individuals with robust toxin A ELISA
responses had less severe disease compared to individuals with low
toxin A antibody levels (Kyne et al., Lancet, 357(9251):189-93,
2001).
[0009] The individual role of toxin A and toxin B in disease
pathogenesis, and the role of anti-toxin antibodies in protection
from C. difficile disease are controversial and may depend on the
host. In humans, the anti-toxin A antibody response has been
correlated to disease outcome, suggesting a requirement for
anti-toxin A response for protection. This observation is in
contrast with reports of disease-causing C. difficile organisms
that express only toxin B, implying that toxin B can contribute to
disease in humans. These toxin A-negative strains can also cause
disease in hamsters (Sambol et al., J. Infect. Dis.,
183(12):1760-6, 2001).
SUMMARY OF THE INVENTION
[0010] This invention is based, in part, on the discovery that
administration of antibodies against C. difficile toxin A to a
subject can protect the subject from relapse of C.
difficile-mediated disease in vivo. Administration of antibodies to
one or both of toxin A and toxin B can prevent primary C.
difficile-mediated disease. High affinity antibodies against C.
difficile toxins can be produced, e.g., in mice, such as transgenic
mice expressing human immunoglobulin gene segments. These
antibodies can neutralize toxin cytotoxicity in vitro, and
neutralize toxin enterotoxicity in vivo. Antibodies that recognize
toxin A and/or toxin B can inhibit and protect from disease in
vivo.
[0011] In one aspect, the invention features isolated human
monoclonal antibodies or antigen binding portions thereof that
specifically bind to an exotoxin of Clostridium difficile (C.
difficile). In certain embodiments, the antibodies or antigen
binding portions thereof specifically bind to C. difficile toxin A
(toxin A). In other embodiments, the antibody or antigen binding
portions thereof specifically bind to C. difficile toxin B (toxin
B). In other embodiments, the antibodies or antigen binding
portions thereof specifically bind to both toxin A and toxin B.
[0012] In certain embodiments, the antibodies or antigen binding
portions thereof neutralize toxin A in vitro, inhibit binding of
toxin A to mammalian cells, and/or inhibit C. difficile-mediated
disease in vivo.
[0013] In various embodiments, the antibodies or antigen binding
portions thereof have one or more of the following characteristics:
when administered to a mouse, they protect the mouse against
administration of a C. difficile toxin in an amount that would be
fatal to a control mouse not administered the antibody; protect
from or inhibit C. difficile-mediated colitis,
antibiotic-associated colitis, or pseudomembranous colitis (PMC) in
a subject; protect from or inhibit diarrhea in a subject; and/or
inhibit relapse of C. difficile-mediated disease.
[0014] The antibodies or antigen binding portions thereof can
specifically bind to an epitope within the N-terminal half of toxin
A, e.g., an epitope between amino acids 1-1256 of toxin A. In other
embodiments, the antibodies or antigen binding portions thereof
specifically bind to an epitope within the C-terminal receptor
binding domain of toxin A, e.g., an epitope between amino acids
1852-2710 of toxin A, or an epitope between amino acids 659-1852,
e.g., an epitope within amino acid residues 900-1852, 900-1200, or
920-1033 of toxin A. In other embodiments, the antibodies or
antigen binding portions thereof specifically bind an epitope
within amino acids 1-600, 400-600, or 415-540 of toxin A. Other
particular antibodies or antigen binding portions thereof, can
specifically bind to an epitope within amino acid residues 1-100,
100-200, 200-300, 300-400, 400-500, 500-600, 600-700, 700-800,
900-1000, 1100-1200, 1200-1300, 1300-1400, 1400-1500, 1500-1600,
1600-1700, 1800-1900, 1900-200, 2100-2200 or 2200-2300, 2300-2400,
2400-2500, 2500-2600, 2600-2710 of toxin A, or any interval,
portion or range thereof.
[0015] In certain embodiments, the antibodies or antigen binding
portions thereof specifically bind to toxin A with a K.sub.D of
less than about 20.times.10.sup.-6 M. In a particular embodiment,
the antibody, or antigen binding portion thereof, specifically
binds to toxin A with a K.sub.D of less than about
10.times.10.sup.-7M, less than about 10.times.10.sup.-8M, less than
about 10.times.10.sup.-9M, or less than about 10.times.10.sup.-10
M. In other particular embodiments, the antibody, or antigen
binding portion thereof, specifically binds to toxin A with a
K.sub.D of less than about 50.times.10.sup.-10 M, less than about
20.times.10.sup.-10 M, less than about 15.times.10.sup.-10 M, less
than about 8.times.10.sup.-10 M, or less than about
5.times.10.sup.-10 M.
[0016] In various other embodiments, the antibodies or antigen
binding portions thereof include a variable heavy chain region
including an amino acid sequence at least 80%, 85%, 90%, 95%, 98%,
99%, or more identical to a variable heavy chain region amino acid
sequence of the antibody produced by clone 3D8 (SEQ ID NO:1), 1B11
(SEQ ID NO:2), or 3H2 (SEQ ID NO:3).
[0017] In certain embodiments, the antibodies or antigen binding
portions thereof include a variable light chain region comprising
an amino acid sequence at least 80%, 85%, 90%, 95%, 98%, 99%, or
more identical to a variable light chain region amino acid sequence
of the antibody produced by clone 3D8 (SEQ ID NO:4), 1B11 (SEQ ID
NO:5), or 3H2 (SEQ ID NO:6).
[0018] In certain embodiments, the antibodies or antigen binding
portions thereof each include both a variable heavy chain region
including an amino acid sequence at least 80%, 85%, 90%, 95%, 98%,
99%, or more identical to a variable heavy chain region amino acid
sequence of the antibody produced by clone 3D8 (SEQ ID NO:1), 1B11
(SEQ ID NO:2), or 3H2 (SEQ ID NO:3), and a variable light chain
region including an amino acid sequence at least 80%, 85%, 90%,
95%, 98%, 99%, or more identical to a variable light chain amino
acid sequence of clone 3D8 (SEQ ID NO:4), 1B11 (SEQ ID NO:5), or
3H2 (SEQ ID NO:6).
[0019] In various embodiments, the antibodies or antigen binding
portions thereof specifically bind to an epitope that overlaps with
an epitope bound by an antibody produced by clone 3D8, 1B11, or 3H2
and/or compete for binding to toxin A with an antibody produced by
clone 3D8, 1B11, or 3H2.
[0020] A variable heavy chain region of the antibodies or antigen
binding portions thereof can include one or more complementarity
determining regions (CDRs) that are at least 80%, 85%, 90%, 95%, or
99%, or more identical to a CDR of the antibody produced by clone
3D8 (SEQ ID NOs:7-9), 1B11(SEQ ID NOs:10-12), or 3H2 (SEQ ID
NOs:13-15) (also shown in Table 1).
[0021] A variable light chain region of the antibodies or antigen
binding portions thereof can include one or more CDRs that are at
least 80%, 85%, 90%, 95%, or 99%, or more identical to a CDR of a
variable light chain region of the antibody produced by clone 3D8
(SEQ ID NOs:16-18), 1B11 (SEQ ID NOs:19-21), or 3H2 (SEQ ID
NOs:22-24) (also shown in Table 2).
[0022] A variable heavy chain region of the antibodies or antigen
binding portions thereof can include one or more complementarity
determining regions (CDRs) that are at least 80%, 85%, 90%, 95%, or
99%, or more identical to a CDR of the antibody produced by clone
3D8 (SEQ ID NOs:7-9), 1B11(SEQ ID NOs:10-12), or 3H2 (SEQ ID
NOs:13-15), and a variable light chain region of the antibodies or
antigen binding portions thereof can include one or more CDRs that
are at least 80%, 85%, 90%, 95%, 99%, or more identical to a CDR of
a variable light chain region of the antibody produced by clone 3D8
(SEQ ID NOs:16-18), 1B11 (SEQ ID NOs:19-21), or 3H2 (SEQ ID
NOs:22-24).
[0023] A variable heavy chain region of the antibodies or antigen
binding portions thereof can include three CDRs that are at least
80%, 85%, 90%, 95%, or 99%, or more identical to a CDR of a
variable heavy chain region of the antibody produced by clone 3D8
(SEQ ID NOs:7-9), 1B11(SEQ ID NOs:10-12), or 3H2 (SEQ ID
NOs:13-15).
[0024] In some embodiments, a variable light chain region of the
antibodies or antigen binding portions thereof includes three CDRs
that are at least 80%, 85%, 90%, 95%, 99%, or more identical to a
CDR of a variable light chain region of the antibody produced by
clone 3D8 (SEQ ID NOs:16-18), 1B11 (SEQ ID NOs:19-21), or 3H2 (SEQ
ID NOs:22-24).
[0025] In some embodiments, a variable light chain region of the
antibodies or antigen binding portions thereof includes one or more
CDRs that are at least 80%, 85%, 90%, 95%, or 99%, or more
identical to a CDR of a variable light chain region of the antibody
produced by clone 3D8 (SEQ ID NOs:16-18), 1B11 (SEQ ID NOs:19-21),
or 3H2 (SEQ ID NOs:22-24), and a variable heavy chain region of the
antibodies or antigen binding portions thereof includes three CDRs
that are at least 80%, 85%, 90%, 95%, or 99%, or more identical to
a CDR of a variable heavy chain region of the antibody produced by
clone 3D8 (SEQ ID NOs:7-9), 1B11(SEQ ID NOs:10-12), or 3H2 (SEQ ID
NOs:13-15). The variable light chain region can include three CDRs
that are at least 80%, 85%, 90%, 95%, or 99%, or more identical to
a CDR of a variable light chain region of the antibody produced by
clone 3D8 (SEQ ID NOs:16-18), 1B11 (SEQ ID NOs:19-21), or 3H2 (SEQ
ID NOs:22-24).
[0026] In certain embodiments, a variable heavy chain region of the
antibodies or antigen binding portions thereof includes three CDRs
that are identical to a CDR of a variable heavy chain region of the
antibody produced by clone 3D8 (SEQ ID NOs:7-9), 1B11 (SEQ ID
NOs:10-12), or 3H2 (SEQ ID NOs:13-15), and a variable light chain
region of the antibodies or antigen binding portions thereof
includes three CDRs that are identical to a CDR of a variable light
chain region of the antibody produced by clone 3D8 (SEQ ID
NOs:16-18), 1B11 (SEQ ID NOs:19-21), or 3H2 (SEQ ID NOs:22-24),
e.g., a variable light chain region and variable heavy chain region
of the antibody or antigen binding portion thereof are identical to
a variable light chain region and variable heavy chain region of
the antibody produced by clone 3D8 (SEQ ID NO:1, SEQ ID NO:4), 1B11
(SEQ ID NO:2, SEQ ID NO:5), or 3H2 (SEQ ID NO:3, SEQ ID NO:6).
[0027] In some embodiments, the antibodies or antigen binding
portions thereof neutralize toxin B in vitro, inhibit binding of
toxin B to mammalian cells, and/or neutralize toxin B in vivo.
[0028] In some embodiments, the antibodies or antigen binding
portions thereof specifically bind to an epitope in a C-terminal
portion of toxin B (e.g., between amino acids 1777-2366 of toxin
B). Other particular antibodies or antigen binding portions
thereof, can specifically bind to an epitope within amino acid
residues 1-100, 100-200, 200-300, 300-400, 400-500, 500-600,
600-700, 700-800, 900-1000, 1100-1200, 1200-1300, 1300-1400,
1400-1500, 1500-1600, 1600-1700, 1800-1900, 1900-200, 2100-2200 or
2200-2366 of toxin B, or any interval, portion or range
thereof.
[0029] In certain embodiments, the antibodies or antigen binding
portions thereof specifically bind to toxin B with a K.sub.D of
less than about 20.times.10.sup.-6M. In a particular embodiment,
the antibody, or antigen binding portion thereof, specifically
binds to toxin B with a K.sub.D of less than about
10.times.10.sup.-7M, less than about 10.times.10.sup.-8 M, less
than about 10.times.10.sup.-9M, or less than about
10.times.10.sup.-10 M. In other particular embodiments, the
antibody, or antigen binding portion thereof, specifically binds to
toxin B with a K.sub.D of less than about 50.times.10.sup.-10 M,
less than about 20.times.10.sup.-10 M, less than about
15.times.10.sup.-10 M, less than about 8.times.10.sup.-10 M, or
less than about 5.times.10.sup.-10 M.
[0030] In various other embodiments, the antibodies or antigen
binding portions thereof include a variable heavy chain region
including an amino acid sequence that is at least 80%, 85%, 90%,
95%, 98%, 99%, or more identical to a variable heavy chain region
amino acid sequence of the antibody produced by clone 124-152
(i.e., the amino acid sequence shown in SEQ ID NO:54), 2A11, or
1G10.
[0031] In certain embodiments, the antibodies or antigen binding
portions thereof include a variable light chain region comprising
an amino acid sequence that is at least 80%, 85%, 90%, 95%, 98%,
99%, or more identical to a variable heavy chain region amino acid
sequence of the antibody produced by clone 124-152 (i.e., the amino
acid sequence shown in SEQ ID NO:58), 2A11, or 1G10.
[0032] In certain embodiments, the antibodies or antigen binding
portions thereof each include both a variable heavy chain region
including an amino acid sequence at least 80%, 85%, 90%, 95%, 98%,
99%, or more identical to a variable heavy chain region amino acid
sequence of the antibody produced by clone 124-152 (i.e., the amino
acid sequence shown in SEQ ID NO:54), 2A11, or 1G10, and a variable
light chain region including an amino acid sequence that is at
least 80%, 85%, 90%, 95%, 98%, 99%, or more identical to a variable
light chain amino acid sequence of the antibody produced by clone
124-152 (i.e., the amino acid sequence shown in SEQ ID NO:58),
2A11, or 1G10.
[0033] In various embodiments, the antibodies or antigen binding
portions thereof specifically bind to an epitope that overlaps with
an epitope bound by an antibody produced by clone 124-152, 2A11, or
1G10 and/or compete for binding to toxin B with an antibody
produced by clone 124-152, 2A11, or 1G10.
[0034] A variable heavy chain region of the antibodies or antigen
binding portions thereof can include one or more complementarity
determining regions (CDRs) that are at least 80%, 85%, 90%, 95%, or
99%, or more identical to a CDR of the antibody produced by clone
124-152 (SEQ ID NOs: 62, 64, or 66), 2A11, or 1G10 (Table 3).
[0035] A variable light chain region of the antibodies or antigen
binding portions thereof can include one or more complementarity
determining regions (CDRs) that are at least 80%, 85%, 90%, 95%, or
99%, or more identical to a CDR of the antibody produced by clone
124-152 (SEQ ID NOs: 68, 70, or 72), 2A11, or 1G10 (Table 4).
[0036] A variable heavy chain region of the antibodies or antigen
binding portions thereof can include one or more complementarity
determining regions (CDRs) that are at least 80%, 85%, 90%, 95%, or
99%, or more identical to a CDR of the antibody produced by clone
124-152 (SEQ ID NOs: 62, 64, or 66), 2A11, or 1G10, and a variable
light chain region of the antibodies or antigen binding portions
thereof can include one or more CDRs that are at least 80%, 85%,
90%, 95%, 99%, or more identical to a CDR of a variable light chain
region of the antibody produced by clone 124-152 (SEQ ID NOs: 68,
70, or 72), 2A11, or 1G10.
[0037] A variable heavy chain region of the antibodies or antigen
binding portions thereof can include three CDRs that are at least
80%, 85%, 90%, 95%, or 99%, or more identical to a CDR of a
variable heavy chain region of the antibody produced by clone
124-152 (SEQ ID NOs: 62, 64, or 66), 2A11, or 1G10.
[0038] In certain embodiments, the variable light chain region of
the antibodies or antigen binding portions thereof includes three
CDRs that are at least 80%, 85%, 90%, 95%, 99%, or more identical
to a CDR of a variable light chain region of the antibody produced
by clone 124-152 (SEQ ID NOs: 68, 70, or 72), 2A11, or 1G10.
[0039] In other embodiments, the variable light chain region of the
antibodies or antigen binding portions thereof includes one or more
CDRs that are at least 80%, 85%, 90%, 95%, or 99%, or more
identical to a CDR of a variable light chain region of the antibody
produced by clone 124-152 (SEQ ID NOs: 68, 70, or 72), 2A11, or
1G10, and a variable heavy chain region of the antibodies or
antigen binding portions thereof includes three CDRs that are at
least 80%, 85%, 90%, 95%, or 99%, or more identical to a CDR of a
variable heavy chain region of the antibody produced by clone
124-152 (SEQ ID NOs: 62, 64, or 66), 2A11, or 1G10. The variable
light chain region can include three CDRs that are at least 80%,
85%, 90%, 95%, or 99%, or more identical to a CDR of a variable
light chain region of the antibody produced by clone 124-152 (SEQ
ID NOs: 68, 70, or 72), 2A11, or 1G10.
[0040] In still other embodiments, the variable heavy chain region
of the antibodies or antigen binding portions thereof includes
three CDRs that are identical to a CDR of a variable heavy chain
region of the antibody produced by clone 124-152 (SEQ ID NOs: 62,
64, or 66), 2A11, or 1G10, and a variable light chain region of the
antibodies or antigen binding portions thereof includes three CDRs
that are identical to a CDR of a variable light chain region of the
antibody produced by clone 124-152 (SEQ ID NOs: 68, 70, or 72),
2A11, or 1G10, e.g., a variable light chain region and variable
heavy chain region of the antibody or antigen binding portion
thereof are identical to a variable light chain region and variable
heavy chain region of the antibody produced by clone 124-152 (SEQ
ID NOs: 62, 64, or 66), 2A11, or 1G10.
[0041] The antibodies or antigen binding portions thereof can be
full-length antibodies, can include an effector domain, e.g., an Fc
domain, can be immunoglobulin gamma isotype antibodies,
single-chain antibodies, or Fab fragments. The antibodies or
antigen binding portions thereof can further include a
pharmaceutically acceptable carrier and/or a label.
[0042] In various embodiments, compositions including the
antibodies or antigen binding portions thereof are free of other
human polypeptides (e.g., they contain less than 5% human
polypeptides other than the antibodies or antigen binding portions
thereof).
[0043] In yet another aspect, the invention features compositions
including: (a) an isolated human monoclonal antibody or antigen
binding portion thereof that specifically binds to an exotoxin of
C. difficile; and (b) a polyclonal antibody or antigen binding
portion thereof that specifically binds to an exotoxin of C.
difficile.
[0044] In one embodiment, the human monoclonal antibody or antigen
binding portion thereof specifically binds to C. difficile toxin A,
and the polyclonal antibody or antigen binding portion thereof
specifically binds to C. difficile toxin B. In one embodiment, the
human monoclonal antibody or antigen binding portion thereof
specifically binds to C. difficile toxin B, and the polyclonal
antibody or antigen binding portion thereof specifically binds to
C. difficile toxin A. The antibodies can include other features
described herein.
[0045] In another aspect, the invention features isolated human
monoclonal antibodies or antigen binding portions thereof that
specifically bind to an exotoxin of Clostridium difficile (C.
difficile), wherein the antibodies: (a) include a heavy chain
variable region that is the product of or derived from a human VH
3-33 gene; and/or (b) include a light chain variable region that is
the product of or derived from a human V.kappa. gene selected from
the group consisting of V.kappa. L19, V.kappa. L6 and V.kappa. L15.
The antibodies or antigen binding portions thereof can include
other features described herein.
[0046] In another aspect, the invention features isolated human
monoclonal antibodies or antigen binding portions thereof that
specifically bind to an exotoxin of Clostridium difficile (C.
difficile), wherein the antibodies: (a) include a heavy chain
variable region that is the product of or derived from a human VH
5-51 gene; and/or (b) include a light chain variable region that is
the product of or derived from a human V.kappa. A27 gene. The
antibodies or antigen binding portions thereof also can include
other features described herein.
[0047] In another aspect, the invention features isolated
polypeptides that include an antigen binding portion of an antibody
produced by hybridoma clone 3D8, 1B11, or 3H2 (also referred to
herein as "3D8", "1B11", and "3H2").
[0048] In another aspect, the invention features isolated
polypeptides that include an antigen binding portion of an antibody
produced by hybridoma clone 124-152, 2A11, or 1G10 (also referred
to herein as "124-152", "2A11", and "1G10").
[0049] In another aspect, the invention features isolated
monoclonal antibodies or antigen binding portions thereof that
specifically bind to an exotoxin of C. difficile, neutralize the
toxin, inhibit, and/or protect from C. difficile-mediated disease.
In one embodiment, the antibodies or antigen binding portions
thereof are mammalian (e.g., human) antibodies or antigen binding
portions thereof. The antibodies or antigen binding portions
thereof can include other features described herein.
[0050] In another aspect, the invention features compositions
including: (a) an isolated human monoclonal antibody or antigen
binding portion thereof that specifically binds to C. difficile
toxin A; and (b) an isolated human monoclonal antibody or antigen
binding portion thereof that specifically binds to C. difficile
toxin B.
[0051] In another aspect, the invention features isolated nucleic
acids including a sequence encoding polypeptides at least 75%, 80%,
85%, 90%, 95%, 99%, or more identical to SEQ ID NOs:1, 2, 3, 4, 5,
or 6; e.g., wherein the nucleic acid sequence is at least 75%, 80%,
85%, 90%, 95%, 99%, or more identical to SEQ ID NOs:38, 39, 40, 35,
36, or 37. The invention also features expression vectors including
a nucleic acid encoding a polypeptide at least 75%, 80%, 85%, 90%,
95%, 99%, or more identical to SEQ ID NOs:1, 2, 3, 4, 5, or 6;
e.g., wherein the nucleic acid sequence is at least 75%, 80%, 85%,
90%, 95%, 99%, or more identical to SEQ ID NOs:38, 39, 40, 35, 36,
or 37, as well as host cells, e.g., bacterial cells, e.g., E. coli
cells, including a nucleic acid encoding a polypeptide at least
75%, 80%, 85%, 90%, 95%, 99%, or more identical to SEQ ID NOs:1, 2,
3, 4, 5, or 6; e.g., wherein the nucleic acid sequence is at least
75%, 80%, 85%, 90%, 95%, 99%, or more identical to SEQ ID NOs:38,
39, 40, 35, 36, or 37.
[0052] In another aspect, the invention features isolated nucleic
acids including a sequence encoding a polypeptide that is at least
75%, 80%, 85%, 90%, 95%, 99%, or more identical to SEQ ID NOs: 54,
56, 58, or 60, for example, wherein the nucleic acid sequence is at
least 75%, 80%, 85%, 90%, 95%, 99%, or more identical to SEQ ID
NOs: 55, 57, 59, or 61. The invention also features expression
vectors including a nucleic acid encoding a polypeptide at least
75%, 80%, 85%, 90%, 95%, 99%, or more identical to SEQ ID NOs: 54,
56, 58, or 60, for example, wherein the nucleic acid sequence is at
least 75%, 80%, 85%, 90%, 95%, 99%, or more identical to SEQ ID
NOs: 55, 57, 59, or 61. The invention also provides host cells,
e.g., bacterial cells, e.g., E. coli cells, that include a nucleic
acid encoding a polypeptide that is at least 75%, 80%, 85%, 90%,
95%, 99%, or more identical to SEQ ID NOs: 54, 56, 58, or 60, for
example, wherein the nucleic acid sequence is at least 75%, 80%,
85%, 90%, 95%, 99%, or more identical to SEQ ID NOs: 55, 57, 59, or
61.
[0053] The host cells can also be eukaryotic cells, e.g., yeast
cells, mammalian cells, e.g., Chinese hamster ovary (CHO) cells,
NS0 cells, or myeloma cells.
[0054] In another aspect, the invention features kits including an
isolated human monoclonal antibody or antigen binding portion
thereof that specifically binds to an exotoxin of Clostridium
difficile (C. difficile), e.g., an antibody or antigen binding
portion thereof described herein. The kit can include instructions
for use in preventing or treating C. difficile-mediated
disease.
[0055] The kit can further include a polyclonal antibody or antigen
binding portion thereof that specifically binds an exotoxin of C.
difficile. In one embodiment, the human monoclonal antibody or
antigen binding portion thereof specifically binds to C. difficile
toxin A. In one embodiment, the polyclonal antibody or antigen
binding portion thereof specifically binds to C. difficile toxin
B.
[0056] In another aspect, the invention features kits including:
(a) an isolated human monoclonal antibody that specifically binds
to C. difficile toxin A; and (b) an isolated human monoclonal
antibody that specifically binds to C. difficile toxin B.
[0057] The invention also features methods of treating C. difficile
disease in a subject by administering to the subject an isolated
human monoclonal antibody or antigen binding portion thereof that
specifically binds to an exotoxin of Clostridium difficile (C.
difficile) in an amount effective to inhibit C. difficile disease,
e.g., C. difficile-mediated colitis, antibiotic-associated colitis,
C. difficile-mediated pseudomembranous colitis (PMC), or diarrhea,
or relapse of C. difficile-mediated disease. The antibody or
antigen binding portion thereof can be administered, e.g.,
intravenously, intramuscularly, or subcutaneously, to the
subject.
[0058] The antibody or antigen binding portion thereof can be
administered alone or in combination with another therapeutic
agent, e.g., a second human monoclonal antibody or antigen binding
portion thereof. In one example, the antibody or antigen binding
portion thereof specifically binds to C. difficile toxin A, and the
second human monoclonal antibody or antigen binding portion thereof
specifically binds to C. difficile toxin B. In another example, the
second agent is an antibiotic, e.g., vancomycin or metronidazole.
The second agent can be polyclonal gamma-globulin (e.g., human
gamma-globulin).
[0059] In a particular embodiment, an antibody or antigen binding
portion thereof is administered which includes a variable light
chain region and a variable heavy chain region identical to the
variable light chain region and variable heavy chain region of the
antibody produced by clone 3D8 (i.e., including a variable light
chain region sequence identical to SEQ ID NO:4 and a variable heavy
chain region sequence identical to SEQ ID NO:1.
[0060] In another embodiment, this antibody or antigen binding
portion thereof is administered in combination with an antibody or
antigen binding portion thereof which includes a variable light
chain region and a variable heavy chain region identical to the
variable light chain region and variable heavy chain region of the
antibody produced by clone 124-152 (i.e., including a variable
light chain region sequence identical to SEQ ID NO:58 and a
variable heavy chain region sequence identical to SEQ ID
NO:54).
[0061] In yet another embodiment, an antibody or antigen binding
portion produced by clone 3D8 (i.e., including a variable light
chain region sequence identical to SEQ ID NO:4 and a variable heavy
chain region sequence identical to SEQ ID NO:1), is administered in
combination with an antibody or antigen binding portion thereof
produced by clone 124-152 (i.e., including a variable light chain
region sequence identical to SEQ ID NO:58 and a variable heavy
chain region sequence identical to SEQ ID NO:54).
[0062] In another aspect, the invention features methods for making
an antibody or antigen binding portion thereof that specifically
binds to an exotoxin of C. difficile, by immunizing a transgenic
non-human animal having a genome comprising a human heavy chain
transgene and a human light chain transgene with a composition that
includes an inactivated exotoxin, and isolating an antibody from
the animal. The exotoxin can be inactivated, for example, by
treatment with UDP-dialdehyde or by mutation (e.g., using
recombinant methods). The method can further include evaluating
binding of the antibody to the exotoxin.
[0063] The invention also features methods for making a human
monoclonal antibody or antigen binding portion thereof by providing
a nucleic acid encoding a human monoclonal antibody or antigen
binding portion thereof that specifically binds to an exotoxin of
C. difficile, and expressing the nucleic acid in a host cell.
[0064] In yet another aspect, the invention features a hybridoma or
transfectoma including a nucleic acid encoding antigen binding
portions (e.g., CDRs, or variable regions) of the antibody produced
by clone 3D8, 1B11, or 3H2.
[0065] In yet another aspect, the invention features a hybridoma or
transfectoma including a nucleic acid encoding antigen binding
portions (e.g., CDRs, or variable regions) of the antibody produced
by clone 124-152, 2A11, or 1G10.
[0066] In addition, the invention features a method for making a
hybridoma that expresses an antibody that specifically binds to an
exotoxin of C. difficile by immunizing a transgenic non-human
animal having a genome that includes a human heavy chain transgene
and a human light chain transgene, with a composition that includes
the exotoxin, wherein the toxin is inactivated; isolating
splenocytes from the animal; generating hybridomas from the
splenocytes; and selecting a hybridoma that produces an antibody
that specifically binds to the exotoxin.
[0067] Treatment of humans with human monoclonal antibodies offers
several advantages. For example, the antibodies are likely to be
less immunogenic in humans than non-human antibodies. The therapy
is rapid; toxin inactivation can occur as soon as the antibody
reaches sites of infection and directly neutralizes the
disease-causing toxin(s). Human antibodies localize to appropriate
sites in humans more efficiently than non-human antibodies.
Furthermore, the treatment is specific for C. difficile, and is
unlikely to disrupt normal gut flora, unlike traditional antibiotic
therapies.
[0068] Other features and advantages of the invention will be
apparent from the following detailed description, and from the
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0069] FIG. 1 is a table listing the amino acid sequences of the VH
and VL chains encoded by mRNA sequences from each clone. Lowercase
letters represent amino acids in the leader peptide. CDRs are
underlined. Clone 3D8, which expresses 6 unique light chain V
regions, only expressed the group I amino acid sequence.
[0070] FIG. 2A is a representation of the amino acid and nucleic
acid sequences of the VL chain expressed by clone 3D8. The
V-segment and J-segment genes are listed above the amino acid and
nucleic acid sequences. The CDRs are overlined.
[0071] FIG. 2B is a representation of the amino acid and nucleic
acid sequences of the VH chain expressed by clone 3D8. The
V-segment, D-segment and J-segment genes are listed above the amino
acid and nucleic acid sequences. The CDRs are overlined.
[0072] FIG. 3A is a representation of the amino acid and nucleic
acid sequences of the VL chain expressed by clone 1B11. The
V-segment and J-segment genes are listed above the amino acid and
nucleic acid sequences. The CDRs are overlined.
[0073] FIG. 3B is a representation of the amino acid and nucleic
acid sequences of the VH chain expressed by clone 1B11. The
V-segment, D-segment, and J-segment genes are listed above the
amino acid and nucleic acid sequences. The CDRs are overlined.
[0074] FIG. 4A is a representation of the amino acid and nucleic
acid sequences of the VL chain expressed by clone 33.3H2 (referred
to herein as 3H2; 33.3H2 and 3H2 are used interchangeably herein).
The V-segment and J-segment genes are listed above the amino acid
and nucleic acid sequences. The CDRs are overlined.
[0075] FIG. 4B is a representation of the amino acid and nucleic
acid sequences of the VH chain expressed by clone 33.3H2. The
V-segment and J-segment genes are listed above the amino acid and
nucleic acid sequences. The CDRs are overlined.
[0076] FIG. 5 is a graph depicting the results of ELISA assays,
which measured binding of anti-toxin A monoclonal antibodies to
toxin A.
[0077] FIGS. 6A-B are a set of graphs depicting results of in vitro
neutralization assays in the presence and absence of anti-toxin A
monoclonal antibodies. FIG. 6A depicts results for assays performed
with IMR-90 cells. FIG. 6B depicts results for assays performed
with T-84 cells.
[0078] FIG. 7 is a schematic representation of the toxin A
polypeptide, indicating fragments that were analyzed for epitope
mapping studies.
[0079] FIG. 8A-B are schematic representations of toxin A fragments
analyzed for epitope mapping studies.
[0080] FIG. 9 is a table listing the results of in vivo assays to
determine mouse protection from lethal challenge with toxin A by
anti-toxin A monoclonal antibodies.
[0081] FIG. 10 is a graph depicting the results of mouse ileal loop
fluid accumulation assays to measure efficacy of anti-toxin
antibody neutralization in vivo.
[0082] FIG. 11A is a schematic diagram of the timeline of
administration of various agents to hamsters in a hamster relapse
model.
[0083] FIG. 11B is a graph depicting the results of the assays as
the percentage of hamsters surviving clindamycin treatment followed
by C. difficile challenge.
[0084] FIG. 12 is a graph depicting results of hamster relapse
assays as the percentage of hamsters surviving clindamycin
treatment followed by C. difficile challenge.
[0085] FIG. 13 is a graph depicting results of assays in which in
vitro neutralization of toxin A and toxin B was measured in the
presence and absence of polyclonal antisera from goats immunized
with toxoid B. "G330" refers to samples in which sera from goat
#330 were tested. "G331" refers to samples in which sera from goat
#331 were tested.
[0086] FIG. 14 is a schematic diagram of the timeline of
administration of various agents to hamsters in a hamster relapse
model.
[0087] FIG. 15 is a graph depicting the results of hamster relapse
assays as the percentage of hamsters surviving clindamycin
treatment followed by C. difficile challenge. Hamsters were treated
with vancomycin, vancomycin and 3D8, vancomycin and antisera from
goat #331, or vancomycin, 3D8, and antisera from goat #331.
[0088] FIG. 16 is a graph depicting the results of hamster relapse
assays as the percentage of healthy animals after clindamycin
treatment followed by C. difficile challenge. "Goat 331" refers to
antisera from goat #331.
[0089] FIG. 17 is a graph depicting the results of hamster relapse
assays as the percentage of hamsters surviving clindamycin
treatment followed by C. difficile challenge. Hamsters were
immunized with a fragment of toxin B prior to clindamycin
treatment. Hamsters were treated with vancomycin, vancomycin and
3D8, or received no treatment.
[0090] FIG. 18 is a graph depicting the results of hamster relapse
assays as the percentage of healthy animals after clindamycin
treatment followed by C. difficile challenge. Hamsters were
immunized with a fragment of toxin B prior to clindamycin
treatment.
[0091] FIG. 19 is a schematic diagram of the timeline of
administration of various agents to hamsters in a C. difficile
direct challenge model. "331" refers to antisera from goat #331.
"Clinda" refers to treatment with clindamycin.
[0092] FIG. 20 is a graph depicting the results of direct challenge
assays as the percentage of hamsters surviving direct C. difficile
challenge.
[0093] FIG. 21 is a graph depicting the results of direct challenge
assays as the percentage of healthy animals after direct challenge
with C. difficile.
[0094] FIG. 22 is a representation of the amino acid sequence of C.
difficile toxin A.
[0095] FIG. 23 is a representation of the amino acid sequence of C.
difficile toxin B.
[0096] FIG. 24 is a graph depicting the results of primary
challenge assays as the percentage of hamsters surviving direct C.
difficile challenge.
[0097] FIG. 25 is a graph depicting the results of primary
challenge assays as the percentage of hamsters surviving direct C.
difficile challenge.
[0098] FIG. 26 is a graph depicting the results of primary
challenge assays as the percentage of hamsters surviving direct C.
difficile challenge.
[0099] FIG. 27 is a graph depicting results of assays in which in
vitro neutralization of toxin A and toxin B was measured in the
presence of monoclonal antibodies to toxin B or goat polyclonal
sera against toxin B.
[0100] FIG. 28 is a representation of the amino acid and nucleic
acid sequences of the VH chain expressed by clone 124-152. The
V-segment, D-segment and J-segment genes are listed above the amino
acid and nucleic acid sequences. The CDRs are overlined.
[0101] FIG. 29 is a representation of the amino acid and nucleic
acid sequences of the VL chain expressed by clone 124-152. The
V-segment and J-segment genes are listed above the amino acid and
nucleic acid sequences. The CDRs are overlined.
[0102] FIG. 30 is a representation of the amino acid and related
germline sequence of the VH chain expressed by clone 124-152. The
V-segment, D-segment and J-segment genes are listed above the amino
acid sequences. The CDRs are overlined.
[0103] FIG. 31 is a representation of the amino acid and related
germline sequences of the VL chain expressed by clone 124-152. The
V-segment and J-segment genes are listed above the amino acid
sequences. The CDRs are overlined.
[0104] FIG. 32 is a schematic representation of the toxin B
polypeptide, indicating fragments that were analyzed for epitope
mapping studies.
[0105] Like reference symbols in the various drawings indicate like
elements.
DETAILED DESCRIPTION OF THE INVENTION
[0106] In order to provide a clear understanding of the
specification and claims, the following definitions are
conveniently provided below.
Definitions
[0107] The term "toxin A" refers to the toxin A protein encoded by
C. difficile. The amino acid sequence of C. difficile toxin A (SEQ
ID NO:41) is provided in GenBank.RTM. under accession number
A37052, version GI 98593 (see also FIG. 22). "Toxin B" refers to
the toxin B protein encoded by C. difficile. The amino acid
sequence of C. difficile toxin B (SEQ ID NO: 42) is provided in
GenBank.RTM. under accession number 570172, version GI 7476000 (see
also FIG. 23). "Protein" is used interchangeably with
"polypeptide."
[0108] An "anti-C. difficile antibody" is an antibody that
interacts with (e.g., binds to) a protein or other component
produced by C. difficile bacteria. An "anti-toxin antibody" is an
antibody that interacts with a toxin produced by C. difficile
(e.g., toxin A or toxin B). An anti-toxin protein antibody may bind
to an epitope, e.g., a conformational or a linear epitope, or to a
fragment of the full-length toxin protein.
[0109] A "human antibody," is an antibody that has variable and
constant regions derived from human germline immunoglobulin
sequences. The human antibodies described herein may include amino
acid residues not encoded by human germline immunoglobulin
sequences (e.g., mutations introduced by random or site-specific
mutagenesis in vitro or by somatic mutation in vivo).
[0110] An anti-toxin antibody, or antigen binding portion thereof,
can be administered alone or in combination with a second agent.
The subject can be a patient infected with C. difficile, or having
a symptom of C. difficile-associated disease ("CDAD"; e.g.,
diarrhea, colitis, abdominal pain) or a predisposition towards C.
difficile-associated disease (e.g., undergoing treatment with
antibiotics, or having experienced C. difficile-associated disease
and at risk for relapse of the disease). The treatment can be to
cure, heal, alleviate, relieve, alter, remedy, ameliorate,
palliate, improve, or affect the infection and the disease
associated with the infection, the symptoms of the disease, or the
predisposition toward the disease.
[0111] An amount of an anti-toxin antibody effective to treat a
CDAD, or a "therapeutically effective amount," is an amount of the
antibody that is effective, upon single or multiple dose
administration to a subject, in inhibiting CDAD in a subject. A
therapeutically effective amount of the antibody or antibody
fragment may vary according to factors such as the disease state,
age, sex, and weight of the individual, and the ability of the
antibody or antibody portion to elicit a desired response in the
individual. A therapeutically effective amount is also one in which
any toxic or detrimental effects of the antibody or antibody
portion is outweighed by the therapeutically beneficial effects.
The ability of an antibody to inhibit a measurable parameter can be
evaluated in an animal model system predictive of efficacy in
humans. For example, the ability of an anti-toxin antibody to
protect mice from lethal challenge with C. difficile can predict
efficacy in humans. Other animal models predictive of efficacy are
described herein, such as the intestinal ligation model described
in the Examples. Alternatively, this property of an antibody or
antibody composition can be evaluated by examining the ability of
the compound to modulate, such modulation in vitro by assays known
to the skilled practitioner. In vitro assays include binding
assays, such as ELISA, and neutralization assays.
[0112] An amount of an anti-toxin antibody effective to prevent a
disorder, or a "a prophylactically effective amount," of the
antibody is an amount that is effective, upon single- or
multiple-dose administration to the subject, in preventing or
delaying the occurrence of the onset or recurrence of CDAD, or
inhibiting a symptom thereof. However, if longer time intervals of
protection are desired, increased doses can be administered.
[0113] The terms "agonize," "induce," "inhibit," "potentiate,"
"elevate," "increase," "decrease," or the like, e.g., which denote
quantitative differences between two states, refer to a difference,
e.g., a statistically or clinically significant difference, between
the two states.
[0114] As used herein, "specific binding" or "specifically binds
to" refers to the ability of an antibody to: (1) bind to a toxin of
C. difficile with an affinity of at least 1.times.10.sup.7
M.sup.-1, and (2) bind to a toxin of C. difficile with an affinity
that is at least two-fold greater than its affinity for a
nonspecific antigen.
[0115] An "antibody" is a protein including at least one or two,
heavy (H) chain variable regions (abbreviated herein as VHC), and
at least one or two light (L) chain variable regions (abbreviated
herein as VLC). The VHC and VLC regions can be further subdivided
into regions of hypervariability, termed "complementarity
determining regions" ("CDR"), interspersed with regions that are
more conserved, termed "framework regions" (FR). The extent of the
framework region and CDRs has been precisely defined (see, Kabat,
E. A., et al. Sequences of Proteins of Immunological Interest,
Fifth Edition, U.S. Department of Health and Human Services, NIH
Publication No. 91-3242, 1991, and Chothia, C. et al., J. Mol.
Biol. 196:901-917, 1987, which are incorporated herein by
reference). Preferably, each VHC and VLC is composed of three CDRs
and four FRs, arranged from amino-terminus to carboxy-terminus in
the following order: FR1, CDR1, FR2, CDR2, FR3, CDR3, FR4.
[0116] The VHC or VLC chain of the antibody can further include all
or part of a heavy or light chain constant region. In one
embodiment, the antibody is a tetramer of two heavy immunoglobulin
chains and two light immunoglobulin chains, wherein the heavy and
light immunoglobulin chains are inter-connected by, e.g., disulfide
bonds. The heavy chain constant region includes three domains, CH1,
CH2 and CH3. The light chain constant region is comprised of one
domain, CL. The variable region of the heavy and light chains
contains a binding domain that interacts with an antigen. The
constant regions of the antibodies typically mediate the binding of
the antibody to host tissues or factors, including various cells of
the immune system (e.g., effector cells) and the first component
(Clq) of the classical complement system. The term "antibody"
includes intact immunoglobulins of types IgA, IgG, IgE, IgD, IgM
(as well as subtypes thereof), wherein the light chains of the
immunoglobulin may be of types kappa or lambda.
[0117] "Immunoglobulin" refers to a protein consisting of one or
more polypeptides substantially encoded by immunoglobulin genes.
The recognized human immunoglobulin genes include the kappa,
lambda, alpha (IgA1 and IgA2), gamma (IgG1, IgG2, IgG3, IgG4),
delta, epsilon, and mu constant region genes, as well as the myriad
immunoglobulin variable region genes. Full-length immunoglobulin
"light chains" (about 25 KD and 214 amino acids) are encoded by a
variable region gene at the NH.sub.2-terminus (about 110 amino
acids) and a kappa or lambda constant region gene at the
COOH-terminus. Full-length immunoglobulin "heavy chains" (about 50
KD and 446 amino acids), are similarly encoded by a variable region
gene (about 116 amino acids) and one of the other aforementioned
constant region genes, e.g., gamma (encoding about 330 amino
acids). The term "immunoglobulin" includes an immunoglobulin
having: CDRs from a human or non-human source. The framework of the
immunoglobulin can be human, humanized, or non-human, e.g., a
murine framework modified to decrease antigenicity in humans, or a
synthetic framework, e.g., a consensus sequence.
[0118] As used herein, "isotype" refers to the antibody class
(e.g., IgM or IgG.sub.1) that is encoded by heavy chain constant
region genes.
[0119] The term "antigen binding portion" of an antibody (or simply
"antibody portion," or "portion"), as used herein, refers to a
portion of an antibody that specifically binds to a toxin of C.
difficile (e.g., toxin A), e.g., a molecule in which one or more
immunoglobulin chains is not full length, but which specifically
binds to a toxin. Examples of binding portions encompassed within
the term "antigen-binding portion" of an antibody include (i) a Fab
fragment, a monovalent fragment consisting of the VLC, VHC, CL and
CH1 domains; (ii) a F(ab').sub.2 fragment, a bivalent fragment
comprising two Fab fragments linked by a disulfide bridge at the
hinge region; (iii) a Fd fragment consisting of the VHC and CH1
domains; (iv) a Fv fragment consisting of the VLC and VHC domains
of a single arm of an antibody, (v) a dAb fragment (Ward et al.,
Nature 341:544-546, 1989), which consists of a VHC domain; and (vi)
an isolated complementarity determining region (CDR) having
sufficient framework to specifically bind, e.g., an antigen binding
portion of a variable region. An antigen binding portion of a light
chain variable region and an antigen binding portion of a heavy
chain variable region, e.g., the two domains of the Fv fragment,
VLC and VHC, can be joined, using recombinant methods, by a
synthetic linker that enables them to be made as a single protein
chain in which the VLC and VHC regions pair to form monovalent
molecules (known as single chain Fv (scFv); see e.g., Bird et al.
(1988) Science 242:423-426; and Huston et al. (1988) Proc. Natl.
Acad. Sci. USA 85:5879-5883). Such single chain antibodies are also
encompassed within the term "antigen binding portion" of an
antibody. These antibody portions are obtained using conventional
techniques known to those with skill in the art, and the portions
are screened for utility in the same manner as are intact
antibodies.
[0120] The term "monospecific antibody" refers to an antibody that
displays a single binding specificity and affinity for a particular
target, e.g., epitope. This term includes a "monoclonal antibody"
or "monoclonal antibody composition," which as used herein refer to
a preparation of antibodies or portions thereof with a single
molecular composition.
[0121] The term "recombinant" antibody, as used herein, refers to
antibodies that are prepared, expressed, created, or isolated by
recombinant means, such as antibodies expressed using a recombinant
expression vector transfected into a host cell, antibodies isolated
from a recombinant, combinatorial antibody library, antibodies
isolated from an animal (e.g., a mouse) that is transgenic for
human immunoglobulin genes or antibodies prepared, expressed,
created, or isolated by any other means that involves splicing of
human immunoglobulin gene sequences to other DNA sequences. Such
recombinant antibodies include humanized, CDR grafted, chimeric, in
vitro generated (e.g., by phage display) antibodies, and may
optionally include constant regions derived from human germline
immunoglobulin sequences.
[0122] As used herein, the term "substantially identical" (or
"substantially homologous") refers to a first amino acid or
nucleotide sequence that contains a sufficient number of identical
or equivalent (e.g., with a similar side chain, e.g., conserved
amino acid substitutions) amino acid residues or nucleotides to a
second amino acid or nucleotide sequence such that the first and
second amino acid or nucleotide sequences have similar activities.
In the case of antibodies, the second antibody has the same
specificity and has at least 50% of the affinity of the first
antibody.
[0123] Calculations of "homology" between two sequences are
performed as follows. The sequences are aligned for optimal
comparison purposes (e.g., gaps can be introduced in one or both of
a first and a second amino acid or nucleic acid sequence for
optimal alignment and non-homologous sequences can be disregarded
for comparison purposes). The length of a reference sequence
aligned for comparison purposes is at least 50% of the length of
the reference sequence. The amino acid residues or nucleotides at
corresponding amino acid positions or nucleotide positions are then
compared. When a position in the first sequence is occupied by the
same amino acid residue or nucleotide as the corresponding position
in the second sequence, then the molecules are identical at that
position (as used herein amino acid or nucleic acid "identity" is
equivalent to amino acid or nucleic acid "homology"). The percent
identity between the two sequences is a function of the number of
identical positions shared by the sequences, taking into account
the number of gaps, and the length of each gap, which need to be
introduced for optimal alignment of the two sequences.
[0124] The comparison of sequences and determination of percent
homology between two sequences can be accomplished using a
mathematical algorithm. The percent homology between two amino acid
sequences is determined using the Needleman and Wunsch, J. Mol.
Biol. 48:444-453, 1970, algorithm which has been incorporated into
the GAP program in the GCG software package, using a Blossum 62
scoring matrix with a gap penalty of 12, a gap extend penalty of 4,
and a frameshift gap penalty of 5.
[0125] As used herein, the term "hybridizes under low stringency,
medium stringency, high stringency, or very high stringency
conditions" describes conditions for hybridization and washing.
Guidance for performing hybridization reactions can be found in
Current Protocols in Molecular Biology, John Wiley & Sons, N.Y.
6.3.1-6.3.6, 1989, which is incorporated herein by reference.
Aqueous and nonaqueous methods are described in that reference and
either can be used. Specific hybridization conditions referred to
herein are as follows: 1) low stringency hybridization conditions:
6.times. sodium chloride/sodium citrate (SSC) at about 45.degree.
C., followed by two washes in 0.2.times.SSC, 0.1% SDS at least at
50.degree. C. (the temperature of the washes can be increased to
55.degree. C. for low stringency conditions); 2) medium stringency
hybridization conditions: 6.times.SSC at about 45.degree. C.,
followed by one or more washes in 0.2.times.SSC, 0.1% SDS at
60.degree. C.; 3) high stringency hybridization conditions:
6.times.SSC at about 45.degree. C., followed by one or more washes
in 0.2.times.SSC, 0.1% SDS at 65.degree. C.; and 4) very high
stringency hybridization conditions: 0.5 M sodium phosphate, 7% SDS
at 65.degree. C., followed by one or more washes at 0.2.times.SSC,
1% SDS at 65.degree. C.
[0126] It is understood that the antibodies and antigen binding
portions thereof described herein may have additional conservative
or non-essential amino acid substitutions, which do not have a
substantial effect on the polypeptide functions. Whether or not a
particular substitution will be tolerated, i.e., will not adversely
affect desired biological properties, such as binding activity, can
be determined as described in Bowie et al., Science, 247:1306-1310,
1990. A "conservative amino acid substitution" is one in which an
amino acid residue is replaced with an amino acid residue having a
similar side chain. Families of amino acid residues having similar
side chains have been defined in the art. These families include
amino acids with basic side chains (e.g., lysine, arginine,
histidine), acidic side chains (e.g., aspartic acid, glutamic
acid), uncharged polar side chains (e.g., asparagine, glutamine,
serine, threonine, tyrosine, cysteine), nonpolar side chains (e.g.,
glycine, alanine, valine, leucine, isoleucine, proline,
phenylalanine, methionine, tryptophan), beta-branched side chains
(e.g., threonine, valine, isoleucine) and aromatic side chains
(e.g., tyrosine, phenylalanine, tryptophan, histidine).
[0127] A "non-essential" amino acid residue is a residue that can
be altered from the wild-type sequence of a polypeptide, such as a
binding agent, e.g., an antibody, without substantially altering a
biological activity, whereas an "essential" amino acid residue
results in such a change.
[0128] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. Although
methods and materials similar or equivalent to those described
herein can be used in the practice or testing of the present
invention, suitable methods and materials are described below. All
publications, patent applications, patents, and other references
mentioned herein are incorporated by reference in their entirety.
In case of conflict, the present specification, including
definitions, will control. In addition, the materials, methods, and
examples are illustrative only and not intended to be limiting.
Overview
[0129] C. difficile is a gram positive, toxin-producing bacterium
that causes antibiotic-associated diarrhea and colitis in humans.
Provided herein are methods and compositions for treatment and
prevention of C. difficile-associated disease (CDAD). The
compositions include antibodies that recognize proteins and other
molecular components (e.g., lipids, carbohydrates, nucleic acids)
of C. difficile bacteria, including antibodies that recognize
toxins produced by C. difficile (e.g., toxin A and toxin B). In
particular, human monoclonal antibodies are provided. In certain
embodiments, these human monoclonal antibodies are produced in mice
expressing human immunoglobulin gene segments (described below).
Combinations of anti-toxin antibodies are also provided.
[0130] The new methods include administering antibodies (and
antigen-binding portions thereof) that bind to a C. difficile toxin
to a subject to inhibit CDAD in the subject. For example, human
monoclonal anti-toxin A antibodies described herein can neutralize
toxin A and inhibit relapse of C. difficile-mediated disease. In
other examples, combinations of anti-toxin A antibodies (e.g.,
anti-toxin A monoclonal antibodies) and anti-toxin B antibodies can
be administered to inhibit primary disease and reduce the incidence
of disease relapse. The human monoclonal antibodies may localize to
sites of disease (e.g., the gut) in vivo.
1. Generation of Antibodies
Immunogens
[0131] In general, animals are immunized with antigens expressed by
C. difficile to produce antibodies. For producing anti-toxin
antibodies, animals are immunized with inactivated toxins, or
toxoids. Toxins can be inactivated, e.g., by treatment with
formaldehyde, glutaraldehyde, peroxide, or oxygen treatment (see,
e.g., Relyveld et al., Methods in Enzymology., 93:24, 1983; Woodrow
and Levine, eds., New Generation Vaccines, Marcel Dekker, Inc., New
York, 1990). Mutant C. difficile toxins with reduced toxicity can
be produced using recombinant methods (see, e.g., U.S. Pat. Nos.
5,085,862; 5,221,618; 5,244,657; 5,332,583; 5,358,868; and
5,433,945). For example, mutants containing deletions or point
mutations in the toxin active site can be made. Recombinant
fragments of the toxins can be used as immunogens. Another approach
is to inactivate the toxin by treatment with UDP-dialdehyde (Genth
et al., Inf and Immun., 68(3):1094-1101, 2000). This method
preserves the native structure of the toxin more readily than other
treatments, and thus can elicit antibodies more reactive to the
native toxin. This method is also described in Example 1,
below.
[0132] Anti-toxin antibodies that bind and neutralize toxin A can
interact with specific epitopes of toxin A. For example, an
anti-toxin A antibody can bind an epitope in an N-terminal region
of toxin A (e.g., between amino acids 1-1033 of toxin A), or a
C-terminal region (e.g., between amino acids 1853-2710 of toxin A).
In one example, an antibody that binds and neutralizes toxin A
binds to an epitope within amino acids 1853-2710 of toxin A.
[0133] Similarly, anti-toxin B antibodies can recognize a specific
epitope of toxin B, e.g., an N-terminal epitope, or a C-terminal
epitope. In one example, an antibody that binds and neutralizes
toxin B binds to an epitope within amino acids 1777-2366 of toxin
B.
Generation of Human Monoclonal Antibodies in HuMAb Mice
[0134] Monoclonal antibodies can be produced in a manner not
possible with polyclonal antibodies. Polyclonal antisera vary from
animal to animal, whereas monoclonal preparations exhibit a uniform
antigenic specificity. Murine animal systems are useful to generate
monoclonal antibodies, and immunization protocols, techniques for
isolating and fusing splenocytes, and methods and reagents for
producing hybridomas are well known. Monoclonal antibodies can be
produced by a variety of techniques, including conventional
monoclonal antibody methodology, e.g., the standard somatic cell
hybridization technique of Kohler and Milstein, Nature, 256: 495,
1975. See generally, Harlow, E. and Lane, D. Antibodies: A
Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring
Harbor, N.Y., 1988.
[0135] Although these standard techniques are known, it is
desirable to use humanized or human antibodies rather than murine
antibodies to treat human subjects, because humans mount an immune
response to antibodies from mice and other species. The immune
response to murine antibodies is called a human anti-mouse antibody
or HAMA response (Schroff, R. et al., Cancer Res., 45, 879-885,
1985) and is a condition that causes serum sickness in humans and
results in rapid clearance of the murine antibodies from an
individual's circulation. The immune response in humans has been
shown to be against both the variable and the constant regions of
murine immunoglobulins. Human monoclonal antibodies are safer for
administration to humans than antibodies derived from other animals
and human polyclonal antibodies.
[0136] One useful type of animal in which to generate human
monoclonal antibodies is a transgenic mouse that expresses human
immunoglobulin genes rather than its own mouse immunoglobulin
genes. Such transgenic mice, e.g., "HuMAb.TM." mice, contain human
immunoglobulin gene miniloci that encode unrearranged human heavy
(.mu. and .gamma.) and .kappa. light chain immunoglobulin
sequences, together with targeted mutations that inactivate the
endogenous .mu. and .kappa. chain loci (see e.g., Lonberg, N. et
al., Nature 368(6474): 856-859, 1994, and U.S. Pat. No. 5,770,429).
Accordingly, the mice exhibit reduced expression of mouse IgM or
.kappa., and in response to immunization, the introduced human
heavy and light chain transgenes undergo class switching and
somatic mutation to generate high affinity human IgG.kappa.
monoclonal antibodies (Lonberg, N. et al., supra; reviewed in
Lonberg, N. Handbook of Experimental Pharmacology 113:49-101, 1994;
Lonberg, N. and Huszar, D., Intern. Rev. Immunol., 13: 65-93, 1995,
and Harding, F. and Lonberg, N., Ann. N.Y. Acad. Sci., 764:536-546,
1995).
[0137] The preparation of such transgenic mice is described in
further detail in Taylor, L. et al., Nucleic Acids Research,
20:6287-6295, 1992; Chen, J. et al., International Immunology 5:
647-656, 1993; Tuaillon et al., Proc. Natl. Acad. Sci., USA
90:3720-3724, 1993; Choi et al., Nature Genetics, 4:117-123, 1993;
Chen, J. et al., EMBO J., 12: 821-830, 1993; Tuaillon et al., J.
Immunol., 152:2912-2920, 1994; Taylor, L. et al., International
Immunology, 6: 579-591, 1994; and Fishwild, D. et al., Nature
Biotechnology, 14: 845-851, 1996. See further, U.S. Pat. No.
5,545,806; U.S. Pat. No. 5,569,825, U.S. Pat. No. 5,625,126, U.S.
Pat. No. 5,633,425, U.S. Pat. No. 5,661,016, U.S. Pat. No.
5,770,429, U.S. Pat. No. 5,789,650, U.S. Pat. No. 5,814,318, U.S.
Pat. No. 5,874,299 and U.S. Pat. No. 5,877,397, all by Lonberg and
Kay, and PCT Publication Nos. WO 01/14424, WO 98/24884, WO
94/25585, WO 93/1227, and WO 92/03918.
[0138] To generate fully human monoclonal antibodies to an antigen,
HuMAb mice can be immunized with an immunogen, as described by
Lonberg, N. et al. Nature, 368(6474): 856-859, 1994; Fishwild, D.
et al., Nature Biotechnology, 14: 845-851, 1996 and WO 98/24884.
Preferably, the mice will be 6-16 weeks of age upon the first
immunization. For example, a purified preparation of inactivated
toxin A can be used to immunize the HuMAb mice intraperitoneally.
To generate antibodies against C. difficile proteins, lipids,
and/or carbohydrate molecules, mice can be immunized with killed or
nonviable C. difficile organisms.
[0139] HuMAb transgenic mice respond best when initially immunized
intraperitoneally (IP) with antigen in complete Freund's adjuvant,
followed by IP immunizations every other week (up to a total of 6)
with antigen in incomplete Freund's adjuvant. The immune response
can be monitored over the course of the immunization protocol with
plasma samples being obtained by retroorbital bleeds. The plasma
can be screened, for example by ELISA or flow cytometry, and mice
with sufficient titers of anti-toxin human immunoglobulin can be
used for fusions. Mice can be boosted intravenously with antigen 3
days before sacrifice and removal of the spleen. It is expected
that 2-3 fusions for each antigen may need to be performed. Several
mice are typically immunized for each antigen.
[0140] The mouse splenocytes can be isolated and fused with PEG to
a mouse myeloma cell line based upon standard protocols. The
resulting hybridomas are then screened for the production of
antigen-specific antibodies. For example, single cell suspensions
of splenic lymphocytes from immunized mice are fused to one-sixth
the number of P3X63-Ag8.653 nonsecreting mouse myeloma cells (ATCC,
CRL 1580) with 50% PEG. Cells are plated at approximately
2.times.10.sup.5 in flat bottom microtiter plate, followed by a two
week incubation in selective medium containing 20% fetal Clone
Serum, 18% "653" conditioned media, 5% origen (IGEN), 4 mM
L-glutamine, 1 mM L-glutamine, 1 mM sodium pyruvate, 5 mM HEPES,
0.055 mM 2-mercaptoethanol, 50 units/ml penicillin, 50 mg/ml
streptomycin, 50 mg/ml gentamycin and 1.times.HAT (Sigma; the HAT
is added 24 hours after the fusion). After two weeks, cells are
cultured in medium in which the HAT is replaced with HT.
Supernatants from individual wells are then screened by ELISA for
human anti-toxin cell monoclonal IgM and IgG antibodies. The
antibody secreting hybridomas are replated, screened again, and if
still positive for human IgG, anti-toxin monoclonal antibodies, can
be subcloned at least twice by limiting dilution. The stable
subclones are then cultured in vitro to generate small amounts of
antibody in tissue culture medium for characterization.
[0141] In one embodiment, the transgenic animal used to generate
human antibodies to the toxin contains at least one, typically
2-10, and sometimes 25-50 or more copies of the transgene described
in Example 12 of WO 98/24884 (e.g., pHC1 or pHC2) bred with an
animal containing a single copy of a light chain transgene
described in Examples 5, 6, 8, or 14 of WO 98/24884, and the
offspring bred with the J.sub.H deleted animal described in Example
10 of WO 98/24884, the contents of which are hereby expressly
incorporated by reference. Animals are bred to homozygosity for
each of these three traits. Such animals have the following
genotype: a single copy (per haploid set of chromosomes) of a human
heavy chain unrearranged mini-locus (described in Example 12 of WO
98/24884), a single copy (per haploid set of chromosomes) of a
rearranged human K light chain construct (described in Example 14
of WO 98/24884), and a deletion at each endogenous mouse heavy
chain locus that removes all of the functional J.sub.H segments
(described in Example 10 of WO 98/24884). Such animals are bred
with mice that are homozygous for the deletion of the J.sub.H
segments (Examples 10 of WO 98/24884) to produce offspring that are
homozygous for the J.sub.H deletion and hemizygous for the human
heavy and light chain constructs. The resultant animals are
injected with antigens and used for production of human monoclonal
antibodies against these antigens.
[0142] B cells isolated from such an animal are monospecific with
regard to the human heavy and light chains because they contain
only a single copy of each gene. Furthermore, they will be
monospecific with regard to human or mouse heavy chains because
both endogenous mouse heavy chain gene copies are nonfunctional by
virtue of the deletion spanning the J.sub.H region introduced as
described in Examples 9 and 12 of WO 98/24884. Furthermore, a
substantial fraction of the B cells will be monospecific with
regards to the human or mouse light chains, because expression of
the single copy of the rearranged human kappa light chain gene will
allelically and isotypically exclude the rearrangement of the
endogenous mouse kappa and lambda chain genes in a significant
fraction of B-cells.
[0143] In one embodiment, the transgenic mouse will exhibit
immunoglobulin production with a significant repertoire, ideally
substantially similar to that of a native mouse. Thus, for example,
in embodiments where the endogenous Ig genes have been inactivated,
the total immunoglobulin levels will range from about 0.1 to 10
mg/ml of serum, e.g., 0.5 to 5 mg/ml, or at least about 1.0 mg/ml.
When a transgene capable of effecting a switch to IgG from IgM has
been introduced into the transgenic mouse, the adult mouse ratio of
serum IgG to IgM is preferably about 10:1. The IgG to IgM ratio
will be much lower in the immature mouse. In general, greater than
about 10%, e.g., about 40 to 80% of the spleen and lymph node B
cells will express exclusively human IgG protein.
[0144] The repertoire in the transgenic mouse will ideally
approximate that shown in a non-transgenic mouse, usually at least
about 10% as high, preferably 25 to 50% or more as high. Generally,
at least about a thousand different immunoglobulins (ideally IgG),
preferably 10.sup.4 to 10.sup.6 or more, will be produced,
depending primarily on the number of different V, J, and D regions
introduced into the mouse genome. Typically, the immunoglobulins
will exhibit an affinity for preselected antigens of at least about
10.sup.7M.sup.-1, 10.sup.9M.sup.-1, 10.sup.10M.sup.-1,
10.sup.11M.sup.-1, 10.sup.12M.sup.-1, or greater, e.g., up to
10.sup.13M.sup.-1 or greater.
[0145] HuMAb mice can produce B cells that undergo class-switching
via intratransgene switch recombination (cis-switching) and express
immunoglobulins reactive with the toxin. The immunoglobulins can be
human sequence antibodies, wherein the heavy and light chain
polypeptides are encoded by human transgene sequences, which may
include sequences derived by somatic mutation and V region
recombinatorial joints, as well as germline-encoded sequences.
These human sequence immunoglobulins can be referred to as being
substantially identical to a polypeptide sequence encoded by a
human VL or VH gene segment and a human JL or JL segment, even
though other non-germline sequences may be present as a result of
somatic mutation and differential V-J and V-D-J recombination
joints. With respect to such human sequence antibodies, the
variable regions of each chain are typically at least 80 percent
encoded by human germline V, J, and, in the case of heavy chains,
D, gene segments. Frequently at least 85 percent of the variable
regions are encoded by human germline sequences present on the
transgene. Often 90 or 95 percent or more of the variable region
sequences are encoded by human germline sequences present on the
transgene. However, since non-germline sequences are introduced by
somatic mutation and VJ and VDJ joining, the human sequence
antibodies will frequently have some variable region sequences (and
less frequently constant region sequences) that are not encoded by
human V, D, or J gene segments as found in the human transgene(s)
in the germline of the mice. Typically, such non-germline sequences
(or individual nucleotide positions) will cluster in or near CDRs,
or in regions where somatic mutations are known to cluster.
[0146] The human sequence antibodies that bind to the toxin can
result from isotype switching, such that human antibodies
comprising a human sequence gamma chain (such as gamma 1, gamma 2,
or gamma 3) and a human sequence light chain (such as K) are
produced. Such isotype-switched human sequence antibodies often
contain one or more somatic mutation(s), typically in the variable
region and often in or within about 10 residues of a CDR) as a
result of affinity maturation and selection of B cells by antigen,
particularly subsequent to secondary (or subsequent) antigen
challenge. These high affinity human sequence antibodies have
binding affinities of at least about 1.times.10.sup.9 M.sup.-1,
typically at least 5.times.10.sup.9 M.sup.-1, frequently more than
1.times.10.sup.10 M.sup.-1, and sometimes 5.times.10.sup.10
M.sup.-1 to 1.times.10.sup.11M.sup.-1 or greater.
[0147] Anti-toxin antibodies can also be raised in other mammals,
including non-transgenic mice, humans, rabbits, and goats.
Anti-Toxin A Antibodies
[0148] Human monoclonal antibodies that specifically bind to toxin
A include antibodies produced by the 3D8, 1B11, and 3H2 clones
described herein. Antibodies with variable heavy chain and variable
light chain regions that are at least 80%, or more, identical to
the variable heavy and light chain regions of 3D8, 1B11, and 3H2
can also bind to toxin A. In related embodiments, anti-toxin A
antibodies include, for example, the complementarity determining
regions (CDR) of variable heavy chains and/or variable light chains
of 3D8, 1B11, or 3H2. The CDRs of the variable heavy chain regions
from these clones are shown in Table 1, below.
TABLE-US-00001 TABLE 1 Variable Heavy Chain CDR Amino Acid
Sequences Clone Chain CDR Amino Acid Sequence SEQ ID NO: 3D8 H CDR1
NYGMH 7 1B11 H CDR1 SYGMH 10 3H2 H CDR1 KYGMH 13 3D8 H CDR2
LIWYDGSNEDYTDSVKG 8 1B11 H CDR2 VIWASGNKKYYIESVEG 11 3H2 H CDR2
VIWYDGTNKYYADSMKG 14 3D8 H CDR3 WGMVRGVIDVFDI 9 1B11 H CDR3 ANFDY
12 3H2 H CDR3 DPPTANY 15
[0149] The CDRs of the variable light chain regions from these
clones are shown in table 2, below.
TABLE-US-00002 TABLE 2 Variable Light Chain CDR Amino Acid
Sequences Clone Chain CDR Amino Acid Sequence SEQ ID NO: 308 L CDR1
RASQGISSWLA 16 1B11 L CDR1 RASQSVSSYLA 19 3H2 L CDR1 RASQGISSWLA 22
308 L CDR2 AASSLQS 17 1B11 L CDR2 DASNRAT 20 3H2 L CDR2 AASSLQS 23
308 L CDR3 QQANSFPWT 18 1B11 L CDR3 QQRSNWSQFT 21 3H2 L CDR3
QQYKSYPVT 24
[0150] CDRs are the portions of immunoglobulins that determine
specificity for a particular antigen. In certain embodiments, CDRs
corresponding to the CDRs in tables 1 and 2 having sequence
variations (e.g., conservative substitutions) may bind to toxin A.
For example, CDRs, in which 1, 2 3, 4, or 5 residues, or less than
20% of total residues in the CDR, are substituted or deleted can be
present in an antibody (or antigen binding portion thereof) that
binds toxin A.
[0151] Similarly, anti-toxin antibodies can have CDRs containing a
consensus sequence, as sequence motifs conserved amongst multiple
antibodies can be important for binding activity. For example, CDR1
of a variable light chain region of the antibodies or antigen
binding portions thereof can include the amino acid sequence
R-A-S-Q-X-X-S-S-X-L-A (SEQ ID NO: 25), CDR2 of a variable light
chain region of the antibodies or antigen binding portions thereof
can include the amino acid sequence A-S-X-X-X-S/T (SEQ ID NO:26),
and/or CDR3 of a variable light chain region of the antibodies or
antigen binding portions thereof can include the amino acid
sequence Q-Q-X-X-S/N-X-P/S (SEQ ID NO:27), wherein X is any amino
acid.
[0152] In some embodiments, CDR1 of a variable heavy chain region
of the antibodies or antigen binding portions thereof includes the
amino acid sequence Y-G-M-H (SEQ ID NO:28), and/or CDR2 of a
variable heavy chain region of the antibodies or antigen binding
portions thereof includes the amino acid sequence
I-W-X-X-G-X-X-X-Y-X-X-S-X-X-G (SEQ ID NO:29), wherein X is any
amino acid.
[0153] Human anti-toxin antibodies can include variable regions
that are the product of, or derived from, specific human
immunoglobulin genes. For example, the antibodies can include a
variable heavy chain region that is the product of, or derived from
a human VH3-33 gene. Numerous sequences for antibodies derived from
this gene are available in GenBank.RTM. (see, e.g., Acc. No:
AJ555951, GI No:29836865; Acc. No:AJ556080, GI No.:29837087; Acc.
No.: AJ556038, GI No.:29837012, and other human VH3-33 rearranged
gene segments provided in GenBank.RTM.). The antibodies can also,
or alternatively, include a light chain variable region that is the
product of, or derived from a human V.kappa. L19 gene (see, e.g.,
GenBank.RTM. Acc. No. AJ556049, GI No:29837033 for a partial
sequence of a rearranged human V.kappa. L19 gene segment). As known
in the art, and described in this section, above, variable
immunoglobulin regions of recombined antibodies are derived by a
process of recombination in vivo in which variability is introduced
to genomic segments encoding the regions. Accordingly, variable
regions derived from a human VH-33 or V.kappa. L19 gene can include
nucleotides that are different that those in the gene found in
non-lymphoid tissues. These nucleotide differences are typically
concentrated in the CDRs.
Anti-Toxin B Antibodies
[0154] Human monoclonal antibodies that specifically bind to toxin
B include antibodies produced by the 124-152, 2A11, and 1G10 clones
described herein. Antibodies with variable heavy chain and variable
light chain regions that are at least 80%, or more, identical to
the variable heavy and light chain regions of -152, 2A11, and 1G10
can also bind to toxin B. In related embodiments, anti-toxin B
antibodies include, for example, the complementarity determining
regions (CDR) of variable heavy chains and/or variable light chains
of -152, 2A11, or 1G10. The CDRs of the variable heavy chain
regions from these clones are shown in Table 3, below.
TABLE-US-00003 TABLE 3 Variable Heavy Chain CDR Amino Acid
Sequences SEQ SEQ ID ID Amino NO: NO: Clone Chain CDR Acid Sequence
(a.a.) (n.t.) 124-152 H CDR1 SYWIG 62 63 124-152 H CDR2
IFYPGDSSTRYSPSFQG 64 65 124-152 H CDR3 RRNWGNAFDI 66 67
[0155] The CDRs of the variable light chain regions from these
clones are shown in Table 4, below.
TABLE-US-00004 TABLE 4 Variable Light Chain CDR Amino Acid
Sequences SEQ SEQ ID ID Amino NO: NO: Clone Chain CDR Acid Sequence
(a.a.) (n.t.) 124-152 L CDR1 RASQSVSSSYLAW 68 69 124-152 L CDR2
GASSRAT 70 71 124-152 L CDR3 QQYGSSTWT 72 73
[0156] CDRs are the portions of immunoglobulins that determine
specificity for a particular antigen. In certain embodiments, CDRs
corresponding to the CDRs in Tables 3 and 4 having sequence
variations (e.g., conservative substitutions) may bind to toxin B.
For example, CDRs, in which 1, 2, 3, 4, or 5 residues, or less than
20% of total residues in the CDR, are substituted or deleted can be
present in an antibody (or antigen binding portion thereof) that
binds toxin B.
[0157] Human anti-toxin B antibodies can include variable regions
that are the product of, or derived from, specific human
immunoglobulin genes (see FIGS. 28-31). For example, the antibodies
can include a variable heavy chain region that is the product of,
or derived from a human VH 5-51 gene. The antibodies can also, or
alternatively, include a light chain variable region that is the
product of, or derived from a human V.kappa. A27 gene and/or JK1
gene. As known in the art, and described in this section, above,
variable immunoglobulin regions of recombined antibodies are
derived by a process of recombination in vivo in which variability
is introduced to genomic segments encoding the regions.
Accordingly, variable regions derived from a human VH-5-51 or
V.kappa. A27/JK1 gene can include nucleotides that are different
that those in the gene found in non-lymphoid tissues. These
nucleotide differences are typically concentrated in the CDRs.
2. Production and Modification of Antibodies
[0158] Many different forms of anti-toxin antibodies can be useful
in the inhibition of CDAD. The antibodies can be of the various
isotypes, including: IgG (e.g., IgG1, IgG2, IgG3, IgG4), IgM, IgA1,
IgA2, IgD, or IgE. Preferably, the antibody is an IgG isotype,
e.g., IgG1. The antibody molecules can be full-length (e.g., an
IgG1 or IgG4 antibody) or can include only an antigen-binding
fragment (e.g., a Fab, F(ab').sub.2, Fv or a single chain Fv
fragment). These include monoclonal antibodies (e.g., human
monoclonal antibodies), recombinant antibodies, chimeric
antibodies, and humanized antibodies, as well as antigen-binding
portions of the foregoing.
[0159] Anti-toxin antibodies or portions thereof useful in the
present invention can also be recombinant antibodies produced by
host cells transformed with DNA encoding immunoglobulin light and
heavy chains of a desired antibody. Recombinant antibodies may be
produced by known genetic engineering techniques. For example,
recombinant antibodies can be produced by cloning a nucleotide
sequence, e.g., a cDNA or genomic DNA, encoding the immunoglobulin
light and heavy chains of the desired antibody. The nucleotide
sequence encoding those polypeptides is then inserted into an
expression vector so that both genes are operatively linked to
their own transcriptional and translational expression control
sequences. The expression vector and expression control sequences
are chosen to be compatible with the expression host cell used.
Typically, both genes are inserted into the same expression vector.
Prokaryotic or eukaryotic host cells may be used.
[0160] Expression in eukaryotic host cells is preferred because
such cells are more likely than prokaryotic cells to assemble and
secrete a properly folded and immunologically active antibody.
However, any antibody produced that is inactive due to improper
folding can be renatured according to well known methods (Kim and
Baldwin, Ann. Rev. Biochem., 51:459-89, 1982). It is possible that
the host cells will produce portions of intact antibodies, such as
light chain dimers or heavy chain dimers, which also are antibody
homologs according to the present invention.
[0161] The antibodies described herein also can be produced in a
host cell transfectoma using, for example, a combination of
recombinant DNA techniques and gene transfection methods as is well
known in the art (Morrison, S., Science, 229:1202, 1985). For
example, in one embodiment, the gene(s) of interest, e.g., human
antibody genes, can be ligated into an expression vector such as a
eukaryotic expression plasmid such as used in a GS gene expression
system disclosed in WO 87/04462, WO 89/01036 and EP 338 841, or in
other expression systems well known in the art. The purified
plasmid with the cloned antibody genes can be introduced in
eukaryotic host cells such as CHO-cells or NSO-cells or
alternatively other eukaryotic cells like a plant derived cells,
fungi or yeast cells. The method used to introduce these genes can
be any method described in the art, such as electroporation,
lipofectine, lipofectamine or ballistic transfection, in which
cells are bombarded with microparticles carrying the DNA of
interest (Rodin, et al. Immunol. Lett., 74(3):197-200, 2000). After
introducing these antibody genes in the host cells, cells
expressing the antibody can be identified and selected. These cells
represent the transfectomas which can then be amplified for their
expression level and upscaled to produce antibodies. Recombinant
antibodies can be isolated and purified from these culture
supernatants and/or cells using standard techniques.
[0162] It will be understood that variations on the above
procedures are useful in the present invention. For example, it may
be desired to transform a host cell with DNA encoding either the
light chain or the heavy chain (but not both) of an antibody.
Recombinant DNA technology may also be used to remove some or all
of the DNA encoding either or both of the light and heavy chains
that is not necessary for binding, e.g., the constant region may be
modified by, for example, deleting specific amino acids. The
molecules expressed from such truncated DNA molecules are useful in
the methods described herein. In addition, bifunctional antibodies
can be produced in which one heavy and one light chain bind to a
toxin, and the other heavy and light chain are specific for an
antigen other than the toxin, or another epitope of the toxin.
[0163] Chimeric antibodies can be produced by recombinant DNA
techniques known in the art. For example, a gene encoding the Fc
constant region of a murine (or other species) monoclonal antibody
molecule is digested with restriction enzymes to remove the region
encoding the murine Fc, and the equivalent portion of a gene
encoding a human Fc constant region is substituted (see Robinson et
al., International Patent Publication PCT/US86/02269; Akira, et
al., European Patent Application 184, 187; Taniguchi, M., European
Patent Application 171,496; Morrison et al., European Patent
Application 173,494; Neuberger et al., International Application WO
86/01533; Cabilly et al. U.S. Pat. No. 4,816,567; Cabilly et al.,
European Patent Application 125,023; Better et al. (1988 Science,
240:1041-1043); Liu et al. (1987) PNAS, 84:3439-3443; Liu et al.,
1987, J. Immunol., 139:3521-3526; Sun et al. (1987) PNAS
84:214-218; Nishimura et al., 1987, Canc. Res., 47:999-1005; Wood
et al. (1985) Nature, 314:446-449; and Shaw et al., 1988, J. Natl.
Cancer Inst., 80:1553-1559). Chimeric antibodies can also be
created by recombinant DNA techniques where DNA encoding murine V
regions can be ligated to DNA encoding the human constant
regions.
[0164] An antibody or an immunoglobulin chain can be humanized by
methods known in the art. For example, once murine antibodies are
obtained, variable regions can be sequenced. The location of the
CDRs and framework residues can be determined (see, Kabat, E. A.,
et al. (1991) Sequences of Proteins of Immunological Interest,
Fifth Edition, U.S. Department of Health and Human Services, NIH
Publication No. 91-3242, and Chothia, C. et al. (1987) J. Mol.
Biol., 196:901-917). The light and heavy chain variable regions
can, optionally, be ligated to corresponding constant regions.
Indeed, it is understood that any of the antibodies described
herein, including fully human antibodies, can be altered (e.g., by
mutation, substitution) to contain a substitute constant region,
e.g., Fc region, or portion(s) thereof to achieve, for example, a
desired antibody structure, function (e.g., effector function),
subtype, allotype, subclass, or the like. Anti-toxin antibodies can
be sequenced using art-recognized techniques. CDR-grafted antibody
molecules or immunoglobulins can be produced by CDR-grafting or CDR
substitution, wherein one, two, or all CDRs of an immunoglobulin
chain can be replaced. See e.g., U.S. Pat. No. 5,225,539; Jones et
al., 1986, Nature, 321:552-525; Verhoeyan et al., 1988, Science,
239:1534; Beidler et al., 1988, J. Immunol., 141:4053-4060; and
Winter, U.S. Pat. No. 5,225,539.
[0165] Winter describes a CDR-grafting method that may be used to
prepare the antibodies of the present invention (UK Patent
Application GB 2188638A, filed on Mar. 26, 1987; Winter U.S. Pat.
No. 5,225,539), the contents of which is expressly incorporated by
reference. For example, all of the CDRs of a particular antibody
may be replaced with at least a portion of a human CDR (e.g., a CDR
from clone 3D8, as shown in Tables 1 and 2, and/or clone 124-152,
as shown in Tables 3 and 4, above) or only some of the CDRs may be
replaced. It is only necessary to replace the number of CDRs
required for binding of the antibody to a predetermined antigen
(e.g., an exotoxin of C.
[0166] Humanized antibodies can be generated by replacing sequences
of the Fv variable region that are not directly involved in antigen
binding with equivalent sequences from human Fv variable regions.
General methods for generating humanized antibodies are provided by
Morrison, S. L., 1985, Science, 229:1202-1207, by Oi et al., 1986,
BioTechniques, 4:214, and by Queen et al. U.S. Pat. No. 5,585,089,
U.S. Pat. No. 5,693,761 and U.S. Pat. No. 5,693,762. Those methods
include isolating, manipulating, and expressing the nucleic acid
sequences that encode all or part of immunoglobulin Fv variable
regions from at least one of a heavy or light chain. Sources of
such nucleic acid are well known to those skilled in the art and,
for example, may be obtained from a hybridoma producing an antibody
against a predetermined target, as described above. The recombinant
DNA encoding the humanized antibody, or fragment thereof, can then
be cloned into an appropriate expression vector. Other techniques
for humanizing antibodies are described in Padlan et al. EP 519596
A1, published on Dec. 23, 1992.
[0167] Also within the scope of the invention are antibodies in
which specific amino acids have been substituted, deleted, or
added. In particular, preferred antibodies have amino acid
substitutions in the framework region, such as to improve binding
to the antigen. For example, a selected, small number of acceptor
framework residues of the immunoglobulin chain can be replaced by
the corresponding donor amino acids. Preferred locations of the
substitutions include amino acid residues adjacent to the CDR, or
which are capable of interacting with a CDR (see e.g., U.S. Pat.
No. 5,585,089). Criteria for selecting amino acids from the donor
are described in U.S. Pat. No. 5,585,089 (e.g., columns 12-16), the
contents of which are hereby incorporated by reference. The
acceptor framework can be a mature human antibody framework
sequence or a consensus sequence.
[0168] A "consensus sequence" is a sequence formed from the most
frequently occurring amino acids (or nucleotides) in a family of
related sequences (See e.g., Winnaker, From Genes to Clones
(Verlagsgesellschaft, Weinheim, Germany 1987). In a family of
proteins, each position in the consensus sequence is occupied by
the amino acid occurring most frequently at that position in the
family. If two amino acids occur equally frequently, either can be
included in the consensus sequence. A "consensus framework" of an
immunoglobulin refers to a framework region in the consensus
immunoglobulin sequence.
[0169] An anti-toxin antibody, or antigen-binding portion thereof,
can be derivatized or linked to another functional molecule (e.g.,
another peptide or protein). For example, an antibody can be
functionally linked (by chemical coupling, genetic fusion,
noncovalent association or otherwise) to one or more other
molecular entities, such as another antibody, a detectable agent, a
cytotoxic agent, a pharmaceutical agent, and/or a protein or
peptide that can mediate association with another molecule (such as
a streptavidin core region or a polyhistidine tag).
[0170] One type of derivatized protein is produced by crosslinking
two or more proteins (of the same type or of different types).
Suitable crosslinkers include those that are heterobifunctional,
having two distinct reactive groups separated by an appropriate
spacer (e.g., m-maleimidobenzoyl-N-hydroxysuccinimide ester) or
homobifunctional (e.g., disuccinimidyl suberate). Such linkers are
available from Pierce Chemical Company, Rockford, Ill.
[0171] Useful detectable agents with which a protein can be
derivatized (or labeled) include fluorescent compounds, various
enzymes, prosthetic groups, luminescent materials, bioluminescent
materials, and radioactive materials. Exemplary fluorescent
detectable agents include fluorescein, fluorescein isothiocyanate,
rhodamine, and, phycoerythrin. A protein or antibody can also be
derivatized with detectable enzymes, such as alkaline phosphatase,
horseradish peroxidase, .beta.-galactosidase, acetylcholinesterase,
glucose oxidase and the like. When a protein is derivatized with a
detectable enzyme, it is detected by adding additional reagents
that the enzyme uses to produce a detectable reaction product. For
example, when the detectable agent horseradish peroxidase is
present, the addition of hydrogen peroxide and diaminobenzidine
leads to a colored reaction product, which is detectable. A protein
can also be derivatized with a prosthetic group (e.g.,
streptavidin/biotin and avidin/biotin). For example, an antibody
can be derivatized with biotin, and detected through indirect
measurement of avidin or streptavidin binding.
[0172] Labeled proteins and antibodies can be used, for example,
diagnostically and/or experimentally in a number of contexts,
including (i) to isolate a predetermined antigen by standard
techniques, such as affinity chromatography or immunoprecipitation;
and (ii) to detect a predetermined antigen (e.g., a toxin, e.g., in
a cellular lysate or a patient sample) in order to monitor protein
levels in tissue as part of a clinical testing procedure, e.g., to
determine the efficacy of a given treatment regimen.
[0173] An anti-toxin antibody or antigen-binding fragment thereof
may be conjugated to another molecular entity, such as a label.
3. Screening Methods
[0174] Anti-toxin antibodies can be characterized for binding to
the toxin by a variety of known techniques. Antibodies are
typically characterized by ELISA first. Briefly, microtiter plates
can be coated with the toxin or toxoid antigen in PBS, and then
blocked with irrelevant proteins such as bovine serum albumin (BSA)
diluted in PBS. Dilutions of plasma from toxin-immunized mice are
added to each well and incubated for 1-2 hours at 37.degree. C. The
plates are washed with PBS/Tween 20 and then incubated with a
goat-anti-human IgG Fc-specific polyclonal reagent conjugated to
alkaline phosphatase for 1 hour at 37.degree. C. After washing, the
plates are developed with ABTS substrate, and analyzed at OD of
405. Preferably, mice which develop the highest titers will be used
for fusions.
[0175] An ELISA assay as described above can be used to screen for
antibodies and, thus, hybridomas that produce antibodies that show
positive reactivity with the toxin. Hybridomas that produce
antibodies that bind, preferably with high affinity, to the toxin
can than be subcloned and further characterized. One clone from
each hybridoma, which retains the reactivity of the parent cells
(by ELISA), can then be chosen for making a cell bank, and for
antibody purification.
[0176] To purify the anti-toxin antibodies, selected hybridomas can
be grown in roller bottles, two-liter spinner-flasks or other
culture systems. Supernatants can be filtered and concentrated
before affinity chromatography with protein A-Sepharose (Pharmacia,
Piscataway, N.J.) to purify the protein. After buffer exchange to
PBS, the concentration can be determined by spectrophotometric
methods.
[0177] To determine if the selected monoclonal antibodies bind to
unique epitopes, each antibody can be biotinylated using
commercially available reagents (Pierce, Rockford, Ill.).
Biotinylated MAb binding can be detected with a streptavidin
labeled probe. Anti-toxin antibodies can be further tested for
reactivity with the toxin by Western blotting.
[0178] Other assays to measure activity of the anti-toxin
antibodies include neutralization assays. In vitro neutralization
assays can measure the ability of an antibody to inhibit a
cytopathic effect on cells in culture (see Example 3, below). In
vivo assays to measure toxin neutralization are described in
Examples 5, 6, and 7, below.
4. Pharmaceutical Compositions and Kits
[0179] In another aspect, the present invention provides
compositions, e.g., pharmaceutically acceptable compositions, which
include an antibody molecule described herein or antigen binding
portion thereof, formulated together with a pharmaceutically
acceptable carrier.
[0180] "Pharmaceutically acceptable carriers" include any and all
solvents, dispersion media, isotonic and absorption delaying
agents, and the like that are physiologically compatible. The
carriers can be suitable for intravenous, intramuscular,
subcutaneous, parenteral, rectal, spinal, or epidermal
administration (e.g., by injection or infusion).
[0181] The compositions of this invention may be in a variety of
forms. These include, for example, liquid, semi-solid and solid
dosage forms, such as liquid solutions (e.g., injectable and
infusible solutions), dispersions or suspensions, liposomes and
suppositories. The preferred form depends on the intended mode of
administration and therapeutic application. Useful compositions are
in the form of injectable or infusible solutions. A useful mode of
administration is parenteral (e.g., intravenous, subcutaneous,
intraperitoneal, intramuscular). For example, the antibody or
antigen binding portion thereof can be administered by intravenous
infusion or injection. In another embodiment, the antibody or
antigen binding portion thereof is administered by intramuscular or
subcutaneous injection.
[0182] The phrases "parenteral administration" and "administered
parenterally" as used herein mean modes of administration other
than enteral and topical administration, usually by injection, and
include, without limitation, intravenous, intramuscular,
intraarterial, intrathecal, intracapsular, intraorbital,
intracardiac, intradermal, intraperitoneal, transtracheal,
subcutaneous, subcuticular, intraarticular, subcapsular,
subarachnoid, intraspinal, epidural, and intrasternal injection and
infusion.
[0183] Therapeutic compositions typically should be sterile and
stable under the conditions of manufacture and storage. The
composition can be formulated as a solution, microemulsion,
dispersion, liposome, or other ordered structure suitable to high
antibody concentration. Sterile injectable solutions can be
prepared by incorporating the active compound (i.e., antibody or
antibody portion) in the required amount in an appropriate solvent
with one or a combination of ingredients enumerated above, as
required, followed by filtered sterilization. Generally,
dispersions are prepared by incorporating the active compound into
a sterile vehicle that contains a basic dispersion medium and the
required other ingredients from those enumerated above. In the case
of sterile powders for the preparation of sterile injectable
solutions, the useful methods of preparation are vacuum drying and
freeze-drying that yields a powder of the active ingredient plus
any additional desired ingredient from a previously
sterile-filtered solution thereof. The proper fluidity of a
solution can be maintained, for example, by the use of a coating
such as lecithin, by the maintenance of the required particle size
in the case of dispersion and by the use of surfactants. Prolonged
absorption of injectable compositions can be brought about by
including in the composition an agent that delays absorption, for
example, monostearate salts and gelatin.
[0184] The antibodies and antibody portions described herein can be
administered by a variety of methods known in the art, and for many
therapeutic applications. As will be appreciated by the skilled
artisan, the route and/or mode of administration will vary
depending upon the desired results.
[0185] In certain embodiments, an antibody, or antibody portion
thereof may be orally administered, for example, with an inert
diluent or an assimilable edible carrier. The compound (and other
ingredients, if desired) may also be enclosed in a hard or soft
shell gelatin capsule, compressed into tablets, or incorporated
directly into the subject's diet. For oral therapeutic
administration, the compounds may be incorporated with excipients
and used in the form of ingestible tablets, buccal tablets,
troches, capsules, elixirs, suspensions, syrups, wafers, and the
like. To administer a compound of the invention by other than
parenteral administration, it may be necessary to coat the compound
with, or co-administer the compound with, a material to prevent its
inactivation. Therapeutic compositions can be administered with
medical devices known in the art.
[0186] Dosage regimens are adjusted to provide the optimum desired
response (e.g., a therapeutic response). For example, a single
bolus may be administered, several divided doses may be
administered over time, or the dose may be proportionally reduced
or increased as indicated by the exigencies of the therapeutic
situation. It is especially advantageous to formulate parenteral
compositions in dosage unit form for ease of administration and
uniformity of dosage. Dosage unit form as used herein refers to
physically discrete units suited as unitary dosages for the
subjects to be treated; each unit contains a predetermined quantity
of active compound calculated to produce the desired therapeutic
effect in association with the required pharmaceutical carrier. The
specification for the dosage unit forms of the invention are
dictated by and directly dependent on (a) the unique
characteristics of the active compound and the particular
therapeutic effect to be achieved, and (b) the limitations inherent
in the art of compounding such an active compound for the treatment
of sensitivity in individuals.
[0187] An exemplary, non-limiting range for a therapeutically or
prophylactically effective amount of an antibody or antibody
portion of the invention is 0.1-60 mg/kg, e.g., 0.5-25 mg/kg, 1-2
mg/kg, or 0.75-10 mg/kg. It is to be further understood that for
any particular subject, specific dosage regimens should be adjusted
over time according to the individual need and the professional
judgment of the person administering or supervising the
administration of the compositions, and that dosage ranges set
forth herein are exemplary only and are not intended to limit the
scope or practice of the claimed composition.
[0188] Also within the scope of the invention are kits including an
anti-toxin antibody or antigen binding portion thereof. The kits
can include one or more other elements including: instructions for
use; other reagents, e.g., a label, a therapeutic agent, or an
agent useful for chelating, or otherwise coupling, an antibody to a
label or therapeutic agent, or other materials for preparing the
antibody for administration; pharmaceutically acceptable carriers;
and devices or other materials for administration to a subject.
[0189] Various combinations of antibodies can be packaged together.
For example, a kit can include antibodies that bind to toxin A
(e.g., antibodies that include the variable heavy and light chain
regions of 3D8) and antibodies that bind to toxin B (e.g., human
monoclonal anti-toxin B antibodies, e.g., 124-152, 2A11, and/or
1G10, or polyclonal antisera reactive with toxin B). The antibodies
can be mixed together, or packaged separately within the kit.
[0190] Instructions for use can include instructions for
therapeutic application including suggested dosages and/or modes of
administration, e.g., in a patient with a symptom of CDAD. Other
instructions can include instructions on coupling of the antibody
to a chelator, a label or a therapeutic agent, or for purification
of a conjugated antibody, e.g., from unreacted conjugation
components.
[0191] The kit can include a detectable label, a therapeutic agent,
and/or a reagent useful for chelating or otherwise coupling a label
or therapeutic agent to the antibody. Coupling agents include
agents such as N-hydroxysuccinimide (NHS). In such cases the kit
can include one or more of a reaction vessel to carry out the
reaction or a separation device, e.g., a chromatographic column,
for use in separating the finished product from starting materials
or reaction intermediates.
[0192] The kit can further contain at least one additional reagent,
such as a diagnostic or therapeutic agent, e.g., a diagnostic or
therapeutic agent as described herein, and/or one or more
additional anti-toxin or anti-C. difficile antibodies (or portions
thereof), formulated as appropriate, in one or more separate
pharmaceutical preparations.
[0193] Other kits can include optimized nucleic acids encoding
anti-toxin antibodies, and instructions for expression of the
nucleic acids.
5. Therapeutic Methods and Compositions
[0194] The new proteins and antibodies have in vitro and in vivo
therapeutic, prophylactic, and diagnostic utilities. For example,
these antibodies can be administered to cells in culture, e.g., in
vitro or ex vivo, or to a subject, e.g., in vivo, to treat,
inhibit, prevent relapse, and/or diagnose C. difficile and disease
associated with C. difficile.
[0195] As used herein, the term "subject" is intended to include
human and non-human animals. The term "non-human animals" includes
all vertebrates, e.g., mammals and non-mammals, such as non-human
primates, chickens, mice, dogs, cats, pigs, cows, and horses.
[0196] The proteins and antibodies can be used on cells in culture,
e.g., in vitro or ex vivo. For example, cells can be cultured in
vitro in culture medium and the contacting step can be effected by
adding the anti-toxin antibody or fragment thereof, to the culture
medium. The methods can be performed on virions or cells present in
a subject, as part of an in vivo (e.g., therapeutic or
prophylactic) protocol. For in vivo embodiments, the contacting
step is effected in a subject and includes administering an
anti-toxin antibody or portion thereof to the subject under
conditions effective to permit binding of the antibody, or portion,
to any toxin expressed by bacteria in the subject, e.g., in the
gut.
[0197] Methods of administering antibody molecules are described
herein. Suitable dosages of the molecules used will depend on the
age and weight of the subject and the particular drug used. The
antibody molecules can be used as competitive agents for ligand
binding to inhibit or reduce an undesirable interaction, e.g., to
inhibit binding of toxins to the gastrointestinal epithelium.
[0198] The anti-toxin antibodies (or antigen binding portions
thereof) can be administered in combination with other anti-C.
difficile antibodies (e.g., other monoclonal antibodies, polyclonal
gamma-globulin). Combinations of antibodies that can be used
include an anti-toxin A antibody or antigen binding portion thereof
and an anti-toxin B antibody or antigen binding portion thereof.
The anti-toxin A antibody can be 3D8, an antibody that includes the
variable regions of 3D8, or an antibody with variable regions at
least 90% identical to the variable regions of 3D8. The anti-toxin
B antibody can be 124-152, 2A11, 1G10, or an antibody with variable
regions at least 90% identical to the variable regions of the
foregoing, e.g., 124-152. Combinations of anti-toxin A (e.g., 3D8)
and anti-toxin B antibodies (e.g., 124-152) can provide potent
inhibition of CDAD.
[0199] It is understood that any of the agents of the invention,
for example, anti-toxin A or anti-toxin B antibodies, or fragments
thereof, can be combined, for example in different ratios or
amounts, for improved therapeutic effect. Indeed, the agents of the
invention can be formulated as a mixture, or chemically or
genetically linked using art recognized techniques thereby
resulting in covalently linked antibodies (or covalently linked
antibody fragments), having both anti-toxin A and anti-toxin B
binding properties. The combined formulation may be guided by a
determination of one or more parameters such as the affinity,
avidity, or biological efficacy of the agent alone or in
combination with another agent. The agents of the invention can
also be administered in combination with other agents that enhance
access, half-life, or stability of the therapeutic agent in
targeting, clearing, and/or sequestering C. difficile or an antigen
thereof.
[0200] Such combination therapies are preferably additive and even
synergistic in their therapeutic activity, e.g., in the inhibition,
prevention (e.g., of relapse), and/or treatment of C.
difficile-related diseases or disorders (see, e.g., Example 16
which shows the efficacy of single and combined antibody
therapies). Administering such combination therapies can decrease
the dosage of the therapeutic agent (e.g., antibody or antibody
fragment mixture, or cross-linked or genetically fused bispecific
antibody or antibody fragment) needed to achieve the desired
effect.
[0201] Immunogenic compositions that contain an immunogenically
effective amount of a toxin, or fragments thereof, are described
herein, and can be used in generating anti-toxin antibodies.
Immunogenic epitopes in a toxin sequence can be identified
according to methods known in the art, and proteins, or fragments
containing those epitopes can be delivered by various means, in a
vaccine composition. Suitable compositions can include, for
example, lipopeptides (e.g., Vitiello et al., J. Clin. Invest.
95:341 (1995)), peptide compositions encapsulated in
poly(DL-lactide-co-glycolide) ("PLG") microspheres (see, e.g.,
Eldridge et al., Molec. Immunol. 28:287-94 (1991); Alonso et al.,
Vaccine 12:299-306 (1994); Jones et al., Vaccine 13:675-81 (1995)),
peptide compositions contained in immune stimulating complexes
(ISCOMS) (see, e.g., Takahashi et al., Nature 344:873-75 (1990); Hu
et al., Clin. Exp. Immunol. 113:235-43 (1998)), and multiple
antigen peptide systems (MAPs) (see, e.g., Tam, Proc. Natl. Acad.
Sci. U.S.A. 85:5409-13 (1988); Tam, J. Immunol. Methods 196:17-32
(1996)).
[0202] Useful carriers that can be used with immunogenic
compositions of the invention are well known, and include, for
example, thyroglobulin, albumins such as human serum albumin,
tetanus toxoid, polyamino acids such as poly L-lysine, poly
L-glutamic acid, influenza, hepatitis B virus core protein, and the
like. The compositions can contain a physiologically tolerable
(i.e., acceptable) diluent such as water, or saline, typically
phosphate buffered saline. The compositions and vaccines also
typically include an adjuvant. Adjuvants such as incomplete
Freund's adjuvant, aluminum phosphate, aluminum hydroxide, or alum
are examples of materials well known in the art. Additionally, CTL
responses can be primed by conjugating toxins (or fragments,
inactive derivatives or analogs thereof) to lipids, such as
tripalmitoyl-S-glycerylcysteinyl-seryl-serine (P.sub.3CSS).
[0203] The anti-toxin antibodies can be administered in combination
with other agents, such as compositions to treat CDAD. For example,
therapeutics that can be administered in combination with
anti-toxin antibodies include antibiotics used to treat CDAD, such
as vancomycin, metronidazole, or bacitracin. The antibodies can be
used in combination with probiotic agents such as Saccharomyces
boulardii. The antibodies can also be administered in combinations
with a C. difficile vaccine, e.g., a toxoid vaccine.
6. Other Methods
[0204] An anti-toxin antibody (e.g., monoclonal antibody) can be
used to isolate toxins by standard techniques, such as affinity
chromatography or immunoprecipitation. Moreover, an anti-toxin
antibody can be used to detect the toxin (e.g., in a stool sample),
e.g., to screen samples for the presence of C. difficile.
Anti-toxin antibodies can be used diagnostically to monitor levels
of the toxin in tissue as part of a clinical testing procedure,
e.g., to, for example, determine the efficacy of a given treatment
regimen.
EXEMPLIFICATION
[0205] Throughout the examples, the following materials and methods
were used unless otherwise stated.
Materials and Methods
[0206] In general, the practice of the present invention employs,
unless otherwise indicated, conventional techniques of chemistry,
molecular biology, recombinant DNA technology, immunology
(especially, e.g., antibody technology), and standard techniques in
polypeptide preparation. See, e.g., Sambrook, Fritsch and Maniatis,
Molecular Cloning: Cold Spring Harbor Laboratory Press (1989);
Antibody Engineering Protocols (Methods in Molecular Biology), 510,
Paul, S., Humana Pr (1996); Antibody Engineering: A Practical
Approach (Practical Approach Series, 169), McCafferty, Ed., Irl Pr
(1996); Antibodies: A Laboratory Manual, Harlow et al., C.S.H.L.
Press, Pub. (1999); and Current Protocols in Molecular Biology,
eds. Ausubel et al., John Wiley & Sons (1992).
Examples
[0207] The invention is further described in the following
examples, which do not limit the scope of the invention described
in the claims.
Example 1. Generation of Anti-Toxin a Monoclonal Antibodies
[0208] C. difficile toxin A was obtained either from Techlab, Inc.
(Blacksburg, Va.), or by recombinant production. The toxin was
purified and inactivated prior to immunization. Inactivation was
performed by treatment with reactive UDP-dialdehyde, which results
in alkylation of catalytic residues while preserving native toxin
structure. For the detailed protocol, see Genth et al., Inf and
Immun. 68(3):1094-1101, 2000. Briefly, purified toxin A was
incubated with UDP-2',3'-dialdehyde (0.1-1.0 mM) in buffer for 18
hours at 37.degree. C., filtered through a 100 kDa-cutoff filter to
remove unreacted UDP-2',3'-dialdehyde, and washed with buffer.
Inactivated toxin A (toxoid A) was used for immunization.
[0209] HCo7 transgenic mice, generated as described above in the
section entitled "Generation of Human Monoclonal Antibodies in
HuMAb Mice" and supplied by Medarex, Milpitas, Calif., were
immunized intraperitoneally 6-12 times each with 10 .mu.g of toxoid
in RIBI adjuvant. In the HCo7 transgenic mice, the endogenous mouse
kappa light chain gene has been homozygously disrupted as described
in Chen et al. (1993) EMBO J. 12:811-820 and the endogenous mouse
heavy chain gene has been homozygously disrupted as described in
Example 1 of PCT Publication WO 01/09187. The HCo7 transgenic mice
carry a human kappa light chain transgene, KCo5, as described in
Fishwild et al. (1996) Nature Biotechnology 14:845-851, and the
HCo7 human heavy chain transgene as described in U.S. Pat. Nos.
5,545,806; 5,625,825; and 5,545,807. Serum was collected from each
mouse and tested for reactivity to toxin A by ELISA and
neutralization of cytotoxicity on IMR-90 cells. Mice that tested
positive for toxin A-reactive and neutralizing antiserum were
injected with 5-10 .mu.g toxoid A through the tail vein. Mice were
sacrificed and spleens were isolated for fusion to hybridomas
approximately 3 days after tail vein injection was performed.
[0210] Clonal hybridomas were generated and screened by ELISA.
Percentages of kappa/gamma light chain positive, antigen-specific,
and neutralizing clones identified by screening clones generated
from four separate hybridoma fusions are listed in Table 5.
TABLE-US-00005 TABLE 5 % kappa/gamma Fusion positive % antigen
specific % neutralizing 1 5.7 (94/1632) 3.4 (56/1632) 0.7 (12/1632)
2 0.2 (1/384) 0 (0/384) 0 (0/384) 3 1.8 (14/768) 0.39 (3/768) 4 4.4
(43/960) 1.7 (17/960)
[0211] Three hybridoma clones were selected for further analysis:
3D8, 1B11, and 33.3H2. CDNAs from each clone were amplified by
RT-PCR from mRNA, cloned, and sequenced. One heavy chain V region
consensus sequence was found for each clone. All three clones
utilized a VH region derived from the same germline V region gene
(VH 3-33), but utilized different J sequences. The amino acid
sequences of the VH and VL regions from each clone are shown in
FIG. 1 (SEQ ID NOs: 1-6). The complementarity determining regions
(CDRs) are overlined in the Figure.
[0212] Sequence analysis of the kappa V (V.kappa. light chain)
genes revealed that HuMAb 1B11 and 33.3H2 each express one
consensus kappa chain V sequence. The 1B11 hybridoma expressed a
V.kappa. light chain derived from the V.kappa. L6 germline gene,
whereas the 33.3H2 hybridoma expresses a V.kappa. light chain
derived from the V.kappa. L15 germline gene. Upon analysis of the
V.kappa. clones from HuMAb 3D8, 6 (I-VI) light chains were
expressed at the mRNA level (FIG. 1). To determine which of the
light chains were expressed at the protein level, mass spectroscopy
and N-terminal sequencing of the purified 3D8 antibody were
performed. When light chains were isolated from cellular protein
and analyzed by mass spectroscopy, a single light chain was seen
with a mass of 23,569 Daltons. This corresponded to the light chain
with the group I amino acid sequence depicted in FIG. 1, which is
derived from the V.kappa. L19 germline gene. N-terminal sequencing
of the light chain confirmed this result. FIGS. 2A, 3A, and 4A
depict the nucleotide and the amino acid sequences of the V.kappa.
of each 3D8 (group I; SEQ ID NOs: 4, and 30-34), 1B11 (SEQ ID NO:
5), and 33.3H2 (SEQ ID NO:6) respectively. The CDRs are overlined
and the germline V.kappa. and J.kappa. are shown.
[0213] Thus, the 3D8 antibody comprises a heavy chain variable
region that is the product of or derived from a human VH 3-33 gene
and a light chain variable region that is the product of or derived
from a human V.kappa. L19 gene. The 1B11 antibody comprises a heavy
chain variable region that is the product of or derived from a
human VH 3-33 gene and a light chain variable region that this the
product of or derived from a human V.kappa. L6 gene. The 33.3H2
antibody comprises a heavy chain variable region that is the
product of or derived from a human VH 3-33 gene and a light chain
variable region that this the product of or derived from a human
V.kappa. L15 gene.
[0214] The antibodies 3D8 and 1B11 express human IgG1 constant
regions, and antibody 33.3H2 expresses human IgG3 constant regions.
The antibodies described in Examples 2-7 were isolated from these
hybridomas, and thus express the variable sequences shown in FIG. 1
along with human constant regions. DNA encoding the antigen binding
portion of each clone was cloned into a vector to be expressed as a
human antibody for administration to humans.
Example 2. Binding Activity of Anti-Toxin a Antibodies
[0215] Binding of each antibody to toxin A was determined by ELISA
using standard techniques. The results of this assay are depicted
in FIG. 5. Antibodies produced by 3D8, 1B11, and 33.3H2 were
compared to a fourth human monoclonal antibody with toxin A binding
activity, 8E6. FIG. 5 shows that the antibodies bind toxin A with
comparable affinities.
[0216] The affinity of the 3D8 and 1B11 antibodies for toxin A was
also measured with Biacore.RTM. instrument, which detects
biomolecular binding interactions with surface plasmon resonance
technology. Each antibody was added to protein A-coated sensor
chips, and toxin A was allowed to flow over the chip to measure
binding. 3D8 had a K.sub.D of 14.6.times.10.sup.-10 M. 1B11 had a
K.sub.D of 7.38.times.10.sup.-10M. Thus, the antibodies bind with
high affinity to toxin A. These binding constants indicate that the
antibodies have affinities suitable for use in human therapy.
Example 3. Toxin Neutralization by Anti-Toxin a Antibodies
[0217] Antibodies expressed by 1B11, 3D8, and 33.3H2 hybridomas
were tested for toxin A neutralization activity in vitro. Cells
were incubated in the presence of varying concentrations of toxin
A, which causes cells to round up and lose adherence to cell
culture dishes. Cytopathic effect (CPE) was determined by visual
inspection of cells. A CPE score from 0-4 was determined, based on
the results of the visual inspection (4=100% cytotoxicity, 0=0%
toxicity). The results of these assays are depicted in FIGS. 6A and
6B. Neutralization of toxicity against a human lung fibroblast cell
line, IMR-90, and a human gut epithelial cell line, T-84, was
determined. FIG. 6A shows that all of the antibodies had
neutralizing capacity towards IMR-90 cells. The relative
neutralizing activity of toxin A cytotoxicity on IMR-90 cells was
1B11>3H2>3D8. Interestingly, the relative neutralizing
activity was 3D8.gtoreq.1B11>3H2 against T-84 cells, which are
human colonic epithelial cells (FIG. 6A). T-84 cells are believed
to be more sensitive to toxin A than other cell types. T-84 cells
may provide a more relevant target cell to determine toxin A
cytotoxicity.
Example 4. Epitope Mapping of Anti-Toxin a Antibodies
[0218] The epitope of toxin A bound by each monoclonal antibody was
determined by western blotting. Recombinant E. coli clones were
constructed which express four fragments of toxin A representing
the enzymatic domain (i.e., amino acids 1-659 of toxin A), the
receptor binding domain (i.e., amino acids 1853-2710 of toxin A),
and the two regions in between (i.e., amino acids 660-1255 and
1256-1852 of toxin A). The appropriate segments of the toxin A gene
were PCR-amplified from genomic DNA prepared from C. difficile
strain ATCC 43255. The fragments were cloned using a pET vector and
transformed into BL21 DE3 cells for expression. The vector provides
inducible expression and affinity domains for purification (i.e., a
His-tag) and detection (i.e., a V5 epitope tag). Expression was
induced with IPTG and fragments were purified by affinity
chromatography. Binding to four different fragments of toxin A was
measured: fragment 1 corresponded to amino acids 1-659; fragment 2
corresponded to amino acids 660-1255; fragment 3 corresponded to
amino acids 1256-1852; and fragment 4 corresponded to amino acids
1853-2710 (FIG. 7). 1B11 reacted with fragments 1 and 2. 33.3H2
reacted with fragment 2. 3D8 and another human monoclonal antibody,
6B4, reacted with fragment 4 (the receptor binding domain). A
polyclonal antiserum from rabbits immunized with toxoid A reacted
with all four fragments.
[0219] The 1B11 and 33.3H2 epitopes were mapped in further detail.
To map the 1B11 epitope, subfragments of fragment 1 (amino acids
1-659) corresponding to amino acids 1-540, 1-415, 1-290, and 1-165,
were generated (FIG. 8A). 1B11 bound to fragment 1 and to the
fragment containing amino acids 1-540. 1B11 did not bind to the
other subfragments. Therefore, the epitope bound by 1B11 maps
between amino acids 415-540 of toxin A.
[0220] To map the 33.3H2 epitope, subfragments of fragment 2 (amino
acids 660-1255) corresponding to amino acids 660-1146, 660-1033,
660-920, and 660-807, were generated (FIG. 8B). 33.3H2 bound to the
fragments corresponding to amino acids 660-1255, 660-1146, and
660-1033. 33.3H2 did not bind to the other subfragments. Therefore,
the epitope bound by 33.3H2 maps between amino acids 920-1033 of
toxin A.
Example 5. Protection of Mice from Lethal Toxin A Challenge by
Administration of Anti-Toxin A Antibodies
[0221] Each antibody was tested for the ability to protect mice
from challenge with a lethal dose of toxin A. Swiss Webster female
mice, each weighing 10-20 grams, were injected intraperitoneally
with up to 250 .mu.g of 3D8, 1B11, or 33.3H2, or a control antibody
(anti-respiratory syncytial virus antibody, MedImmune) prior to
challenge with toxin A. Approximately 24 hours after injection,
mice were challenged with a dose of toxin A greater than 10 times
the lethal dose (LD.sub.50), typically 100 ng. Animals were
observed for signs of toxicity for the next 7 days. The results of
these experiments are summarized in FIG. 9. The data is expressed
as percentage survival. Numbers in parenthesis refer to antibody
dose, if a dose other than 250 .mu.g was given. FIG. 9 shows that
each of the antibodies was able to protect mice from lethal toxin A
challenge to some extent. The percentage of mice surviving when
treated with 3D8 ranged from 10-100 percent. The percentage of mice
surviving when treated with 33.3H2 ranged from 20-100 percent. The
percentage of mice surviving when treated with 1B11 ranged from
0-60 percent. The relative ability of these monoclonals to protect
mice was 3H2.gtoreq.3D8>1B11.
Example 6. Neutralization of Toxin A Enterotoxicity in Ligated
Mouse Intestinal Loops with Anti-Toxin A Antibodies
[0222] 3D8 and 33.3H2 antibodies were tested for neutralization of
toxin A enterotoxicity in a mouse ileal loop model. This model
measures toxin A-induced fluid accumulation in mouse intestine. To
perform these experiments, each mouse was starved for 16 hours,
anesthetized, and the ileum next to the cecum was exposed. A loop
of 3 to 5 centimeters was doubly ligated at each end and injected
with 10 .mu.g of toxin A. The ileal loop was returned to the
abdominal cavity, the wound was closed, and the animal was allowed
to recover. Four hours after surgery, the animal was euthanized and
the loop was removed from the animal. The length of each segment
was remeasured, and the intraluminal fluid was extracted. The
volume of the fluid and the volume-to-length (V:L) ratio in
milliliters per centimeter was calculated for each loop. Test mice
were injected with antibody parenterally 1-2 days before surgery.
The results of these experiments are depicted in FIG. 10. Injection
with toxin A increased the weight to length ratio of intestinal
fluid by 50%. Both 3D8 and 33.3H2 prevented this increase in fluid
accumulation. Mice administered either antibody had a weight to
length ratio comparable to mice that did not receive any toxin A
injection. Therefore, 3D8 and 33.3H2 protect from intestinal fluid
accumulation in vivo.
[0223] These results indicate that the anti-toxin A monoclonal
antibodies protect from toxin A-mediated enterotoxicity in vivo.
The mouse ligated loop data shows that these monoclonal antibodies
can protect from mucosal damage when administered systemically.
Example 7. Protection of Hamsters from C. difficile Relapse with
Anti-Toxin A Antibodies
[0224] 3D8 was tested in a hamster relapse model. Hamsters are
sensitive to the toxic effects of C. difficile toxins, and
typically die within 2-3 days of receiving a single dose of
clindamycin in the presence of C. difficile. To test the efficacy
of 3D8 in hamsters, a relapse model was used. In this model,
hamsters were given a dose of clindamycin and a dose of C.
difficile B1 spores one day later. One set of control hamsters
received no additional antibiotic or antibody. A second set of
control hamsters were treated with 10 mg/kg/day vancomycin.
Vancomycin is an antibiotic used in the treatment of C. difficile
disease. As shown in FIG. 11A, a test set of hamsters received 10
mg/kg/day vancomycin and 2 mg/kg/day of a rabbit polyclonal
antiserum raised against toxin A each day for seven days after C.
difficile exposure, as indicated by the arrows in the figure. A
second test set of hamsters received 10 mg/kg/day vancomycin and 50
mg/kg/day 3D8 at the same time intervals. Hamster survival was
plotted versus time and is shown in FIG. 11B.
[0225] FIG. 11B shows that all of the hamsters that received only
clindamycin and C. difficile (diamonds) died within two days of
challenge with the bacteria. Twelve percent ( 2/17) of hamsters
treated with vancomycin (squares) survived challenge with bacteria;
eighty-eight percent ( 15/17) died within eight days. Forty-one
percent ( 7/17) of hamsters treated with vancomycin and 3D8
(crosses) survived challenge; fifty-nine ( 10/17) percent died
within seven days. Sixty-four percent ( 7/11) of hamsters treated
with vancomycin and polyclonal rabbit serum (triangles) survived
the challenge with bacteria; thirty-six percent ( 4/11) died within
nine days. These data are also depicted in FIG. 12 as the
percentage of total survivors in each treatment group. As shown in
the figure, the percentage of survivors was highest (sixty-four
percent) in the group receiving vancomycin and polyclonal rabbit
serum. The group receiving 3D8 and vancomycin had the second
highest rate of survival (forty-one percent). Only twelve percent
of vancomycin-treated hamsters survived. Those with no treatment
all died. These data show that polyclonal and monoclonal anti-toxin
antibodies protect from relapse of C. difficile disease in vivo
when administered after infection.
Example 8. Production of Anti-Toxin A Antibodies for Administration
in Humans
[0226] Nucleic acid sequences encoding the variable heavy chain and
light chains of the 3D8 antibody were cloned into a pIE-Ugamma1F
vector using standard recombinant DNA methodology. The vector was
amplified in E. coli, purified, and transfected into CHO-dg44
cells. Transfected cells were plated at 4.times.10.sup.5 cells per
well in a 96-well dish and selected for vector transfection with
G418. One clone, designated 1D3, was originally selected by G418
resistance, then assayed along with other transfectomas for
production of IgG. 1D3 had a higher level of IgG production
relative to other transfectants during several rounds of expansion.
The expression of the 3D8 antibody was amplified by growth in the
presence of increasing concentrations of methotrexate. A culture
capable of growth in 175 nM methotrexate was chosen for cloning
single cells for further development. Plating the culture in 96
well plates at low density allowed generation of cultures arising
from a single cell or clones. The cultures were screened for
production of human IgG, and the cell that produced the highest
level of IgG was selected for further use. The
methotrexate-amplified clone was expanded to produce a cell bank
including multiple frozen vials of cells.
[0227] To prepare antibodies from transfected cells, cells from a
clone isolated in the previous steps are cultured and expanded as
inoculum for a bioreactor. The bioreactor typically holds a 500
liter volume of culture medium. The cells are cultured in the
bioreactor until cell viability drops, which indicates a maximal
antibody concentration has been produced in the culture. The cells
are removed by filtration. The filtrate is applied to a protein A
column. Antibodies bind to the column, and are eluted with a low pH
wash. Next, the antibodies are applied to a Q-Sepharose column to
remove residual contaminants, such as CHO cell proteins, DNA, and
other contaminants (e.g., viral contaminants, if present).
Antibodies are eluted from the Q-Sepharose column, nano-filtered,
concentrated, and washed in a buffer such as PBS. The preparation
is then aseptically aliquoted into vials for administration.
Example 9. Preparation and Characterization of Polyclonal
Anti-Toxin B Antibodies
[0228] Two Nubian goats (#330 and #331) were injected
intramuscularly with 50 .mu.g UDP dialdehyde-inactivated toxin B
(Techlab) and complete Freund's adjuvant. Booster doses of 25 .mu.g
toxoid B with Freund's incomplete adjuvant were given
intramuscularly at two-week intervals. Test bleeds were obtained
after 4 immunizations. ELISA reactivity and neutralization of
cytotoxicity against both toxin A and toxin B were assayed to
measure the specificity and cross reactivity of the sera.
[0229] Both animals responded well to toxin B and to a lesser
extent to toxin A as measured by ELISA. Sera from goat #331 had
less toxin A cross-reactivity and was chosen for the majority of
the subsequent experiments. Neutralization of cytotoxicity to
IMR-90 cells was determined as described in Example 3. The results
of cytotoxicity neutralization are depicted in FIG. 13, which shows
that sera from both animals exhibited good toxin B neutralizing
antibody titers and very low, but detectable, toxin A neutralizing
antibody titers. The ability of the goat sera to protect mice from
a lethal intraperitoneal challenge with toxin B (100 ng) was also
confirmed (data not shown).
Example 10. Protection of Hamsters from C. difficile Relapse with
Anti-Toxin A and Anti-Toxin B Antibodies
[0230] Groups of hamsters (n=20) were challenged with clindamycin
and C. difficile, and then treated with vancomycin as described in
the hamster model of relapse in Example 7. Antibodies (either 3D8,
serum from goat #331, or 3D8 and serum from goat #331) were given
twice daily after vancomycin treatment (FIG. 14). Animals were
monitored for survival (FIG. 15) or illness (FIG. 16). Antibody
doses were 1 ml twice daily for serum from goat #331 and 3 mg for
3D8 given twice daily. Animals receiving vancomycin only (i.e., no
antibody treatment) served as a negative controls. As observed
previously, 3D8 and vancomycin treatment alone demonstrated a
partial protective effect, in which 10 out of 20 animals were
protected from lethality (FIG. 15). Fifty percent of animals in
this group remained healthy (FIG. 16). Six out of 20 animals
receiving vancomycin treatment alone were protected (FIG. 15).
Thirty percent remained healthy (FIG. 16). Partial protection (
9/20 animals protected) was also observed when the goat serum was
used alone (FIG. 15). Forty percent remained healthy. Protection
was increased to nearly 100% when both goat serum and 3D8 were
given together ( 18/20) and disease onset was delayed (FIG. 15).
Ninety percent of these animals remained healthy (FIG. 16).
Clearly, protection from illness followed a pattern similar to
protection from lethality. These data demonstrate that 3D8 can be
fully protective in the hamster disease model when toxin B is also
neutralized.
Example 11. Protection of Hamsters from C. difficile Relapse in
Hamsters Immunized with Toxin B
[0231] Hamsters were immunized intraperitoneally with 10 .mu.g of
the COOH-terminal fragment of toxin B (corresponding to amino acids
1777-2366 of toxin B) expressed in E. coli and using RIBI as
adjuvant. Animals received 7 doses of toxin B antigen. Neutralizing
antibody responses were observed in the animals that were tested.
Groups of immunized hamsters were challenged with clindamycin and
C. difficile then treated with vancomycin as described in the
hamster model of relapse in Example 7. Antibody (3D8, 3 mg/dose)
was given twice daily after vancomycin treatment to 19 animals and
compared to a negative control group (n=20) that received no
treatment (FIGS. 17 and 18). Six animals were challenged without
vancomycin treatment to ensure that hamsters immunized with toxin B
antigen were susceptible to C. difficile infection. Animals were
monitored for survival (FIG. 17) or illness (FIG. 18). FIG. 17
shows that immunized animals that were not given 3D8 relapsed at a
similar rate to that observed previously (65% relapse). Toxin
B-immunized animals receiving 3D8 were more fully protected from
relapse than observed previously (10% relapse, as compared to
approximately 50% relapse in animals not previously immunized with
toxin B in other experiments).
[0232] FIG. 18 shows that some of the immunized animals receiving
3D8 became ill but recovered from their diarrhea. Thirty five
percent of immunized animals receiving vancomycin alone remained
healthy. In experiments in which toxin B reactive sera were not
present in animals, virtually all animals that had diarrhea later
died. These data provide further evidence that 3D8 can be fully
protective in the hamster disease model when toxin B is also
neutralized. Neutralization of toxin B in addition to toxin A was
required for optimal protection from C. difficile disease in this
model.
Example 12. Protection of Hamsters from Primary C. difficile
Challenge Using 3D8 in Hamsters Treated with Goat Anti-Toxin B
Sera
[0233] Prevention of relapse of C. difficile disease in the
hamsters was easier to demonstrate than protection from direct
challenge (i.e., challenge without vancomycin administration).
Experiments with rabbit sera demonstrated only weak protection from
direct challenge and 3D8 had no detectable affect on direct
challenge. Since 3D8 was more protective in a background of toxin B
neutralizing antibodies, it was determined whether the combined
administration of 3D8 and anti-toxin B anti sera could prevent
disease due to direct challenge. Groups of 5 hamsters were
challenged after receiving once daily doses of 3D8 (3 mg), combined
3D8 (3 mg) and goat #331 (1 ml) sera, or no antibodies for the 3
days prior to challenge as depicted in FIG. 19. The data in FIG. 20
shows that animals receiving no antibodies or either 3D8 or goat
sera alone all died with 48 hours of C. difficile challenge. Most
animals (80%) receiving both 3D8 and goat sera survived and the
affected animals survived for 10 days after challenge. FIG. 21
shows that animals treated with 3D8 and goat sera became ill but
recovered. These data provide further evidence that 3D8 can be
fully protective in the hamster disease model when toxin B is also
neutralized. Neutralization of toxin B in addition to toxin A was
required for optimal protection from C. difficile disease in this
model.
[0234] The successful protection of hamsters directly challenged
with C. difficile offers several advantages to the screening of new
toxin B candidates. Smaller numbers of animals can be used since
100% of untreated animals die. Antibodies, such as monoclonal
antibodies (e.g., human monoclonal antibodies) can be screened
directly in hamsters because the procedure requires 100 mg or less
of the test antibody. Other modes of testing, such as the relapse
model, require the effort of producing gram quantities due to the
low attack rate in the relapse model, which necessitates testing
larger numbers of animals. Direct challenge experiments are also
shorter in duration with a definitive read out within 3-4 days of
C. difficile challenge compared to 7-10 in the relapse model. In
addition, the elimination of vancomycin treatment from the
screening method reduces the number of times animals are
handled.
Example 13. Generation of Anti-Toxin B Monoclonal Antibodies
[0235] C. difficile toxin B was obtained either from Techlab, Inc.
(Blacksburg, Va.), or by recombinant production. The toxin was
purified and inactivated prior to immunization. Inactivation was
performed by treatment with reactive UDP-dialdehyde, which results
in alkylation of catalytic residues while preserving native toxin
structure. Briefly, purified toxin B was incubated with
UDP-2',3'-dialdehyde (0.1-1.0 mM) in buffer for 18 hours at
37.degree. C., filtered through a 100 kDa-cutoff filter to remove
unreacted UDP-2',3'-dialdehyde, and washed with buffer. Inactivated
toxin B (toxoid B) or recombinant toxin B fragments were used as
immunogens. A toxin B receptor binding domain (amino acid residues
1777-2366) was expressed in E. coli as a fusion protein containing
an immunotag (hexahistadine) for affinity purification using nickel
chelate affinity chromatography (designated fragment 4; see Example
11).
[0236] Hco12 transgenic mice, generated as described above in the
section entitled "Generation of Human Monoclonal Antibodies in
HuMAb Mice" and supplied by Medarex, Milpitas, Calif., were
immunized intraperitoneally 6-12 times each with 10 .mu.g of toxoid
in RIBI adjuvant. In the Hco12 transgenic mice, the endogenous
mouse kappa light chain gene has been homozygously disrupted as
described in Chen et al. (1993) EMBO J. 12:811-820 and the
endogenous mouse heavy chain gene has been homozygously disrupted
as described in Example 1 of PCT Publication WO 01/09187. The Hco12
transgenic mice carry a human kappa light chain transgene, KCo5, as
described in Fishwild et al. (1996) Nature Biotechnology
14:845-851, and the Hco12 human heavy chain transgene as described
in U.S. Pat. Nos. 5,545,806; 5,625,825; and 5,545,807. Serum was
collected from each mouse and tested for reactivity to toxin B by
ELISA and neutralization of cytotoxicity on IMR-90 cells. Mice that
tested positive for toxin B-reactive and neutralizing antiserum
were injected with 5-10 .mu.g toxoid B or fragment 4 through the
tail vein. Mice were sacrificed and spleens were isolated for
fusion to hybridomas approximately 3 days after tail vein injection
was performed.
[0237] Clonal hybridomas were generated and screened by ELISA.
Three hybridoma clones were selected for further analysis: 124-152;
2A11; and 1G10. In particular, cDNAs from the 124-152 clone were
amplified by RT-PCR from mRNA, cloned, and sequenced. The heavy
chain V region was determined to be derived from the germline
sequence VH 5-51, the D region derived from the germline sequence
7-27, and the J sequence from the germline region JH3b. The light
chain (kappa) regions were determined to be derived from A27 and
the J region from JK1. The isotype of the 124-152 clone was
determined to be IgG1. The amino acid sequences of the VH and VL
regions of the 124-152 clone are shown in FIGS. 27-28. The
complementarity determining regions (CDRs) are indicated in the
Figures. The related germline sequences of the VH and VL regions
are shown in FIGS. 30-31.
[0238] The antibodies 124-152; 2A11; and 1G10 were isolated from
corresponding hybridomas and tested for their binding
characteristics (infra). DNA encoding the 124-152 clone was cloned
into a vector to be expressed as a human antibody for
administration to humans.
Example 14. Binding Activity of Anti-Toxin B Antibodies
[0239] Binding of each antibody to toxin B was determined by
Biacore using standard techniques. The results of this assay are
depicted in Table 6. Antibodies produced by 124-152; 2A11; and 1G10
were compared to appropriate controls.
[0240] In particular, the affinity of the 124-152; 2A11; and 1G10
antibodies for toxin B was measured with Biacore.RTM. instrument,
which detects biomolecular binding interactions with surface
plasmon resonance technology. Each antibody was added to protein
A-coated sensor chips, and toxin B was allowed to flow over the
chip to measure binding. 124-152 had a K.sub.D of
1.64.times.10.sup.-10 M; 2A11 had a K.sub.D of
0.24.times.10.sup.-10 M; and 1G10 had a K.sub.D of
2.98.times.10.sup.-10 M. Thus, the antibodies bind with high
affinity to toxin B. These binding constants indicate that the
antibodies have affinities suitable for use in vivo application,
for example, human therapy.
TABLE-US-00006 TABLE 6 K.sub.D .times. 10.sup.-10 k.sub.a .times.
10.sup.5 k.sub.d .times. 10.sup.-5 Sample ID (M) (1/Ms) (1/s) 2A11
0.24 21 5.07 124.152 1.64 34.5 56.4 51.1G10 2.98 1.31 3.89
Example 15. Toxin Neutralization by Anti-Toxin B Antibodies
[0241] Antibodies expressed by 124-152; 2A11; and 1G10 hybridomas
were tested for toxin B neutralization activity in vitro. Cells
were incubated in the presence of varying concentrations of a
monoclonal antibody specific to toxin B which would prevent cells
from rounding up after exposure to toxin B. Cytopathic effect (CPE)
was determined by visual inspection of cells. A CPE score from 0-4
was determined, based on the results of the visual inspection
(4=100% cytotoxicity, 0=0% toxicity). The results of these assays
are depicted in FIG. 27. Neutralization of toxicity against a human
lung fibroblast cell line, IMR-90. FIG. 27 shows that all of the
antibodies had neutralizing capacity towards IMR-90 cells. The
relative neutralizing activity of toxin A cytotoxicity on IMR-90
cells was 124-152>1G10>2A11.
Example 16. Protection of Hamsters from Primary C. difficile
Challenge Using Anti-Toxin B Antibodies
[0242] Protection from direct challenge of an inoculum of C.
difficile (clindamycin on day -1 and C. difficile spores on day 0
(1/100,000 dilution) was performed over a period of 4 to 10 days in
the presence or absence of anti-toxin B antibodies. Groups of 5
hamsters were challenged after receiving once daily doses of 3D8
(20 mg total over 4 days), combined 3D8 (Id.) and goat #331 (3 ml)
sera, 3D8 in combination with anti-toxin B antibodies 124-152 (18
mg total over 4 days), 2A11 (20 mg total over 4 days), or 1G10 (20
mg total over 4 days) or no antibodies for 3 days prior to
challenge as depicted in FIG. 24. The data in FIG. 24 shows that
animals receiving no antibodies or either 3D8 or goat sera alone
all died within 72 hours of C. difficile challenge whereas animals
receiving 3D8 and an anti-toxin B antibody, and preferably in
combination with 124-152, had a 40% survival rate (FIG. 24). A 10
day study similar to the foregoing (but using a more dilute C.
difficile inoculum) was performed with increasing amounts of the
anti-toxin B antibody 124-152 (0.56 mg, 1.7 mg, or 5.0 mg given at
days -3, -2, -1, and 0). Animals receiving both 3D8 and goat sera
survived and most animals (60%-70%) survived for 10 days after
challenge if given 3D8 in combination with 124-152. Even the lowest
dosage of the anti-toxin B antibody 124-152 (0.56 mg in combination
with 3D8) was highly effective (70% survival; see FIG. 25). Results
show that 124-152 and 3D8, alone, are less effective then when used
in combination where a more than additive, indeed, synergistic
therapeutic result is achieved (FIGS. 24-26). These data provide
further evidence that the anti-toxin B antibody is highly
effective, especially in combination with the anti-toxin A antibody
3D8. Neutralization of toxin B in addition to toxin A was
determined to provide for protection from C. difficile disease in
this model.
Example 17. Epitope Mapping of Anti-Toxin B Antibodies
[0243] The epitope of toxin B bound by each monoclonal antibody was
determined by western blotting. Recombinant E. coli clones were
constructed which express fragments of toxin B representing
different domains of toxin B. The appropriate segments of the toxin
B gene were PCR-amplified from DNA prepared from an appropriate C.
difficile strain. The fragments were cloned into an expression
vector and expressed in E. coli. Human monoclonal antibody 152 was
used to probe toxin B fragment in western blots in order to map the
binding epitope. Toxin B protein fragments were isolated from E.
coli containing a portion of the toxin B genes and separated using
SDS-PAGE. After electrophoresis, the toxin B fragments were
transferred to nitrocellulose and probed with monoclonal antibody
152 followed by alkaline phosphatase conjugated goat anti human to
detect MAb 152 binding. HuMab 152 was determined to bind to the
--COOH fragment portion of toxin B between amino acids 1777 and
2366 (see, for example, FIG. 32).
Other Embodiments
[0244] A number of embodiments of the invention have been
described. Nevertheless, it will be understood that various
modifications may be made without departing from the spirit and
scope of the invention. Accordingly, other embodiments are within
the scope of the following claims.
Sequence CWU 1
1
831122PRTHomo sapiens 1Gln Val Gln Leu Val Glu Ser Gly Gly Gly Val
Val Gln Pro Gly Arg 1 5 10 15 Ser Leu Arg Leu Ser Cys Ala Ala Ser
Gly Phe Ser Phe Ser Asn Tyr 20 25 30 Gly Met His Trp Val Arg Gln
Ala Pro Gly Lys Gly Leu Glu Trp Val 35 40 45 Ala Leu Ile Trp Tyr
Asp Gly Ser Asn Glu Asp Tyr Thr Asp Ser Val 50 55 60 Lys Gly Arg
Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn Thr Leu Tyr 65 70 75 80 Leu
Gln Met Asn Ser Leu Arg Ala Glu Asp Thr Ala Val Tyr Tyr Cys 85 90
95 Ala Arg Trp Gly Met Val Arg Gly Val Ile Asp Val Phe Asp Ile Trp
100 105 110 Gly Gln Gly Thr Val Val Thr Val Ser Ser 115 120
2114PRTHomo sapiens 2Gln Met Gln Leu Val Glu Ser Gly Gly Gly Val
Val Gln Pro Gly Arg 1 5 10 15 Ser Leu Arg Leu Ser Cys Glu Ala Ser
Gly Phe Ser Phe Asn Ser Tyr 20 25 30 Gly Met His Trp Val Arg Gln
Ala Pro Gly Lys Gly Leu Glu Trp Val 35 40 45 Ser Val Ile Trp Ala
Ser Gly Asn Lys Lys Tyr Tyr Ile Glu Ser Val 50 55 60 Glu Gly Arg
Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn Thr Leu Tyr 65 70 75 80 Leu
Gln Met Asn Ser Leu Arg Ala Glu Asp Thr Ala Val Tyr Tyr Cys 85 90
95 Ala Arg Ala Asn Phe Asp Tyr Trp Gly Gln Gly Thr Leu Val Thr Val
100 105 110 Ser Ser 3116PRTHomo sapiens 3Gln Val Gln Leu Val Glu
Ser Gly Gly Gly Val Val Gln Pro Gly Arg 1 5 10 15 Ser Leu Arg Leu
Ser Cys Ala Ala Ser Gly Phe Thr Phe Asn Lys Tyr 20 25 30 Gly Met
His Trp Val Arg Gln Ala Pro Gly Lys Gly Leu Glu Trp Val 35 40 45
Ala Val Ile Trp Tyr Asp Gly Thr Asn Lys Tyr Tyr Ala Asp Ser Met 50
55 60 Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn Met Leu
Tyr 65 70 75 80 Leu Gln Met Asn Ser Leu Arg Ala Glu Asp Thr Ala Val
Tyr Tyr Cys 85 90 95 Ala Arg Asp Pro Pro Thr Ala Asn Tyr Trp Gly
Gln Gly Thr Leu Val 100 105 110 Thr Val Ser Ser 115 4107PRTHomo
sapiens 4Asp Ile Gln Met Thr Gln Ser Pro Ser Ser Val Ser Ala Ser
Val Gly 1 5 10 15 Asp Arg Val Thr Ile Thr Cys Arg Ala Ser Gln Gly
Ile Ser Ser Trp 20 25 30 Leu Ala Trp Tyr Gln His Lys Pro Gly Lys
Ala Pro Lys Leu Leu Ile 35 40 45 Tyr Ala Ala Ser Ser Leu Gln Ser
Gly Val Pro Ser Arg Phe Ser Gly 50 55 60 Ser Gly Ser Gly Thr Asp
Phe Thr Leu Thr Ile Ser Ser Leu Gln Pro 65 70 75 80 Glu Asp Phe Ala
Thr Tyr Tyr Cys Gln Gln Ala Asn Ser Phe Pro Trp 85 90 95 Thr Phe
Gly Gln Gly Thr Lys Val Glu Ile Lys 100 105 5108PRTHomo sapiens
5Glu Ile Val Leu Thr Gln Ser Pro Ala Thr Leu Ser Leu Ser Pro Gly 1
5 10 15 Glu Arg Ala Thr Leu Ser Cys Arg Ala Ser Gln Ser Val Ser Ser
Tyr 20 25 30 Leu Ala Trp Tyr Gln Gln Lys Pro Gly Gln Ala Pro Arg
Leu Leu Ile 35 40 45 Tyr Asp Ala Ser Asn Arg Ala Thr Gly Ile Pro
Ala Arg Phe Ser Gly 50 55 60 Ser Gly Ser Gly Thr Asp Phe Thr Leu
Thr Ile Ser Ser Leu Glu Pro 65 70 75 80 Glu Asp Phe Ala Val Tyr Tyr
Cys Gln Gln Arg Ser Asn Trp Ser Gln 85 90 95 Phe Thr Phe Gly Pro
Gly Thr Lys Val Asp Ile Lys 100 105 6107PRTHomo sapiens 6Asp Ile
Gln Met Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly 1 5 10 15
Asp Arg Val Thr Ile Thr Cys Arg Ala Ser Gln Gly Ile Ser Ser Trp 20
25 30 Leu Ala Trp Tyr Gln Gln Lys Pro Glu Lys Ala Pro Lys Ser Leu
Ile 35 40 45 Tyr Ala Ala Ser Ser Leu Gln Ser Gly Val Pro Ser Arg
Phe Ser Gly 50 55 60 Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile
Ser Ser Leu Gln Pro 65 70 75 80 Glu Asp Phe Ala Thr Tyr Tyr Cys Gln
Gln Tyr Lys Ser Tyr Pro Val 85 90 95 Thr Phe Gly Gly Gly Thr Lys
Val Glu Ile Lys 100 105 75PRTHomo sapiens 7Asn Tyr Gly Met His 1 5
817PRTHomo sapiens 8Leu Ile Trp Tyr Asp Gly Ser Asn Glu Asp Tyr Thr
Asp Ser Val Lys 1 5 10 15 Gly 913PRTHomo sapiens 9Trp Gly Met Val
Arg Gly Val Ile Asp Val Phe Asp Ile 1 5 10 105PRTHomo sapiens 10Ser
Tyr Gly Met His 1 5 1117PRTHomo sapiens 11Val Ile Trp Ala Ser Gly
Asn Lys Lys Tyr Tyr Ile Glu Ser Val Glu 1 5 10 15 Gly 125PRTHomo
sapiens 12Ala Asn Phe Asp Tyr 1 5 135PRTHomo sapiens 13Lys Tyr Gly
Met His 1 5 1417PRTHomo sapiens 14Val Ile Trp Tyr Asp Gly Thr Asn
Lys Tyr Tyr Ala Asp Ser Met Lys 1 5 10 15 Gly 157PRTHomo sapiens
15Asp Pro Pro Thr Ala Asn Tyr 1 5 1611PRTHomo sapiens 16Arg Ala Ser
Gln Gly Ile Ser Ser Trp Leu Ala 1 5 10 177PRTHomo sapiens 17Ala Ala
Ser Ser Leu Gln Ser 1 5 189PRTHomo sapiens 18Gln Gln Ala Asn Ser
Phe Pro Trp Thr 1 5 1911PRTHomo sapiens 19Arg Ala Ser Gln Ser Val
Ser Ser Tyr Leu Ala 1 5 10 207PRTHomo sapiens 20Asp Ala Ser Asn Arg
Ala Thr 1 5 2110PRTHomo sapiens 21Gln Gln Arg Ser Asn Trp Ser Gln
Phe Thr 1 5 10 2211PRTHomo sapiens 22Arg Ala Ser Gln Gly Ile Ser
Ser Trp Leu Ala 1 5 10 237PRTHomo sapiens 23Ala Ala Ser Ser Leu Gln
Ser 1 5 249PRTHomo sapiens 24Gln Gln Tyr Lys Ser Tyr Pro Val Thr 1
5 2511PRTHomo sapiensMOD_RES(5)..(6)Any amino
acidMOD_RES(9)..(9)Any amino acid 25Arg Ala Ser Gln Xaa Xaa Ser Ser
Xaa Leu Ala 1 5 10 266PRTHomo sapiensMOD_RES(3)..(5)Any amino
acidMOD_RES(6)..(6)Ser or Thr 26Ala Ser Xaa Xaa Xaa Xaa 1 5
277PRTHomo sapiensMOD_RES(3)..(4)Any amino acidMOD_RES(5)..(5)Ser
or AsnMOD_RES(6)..(6)Any amino acidMOD_RES(7)..(7)Pro or Ser 27Gln
Gln Xaa Xaa Xaa Xaa Xaa 1 5 284PRTHomo sapiens 28Tyr Gly Met His 1
2915PRTHomo sapiensMOD_RES(3)..(4)Any amino acidMOD_RES(6)..(8)Any
amino acidMOD_RES(10)..(11)Any amino acidMOD_RES(13)..(14)Any amino
acid 29Ile Trp Xaa Xaa Gly Xaa Xaa Xaa Tyr Xaa Xaa Ser Xaa Xaa Gly
1 5 10 15 30107PRTHomo sapiens 30Asp Ile Gln Met Thr Gln Ser Pro
Ser Ser Leu Ser Ala Ser Val Gly 1 5 10 15 Asp Arg Val Thr Ile Thr
Cys Arg Ala Ser Gln Gly Ile Ser Ser Trp 20 25 30 Leu Ala Trp Tyr
Gln Gln Lys Pro Glu Lys Ala Pro Lys Ser Leu Ile 35 40 45 Tyr Ala
Ala Ser Ser Leu Gln Ser Gly Val Pro Ser Arg Phe Ser Gly 50 55 60
Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Ser Leu Gln Pro 65
70 75 80 Glu Asp Phe Ala Thr Tyr Tyr Cys Gln Gln Tyr Asn Ser Tyr
Pro Trp 85 90 95 Thr Phe Gly Gln Gly Thr Lys Val Glu Ile Lys 100
105 31107PRTHomo sapiens 31Val Ile Trp Met Thr Gln Ser Pro Ser Leu
Leu Ser Ala Ser Thr Gly 1 5 10 15 Asp Arg Val Thr Ile Ser Cys Arg
Met Ser Gln Gly Ile Ser Ser Tyr 20 25 30 Leu Ala Trp Tyr Gln Gln
Lys Pro Gly Lys Ala Pro Glu Leu Leu Ile 35 40 45 Tyr Ala Ala Ser
Thr Leu Gln Ser Gly Val Pro Ser Arg Phe Ser Gly 50 55 60 Ser Gly
Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Ser Leu Gln Pro 65 70 75 80
Glu Asp Phe Ala Thr Tyr Tyr Cys Gln Gln Tyr Asn Ser Tyr Pro Trp 85
90 95 Thr Phe Gly Gln Gly Thr Lys Val Glu Ile Lys 100 105
32107PRTHomo sapiens 32Asp Ile Gln Met Thr Gln Ser Pro Ser Ser Val
Ser Ala Ser Val Gly 1 5 10 15 Asp Arg Val Thr Ile Thr Cys Arg Ala
Ser Gln Gly Ile Ser Ser Trp 20 25 30 Leu Ala Trp Tyr Gln His Lys
Pro Gly Lys Ala Pro Lys Leu Leu Ile 35 40 45 Tyr Ala Ala Ser Ser
Leu Gln Ser Gly Val Pro Ser Arg Phe Ser Gly 50 55 60 Ser Gly Ser
Gly Thr Asp Phe Thr Leu Thr Ile Ser Ser Leu Gln Pro 65 70 75 80 Glu
Asp Phe Ala Thr Tyr Tyr Cys Gln Gln Tyr Asn Ser Tyr Pro Trp 85 90
95 Thr Phe Gly Gln Gly Thr Lys Val Glu Ile Lys 100 105 33107PRTHomo
sapiens 33Asp Ile Gln Met Thr Gln Ser Pro Ser Ser Val Ser Ala Ser
Val Gly 1 5 10 15 Asp Arg Val Thr Ile Thr Cys Arg Ala Ser Gln Gly
Ile Ser Ser Trp 20 25 30 Leu Ala Trp Tyr Gln Gln Lys Pro Glu Lys
Ala Pro Lys Ser Leu Ile 35 40 45 Tyr Ala Ala Ser Ser Leu Gln Ser
Gly Val Pro Ser Arg Phe Ser Gly 50 55 60 Ser Gly Ser Gly Thr Asp
Phe Thr Leu Thr Ile Ser Ser Leu Gln Pro 65 70 75 80 Glu Asp Phe Ala
Thr Tyr Tyr Cys Gln Gln Tyr Asn Ser Tyr Pro Trp 85 90 95 Thr Phe
Gly Gln Gly Thr Lys Val Glu Ile Lys 100 105 34107PRTHomo sapiens
34Asp Ile Gln Met Thr Gln Ser Leu Ser Ser Leu Ser Ala Ser Val Gly 1
5 10 15 Asp Arg Val Thr Ile Thr Cys Arg Ala Ser Gln Gly Ile Ser Ser
Trp 20 25 30 Leu Ala Trp Tyr Gln Gln Lys Pro Glu Lys Ala Pro Lys
Ser Leu Ile 35 40 45 Tyr Ala Ala Ser Ser Leu Gln Ser Gly Val Pro
Ser Arg Phe Ser Gly 50 55 60 Ser Gly Ser Gly Thr Asp Phe Thr Leu
Thr Ile Ser Ser Leu Gln Pro 65 70 75 80 Glu Asp Phe Ala Thr Tyr Tyr
Cys Gln Gln Ala Asn Ser Phe Pro Trp 85 90 95 Thr Phe Gly Gln Gly
Thr Lys Val Glu Ile Lys 100 105 35321DNAHomo sapiensCDS(1)..(321)
35gac atc cag atg acc cag tct cca tct tcc gtg tct gca tct gta gga
48Asp Ile Gln Met Thr Gln Ser Pro Ser Ser Val Ser Ala Ser Val Gly 1
5 10 15 gac aga gtc acc atc act tgt cgg gcg agt cag ggt att agc agc
tgg 96Asp Arg Val Thr Ile Thr Cys Arg Ala Ser Gln Gly Ile Ser Ser
Trp 20 25 30 tta gcc tgg tat cag cat aaa cca ggg aaa gcc cct aag
ctc ctg atc 144Leu Ala Trp Tyr Gln His Lys Pro Gly Lys Ala Pro Lys
Leu Leu Ile 35 40 45 tat gct gca tcc agt ttg caa agt ggg gtc cca
tca agg ttc agc ggc 192Tyr Ala Ala Ser Ser Leu Gln Ser Gly Val Pro
Ser Arg Phe Ser Gly 50 55 60 agt gga tct ggg aca gat ttc act ctc
acc atc agc agc ctg cag cct 240Ser Gly Ser Gly Thr Asp Phe Thr Leu
Thr Ile Ser Ser Leu Gln Pro 65 70 75 80 gaa gat ttt gca act tac tat
tgt caa cag gct aat agt ttc cct tgg 288Glu Asp Phe Ala Thr Tyr Tyr
Cys Gln Gln Ala Asn Ser Phe Pro Trp 85 90 95 acg ttc ggc caa ggg
acc aag gtg gaa atc aaa 321Thr Phe Gly Gln Gly Thr Lys Val Glu Ile
Lys 100 105 36324DNAHomo sapiensCDS(1)..(324) 36gaa att gtg ttg aca
cag tct cca gcc acc ctg tct ttg tct cca ggg 48Glu Ile Val Leu Thr
Gln Ser Pro Ala Thr Leu Ser Leu Ser Pro Gly 1 5 10 15 gaa aga gcc
acc ctc tcc tgc agg gcc agt cag agt gtt agc agc tac 96Glu Arg Ala
Thr Leu Ser Cys Arg Ala Ser Gln Ser Val Ser Ser Tyr 20 25 30 tta
gcc tgg tac caa cag aaa cct ggc cag gct ccc agg ctc ctc atc 144Leu
Ala Trp Tyr Gln Gln Lys Pro Gly Gln Ala Pro Arg Leu Leu Ile 35 40
45 tat gat gca tcc aac agg gcc act ggc atc cca gcc agg ttc agt ggc
192Tyr Asp Ala Ser Asn Arg Ala Thr Gly Ile Pro Ala Arg Phe Ser Gly
50 55 60 agt ggg tct ggg aca gac ttc act ctc acc atc agc agc cta
gag cct 240Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Ser Leu
Glu Pro 65 70 75 80 gaa gat ttt gca gtt tat tac tgt cag cag cgt agc
aac tgg tct caa 288Glu Asp Phe Ala Val Tyr Tyr Cys Gln Gln Arg Ser
Asn Trp Ser Gln 85 90 95 ttc act ttc ggc cct ggg acc aaa gtg gat
atc aaa 324Phe Thr Phe Gly Pro Gly Thr Lys Val Asp Ile Lys 100 105
37321DNAHomo sapiensCDS(1)..(321) 37gac atc cag atg acc cag tct cca
tcc tca ctg tct gca tct gta gga 48Asp Ile Gln Met Thr Gln Ser Pro
Ser Ser Leu Ser Ala Ser Val Gly 1 5 10 15 gac aga gtc acc atc act
tgt cgg gcg agt cag ggt att agc agc tgg 96Asp Arg Val Thr Ile Thr
Cys Arg Ala Ser Gln Gly Ile Ser Ser Trp 20 25 30 tta gcc tgg tat
cag cag aaa cca gag aaa gcc cct aag tcc ctg atc 144Leu Ala Trp Tyr
Gln Gln Lys Pro Glu Lys Ala Pro Lys Ser Leu Ile 35 40 45 tat gct
gca tcc agt ttg caa agt ggg gtc cca tca agg ttc agc ggc 192Tyr Ala
Ala Ser Ser Leu Gln Ser Gly Val Pro Ser Arg Phe Ser Gly 50 55 60
agt gga tct ggg aca gat ttc act ctc acc atc agc agc ctg cag cct
240Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Ser Leu Gln Pro
65 70 75 80 gaa gat ttt gca act tat tac tgc caa cag tat aag agt tac
ccg gtc 288Glu Asp Phe Ala Thr Tyr Tyr Cys Gln Gln Tyr Lys Ser Tyr
Pro Val 85 90 95 act ttc ggc gga ggg acc aag gtg gag atc aaa 321Thr
Phe Gly Gly Gly Thr Lys Val Glu Ile Lys 100 105 38366DNAHomo
sapiensCDS(1)..(366) 38cag gtg cag ctg gtg gag tct ggg gga ggc gtg
gtc cag cct ggc agg 48Gln Val Gln Leu Val Glu Ser Gly Gly Gly Val
Val Gln Pro Gly Arg 1 5 10 15 tcc ctg aga ctc tcc tgt gcg gcg tct
gga ttc agc ttc agt aac tat 96Ser Leu Arg Leu Ser Cys Ala Ala Ser
Gly Phe Ser Phe Ser Asn Tyr 20 25 30 ggc atg cac tgg gtc cgc cag
gct cca ggc aag ggg ctg gag tgg gtg 144Gly Met His Trp Val Arg Gln
Ala Pro Gly Lys Gly Leu Glu Trp Val 35 40 45 gca ctt ata tgg tat
gat gga agt aat gag gac tat aca gac tcc gtg 192Ala Leu Ile Trp Tyr
Asp Gly Ser Asn Glu Asp Tyr Thr Asp Ser Val 50 55 60 aag ggc cga
ttc acc atc tcc aga gac aat tcc aag aac acg ctg tat 240Lys Gly Arg
Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn Thr Leu Tyr 65 70 75 80 ctg
caa atg aac agc ctg aga gcc gag gac acg gct gtg tat tac
tgt 288Leu Gln Met Asn Ser Leu Arg Ala Glu Asp Thr Ala Val Tyr Tyr
Cys 85 90 95 gcg aga tgg ggg atg gtt cgg gga gtt atc gat gtt ttt
gat atc tgg 336Ala Arg Trp Gly Met Val Arg Gly Val Ile Asp Val Phe
Asp Ile Trp 100 105 110 ggc caa ggg aca gtg gtc acc gtc tct tca
366Gly Gln Gly Thr Val Val Thr Val Ser Ser 115 120 39342DNAHomo
sapiensCDS(1)..(342) 39cag atg cag ctg gtg gag tct ggg ggc ggc gtg
gtc cag cct ggg agg 48Gln Met Gln Leu Val Glu Ser Gly Gly Gly Val
Val Gln Pro Gly Arg 1 5 10 15 tcc ctg aga ctc tcc tgt gaa gcg tct
gga ttc tcc ttc aat agc tat 96Ser Leu Arg Leu Ser Cys Glu Ala Ser
Gly Phe Ser Phe Asn Ser Tyr 20 25 30 ggc atg cac tgg gtc cgc cag
gct cca ggc aag ggg ctg gag tgg gtg 144Gly Met His Trp Val Arg Gln
Ala Pro Gly Lys Gly Leu Glu Trp Val 35 40 45 tca gtc ata tgg gcc
agt gga aat aag aaa tat tat ata gaa tcc gtg 192Ser Val Ile Trp Ala
Ser Gly Asn Lys Lys Tyr Tyr Ile Glu Ser Val 50 55 60 gag ggc cga
ttc acc atc tcc aga gac aat tcc aag aac acg ctg tat 240Glu Gly Arg
Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn Thr Leu Tyr 65 70 75 80 ctg
caa atg aac agc ctg aga gcc gag gac acg gct gtg tat tac tgt 288Leu
Gln Met Asn Ser Leu Arg Ala Glu Asp Thr Ala Val Tyr Tyr Cys 85 90
95 gcg aga gcc aat ttt gac tac tgg ggc cag gga acc ctg gtc acc gtc
336Ala Arg Ala Asn Phe Asp Tyr Trp Gly Gln Gly Thr Leu Val Thr Val
100 105 110 tcc tca 342Ser Ser 40348DNAHomo sapiensCDS(1)..(348)
40cag gtg cag ctg gtg gag tct ggg gga ggc gtg gtc cag cct ggg agg
48Gln Val Gln Leu Val Glu Ser Gly Gly Gly Val Val Gln Pro Gly Arg 1
5 10 15 tcc ctg aga ctc tcc tgt gca gcg tct gga ttc acc ttc aat aaa
tat 96Ser Leu Arg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe Asn Lys
Tyr 20 25 30 ggc atg cac tgg gtc cgc cag gct cca ggc aag ggg ctg
gag tgg gtg 144Gly Met His Trp Val Arg Gln Ala Pro Gly Lys Gly Leu
Glu Trp Val 35 40 45 gca gtt ata tgg tat gat gga act aat aaa tac
tat gca gac tcc atg 192Ala Val Ile Trp Tyr Asp Gly Thr Asn Lys Tyr
Tyr Ala Asp Ser Met 50 55 60 aag ggc cga ttc acc atc tcc aga gac
aat tcc aag aat atg ctg tat 240Lys Gly Arg Phe Thr Ile Ser Arg Asp
Asn Ser Lys Asn Met Leu Tyr 65 70 75 80 ctg caa atg aac agc cta aga
gcc gag gac acg gct gtg tat tac tgt 288Leu Gln Met Asn Ser Leu Arg
Ala Glu Asp Thr Ala Val Tyr Tyr Cys 85 90 95 gcg aga gat ccc ccc
act gct aac tac tgg ggc cag gga acc ctg gtc 336Ala Arg Asp Pro Pro
Thr Ala Asn Tyr Trp Gly Gln Gly Thr Leu Val 100 105 110 acc gtc tcc
tca 348Thr Val Ser Ser 115 412710PRTClostridium difficile 41Met Ser
Leu Ile Ser Lys Glu Glu Leu Ile Lys Leu Ala Tyr Ser Ile 1 5 10 15
Arg Pro Arg Glu Asn Glu Tyr Lys Thr Ile Leu Thr Asn Leu Asp Glu 20
25 30 Tyr Asn Lys Leu Thr Thr Asn Asn Asn Glu Asn Lys Tyr Leu Gln
Leu 35 40 45 Lys Lys Leu Asn Glu Ser Ile Asp Val Phe Met Asn Lys
Tyr Lys Thr 50 55 60 Ser Ser Arg Asn Arg Ala Leu Ser Asn Leu Lys
Lys Asp Ile Leu Lys 65 70 75 80 Glu Val Ile Leu Ile Lys Asn Ser Asn
Thr Ser Pro Val Glu Lys Asn 85 90 95 Leu His Phe Val Trp Ile Gly
Gly Glu Val Ser Asp Ile Ala Leu Glu 100 105 110 Tyr Ile Lys Gln Trp
Ala Asp Ile Asn Ala Glu Tyr Asn Ile Lys Leu 115 120 125 Trp Tyr Asp
Ser Glu Ala Phe Leu Val Asn Thr Leu Lys Lys Ala Ile 130 135 140 Val
Glu Ser Ser Thr Thr Glu Ala Leu Gln Leu Leu Glu Glu Glu Ile 145 150
155 160 Gln Asn Pro Gln Phe Asp Asn Met Lys Phe Tyr Lys Lys Arg Met
Glu 165 170 175 Phe Ile Tyr Asp Arg Gln Lys Arg Phe Ile Asn Tyr Tyr
Lys Ser Gln 180 185 190 Ile Asn Lys Pro Thr Val Pro Thr Ile Asp Asp
Ile Ile Lys Ser His 195 200 205 Leu Val Ser Glu Tyr Asn Arg Asp Glu
Thr Val Leu Glu Ser Tyr Arg 210 215 220 Thr Asn Ser Leu Arg Lys Ile
Asn Ser Asn His Gly Ile Asp Ile Arg 225 230 235 240 Ala Asn Ser Leu
Phe Thr Glu Gln Glu Leu Leu Asn Ile Tyr Ser Gln 245 250 255 Glu Leu
Leu Asn Arg Gly Asn Leu Ala Ala Ala Ser Asp Ile Val Arg 260 265 270
Leu Leu Ala Leu Lys Asn Phe Gly Gly Val Tyr Leu Asp Val Asp Met 275
280 285 Leu Pro Gly Ile His Ser Asp Leu Phe Lys Thr Ile Ser Arg Pro
Ser 290 295 300 Ser Ile Gly Leu Asp Arg Trp Glu Met Ile Lys Leu Glu
Ala Ile Met 305 310 315 320 Lys Tyr Lys Lys Tyr Ile Asn Asn Tyr Thr
Ser Glu Asn Phe Asp Lys 325 330 335 Leu Asp Gln Gln Leu Lys Asp Asn
Phe Lys Leu Ile Ile Glu Ser Lys 340 345 350 Ser Glu Lys Ser Glu Ile
Phe Ser Lys Leu Glu Asn Leu Asn Val Ser 355 360 365 Asp Leu Glu Ile
Lys Ile Ala Phe Ala Leu Gly Ser Val Ile Asn Gln 370 375 380 Ala Leu
Ile Ser Lys Gln Gly Ser Tyr Leu Thr Asn Leu Val Ile Glu 385 390 395
400 Gln Val Lys Asn Arg Tyr Gln Phe Leu Asn Gln His Leu Asn Pro Ala
405 410 415 Ile Glu Ser Asp Asn Asn Phe Thr Asp Thr Thr Lys Ile Phe
His Asp 420 425 430 Ser Leu Phe Asn Ser Ala Thr Ala Glu Asn Ser Met
Phe Leu Thr Lys 435 440 445 Ile Ala Pro Tyr Leu Gln Val Gly Phe Met
Pro Glu Ala Arg Ser Thr 450 455 460 Ile Ser Leu Ser Gly Pro Gly Ala
Tyr Ala Ser Ala Tyr Tyr Asp Phe 465 470 475 480 Ile Asn Leu Gln Glu
Asn Thr Ile Glu Lys Thr Leu Lys Ala Ser Asp 485 490 495 Leu Ile Glu
Phe Lys Phe Pro Glu Asn Asn Leu Ser Gln Leu Thr Glu 500 505 510 Gln
Glu Ile Asn Ser Leu Trp Ser Phe Asp Gln Ala Ser Ala Lys Tyr 515 520
525 Gln Phe Glu Lys Tyr Val Arg Asp Tyr Thr Gly Gly Ser Leu Ser Glu
530 535 540 Asp Asn Gly Val Asp Phe Asn Lys Asn Thr Ala Leu Asp Lys
Asn Tyr 545 550 555 560 Leu Leu Asn Asn Lys Ile Pro Ser Asn Asn Val
Glu Glu Ala Gly Ser 565 570 575 Lys Asn Tyr Val His Tyr Ile Ile Gln
Leu Gln Gly Asp Asp Ile Ser 580 585 590 Tyr Glu Ala Thr Cys Asn Leu
Phe Ser Lys Asn Pro Lys Asn Ser Ile 595 600 605 Ile Ile Gln Arg Asn
Met Asn Glu Ser Ala Lys Ser Tyr Phe Leu Ser 610 615 620 Asp Asp Gly
Glu Ser Ile Leu Glu Leu Asn Lys Tyr Arg Ile Pro Glu 625 630 635 640
Arg Leu Lys Asn Lys Glu Lys Val Lys Val Thr Phe Ile Gly His Gly 645
650 655 Lys Asp Glu Phe Asn Thr Ser Glu Phe Ala Arg Leu Ser Val Asp
Ser 660 665 670 Leu Ser Asn Glu Ile Ser Ser Phe Leu Asp Thr Ile Lys
Leu Asp Ile 675 680 685 Ser Pro Lys Asn Val Glu Val Asn Leu Leu Gly
Cys Asn Met Phe Ser 690 695 700 Tyr Asp Phe Asn Val Glu Glu Thr Tyr
Pro Gly Lys Leu Leu Leu Ser 705 710 715 720 Ile Met Asp Lys Ile Thr
Ser Thr Leu Pro Asp Val Asn Lys Asn Ser 725 730 735 Ile Thr Ile Gly
Ala Asn Gln Tyr Glu Val Arg Ile Asn Ser Glu Gly 740 745 750 Arg Lys
Glu Leu Leu Ala His Ser Gly Lys Trp Ile Asn Lys Glu Glu 755 760 765
Ala Ile Met Ser Asp Leu Ser Ser Lys Glu Tyr Ile Phe Phe Asp Ser 770
775 780 Ile Asp Asn Lys Leu Lys Ala Lys Ser Lys Asn Ile Pro Gly Leu
Ala 785 790 795 800 Ser Ile Ser Glu Asp Ile Lys Thr Leu Leu Leu Asp
Ala Ser Val Ser 805 810 815 Pro Asp Thr Lys Phe Ile Leu Asn Asn Leu
Lys Leu Asn Ile Glu Ser 820 825 830 Ser Ile Gly Asp Tyr Ile Tyr Tyr
Glu Lys Leu Glu Pro Val Lys Asn 835 840 845 Ile Ile His Asn Ser Ile
Asp Asp Leu Ile Asp Glu Phe Asn Leu Leu 850 855 860 Glu Asn Val Ser
Asp Glu Leu Tyr Glu Leu Lys Lys Leu Asn Asn Leu 865 870 875 880 Asp
Glu Lys Tyr Leu Ile Ser Phe Glu Asp Ile Ser Lys Asn Asn Ser 885 890
895 Thr Tyr Ser Val Arg Phe Ile Asn Lys Ser Asn Gly Glu Ser Val Tyr
900 905 910 Val Glu Thr Glu Lys Glu Ile Phe Ser Lys Tyr Ser Glu His
Ile Thr 915 920 925 Lys Glu Ile Ser Thr Ile Lys Asn Ser Ile Ile Thr
Asp Val Asn Gly 930 935 940 Asn Leu Leu Asp Asn Ile Gln Leu Asp His
Thr Ser Gln Val Asn Thr 945 950 955 960 Leu Asn Ala Ala Phe Phe Ile
Gln Ser Leu Ile Asp Tyr Ser Ser Asn 965 970 975 Lys Asp Val Leu Asn
Asp Leu Ser Thr Ser Val Lys Val Gln Leu Tyr 980 985 990 Ala Gln Leu
Phe Ser Thr Gly Leu Asn Thr Ile Tyr Asp Ser Ile Gln 995 1000 1005
Leu Val Asn Leu Ile Ser Asn Ala Val Asn Asp Thr Ile Asn Val 1010
1015 1020 Leu Pro Thr Ile Thr Glu Gly Ile Pro Ile Val Ser Thr Ile
Leu 1025 1030 1035 Asp Gly Ile Asn Leu Gly Ala Ala Ile Lys Glu Leu
Leu Asp Glu 1040 1045 1050 His Asp Pro Leu Leu Lys Lys Glu Leu Glu
Ala Lys Val Gly Val 1055 1060 1065 Leu Ala Ile Asn Met Ser Leu Ser
Ile Ala Ala Thr Val Ala Ser 1070 1075 1080 Ile Val Gly Ile Gly Ala
Glu Val Thr Ile Phe Leu Leu Pro Ile 1085 1090 1095 Ala Gly Ile Ser
Ala Gly Ile Pro Ser Leu Val Asn Asn Glu Leu 1100 1105 1110 Ile Leu
His Asp Lys Ala Thr Ser Val Val Asn Tyr Phe Asn His 1115 1120 1125
Leu Ser Glu Ser Lys Lys Tyr Gly Pro Leu Lys Thr Glu Asp Asp 1130
1135 1140 Lys Ile Leu Val Pro Ile Asp Asp Leu Val Ile Ser Glu Ile
Asp 1145 1150 1155 Phe Asn Asn Asn Ser Ile Lys Leu Gly Thr Cys Asn
Ile Leu Ala 1160 1165 1170 Met Glu Gly Gly Ser Gly His Thr Val Thr
Gly Asn Ile Asp His 1175 1180 1185 Phe Phe Ser Ser Pro Ser Ile Ser
Ser His Ile Pro Ser Leu Ser 1190 1195 1200 Ile Tyr Ser Ala Ile Gly
Ile Glu Thr Glu Asn Leu Asp Phe Ser 1205 1210 1215 Lys Lys Ile Met
Met Leu Pro Asn Ala Pro Ser Arg Val Phe Trp 1220 1225 1230 Trp Glu
Thr Gly Ala Val Pro Gly Leu Arg Ser Leu Glu Asn Asp 1235 1240 1245
Gly Thr Arg Leu Leu Asp Ser Ile Arg Asp Leu Tyr Pro Gly Lys 1250
1255 1260 Phe Tyr Trp Arg Phe Tyr Ala Phe Phe Asp Tyr Ala Ile Thr
Thr 1265 1270 1275 Leu Lys Pro Val Tyr Glu Asp Thr Asn Ile Lys Ile
Lys Leu Asp 1280 1285 1290 Lys Asp Thr Arg Asn Phe Ile Met Pro Thr
Ile Thr Thr Asn Glu 1295 1300 1305 Ile Arg Asn Lys Leu Ser Tyr Ser
Phe Asp Gly Ala Gly Gly Thr 1310 1315 1320 Tyr Ser Leu Leu Leu Ser
Ser Tyr Pro Ile Ser Thr Asn Ile Asn 1325 1330 1335 Leu Ser Lys Asp
Asp Leu Trp Ile Phe Asn Ile Asp Asn Glu Val 1340 1345 1350 Arg Glu
Ile Ser Ile Glu Asn Gly Thr Ile Lys Lys Gly Lys Leu 1355 1360 1365
Ile Lys Asp Val Leu Ser Lys Ile Asp Ile Asn Lys Asn Lys Leu 1370
1375 1380 Ile Ile Gly Asn Gln Thr Ile Asp Phe Ser Gly Asp Ile Asp
Asn 1385 1390 1395 Lys Asp Arg Tyr Ile Phe Leu Thr Cys Glu Leu Asp
Asp Lys Ile 1400 1405 1410 Ser Leu Ile Ile Glu Ile Asn Leu Val Ala
Lys Ser Tyr Ser Leu 1415 1420 1425 Leu Leu Ser Gly Asp Lys Asn Tyr
Leu Ile Ser Asn Leu Ser Asn 1430 1435 1440 Thr Ile Glu Lys Ile Asn
Thr Leu Gly Leu Asp Ser Lys Asn Ile 1445 1450 1455 Ala Tyr Asn Tyr
Thr Asp Glu Ser Asn Asn Lys Tyr Phe Gly Ala 1460 1465 1470 Ile Ser
Lys Thr Ser Gln Lys Ser Ile Ile His Tyr Lys Lys Asp 1475 1480 1485
Ser Lys Asn Ile Leu Glu Phe Tyr Asn Asp Ser Thr Leu Glu Phe 1490
1495 1500 Asn Ser Lys Asp Phe Ile Ala Glu Asp Ile Asn Val Phe Met
Lys 1505 1510 1515 Asp Asp Ile Asn Thr Ile Thr Gly Lys Tyr Tyr Val
Asp Asn Asn 1520 1525 1530 Thr Asp Lys Ser Ile Asp Phe Ser Ile Ser
Leu Val Ser Lys Asn 1535 1540 1545 Gln Val Lys Val Asn Gly Leu Tyr
Leu Asn Glu Ser Val Tyr Ser 1550 1555 1560 Ser Tyr Leu Asp Phe Val
Lys Asn Ser Asp Gly His His Asn Thr 1565 1570 1575 Ser Asn Phe Met
Asn Leu Phe Leu Asp Asn Ile Ser Phe Trp Lys 1580 1585 1590 Leu Phe
Gly Phe Glu Asn Ile Asn Phe Val Ile Asp Lys Tyr Phe 1595 1600 1605
Thr Leu Val Gly Lys Thr Asn Leu Gly Tyr Val Glu Phe Ile Cys 1610
1615 1620 Asp Asn Asn Lys Asn Ile Asp Ile Tyr Phe Gly Glu Trp Lys
Thr 1625 1630 1635 Ser Ser Ser Lys Ser Thr Ile Phe Ser Gly Asn Gly
Arg Asn Val 1640 1645 1650 Val Val Glu Pro Ile Tyr Asn Pro Asp Thr
Gly Glu Asp Ile Ser 1655 1660 1665 Thr Ser Leu Asp Phe Ser Tyr Glu
Pro Leu Tyr Gly Ile Asp Arg 1670 1675 1680 Tyr Ile Asn Lys Val Leu
Ile Ala Pro Asp Leu Tyr Thr Ser Leu 1685 1690 1695 Ile Asn Ile Asn
Thr Asn Tyr Tyr Ser Asn Glu Tyr Tyr Pro Glu 1700 1705 1710 Ile Ile
Val Leu Asn Pro Asn Thr Phe His Lys Lys Val Asn Ile 1715 1720 1725
Asn Leu Asp Ser Ser Ser Phe Glu Tyr Lys Trp Ser Thr Glu Gly 1730
1735 1740 Ser Asp Phe Ile Leu Val Arg Tyr Leu Glu Glu Ser Asn Lys
Lys 1745 1750 1755 Ile Leu Gln Lys Ile Arg Ile Lys Gly Ile Leu Ser
Asn Thr Gln 1760 1765 1770 Ser Phe Asn Lys Met Ser Ile Asp Phe
Lys
Asp Ile Lys Lys Leu 1775 1780 1785 Ser Leu Gly Tyr Ile Met Ser Asn
Phe Lys Ser Phe Asn Ser Glu 1790 1795 1800 Asn Glu Leu Asp Arg Asp
His Leu Gly Phe Lys Ile Ile Asp Asn 1805 1810 1815 Lys Thr Tyr Tyr
Tyr Asp Glu Asp Ser Lys Leu Val Lys Gly Leu 1820 1825 1830 Ile Asn
Ile Asn Asn Ser Leu Phe Tyr Phe Asp Pro Ile Glu Phe 1835 1840 1845
Asn Leu Val Thr Gly Trp Gln Thr Ile Asn Gly Lys Lys Tyr Tyr 1850
1855 1860 Phe Asp Ile Asn Thr Gly Ala Ala Leu Thr Ser Tyr Lys Ile
Ile 1865 1870 1875 Asn Gly Lys His Phe Tyr Phe Asn Asn Asp Gly Val
Met Gln Leu 1880 1885 1890 Gly Val Phe Lys Gly Pro Asp Gly Phe Glu
Tyr Phe Ala Pro Ala 1895 1900 1905 Asn Thr Gln Asn Asn Asn Ile Glu
Gly Gln Ala Ile Val Tyr Gln 1910 1915 1920 Ser Lys Phe Leu Thr Leu
Asn Gly Lys Lys Tyr Tyr Phe Asp Asn 1925 1930 1935 Asn Ser Lys Ala
Val Thr Gly Trp Arg Ile Ile Asn Asn Glu Lys 1940 1945 1950 Tyr Tyr
Phe Asn Pro Asn Asn Ala Ile Ala Ala Val Gly Leu Gln 1955 1960 1965
Val Ile Asp Asn Asn Lys Tyr Tyr Phe Asn Pro Asp Thr Ala Ile 1970
1975 1980 Ile Ser Lys Gly Trp Gln Thr Val Asn Gly Ser Arg Tyr Tyr
Phe 1985 1990 1995 Asp Thr Asp Thr Ala Ile Ala Phe Asn Gly Tyr Lys
Thr Ile Asp 2000 2005 2010 Gly Lys His Phe Tyr Phe Asp Ser Asp Cys
Val Val Lys Ile Gly 2015 2020 2025 Val Phe Ser Thr Ser Asn Gly Phe
Glu Tyr Phe Ala Pro Ala Asn 2030 2035 2040 Thr Tyr Asn Asn Asn Ile
Glu Gly Gln Ala Ile Val Tyr Gln Ser 2045 2050 2055 Lys Phe Leu Thr
Leu Asn Gly Lys Lys Tyr Tyr Phe Asp Asn Asn 2060 2065 2070 Ser Lys
Ala Val Thr Gly Trp Gln Thr Ile Asp Ser Lys Lys Tyr 2075 2080 2085
Tyr Phe Asn Thr Asn Thr Ala Glu Ala Ala Thr Gly Trp Gln Thr 2090
2095 2100 Ile Asp Gly Lys Lys Tyr Tyr Phe Asn Thr Asn Thr Ala Glu
Ala 2105 2110 2115 Ala Thr Gly Trp Gln Thr Ile Asp Gly Lys Lys Tyr
Tyr Phe Asn 2120 2125 2130 Thr Asn Thr Ala Ile Ala Ser Thr Gly Tyr
Thr Ile Ile Asn Gly 2135 2140 2145 Lys His Phe Tyr Phe Asn Thr Asp
Gly Ile Met Gln Ile Gly Val 2150 2155 2160 Phe Lys Gly Pro Asn Gly
Phe Glu Tyr Phe Ala Pro Ala Asn Thr 2165 2170 2175 Asp Ala Asn Asn
Ile Glu Gly Gln Ala Ile Leu Tyr Gln Asn Glu 2180 2185 2190 Phe Leu
Thr Leu Asn Gly Lys Lys Tyr Tyr Phe Gly Ser Asp Ser 2195 2200 2205
Lys Ala Val Thr Gly Trp Arg Ile Ile Asn Asn Lys Lys Tyr Tyr 2210
2215 2220 Phe Asn Pro Asn Asn Ala Ile Ala Ala Ile His Leu Cys Thr
Ile 2225 2230 2235 Asn Asn Asp Lys Tyr Tyr Phe Ser Tyr Asp Gly Ile
Leu Gln Asn 2240 2245 2250 Gly Tyr Ile Thr Ile Glu Arg Asn Asn Phe
Tyr Phe Asp Ala Asn 2255 2260 2265 Asn Glu Ser Lys Met Val Thr Gly
Val Phe Lys Gly Pro Asn Gly 2270 2275 2280 Phe Glu Tyr Phe Ala Pro
Ala Asn Thr His Asn Asn Asn Ile Glu 2285 2290 2295 Gly Gln Ala Ile
Val Tyr Gln Asn Lys Phe Leu Thr Leu Asn Gly 2300 2305 2310 Lys Lys
Tyr Tyr Phe Asp Asn Asp Ser Lys Ala Val Thr Gly Trp 2315 2320 2325
Gln Thr Ile Asp Gly Lys Lys Tyr Tyr Phe Asn Leu Asn Thr Ala 2330
2335 2340 Glu Ala Ala Thr Gly Trp Gln Thr Ile Asp Gly Lys Lys Tyr
Tyr 2345 2350 2355 Phe Asn Leu Asn Thr Ala Glu Ala Ala Thr Gly Trp
Gln Thr Ile 2360 2365 2370 Asp Gly Lys Lys Tyr Tyr Phe Asn Thr Asn
Thr Phe Ile Ala Ser 2375 2380 2385 Thr Gly Tyr Thr Ser Ile Asn Gly
Lys His Phe Tyr Phe Asn Thr 2390 2395 2400 Asp Gly Ile Met Gln Ile
Gly Val Phe Lys Gly Pro Asn Gly Phe 2405 2410 2415 Glu Tyr Phe Ala
Pro Ala Asn Thr Asp Ala Asn Asn Ile Glu Gly 2420 2425 2430 Gln Ala
Ile Leu Tyr Gln Asn Lys Phe Leu Thr Leu Asn Gly Lys 2435 2440 2445
Lys Tyr Tyr Phe Gly Ser Asp Ser Lys Ala Val Thr Gly Leu Arg 2450
2455 2460 Thr Ile Asp Gly Lys Lys Tyr Tyr Phe Asn Thr Asn Thr Ala
Val 2465 2470 2475 Ala Val Thr Gly Trp Gln Thr Ile Asn Gly Lys Lys
Tyr Tyr Phe 2480 2485 2490 Asn Thr Asn Thr Ser Ile Ala Ser Thr Gly
Tyr Thr Ile Ile Ser 2495 2500 2505 Gly Lys His Phe Tyr Phe Asn Thr
Asp Gly Ile Met Gln Ile Gly 2510 2515 2520 Val Phe Lys Gly Pro Asp
Gly Phe Glu Tyr Phe Ala Pro Ala Asn 2525 2530 2535 Thr Asp Ala Asn
Asn Ile Glu Gly Gln Ala Ile Arg Tyr Gln Asn 2540 2545 2550 Arg Phe
Leu Tyr Leu His Asp Asn Ile Tyr Tyr Phe Gly Asn Asn 2555 2560 2565
Ser Lys Ala Ala Thr Gly Trp Val Thr Ile Asp Gly Asn Arg Tyr 2570
2575 2580 Tyr Phe Glu Pro Asn Thr Ala Met Gly Ala Asn Gly Tyr Lys
Thr 2585 2590 2595 Ile Asp Asn Lys Asn Phe Tyr Phe Arg Asn Gly Leu
Pro Gln Ile 2600 2605 2610 Gly Val Phe Lys Gly Ser Asn Gly Phe Glu
Tyr Phe Ala Pro Ala 2615 2620 2625 Asn Thr Asp Ala Asn Asn Ile Glu
Gly Gln Ala Ile Arg Tyr Gln 2630 2635 2640 Asn Arg Phe Leu His Leu
Leu Gly Lys Ile Tyr Tyr Phe Gly Asn 2645 2650 2655 Asn Ser Lys Ala
Val Thr Gly Trp Gln Thr Ile Asn Gly Lys Val 2660 2665 2670 Tyr Tyr
Phe Met Pro Asp Thr Ala Met Ala Ala Ala Gly Gly Leu 2675 2680 2685
Phe Glu Ile Asp Gly Val Ile Tyr Phe Phe Gly Val Asp Gly Val 2690
2695 2700 Lys Ala Pro Gly Ile Tyr Gly 2705 2710
422367PRTClostridium difficile 42Met Ser Leu Val Asn Arg Lys Gln
Leu Glu Lys Met Ala Asn Val Arg 1 5 10 15 Phe Arg Val Gln Glu Asp
Glu Tyr Val Ala Ile Leu Asp Ala Leu Glu 20 25 30 Glu Tyr His Asn
Met Ser Glu Asn Thr Val Val Glu Lys Tyr Leu Lys 35 40 45 Leu Lys
Asp Ile Asn Ser Leu Thr Asp Thr Tyr Ile Asp Thr Tyr Lys 50 55 60
Lys Ser Gly Arg Asn Lys Ala Leu Lys Lys Phe Lys Glu Tyr Leu Val 65
70 75 80 Ile Glu Ile Leu Glu Leu Lys Asn Ser Asn Leu Thr Pro Val
Glu Lys 85 90 95 Asn Leu His Phe Ile Trp Ile Gly Gly Gln Ile Asn
Asp Thr Ala Ile 100 105 110 Asn Tyr Ile Asn Gln Trp Lys Asp Val Asn
Ser Asp Tyr Asn Val Asn 115 120 125 Val Phe Tyr Asp Ser Asn Ala Phe
Leu Ile Asn Thr Leu Lys Lys Thr 130 135 140 Ile Ile Glu Ser Ala Ser
Asn Asp Thr Leu Glu Ser Phe Arg Glu Asn 145 150 155 160 Leu Asn Asp
Pro Glu Phe Asn His Thr Ala Phe Phe Arg Lys Arg Met 165 170 175 Gln
Ile Ile Tyr Asp Lys Gln Gln Asn Phe Ile Asn Tyr Tyr Lys Ala 180 185
190 Gln Lys Glu Glu Asn Pro Asp Leu Ile Ile Asp Asp Ile Val Lys Thr
195 200 205 Tyr Leu Ser Asn Glu Tyr Ser Lys Asp Ile Asp Glu Leu Asn
Ala Tyr 210 215 220 Ile Glu Glu Ser Leu Asn Lys Val Thr Glu Asn Ser
Gly Asn Asp Val 225 230 235 240 Arg Asn Phe Glu Glu Phe Lys Thr Gly
Glu Val Phe Asn Leu Tyr Glu 245 250 255 Gln Glu Ser Val Glu Arg Trp
Asn Leu Ala Gly Ala Ser Asp Ile Leu 260 265 270 Arg Val Ala Ile Leu
Lys Asn Ile Gly Gly Val Tyr Leu Asp Val Asp 275 280 285 Met Leu Pro
Gly Ile His Pro Asp Leu Phe Lys Asp Ile Asn Lys Pro 290 295 300 Asp
Ser Val Lys Thr Ala Val Asp Trp Glu Glu Met Gln Leu Glu Ala 305 310
315 320 Ile Met Lys His Lys Glu Tyr Ile Pro Glu Tyr Thr Ser Lys His
Phe 325 330 335 Asp Thr Leu Asp Glu Glu Val Gln Ser Ser Phe Glu Ser
Val Leu Ala 340 345 350 Ser Lys Ser Asp Lys Ser Glu Ile Phe Leu Pro
Leu Gly Asp Ile Glu 355 360 365 Val Ser Pro Leu Glu Val Lys Ile Ala
Phe Ala Lys Gly Ser Ile Ile 370 375 380 Asn Gln Ala Leu Ile Ser Ala
Lys Asp Ser Tyr Cys Ser Asp Leu Leu 385 390 395 400 Ile Lys Gln Ile
Gln Asn Arg Tyr Lys Ile Leu Asn Asp Thr Leu Gly 405 410 415 Pro Ile
Ile Ser Gln Gly Asn Asp Phe Asn Thr Thr Met Asn Asn Phe 420 425 430
Gly Glu Ser Leu Gly Ala Ile Ala Asn Glu Glu Asn Ile Ser Phe Ile 435
440 445 Ala Lys Ile Gly Ser Tyr Leu Arg Val Gly Phe Tyr Pro Glu Ala
Asn 450 455 460 Thr Thr Ile Thr Leu Ser Gly Pro Thr Ile Tyr Ala Gly
Ala Tyr Lys 465 470 475 480 Asp Leu Leu Thr Phe Lys Glu Met Ser Ile
Asp Thr Ser Ile Leu Ser 485 490 495 Ser Glu Leu Arg Asn Phe Glu Phe
Pro Lys Val Asn Ile Ser Gln Ala 500 505 510 Thr Glu Gln Glu Lys Asn
Ser Leu Trp Gln Phe Asn Glu Glu Arg Ala 515 520 525 Lys Ile Gln Phe
Glu Glu Tyr Lys Lys Asn Tyr Phe Glu Gly Ala Leu 530 535 540 Gly Glu
Asp Asp Asn Leu Asp Phe Ser Gln Asn Thr Val Thr Asp Lys 545 550 555
560 Glu Tyr Leu Leu Glu Lys Ile Ser Ser Ser Thr Lys Ser Ser Glu Gly
565 570 575 Gly Tyr Val His Tyr Ile Val Gln Leu Gln Gly Asp Lys Ile
Ser Tyr 580 585 590 Glu Ala Ala Cys Asn Leu Phe Ala Lys Asn Pro Tyr
Asp Ser Ile Leu 595 600 605 Phe Gln Arg Asn Ile Glu Asp Ser Glu Val
Ala Tyr Tyr Tyr Asn Pro 610 615 620 Thr Asp Ser Glu Ile Gln Glu Ile
Asp Lys Tyr Arg Ile Pro Asp Arg 625 630 635 640 Ile Ser Asp Arg Pro
Lys Ile Lys Leu Thr Phe Ile Gly His Gly Lys 645 650 655 Ala Glu Phe
Asn Thr Asp Ile Phe Ala Gly Leu Asp Val Asp Ser Leu 660 665 670 Ser
Ser Glu Ile Glu Thr Ala Ile Gly Leu Ala Lys Glu Asp Ile Ser 675 680
685 Pro Lys Ser Ile Glu Ile Asn Leu Leu Gly Cys Asn Met Phe Ser Tyr
690 695 700 Ser Val Asn Val Glu Glu Thr Tyr Pro Gly Lys Leu Leu Leu
Arg Val 705 710 715 720 Lys Asp Lys Val Ser Glu Leu Met Pro Ser Met
Ser Gln Asp Ser Ile 725 730 735 Ile Val Ser Ala Asn Gln Tyr Glu Val
Arg Ile Asn Ser Glu Gly Arg 740 745 750 Arg Glu Leu Leu Asp His Ser
Gly Glu Trp Ile Asn Lys Glu Glu Ser 755 760 765 Ile Ile Lys Asp Ile
Ser Ser Lys Glu Tyr Ile Ser Phe Asn Pro Lys 770 775 780 Glu Asn Lys
Ile Ile Val Lys Ser Lys Asn Leu Pro Glu Leu Ser Thr 785 790 795 800
Leu Leu Gln Glu Ile Arg Asn Asn Ser Asn Ser Ser Asp Ile Glu Leu 805
810 815 Glu Glu Lys Val Met Leu Ala Glu Cys Glu Ile Asn Val Ile Ser
Asn 820 825 830 Ile Glu Thr Gln Val Val Glu Glu Arg Ile Glu Glu Ala
Lys Ser Leu 835 840 845 Thr Ser Asp Ser Ile Asn Tyr Ile Lys Asn Glu
Phe Lys Leu Ile Glu 850 855 860 Ser Ile Ser Glu Ala Leu Cys Asp Leu
Lys Gln Gln Asn Glu Leu Glu 865 870 875 880 Asp Ser His Phe Ile Ser
Phe Glu Asp Ile Ser Glu Thr Asp Glu Gly 885 890 895 Phe Ser Ile Arg
Phe Ile Asn Lys Glu Thr Gly Glu Ser Ile Phe Val 900 905 910 Glu Thr
Glu Lys Thr Ile Phe Ser Glu Tyr Ala Asn His Ile Thr Glu 915 920 925
Glu Ile Ser Lys Ile Lys Gly Thr Ile Phe Asp Thr Val Asn Gly Lys 930
935 940 Leu Val Lys Lys Val Asn Leu Asp Thr Thr His Glu Val Asn Thr
Leu 945 950 955 960 Asn Ala Ala Phe Phe Ile Gln Ser Leu Ile Glu Tyr
Asn Ser Ser Lys 965 970 975 Glu Ser Leu Ser Asn Leu Ser Val Ala Met
Lys Val Gln Val Tyr Ala 980 985 990 Gln Leu Phe Ser Thr Gly Leu Asn
Thr Ile Thr Asp Ala Ala Lys Val 995 1000 1005 Val Glu Leu Val Ser
Thr Ala Leu Asp Glu Thr Ile Asp Leu Leu 1010 1015 1020 Pro Thr Leu
Ser Glu Gly Leu Pro Ile Ile Ala Thr Ile Ile Asp 1025 1030 1035 Gly
Val Ser Leu Gly Ala Ala Ile Lys Glu Leu Ser Glu Thr Ser 1040 1045
1050 Asp Pro Leu Leu Arg Gln Glu Ile Glu Ala Lys Ile Gly Ile Met
1055 1060 1065 Ala Val Asn Leu Thr Thr Ala Thr Thr Ala Ile Ile Thr
Ser Ser 1070 1075 1080 Leu Gly Ile Ala Ser Gly Phe Ser Ile Leu Leu
Val Pro Leu Ala 1085 1090 1095 Gly Ile Ser Ala Gly Ile Pro Ser Leu
Val Asn Asn Glu Leu Val 1100 1105 1110 Leu Arg Asp Lys Ala Thr Lys
Val Val Asp Tyr Phe Lys His Val 1115 1120 1125 Ser Leu Val Glu Thr
Glu Gly Val Phe Thr Leu Leu Asp Asp Lys 1130 1135 1140 Val Met Met
Gln Gln Asp Asp Leu Val Ile Ser Glu Ile Asp Phe 1145 1150 1155 Asn
Asn Asn Ser Ile Val Leu Gly Lys Cys Glu Ile Trp Arg Met 1160 1165
1170 Glu Gly Gly Ser Gly His Thr Val Thr Asp Asp Ile Asp His Phe
1175 1180 1185 Phe Ser Ala Pro Ser Ile Thr Tyr Arg Glu Pro His Leu
Ser Ile 1190 1195 1200 Tyr Asp Val Leu Glu Val Gln Lys Glu Glu Leu
Asp Leu Ser Lys 1205 1210 1215 Asp Leu Met Val Leu Pro Asn Ala Pro
Asn Arg Val Phe Ala Trp 1220 1225 1230 Glu Thr Gly Trp Thr Pro Gly
Leu Arg Ser Leu Glu Asn Asp Gly 1235 1240 1245 Thr Lys Leu Leu Asp
Arg Ile Arg Asp Asn Tyr Glu Gly Glu Phe 1250 1255 1260 Tyr Trp Arg
Tyr Phe Ala Phe Ile Ala Asp Ala Leu Ile Thr Thr 1265 1270 1275 Leu
Lys Pro Arg Tyr Glu Asp Thr Asn Ile Arg Ile Asn Leu Asp 1280 1285
1290 Ser Asn Thr Arg Ser Phe Ile Val Pro Ile Ile Thr Thr Glu Tyr
1295 1300 1305 Ile Arg Glu Lys Leu Ser Tyr Ser Phe Tyr Gly Ser Gly
Gly Thr 1310 1315 1320 Tyr Ala Leu Pro Leu Ser Gln Tyr Asn Met Gly
Ile Asn Ile Glu 1325 1330 1335 Leu Ser Glu Ser Asp Val Trp Ile Ile
Asp
Val Asp Asn Val Val 1340 1345 1350 Arg Asp Val Thr Ile Glu Ser Asp
Lys Ile Lys Lys Gly Asp Leu 1355 1360 1365 Ile Glu Gly Ile Leu Ser
Thr Leu Ser Ile Glu Glu Asn Lys Ile 1370 1375 1380 Ile Leu Asn Ser
His Glu Ile Asn Phe Ser Gly Glu Val Asn Gly 1385 1390 1395 Ser Asn
Gly Phe Val Ser Leu Thr Phe Ser Ile Leu Glu Gly Ile 1400 1405 1410
Asn Ala Ile Ile Glu Val Asp Leu Leu Ser Lys Ser Tyr Lys Leu 1415
1420 1425 Leu Ile Ser Gly Glu Leu Lys Ile Leu Met Leu Asn Ser Asn
His 1430 1435 1440 Ile Gln Gln Lys Ile Asp Tyr Ile Gly Phe Asn Ser
Glu Leu Gln 1445 1450 1455 Lys Asn Ile Pro Tyr Ser Phe Val Asp Ser
Glu Gly Lys Glu Asn 1460 1465 1470 Gly Phe Ile Asn Gly Ser Thr Lys
Glu Gly Leu Phe Val Ser Glu 1475 1480 1485 Leu Pro Asp Val Val Leu
Ile Ser Lys Val Tyr Met Asp Asp Ser 1490 1495 1500 Lys Pro Ser Phe
Gly Tyr Tyr Ser Asn Asn Leu Lys Asp Val Lys 1505 1510 1515 Val Ile
Thr Lys Asp Asn Val Asn Ile Leu Thr Gly Tyr Tyr Leu 1520 1525 1530
Lys Asp Asp Ile Lys Ile Ser Leu Ser Leu Thr Leu Gln Asp Glu 1535
1540 1545 Lys Thr Ile Lys Leu Asn Ser Val His Leu Asp Glu Ser Gly
Val 1550 1555 1560 Ala Glu Ile Leu Lys Phe Met Asn Arg Lys Gly Ser
Thr Asn Thr 1565 1570 1575 Ser Asp Ser Leu Met Ser Phe Leu Glu Ser
Met Asn Ile Lys Ser 1580 1585 1590 Ile Phe Val Asn Phe Leu Gln Ser
Asn Ile Lys Phe Ile Leu Asp 1595 1600 1605 Ala Asn Phe Ile Ile Ser
Gly Thr Thr Ser Ile Gly Gln Phe Glu 1610 1615 1620 Phe Ile Cys Asp
Glu Asn Asn Asn Ile Gln Pro Tyr Phe Ile Lys 1625 1630 1635 Phe Asn
Thr Leu Glu Thr Asn Tyr Thr Leu Tyr Val Gly Asn Arg 1640 1645 1650
Gln Asn Met Ile Val Glu Pro Asn Tyr Asp Leu Asp Asp Ser Gly 1655
1660 1665 Asp Ile Ser Ser Thr Val Ile Asn Phe Ser Gln Lys Tyr Leu
Tyr 1670 1675 1680 Gly Ile Asp Ser Cys Val Asn Lys Val Val Ile Ser
Pro Asn Ile 1685 1690 1695 Tyr Thr Asp Glu Ile Asn Ile Thr Pro Val
Tyr Glu Thr Asn Asn 1700 1705 1710 Thr Tyr Pro Glu Val Ile Val Leu
Asp Ala Asn Tyr Ile Asn Glu 1715 1720 1725 Lys Ile Asn Val Asn Ile
Asn Asp Leu Ser Ile Arg Tyr Val Trp 1730 1735 1740 Ser Asn Asp Gly
Asn Asp Phe Ile Leu Met Ser Thr Ser Glu Glu 1745 1750 1755 Asn Lys
Val Ser Gln Val Lys Ile Arg Phe Val Asn Val Phe Lys 1760 1765 1770
Asp Lys Thr Leu Ala Asn Lys Leu Ser Phe Asn Phe Ser Asp Lys 1775
1780 1785 Gln Asp Val Pro Val Ser Glu Ile Ile Leu Ser Phe Thr Pro
Ser 1790 1795 1800 Tyr Tyr Glu Asp Gly Leu Ile Gly Tyr Asp Leu Gly
Leu Val Ser 1805 1810 1815 Leu Tyr Asn Glu Lys Phe Tyr Ile Asn Asn
Phe Gly Met Met Val 1820 1825 1830 Ser Gly Leu Ile Tyr Ile Asn Asp
Ser Leu Tyr Tyr Phe Lys Pro 1835 1840 1845 Pro Val Asn Asn Leu Ile
Thr Gly Phe Val Thr Val Gly Asp Asp 1850 1855 1860 Lys Tyr Tyr Phe
Asn Pro Ile Asn Gly Gly Ala Ala Ser Ile Gly 1865 1870 1875 Glu Thr
Ile Ile Asp Asp Lys Asn Tyr Tyr Phe Asn Gln Ser Gly 1880 1885 1890
Val Leu Gln Thr Gly Val Phe Ser Thr Glu Asp Gly Phe Lys Tyr 1895
1900 1905 Phe Ala Pro Ala Asn Thr Leu Asp Glu Asn Leu Glu Gly Glu
Ala 1910 1915 1920 Ile Asp Phe Thr Gly Lys Leu Ile Ile Asp Glu Asn
Ile Tyr Tyr 1925 1930 1935 Phe Glu Asp Asn Tyr Arg Gly Ala Val Glu
Trp Lys Glu Leu Asp 1940 1945 1950 Gly Glu Met His Tyr Phe Ser Pro
Glu Thr Gly Lys Ala Phe Lys 1955 1960 1965 Gly Leu Asn Gln Ile Gly
Asp Asp Lys Tyr Tyr Phe Asn Ser Asp 1970 1975 1980 Gly Val Met Gln
Lys Gly Phe Val Ser Ile Asn Asp Asn Lys His 1985 1990 1995 Tyr Phe
Asp Asp Ser Gly Val Met Lys Val Gly Tyr Thr Glu Ile 2000 2005 2010
Asp Gly Lys His Phe Tyr Phe Ala Glu Asn Gly Glu Met Gln Ile 2015
2020 2025 Gly Val Phe Asn Thr Glu Asp Gly Phe Lys Tyr Phe Ala His
His 2030 2035 2040 Asn Glu Asp Leu Gly Asn Glu Glu Gly Glu Glu Ile
Ser Tyr Ser 2045 2050 2055 Gly Ile Leu Asn Phe Asn Asn Lys Ile Tyr
Tyr Phe Asp Asp Ser 2060 2065 2070 Phe Thr Ala Val Val Gly Trp Lys
Asp Leu Glu Asp Gly Ser Lys 2075 2080 2085 Tyr Tyr Phe Asp Glu Asp
Thr Ala Glu Ala Tyr Ile Gly Leu Ser 2090 2095 2100 Leu Ile Asn Asp
Gly Gln Tyr Tyr Phe Asn Asp Asp Gly Ile Met 2105 2110 2115 Gln Val
Gly Phe Val Thr Ile Asn Asp Lys Val Phe Tyr Phe Ser 2120 2125 2130
Asp Ser Gly Ile Ile Glu Ser Gly Val Gln Asn Ile Asp Asp Asn 2135
2140 2145 Tyr Phe Tyr Ile Asp Asp Asn Gly Ile Val Gln Ile Gly Val
Phe 2150 2155 2160 Asp Thr Ser Asp Gly Tyr Lys Tyr Phe Ala Pro Ala
Asn Thr Val 2165 2170 2175 Asn Asp Asn Ile Tyr Gly Gln Ala Val Glu
Tyr Ser Gly Leu Val 2180 2185 2190 Arg Val Gly Glu Asp Val Tyr Tyr
Phe Gly Glu Thr Tyr Thr Ile 2195 2200 2205 Glu Thr Gly Trp Ile Tyr
Asp Met Glu Asn Glu Ser Asp Lys Tyr 2210 2215 2220 Tyr Phe Val Pro
Glu Thr Lys Lys Ala Cys Lys Gly Ile Asn Leu 2225 2230 2235 Ile Asp
Asp Ile Lys Tyr Tyr Phe Asp Glu Lys Gly Ile Met Arg 2240 2245 2250
Thr Gly Leu Ile Ser Phe Glu Asn Asn Asn Tyr Tyr Phe Asn Glu 2255
2260 2265 Asn Gly Glu Ile Gln Phe Gly Tyr Ile Asn Ile Glu Asp Lys
Met 2270 2275 2280 Phe Tyr Phe Gly Glu Asp Gly Val Met Gln Ile Gly
Val Phe Asn 2285 2290 2295 Thr Pro Asp Gly Phe Lys Tyr Phe Ala His
Gln Asn Thr Leu Asp 2300 2305 2310 Glu Asn Phe Glu Gly Glu Ser Ile
Asn Tyr Thr Gly Trp Leu Gly 2315 2320 2325 Leu Asp Glu Lys Arg Tyr
Tyr Phe Thr Asp Glu Tyr Ile Ala Ala 2330 2335 2340 Thr Gly Ser Val
Ile Ile Asp Gly Glu Glu Tyr Tyr Phe Asp Pro 2345 2350 2355 Asp Thr
Ala Gln Leu Val Ile Ser Glu 2360 2365 43129PRTHomo sapiens 43Met
Asp Met Met Val Pro Ala Gln Leu Leu Gly Leu Leu Leu Leu Trp 1 5 10
15 Phe Pro Gly Ser Arg Cys Asp Ile Gln Met Thr Gln Ser Pro Ser Ser
20 25 30 Val Ser Ala Ser Val Gly Asp Arg Val Thr Ile Thr Cys Arg
Ala Ser 35 40 45 Gln Gly Ile Ser Ser Trp Leu Ala Trp Tyr Gln His
Lys Pro Gly Lys 50 55 60 Ala Pro Lys Leu Leu Ile Tyr Ala Ala Ser
Ser Leu Gln Ser Gly Val 65 70 75 80 Pro Ser Arg Phe Ser Gly Ser Gly
Ser Gly Thr Asp Phe Thr Leu Thr 85 90 95 Ile Ser Ser Leu Gln Pro
Glu Asp Phe Ala Thr Tyr Tyr Cys Gln Gln 100 105 110 Ala Asn Ser Phe
Pro Trp Thr Phe Gly Gln Gly Thr Lys Val Glu Ile 115 120 125 Lys
44129PRTHomo sapiens 44Met Asp Met Arg Val Leu Ala Gln Leu Leu Gly
Leu Leu Leu Leu Cys 1 5 10 15 Phe Pro Gly Ala Arg Cys Asp Ile Gln
Met Thr Gln Ser Pro Ser Ser 20 25 30 Leu Ser Ala Ser Val Gly Asp
Arg Val Thr Ile Thr Cys Arg Ala Ser 35 40 45 Gln Gly Ile Ser Ser
Trp Leu Ala Trp Tyr Gln Gln Lys Pro Glu Lys 50 55 60 Ala Pro Lys
Ser Leu Ile Tyr Ala Ala Ser Ser Leu Gln Ser Gly Val 65 70 75 80 Pro
Ser Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr 85 90
95 Ile Ser Ser Leu Gln Pro Glu Asp Phe Ala Thr Tyr Tyr Cys Gln Gln
100 105 110 Tyr Asn Ser Tyr Pro Trp Thr Phe Gly Gln Gly Thr Lys Val
Glu Ile 115 120 125 Lys 45129PRTHomo sapiens 45Met Asp Met Arg Val
Pro Ala Gln Leu Leu Gly Leu Leu Leu Leu Trp 1 5 10 15 Leu Pro Gly
Ala Arg Cys Val Ile Trp Met Thr Gln Ser Pro Ser Leu 20 25 30 Leu
Ser Ala Ser Thr Gly Asp Arg Val Thr Ile Ser Cys Arg Met Ser 35 40
45 Gln Gly Ile Ser Ser Tyr Leu Ala Trp Tyr Gln Gln Lys Pro Gly Lys
50 55 60 Ala Pro Glu Leu Leu Ile Tyr Ala Ala Ser Thr Leu Gln Ser
Gly Val 65 70 75 80 Pro Ser Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp
Phe Thr Leu Thr 85 90 95 Ile Ser Ser Leu Gln Pro Glu Asp Phe Ala
Thr Tyr Tyr Cys Gln Gln 100 105 110 Tyr Asn Ser Tyr Pro Trp Thr Phe
Gly Gln Gly Thr Lys Val Glu Ile 115 120 125 Lys 46129PRTHomo
sapiens 46Met Asp Met Met Val Pro Ala Gln Leu Leu Gly Leu Leu Leu
Leu Trp 1 5 10 15 Phe Pro Gly Ser Arg Cys Asp Ile Gln Met Thr Gln
Ser Pro Ser Ser 20 25 30 Val Ser Ala Ser Val Gly Asp Arg Val Thr
Ile Thr Cys Arg Ala Ser 35 40 45 Gln Gly Ile Ser Ser Trp Leu Ala
Trp Tyr Gln His Lys Pro Gly Lys 50 55 60 Ala Pro Lys Leu Leu Ile
Tyr Ala Ala Ser Ser Leu Gln Ser Gly Val 65 70 75 80 Pro Ser Arg Phe
Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr 85 90 95 Ile Ser
Ser Leu Gln Pro Glu Asp Phe Ala Thr Tyr Tyr Cys Gln Gln 100 105 110
Tyr Asn Ser Tyr Pro Trp Thr Phe Gly Gln Gly Thr Lys Val Glu Ile 115
120 125 Lys 47129PRTHomo sapiens 47Met Asp Met Arg Val Pro Ala Gln
Leu Leu Gly Leu Leu Leu Leu Cys 1 5 10 15 Phe Pro Gly Ala Arg Cys
Asp Ile Gln Met Thr Gln Ser Pro Ser Ser 20 25 30 Val Ser Ala Ser
Val Gly Asp Arg Val Thr Ile Thr Cys Arg Ala Ser 35 40 45 Gln Gly
Ile Ser Ser Trp Leu Ala Trp Tyr Gln Gln Lys Pro Glu Lys 50 55 60
Ala Pro Lys Ser Leu Ile Tyr Ala Ala Ser Ser Leu Gln Ser Gly Val 65
70 75 80 Pro Ser Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr
Leu Thr 85 90 95 Ile Ser Ser Leu Gln Pro Glu Asp Phe Ala Thr Tyr
Tyr Cys Gln Gln 100 105 110 Tyr Asn Ser Tyr Pro Trp Thr Phe Gly Gln
Gly Thr Lys Val Glu Ile 115 120 125 Lys 48129PRTHomo sapiens 48Met
Asp Met Arg Val Leu Ala Gln Leu Leu Gly Leu Leu Leu Leu Cys 1 5 10
15 Phe Pro Gly Ala Arg Cys Asp Ile Gln Met Thr Gln Ser Leu Ser Ser
20 25 30 Leu Ser Ala Ser Val Gly Asp Arg Val Thr Ile Thr Cys Arg
Ala Ser 35 40 45 Gln Gly Ile Ser Ser Trp Leu Ala Trp Tyr Gln Gln
Lys Pro Glu Lys 50 55 60 Ala Pro Lys Ser Leu Ile Tyr Ala Ala Ser
Ser Leu Gln Ser Gly Val 65 70 75 80 Pro Ser Arg Phe Ser Gly Ser Gly
Ser Gly Thr Asp Phe Thr Leu Thr 85 90 95 Ile Ser Ser Leu Gln Pro
Glu Asp Phe Ala Thr Tyr Tyr Cys Gln Gln 100 105 110 Ala Asn Ser Phe
Pro Trp Thr Phe Gly Gln Gly Thr Lys Val Glu Ile 115 120 125 Lys
49141PRTHomo sapiens 49Met Glu Phe Gly Leu Ser Trp Val Phe Leu Val
Ala Leu Leu Arg Gly 1 5 10 15 Val Gln Cys Gln Val Gln Leu Val Glu
Ser Gly Gly Gly Val Val Gln 20 25 30 Pro Gly Arg Ser Leu Arg Leu
Ser Cys Ala Ala Ser Gly Phe Ser Phe 35 40 45 Ser Asn Tyr Gly Met
His Trp Val Arg Gln Ala Pro Gly Lys Gly Leu 50 55 60 Glu Trp Val
Ala Leu Ile Trp Tyr Asp Gly Ser Asn Glu Asp Tyr Thr 65 70 75 80 Asp
Ser Val Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn Ser Lys Asn 85 90
95 Thr Leu Tyr Leu Gln Met Asn Ser Leu Arg Ala Glu Asp Thr Ala Val
100 105 110 Tyr Tyr Cys Ala Arg Trp Gly Met Val Arg Gly Val Ile Asp
Val Phe 115 120 125 Asp Ile Trp Gly Gln Gly Thr Val Val Thr Val Ser
Ser 130 135 140 50128PRTHomo sapiens 50Met Glu Ala Pro Ala Gln Leu
Leu Phe Leu Leu Leu Leu Trp Leu Pro 1 5 10 15 Asp Thr Thr Gly Glu
Ile Val Leu Thr Gln Ser Pro Ala Thr Leu Ser 20 25 30 Leu Ser Pro
Gly Glu Arg Ala Thr Leu Ser Cys Arg Ala Ser Gln Ser 35 40 45 Val
Ser Ser Tyr Leu Ala Trp Tyr Gln Gln Lys Pro Gly Gln Ala Pro 50 55
60 Arg Leu Leu Ile Tyr Asp Ala Ser Asn Arg Ala Thr Gly Ile Pro Ala
65 70 75 80 Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr
Ile Ser 85 90 95 Ser Leu Glu Pro Glu Asp Phe Ala Val Tyr Tyr Cys
Gln Gln Arg Ser 100 105 110 Asn Trp Ser Gln Phe Thr Phe Gly Pro Gly
Thr Lys Val Asp Ile Lys 115 120 125 51133PRTHomo sapiens 51Met Glu
Phe Gly Leu Ser Trp Val Phe Leu Val Ala Leu Leu Arg Gly 1 5 10 15
Val Gln Cys Gln Met Gln Leu Val Glu Ser Gly Gly Gly Val Val Gln 20
25 30 Pro Gly Arg Ser Leu Arg Leu Ser Cys Glu Ala Ser Gly Phe Ser
Phe 35 40 45 Asn Ser Tyr Gly Met His Trp Val Arg Gln Ala Pro Gly
Lys Gly Leu 50 55 60 Glu Trp Val Ser Val Ile Trp Ala Ser Gly Asn
Lys Lys Tyr Tyr Ile 65 70 75 80 Glu Ser Val Glu Gly Arg Phe Thr Ile
Ser Arg Asp Asn Ser Lys Asn 85 90 95 Thr Leu Tyr Leu Gln Met Asn
Ser Leu Arg Ala Glu Asp Thr Ala Val 100 105 110 Tyr Tyr Cys Ala Arg
Ala Asn Phe Asp Tyr Trp Gly Gln Gly Thr Leu 115 120 125 Val Thr Val
Ser Ser 130 52129PRTHomo sapiens 52Met Asp Met Arg Val Leu Ala Gln
Leu Leu Gly Leu Leu Leu Leu Cys 1 5 10 15 Phe Pro Gly Ala Arg Cys
Asp Ile Gln Met Thr Gln Ser Pro Ser Ser 20 25 30 Leu Ser Ala Ser
Val Gly Asp Arg Val Thr Ile Thr Cys Arg Ala Ser 35 40 45 Gln Gly
Ile Ser Ser Trp Leu Ala Trp Tyr Gln Gln Lys Pro Glu Lys 50 55 60
Ala Pro Lys Ser
Leu Ile Tyr Ala Ala Ser Ser Leu Gln Ser Gly Val 65 70 75 80 Pro Ser
Arg Phe Ser Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr 85 90 95
Ile Ser Ser Leu Gln Pro Glu Asp Phe Ala Thr Tyr Tyr Cys Gln Gln 100
105 110 Tyr Lys Ser Tyr Pro Val Thr Phe Gly Gly Gly Thr Lys Val Glu
Ile 115 120 125 Lys 53135PRTHomo sapiens 53Met Glu Phe Gly Leu Ser
Trp Val Phe Leu Val Ala Leu Leu Arg Gly 1 5 10 15 Val Gln Cys Gln
Val Gln Leu Val Glu Ser Gly Gly Gly Val Val Gln 20 25 30 Pro Gly
Arg Ser Leu Arg Leu Ser Cys Ala Ala Ser Gly Phe Thr Phe 35 40 45
Asn Lys Tyr Gly Met His Trp Val Arg Gln Ala Pro Gly Lys Gly Leu 50
55 60 Glu Trp Val Ala Val Ile Trp Tyr Asp Gly Thr Asn Lys Tyr Tyr
Ala 65 70 75 80 Asp Ser Met Lys Gly Arg Phe Thr Ile Ser Arg Asp Asn
Ser Lys Asn 85 90 95 Met Leu Tyr Leu Gln Met Asn Ser Leu Arg Ala
Glu Asp Thr Ala Val 100 105 110 Tyr Tyr Cys Ala Arg Asp Pro Pro Thr
Ala Asn Tyr Trp Gly Gln Gly 115 120 125 Thr Leu Val Thr Val Ser Ser
130 135 54119PRTHomo sapiens 54Glu Val Gln Leu Val Gln Ser Gly Ala
Glu Val Lys Lys Ser Gly Glu 1 5 10 15 Ser Leu Lys Ile Ser Cys Lys
Gly Ser Gly Tyr Ser Phe Thr Ser Tyr 20 25 30 Trp Ile Gly Trp Val
Arg Gln Met Pro Gly Lys Gly Leu Glu Trp Met 35 40 45 Gly Ile Phe
Tyr Pro Gly Asp Ser Ser Thr Arg Tyr Ser Pro Ser Phe 50 55 60 Gln
Gly Gln Val Thr Ile Ser Ala Asp Lys Ser Val Asn Thr Ala Tyr 65 70
75 80 Leu Gln Trp Ser Ser Leu Lys Ala Ser Asp Thr Ala Met Tyr Tyr
Cys 85 90 95 Ala Arg Arg Arg Asn Trp Gly Asn Ala Phe Asp Ile Trp
Gly Gln Gly 100 105 110 Thr Met Val Thr Val Ser Ser 115
55357DNAHomo sapiensCDS(1)..(357) 55gag gtg cag ctg gtg cag tct gga
gca gag gtg aaa aag tcc ggg gag 48Glu Val Gln Leu Val Gln Ser Gly
Ala Glu Val Lys Lys Ser Gly Glu 1 5 10 15 tct ctg aag atc tcc tgt
aag ggt tct gga tac agc ttt acc agc tac 96Ser Leu Lys Ile Ser Cys
Lys Gly Ser Gly Tyr Ser Phe Thr Ser Tyr 20 25 30 tgg atc ggc tgg
gtg cgc cag atg ccc ggg aag ggc ctg gag tgg atg 144Trp Ile Gly Trp
Val Arg Gln Met Pro Gly Lys Gly Leu Glu Trp Met 35 40 45 ggg atc
ttc tat cct ggt gac tct agt acc aga tac agc ccg tcc ttc 192Gly Ile
Phe Tyr Pro Gly Asp Ser Ser Thr Arg Tyr Ser Pro Ser Phe 50 55 60
caa ggc cag gtc acc atc tca gcc gac aag tcc gtc aac acc gcc tac
240Gln Gly Gln Val Thr Ile Ser Ala Asp Lys Ser Val Asn Thr Ala Tyr
65 70 75 80 ctg cag tgg agc agc ctg aag gcc tcg gac acc gcc atg tat
tac tgt 288Leu Gln Trp Ser Ser Leu Lys Ala Ser Asp Thr Ala Met Tyr
Tyr Cys 85 90 95 gcg aga cgt cga aac tgg gga aat gct ttt gat atc
tgg ggc caa ggg 336Ala Arg Arg Arg Asn Trp Gly Asn Ala Phe Asp Ile
Trp Gly Gln Gly 100 105 110 aca atg gtc acc gtc tct tca 357Thr Met
Val Thr Val Ser Ser 115 56138PRTHomo sapiens 56Met Gly Ser Thr Ala
Ile Leu Ala Leu Leu Leu Ala Val Leu Gln Gly 1 5 10 15 Val Cys Ala
Glu Val Gln Leu Val Gln Ser Gly Ala Glu Val Lys Lys 20 25 30 Ser
Gly Glu Ser Leu Lys Ile Ser Cys Lys Gly Ser Gly Tyr Ser Phe 35 40
45 Thr Ser Tyr Trp Ile Gly Trp Val Arg Gln Met Pro Gly Lys Gly Leu
50 55 60 Glu Trp Met Gly Ile Phe Tyr Pro Gly Asp Ser Ser Thr Arg
Tyr Ser 65 70 75 80 Pro Ser Phe Gln Gly Gln Val Thr Ile Ser Ala Asp
Lys Ser Val Asn 85 90 95 Thr Ala Tyr Leu Gln Trp Ser Ser Leu Lys
Ala Ser Asp Thr Ala Met 100 105 110 Tyr Tyr Cys Ala Arg Arg Arg Asn
Trp Gly Asn Ala Phe Asp Ile Trp 115 120 125 Gly Gln Gly Thr Met Val
Thr Val Ser Ser 130 135 57414DNAHomo sapiens 57atggggtcaa
ccgccatcct cgccctcctc ctggctgttc tccaaggagt ctgtgccgag 60gtgcagctgg
tgcagtctgg agcagaggtg aaaaagtccg gggagtctct gaagatctcc
120tgtaagggtt ctggatacag ctttaccagc tactggatcg gctgggtgcg
ccagatgccc 180gggaagggcc tggagtggat ggggatcttc tatcctggtg
actctagtac cagatacagc 240ccgtccttcc aaggccaggt caccatctca
gccgacaagt ccgtcaacac cgcctacctg 300cagtggagca gcctgaaggc
ctcggacacc gccatgtatt actgtgcgag acgtcgaaac 360tggggaaatg
cttttgatat ctggggccaa gggacaatgg tcaccgtctc ttca 41458108PRTHomo
sapiens 58Glu Ile Val Leu Thr Gln Ser Pro Gly Thr Leu Ser Leu Ser
Pro Gly 1 5 10 15 Glu Arg Ala Thr Leu Ser Cys Arg Ala Ser Gln Ser
Val Ser Ser Ser 20 25 30 Tyr Leu Ala Trp Tyr Gln Gln Lys Pro Gly
Gln Ala Pro Arg Leu Leu 35 40 45 Ile Tyr Gly Ala Ser Ser Arg Ala
Thr Gly Ile Pro Asp Arg Phe Ser 50 55 60 Gly Ser Gly Ser Gly Thr
Asp Phe Thr Leu Thr Ile Ser Arg Leu Glu 65 70 75 80 Pro Glu Asp Phe
Ala Val Tyr Tyr Cys Gln Gln Tyr Gly Ser Ser Thr 85 90 95 Trp Thr
Phe Gly Gln Gly Thr Lys Val Glu Ile Lys 100 105 59324DNAHomo
sapiensCDS(1)..(324) 59gaa att gtg ttg acg cag tct cca ggc acc ctg
tct ttg tct cca ggg 48Glu Ile Val Leu Thr Gln Ser Pro Gly Thr Leu
Ser Leu Ser Pro Gly 1 5 10 15 gaa aga gcc acc ctc tcc tgc agg gcc
agt cag agt gtt agc agc agc 96Glu Arg Ala Thr Leu Ser Cys Arg Ala
Ser Gln Ser Val Ser Ser Ser 20 25 30 tac tta gcc tgg tac cag cag
aaa cct ggc cag gct ccc agg ctc ctc 144Tyr Leu Ala Trp Tyr Gln Gln
Lys Pro Gly Gln Ala Pro Arg Leu Leu 35 40 45 atc tat ggt gca tcc
agc agg gcc act ggc atc cca gac agg ttc agt 192Ile Tyr Gly Ala Ser
Ser Arg Ala Thr Gly Ile Pro Asp Arg Phe Ser 50 55 60 ggc agt ggg
tct ggg aca gac ttc act ctc acc atc agc aga ctg gag 240Gly Ser Gly
Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Arg Leu Glu 65 70 75 80 cct
gaa gat ttt gca gtg tat tac tgt cag cag tat ggt agc tca acg 288Pro
Glu Asp Phe Ala Val Tyr Tyr Cys Gln Gln Tyr Gly Ser Ser Thr 85 90
95 tgg acg ttc ggc caa ggg acc aag gtg gaa atc aaa 324Trp Thr Phe
Gly Gln Gly Thr Lys Val Glu Ile Lys 100 105 60128PRTHomo sapiens
60Met Glu Thr Pro Ala Gln Leu Leu Phe Leu Leu Leu Leu Trp Leu Pro 1
5 10 15 Asp Thr Thr Gly Glu Ile Val Leu Thr Gln Ser Pro Gly Thr Leu
Ser 20 25 30 Leu Ser Pro Gly Glu Arg Ala Thr Leu Ser Cys Arg Ala
Ser Gln Ser 35 40 45 Val Ser Ser Ser Tyr Leu Ala Trp Tyr Gln Gln
Lys Pro Gly Gln Ala 50 55 60 Pro Arg Leu Leu Ile Tyr Gly Ala Ser
Ser Arg Ala Thr Gly Ile Pro 65 70 75 80 Asp Arg Phe Ser Gly Ser Gly
Ser Gly Thr Asp Phe Thr Leu Thr Ile 85 90 95 Ser Arg Leu Glu Pro
Glu Asp Phe Ala Val Tyr Tyr Cys Gln Gln Tyr 100 105 110 Gly Ser Ser
Thr Trp Thr Phe Gly Gln Gly Thr Lys Val Glu Ile Lys 115 120 125
61384DNAHomo sapiens 61atggaaaccc cagcgcagct tctcttcctc ctgctactct
ggctcccaga taccaccgga 60gaaattgtgt tgacgcagtc tccaggcacc ctgtctttgt
ctccagggga aagagccacc 120ctctcctgca gggccagtca gagtgttagc
agcagctact tagcctggta ccagcagaaa 180cctggccagg ctcccaggct
cctcatctat ggtgcatcca gcagggccac tggcatccca 240gacaggttca
gtggcagtgg gtctgggaca gacttcactc tcaccatcag cagactggag
300cctgaagatt ttgcagtgta ttactgtcag cagtatggta gctcaacgtg
gacgttcggc 360caagggacca aggtggaaat caaa 384625PRTHomo sapiens
62Ser Tyr Trp Ile Gly 1 5 6315DNAHomo sapiensCDS(1)..(15) 63agc tac
tgg atc ggc 15Ser Tyr Trp Ile Gly 1 5 6417PRTHomo sapiens 64Ile Phe
Tyr Pro Gly Asp Ser Ser Thr Arg Tyr Ser Pro Ser Phe Gln 1 5 10 15
Gly 6551DNAHomo sapiensCDS(1)..(51) 65atc ttc tat cct ggt gac tct
agt acc aga tac agc ccg tcc ttc caa 48Ile Phe Tyr Pro Gly Asp Ser
Ser Thr Arg Tyr Ser Pro Ser Phe Gln 1 5 10 15 ggc 51Gly 6610PRTHomo
sapiens 66Arg Arg Asn Trp Gly Asn Ala Phe Asp Ile 1 5 10
6730DNAHomo sapiensCDS(1)..(30) 67cgt cga aac tgg gga aat gct ttt
gat atc 30Arg Arg Asn Trp Gly Asn Ala Phe Asp Ile 1 5 10
6812PRTHomo sapiens 68Arg Ala Ser Gln Ser Val Ser Ser Ser Tyr Leu
Ala 1 5 10 6936DNAHomo sapiensCDS(1)..(36) 69agg gcc agt cag agt
gtt agc agc agc tac tta gcc 36Arg Ala Ser Gln Ser Val Ser Ser Ser
Tyr Leu Ala 1 5 10 707PRTHomo sapiens 70Gly Ala Ser Ser Arg Ala Thr
1 5 7121DNAHomo sapiensCDS(1)..(21) 71ggt gca tcc agc agg gcc act
21Gly Ala Ser Ser Arg Ala Thr 1 5 729PRTHomo sapiens 72Gln Gln Tyr
Gly Ser Ser Thr Trp Thr 1 5 7327DNAHomo sapiensCDS(1)..(27) 73cag
cag tat ggt agc tca acg tgg acg 27Gln Gln Tyr Gly Ser Ser Thr Trp
Thr 1 5 7415PRTHomo sapiens 74Ala Phe Asp Ile Trp Gly Gln Gly Thr
Met Val Thr Val Ser Ser 1 5 10 15 755PRTHomo sapiens 75Ser Tyr Trp
Ile Gly 1 5 7617PRTHomo sapiens 76Ile Ile Tyr Pro Gly Asp Ser Asp
Thr Arg Tyr Ser Pro Ser Phe Gln 1 5 10 15 Gly 7710PRTHomo sapiens
77Ala Arg Arg Arg Asn Trp Gly Asn Ala Phe 1 5 10 7812PRTHomo
sapiens 78Arg Ala Ser Gln Ser Val Ser Ser Ser Tyr Leu Ala 1 5 10
7912PRTHomo sapiens 79Trp Thr Phe Gly Gln Gly Thr Lys Val Glu Ile
Lys 1 5 10 807PRTHomo sapiens 80Gln Gln Tyr Gly Ser Ser Pro 1 5
8198PRTHomo sapiens 81Glu Val Gln Leu Val Gln Ser Gly Ala Glu Val
Lys Lys Pro Gly Glu 1 5 10 15 Ser Leu Lys Ile Ser Cys Lys Gly Ser
Gly Tyr Ser Phe Thr Ser Tyr 20 25 30 Trp Ile Gly Trp Val Arg Gln
Met Pro Gly Lys Gly Leu Glu Trp Met 35 40 45 Gly Ile Ile Tyr Pro
Gly Asp Ser Asp Thr Arg Tyr Ser Pro Ser Phe 50 55 60 Gln Gly Gln
Val Thr Ile Ser Ala Asp Lys Ser Ile Ser Thr Ala Tyr 65 70 75 80 Leu
Gln Trp Ser Ser Leu Lys Ala Ser Asp Thr Ala Met Tyr Tyr Cys 85 90
95 Ala Arg 8296PRTHomo sapiens 82Glu Ile Val Leu Thr Gln Ser Pro
Gly Thr Leu Ser Leu Ser Pro Gly 1 5 10 15 Glu Arg Ala Thr Leu Ser
Cys Arg Ala Ser Gln Ser Val Ser Ser Ser 20 25 30 Tyr Leu Ala Trp
Tyr Gln Gln Lys Pro Gly Gln Ala Pro Arg Leu Leu 35 40 45 Ile Tyr
Gly Ala Ser Ser Arg Ala Thr Gly Ile Pro Asp Arg Phe Ser 50 55 60
Gly Ser Gly Ser Gly Thr Asp Phe Thr Leu Thr Ile Ser Arg Leu Glu 65
70 75 80 Pro Glu Asp Phe Ala Val Tyr Tyr Cys Gln Gln Tyr Gly Ser
Ser Pro 85 90 95 836PRTArtificial SequenceDescription of Artificial
Sequence Synthetic 6xHis tag 83His His His His His His 1 5
* * * * *