U.S. patent number 5,422,427 [Application Number 07/791,377] was granted by the patent office on 1995-06-06 for pneumococcal fimbrial protein a.
This patent grant is currently assigned to The United States of America as represented by the United States. Invention is credited to Steven P. O'Connor, Harold Russell, Jacquelyn Sampson.
United States Patent |
5,422,427 |
Russell , et al. |
June 6, 1995 |
Pneumococcal fimbrial protein A
Abstract
The present invention relates, in general, to pneumococcal
fimbrial protein A. In particular, the present invention relates to
a DNA segment encoding a pneumococcal fimbrial protein A gene;
polypeptides encoded by said DNA segment; recombinant DNA molecules
containing the DNA segment; cells containing the recombinant DNA
molecule; a method of producing a pneumococcal fimbrial protein A
polypeptide; antibodies specific to pneumococcal fimbrial protein
A; and a method of measuring the amount of pneumococcal fimbrial
protein A in a sample.
Inventors: |
Russell; Harold (Atlanta,
GA), Sampson; Jacquelyn (College Park, GA), O'Connor;
Steven P. (Roswell, GA) |
Assignee: |
The United States of America as
represented by the United States (Washington, DC)
|
Family
ID: |
25153553 |
Appl.
No.: |
07/791,377 |
Filed: |
September 17, 1991 |
Current U.S.
Class: |
530/350; 530/300;
530/324; 530/325; 530/326; 530/327; 530/328; 530/329; 530/330;
530/402; 530/825 |
Current CPC
Class: |
C07K
14/3156 (20130101); C07K 16/1275 (20130101); Y10S
530/825 (20130101) |
Current International
Class: |
C07K
14/195 (20060101); C07K 14/315 (20060101); C07K
16/12 (20060101); C07K 014/00 (); C07K 016/00 ();
C07K 017/00 () |
Field of
Search: |
;530/350,402,825,300,330,329,328,327,326,325,324 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
0206852AI |
|
Dec 1986 |
|
EP |
|
0429816AI |
|
Jun 1991 |
|
EP |
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Other References
Harold Russell et al., "Monoclonal Antibody Recognizing a
Species-Specific Protein from Streptococcus pneumoniae" Journal of
Clinical Microbiology, vol. 28, pp. 2191-2195, Oct. 1990. .
Ganeshkumar et al., "Nucleotide Sequence of a Gene Coding for a
Saliva-Binding Protein (SsaB) from Streptococcus sanguis 12 and
Possible Role of the Protein in Coaggregation with Actinomyces",
Inspection and Immunity, vol. 59, No. 3, 1093-1099, Mar. 1991.
.
Clarke-Lewis et al (1986) Science 231: 134-139. .
Caruthers (1985) Science 230: 281-285. .
Science (1988) 240: 362. .
Fenno, et al. (1989) Infection & Immunity 57: 3527-3533. .
Fives-Taylor et al. (1987) Infection & Immunity 55: 123-128.
.
Russell, et al. (1990) Journal of Clinical Microbiology 28:
2191-2195. .
Russell, et al. (1990) Abstracts of the Annual Meeting of the
American Society for Microbiology 90: 436. .
Sampson (et al) (1991) Abstracts of the Annual Meeting of the
American Society for Microbiology 91: 97..
|
Primary Examiner: Furman; Keith C.
Assistant Examiner: Kim; Hyosuk
Attorney, Agent or Firm: Needle & Rosenberg
Claims
What is claimed is:
1. A polypeptide free of the proteins with which it is naturally
associated comprising the amino acid sequence of pneumococcal
fimbrial protein A set forth in SEQ ID NO:2, or an allelic
variation thereof.
2. The polypeptide according to claim 1, wherein said polypeptide
comprises the amino acid sequence set forth in SEQ ID NO:2.
3. The polypeptide of claim 1 wherein the polypeptide is bound to a
solid support.
4. The polypeptide according to claim 3, wherein said polypeptide
comprises the amino acid sequence set forth in SEQ ID NO:2.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, in general, to pneumococcal fimbrial
protein A (PfpA). In particular, the present invention relates to a
DNA segment encoding a pneumococcal fimbrial protein A gene (pfpA);
polypeptides encoded by the DNA segment; recombinant DNA molecules
containing the DNA segment; cells containing the recombinant DNA
molecule; a method of producing a pneumococcal fimbrial protein A
polypeptide; antibodies specific to pneumococcal fimbrial protein
A; and a method of measuring the amount of pneumococcal fimbrial
protein A in a sample.
2. Background Information
Disease caused by Streptococcus pneumoniae (pneumococcus) is an
important cause of morbidity and mortality in the United States and
developing countries (Sorensen, J. et al. (1986) Scand. J. Infect.
Dis. 18:329-335; Wall, R. A. et al. (1986) Bull. WHO 64-4:553-558;
Walsh, J. A., and K. S. Warren (1979) N. Eng. J. Med. 301:967-974;
Williams, W. W. et al. (1988) Ann. Intern. Med. 108:616-625;
Yolken, R. H. et al. (1984) J. Clin. Microbiol. 20:802-805).
Pneumococcal disease is very prevalent among the very young, the
elderly, and immunocompromised persons. Despite its prevalence,
diagnosis of the disease continues to be a problem.
Several tests have been developed to detect pneumococcus antigens
and/or antibodies as a means of diagnosing pneumococcus infections
(Coonrod, J. D., and M. W. Rytel (1973) J. Lab Clin. Med.
81:778-786; Holmberg, H. et al. (1985) J. Clin. Microbiol.
22:111-115; Ingram, D. L. et al. (1983) J. Clin. Microbiol.
18:1119-1121; Jalonen, E. et al. (1989) J. Infect. 19:127-134;
Kanclerski, K. et al. (1988) J. Clin. Microbiol. 26-1:96-100;
Makela, P. H. (1982) Scand. J. Infect. Dis. Suppl. 36:111-113;
Perlino, C. A. (1984) J. Infect. Dis. 150:139-144; Sippel, J. E. et
al. (1984) J. Clin. Microbiol. 20:884-886; Whitby, M. et al. (1985)
J. Clin. Pathol. 38:341-344; Yolken, R. H. et al. (1984) J. Clin.
Microbiol. 20:802-805). The sensitivity of existing antigen
detection tests utilizing body fluids such as serum and urine,
remains very low (Ajello, G. W. et al. (1987) J. Clin. Microbiol.
25:1388-1391; Anhalt, J. P., and P. K. W. Yu (1975) J. Clin.
Microbiol. 2:510-515; Bartram, C. E. Jr. et al. (1974) J. Lab.
Clin. Med. 83:591-598; Congeni, B. L. et al. (1984) Ped. Infect.
Dis. 3:417-419; Coonrod, J. D. (1983) Proceedings of the American
Journal of Medicine Symposium, Jul. 28, 1983, Am. J. Med. 75:85-92;
Coovadia, Y. B. and K. K. Naidu (1985) J. Clin. Pathol. 38:561-564;
Dilworth, J. A. (1975) J. Clin. Microbiol. 2:453-455; Doskeland, S.
O., and B. P. Berdal (1980) J. Clin. Microbiol. 11:380-384; Martin,
S. J. et al. (1987) J. Clin. Microbiol. 25:248-250), except for
antigen detection in cerebrospinal fluids (Henrichsen, J. et al.
(1980) J. Clin. Microbiol. 11:589-592; Ingram, D. L. et al. (1983)
J. Clin. Microbiol. 18:1119-1121; Lenthe-Eboa, S. et al. (1987)
Eur. J. Clin. Microbiol. 6:28-34; Tilton, R. C. et al. (1984) J.
Clin. Microbiol. 20:231-234; Yolken, R. H. et al. (1984) J. Clin.
Microbiol. 20:802-805). The measurement of antibody response to
pneumolysin by enzyme immunoassay (ELISA) appears to be promising
for presumptive etiologic diagnosis (Jalonen, E. et al. (1989) J.
Infect. 19:127-134; Kalin, M. et al. (1987) J. Clin. Microbiol.
25:226-229; Kanclerski, K. et al. (1988) J. Clin. Microbiol.
26-1:96-100), but the sensitivity and specificity of the test need
improvement.
Although a positive blood culture is diagnostic for pneumococcus
disease, most patients with bacterial pneumonia do not have
bacteremia (Austrian, R. (1974) Prev. Med. 3:443-445; Austrian, R.,
and I. Gold (1964) Ann. Intern. Med. 60:759-776; Kalin, M. and A.
A. Lindberg (1983) Scand. J. Infect. Dis. 15:247-255). The value of
sputum cultures has also been questioned because of contamination
of the specimens with pharyngeal flora that can include pneumococci
(Barrett-Cooner, E. (1971) Ann. Rev. Resp. Dis. 103:845-848). Thus,
clinical laboratories are rarely successful in establishing a firm
bacterial etiology for those patients with respiratory infections
diagnosed presumptively as pneumococcus pneumonia. Researchers have
been in constant search for immunodiagnostic markers or tests to
aid in the early diagnosis of pneumococcus infections.
SUMMARY OF THE INVENTION
It is a general object of this invention to provide pneumococcal
fimbrial protein A (PfpA) (a 37-kilodalton protein).
It is a specific object of this invention to provide a DNA segment
which encodes a pneumococcal fimbrial protein A gene (pfpA).
It is a further object of the invention to provide a polypeptide
corresponding to a pneumococcal fimbrial protein A gene (pfpA).
It is another object of the invention to provide a recombinant DNA
molecule comprising a vector and a DNA segment encoding a
pneumococcal fimbrial protein A gene (pfpA).
It is a further object of the invention to provide a cell that
contains the above-described recombinant molecule.
It is another object of the invention to provide a method of
producing a polypeptide encoding a pneumococcal fimbrial protein A
gene (pfpA).
It is a further object of the invention to provide antibodies
having binding affinity to a pneumococcal fimbrial protein A gene
(pfpA), or a unique portion thereof.
It is a further object of the invention to provide a method of
measuring the amount of pneumococcal fimbrial protein A in a
sample.
Further objects and advantages of the present invention will be
clear from the description that follows.
In one embodiment, the present invention relates to a DNA segment
coding for a polypeptide comprising an amino acid sequence
corresponding to a pneumococcal fimbrial protein A gene.
In another embodiment, the present invention relates to a
polypeptide free of proteins with which it is naturally associated
and comprising an amino acid sequence corresponding to a
pneumococcal fimbrial protein A gene.
In a further embodiment, the present invention relates to a
recombinant DNA molecule comprising a vector and a DNA segment that
codes for a polypeptide comprising an amino acid sequence
corresponding to a pneumococcal fimbrial protein A gene.
In yet another embodiment, the present invention relates to a cell
that contains the above-described recombinant DNA molecule.
In a further embodiment, the present invention relates to a method
of producing a polypeptide comprising an amino acid sequence
corresponding to a pneumococcal fimbrial protein A gene.
In yet another embodiment, the present invention relates to an
antibody having binding affinity to a polypeptide encoding a
pneumococcal fimbrial protein A gene, or a unique portion
thereof.
In a further embodiment, the present invention relates to a method
of measuring the amount of pneumococcal fimbrial protein A in a
sample, comprising contacting the sample with the above-described
antibodies and measuring the amount of immunocomplexes formed
between the antibodies and any pneumococcal fimbrial protein A in
the sample.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1. Immunoblot of S. pneumoniae whole-cell antigen preparations
with pneumococcus MAbs. Protein standards (STD) (in kilodaltons)
and different serotypes of S. pneumoniae are shown. Lanes: 1,
serotype 3; 2, serotype 6B; 3, serotype 7F; 4, serotype 8; 5,
serotype 9V; 6, serotype 10A; 7, serotype 11A; 8, serotype 12F; 9,
serotype 15B; 10, serotype 19A; 11, serotype 19F; 12, serotype 22F.
The MAbs revealed an antigen at 37 kDa (arrow) in all serotypes
tested.
FIG. 2. Immunofluorescence assay staining of S. pneumoniae cells
with pneumococcal MAbs.
FIG. 3. Transmission electron microscopy of S. pneumoniae R36A
after embedding, cutting, reacting with MAbs, and staining with
gold-labeled goat anti-mouse immunoglobulin.
DETAILED DESCRIPTION OF THE INVENTION
In one embodiment, the present invention relates to a DNA segment
coding for a polypeptide comprising an amino acid sequence
corresponding to pneumococcal fimbrial protein A, or at least 5
contiguous amino acids thereof. In one preferred embodiment, the
DNA segment comprises the sequence shown in SEQ ID NO:1, allelic or
species variation thereof, or at least 15 contiguous nucleotides
thereof (preferably, at least 20, 30, 40, or 50 contiguous
nucleotides thereof). In a further preferred embodiment, the DNA
segment encodes the amino acid sequence set forth in SEQ ID NO:2,
allelic or species variation thereof, or at least 5 contiguous
amino acids thereof (preferably, at least 5, 10, 15, 20, 30 or 50
contiguous amino acids thereof).
In a further embodiment, the present invention relates to a
polypeptide free of proteins with which it is naturally associated
or a polypeptide bound to a solid support and comprising an amino
acid sequence corresponding to pneumococcal fimbrial protein A, or
at least 5 contiguous amino acids thereof (preferably, at least 5,
10, 15, 20, 30 or 50 contiguous amino acids thereof). In one
preferred embodiment, the polypeptide comprises the amino acid
sequence set forth in SEQ ID NO:2, or allelic or species variation
thereof equivalent thereto (for example, immunologically or
functionally, equivalent thereto), or at least 5 contiguous amino
acids thereof (preferably, at least 5, 10, 15, 20, 30 or 50
contiguous amino acids thereof).
In another embodiment, the present invention relates to a
recombinant DNA molecule comprising a vector (for example plasmid
or viral vector) and a DNA segment (as described above) coding for
a polypeptide corresponding to pneumococcal fimbrial protein A, as
described above. In a preferred embodiment, the encoding segment is
present in the vector operably linked to a promoter.
In a further embodiment, the present invention relates to a cell
containing the above described recombinant DNA molecule. Suitable
host cells include procaryotes (such as bacteria, including E.
coli) and both lower eucaryotes (for example yeast) and higher
eucaryotes (for example, mammalian cells). Introduction of the
recombinant molecule into the cell can be effected using methods
known in the art.
In another embodiment, the present invention relates to a method of
producing a polypeptide having an amino acid sequence corresponding
to pneumococcal fimbrial protein A comprising culturing the
above-described cell under conditions such that the DNA segment is
expressed and the polypeptide thereby produced and isolating the
polypeptide.
In yet another embodiment, the present invention relates to an
antibody having binding affinity for pneumococcal fimbrial protein
A, or a unique portion thereof. In one preferred embodiment,
pneumococcal fimbrial protein A comprises the amino acid sequence
set forth in SEQ ID NO:2, allelic or species variation thereof, or
at least 5 contiguous amino acids thereof (preferably, at least 5,
10, 15, 20, 30 or 50 contiguous amino acids thereof).
Antibodies (monoclonal or polyclonal) can be raised to pneumococcal
fimbrial protein A, or unique portions thereof, in its naturally
occuring form and in its recombinant form. Binding fragments of
such antibodies are also within the scope of the invention.
Pneumococcal fimbrial protein A may be joined to other materials,
particularly polypeptides, as fused or covalently joined
polypeptides to be used as immunogens. Pneumococcal fimbrial
protein A or its fragments may be fused or covalently linked to a
variety of immunogens, such as keyhole limpet hemocyanin, bovine
serum albumin, tetanus toxoid, etc. See for example, Microbiology,
Hoeber Medical Division (Harper and Row, 1969), Landsteiner,
Specificity of Serological Reactions (Dover Publications, New York,
1962) and Williams et al., Methods in Immunology and
Immunochemistry, Vol. 1 (Academic Press, New York, 1967), for
descriptions of methods of preparing polyclonal antisera. A typical
method involves hyperimmunization of an animal with an antigen. The
blood of the animal is then collected shortly after the repeated
immunizations and the gamma globulin is isolated.
In some instances, it is desirable to prepare monoclonal antibodies
from various mammalian hosts. Description of techniques for
preparing such monoclonal antibodies may be found in Stites et al.,
editors, Basic and Clinical Immunology, (Lange Medical
Publications, Los Altos, Calif., Fourth edition) and references
cited therein, and in particular in Kohler and Milstein in Nature
256:495-497 (1975), which discusses one method of generating
monoclonal antibodies.
In another embodiment, the present invention relates to a hybridoma
which produces a monoclonal antibody or binding fragment thereof
having binding affinity for pneumococcal fimbrial protein A. In one
preferred embodiment, the pneumococcal fimbrial protein A has the
amino acid sequence set forth in SEQ ID NO:2, allelic or species
variation thereof, or at least 5 contiguous amino acids thereof
(preferably, at least 5, 10, 15, 20, 30 or 50 contiguous amino
acids thereof). In another preferred embodiment, the hybridoma
comprises 1E7A3D7C2.
In yet another embodiment, the present invention relates to a
diagnostic kit comprising:
i) at least one of the above-described monoclonal antibodies,
and
ii) a conjugate comprising a binding partner of said monoclonal
antibody and a label.
In a further embodiment, the present invention relates to a
diagnostic kit comprising a conjugate comprising:
i) at least one of the above-described monoclonal antibodies,
and
ii) a label.
In a further embodiment, the present invention relates to a method
of measuring the amount of pneumococcal fimbrial protein A in a
sample, comprising contacting the sample with the above-described
antibodies and measuring the amount of immunocomplexes formed
between the antibodies and any pneumococcal fimbrial protein A in
the sample. Methods of measuring the amount of immunocomplexes
formed can be those well known in the art, such as RIA, ELISA, and
direct and indirect immunoassays.
In another embodiment, the present invention relates to a vaccine
comprising the above-identified polypeptides. The presently used
commercial vaccine, Pneumovax, is a mixture of 23 capsular
polysaccharides from S. pneumoniae. The vaccine is efficacious in
adults but not effective in children less than two years of age.
Since the polypeptides of the present invention are proteins, they
can be used to protect against pneumococcal disease in children and
adults. In one preferred embodiment, the polypeptides
describe-above, may be conjugated to components of the existing
commercial vaccine. Preliminary data indicate that some children
less than two years of age produce antibodies to the pneumococcal
fimbrial protein A (the 37-kDa protein).
The present invention is described in further detail in the
following non-limiting Examples.
EXAMPLES
The following protocols and experimental details are referenced in
the Examples that follow:
Bacterial Strains
The S. pneumoniae strain R36A was kindly provided by D. E. Briles
(University of Alabama at Birmingham). Twenty-four serotypes of S.
pneumoniae were provided by R. Facklam, Centers for Disease Control
(CDC), Atlanta, Ga. These serotypes are 1, 2, 3, 4, 5, 6A, 6B, 7F,
8, 9N, 9V, 10A, 11F, 11A, 12F, 14, 15B, 18C, 19A, 19F, 20, 22F,
23F, and 33F. Enterococcus avium, E. casseliflavus, and E.
gallinarum were also provided by R. Facklam. Anaerobic bacteria
were obtained from V. R. Dowell, CDC. These included Bacteroides
asaccharolyticus, B. fragilis, B. intermedius, B. thetaiotaomicron,
Eubacterium lentum, Fusobacterium necrophorum, F. nucleatum,
Peptostreptococcus anaerobius, P. asaccharolyticus,
Propionibacterium acnes, and Staphylococcus saccharolyticus.
Branhamella catarrhalis and Bordetella parapertussis were obtained
from R. Weaver, CDC. Mycobacterium tuberculosis was provided by R.
C. Good, CDC. R. Barnes, CDC, provided Chlamydia pneumoniae. The
following remaining bacteria were from the stock collection of the
Immunology Laboratory, CDC: Bordetella pertussis, Enterobacter
aerogenes, E. agglomerans, E. cloacae, E. gergoviae, Escherichia
coli, Klebsielia pneumoniae, Haemophilus influenzae (types a-f),
Legionella micdadei, L. pneumophila, Mycoplasma pneumoniae,
Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus aureus,
Streptococcus agalactiae, S. equisimilis, S. pyogenes, and group G
streptococci.
Production of MAbS
Female BALB/c mice were immunized with whole cell suspensions of S.
pneumoniae R36A, a rough derivative of the capsular type 2 strain
D39 (Avery, O. T. et al. (1944) J. Exp. Med. 79:137-157). The mice
were immunized by intravenous injection three times and
intraperitoneal injection one time. The maximum number of cells
injected at any time was 10.sup.8. Fusion was done on day 25 by
using standard procedures (Clafin, L., and K. Williams (1978) Curr.
Top. Microbiol. Immunol. 81:107-109). Spleen cells of 4 mice were
fused with Sp2/0-Ag14 myeloma cells (Schulman, M. et al. (1978)
Nature (London) 276:269-270). Culture fluids of the growing
hybridomas were tested for antibodies to S. pneumoniae whole cells
in an ELISA. A clone designated 1E7A3D7C2 was one of 10 selected
for further study. Further references to MAbs in this article refer
to hybridoma clone 1E7A3D7C2.
ELISA
Screening of hybridoma culture supernatants was done by ELISA.
U-bottom microtitration plates (Costar, Cambridge, Mass.) were
sensitized with 50 .mu.l of S. pneumoniae whole cell suspension
(10.sup.9 CFU/ml) diluted 1:4,000 in 0.1M carbonate buffer, pH 9.6,
and kept for 16 h at 4.degree. C. The plates were washed 5 times
with 0.9% NaCl containing 0.05% Tween 20 (NaCl-T). Culture
supernatants (50 .mu.l) from the fusion plates were added to 50
.mu.l of a solution containing 2% bovine serum albumin (BSA), 10%
normal rabbit serum, 0.3% Tween-20, and 0.02% Merthiolate in
phosphate buffered saline (PBS), pH 7.2, (ELISA diluent) (Wells, D.
E. et al. (1987) J. Clin. Microbiol. 25:516-521) in the plates and
were incubated for 30 min at 37.degree. C. The plates were washed 5
times with NaCl-T. Fifty microliters of goat anti-mouse
immunoglobulin horseradish peroxidase conjugate, diluted in ELISA
diluent was added to each well. The plates were incubated for 30
min at 37.degree. C. The plates were washed, and 50 .mu.l of
3,3',5,5'-tetramethylbenzidine (0.1 mg/ml in 0.1M sodium acetate,
0.1M citric acid [pH 5.7] with 0.005% hydrogen peroxide) was added
to each well and incubated for 30 min at 37.degree. C. The reaction
was stopped by adding 1 ml of 4M H.sub.2 SO.sub.4 and the optical
density was read on a Dynatech ELISA Reader (Dynatech Laboratories,
Inc., Alexandria, Va.) at 450 nm. An optical density of >0.200
was considered positive.
SDS-PAGE and Immunoblot Analysis
Sodium dodecyl sulfate-polyacrylamide gel electrophoresis
(SDS-PAGE) was performed by the method of Tsang et al. (Tsang, V.
C. W. et al. (1983) Methods Enzymol. 92:377-391), using an 8%
acrylamide resolving gel. Equal volumes of sample buffer (5%
SDS-10% 2-mercaptoethanol-20% glycerol in 0.01M Tris HCL, [pH 8.0])
and cell suspension containing 2.4 .mu.g protein per .mu.l were
mixed, heated at 100.degree. C. for 5 min, and a 5-.mu.l portion
was applied to 1 of 15 wells. If the final protein content of the
portion of sample to be tested was <1.2 .mu.g/.mu.l, a volume up
to 10 .mu.l of sample was applied to achieve a final concentration
of 6 .mu.g of protein per well. Protein concentrations were
determined by the method of Markwell et al. (Markwell, M. A. et al.
(1978) Anal. Biochem. 87:206-210), with BSA as the standard.
Proteins separated by SDS-PAGE were either silver stained by the
method of Morrissey (Morrissey, J. H. (1981) Anal. Biochem.
117:307-310) or electroblotted onto nitrocellulose (Schleicher
& Schnell, Inc., Keene, N.H.). The immunoblot procedure was
done according to the method of Tsang et al. (Tsang, V. C. W. et
al. (1983) Methods Enzymol. 92:377-391) with slight modifications.
The blots were given three 5-min washes with PBS, pH 7.2,
containing 0.3% Tween-20 and were gently agitated overnight (16 h)
at 25.degree. C. The blots were blocked for 1 h with
casein-thimerosal buffer (CTB) (Kenna, J. G. et al. (1985) J.
Immunol. Meth. 85:409-419). After three rinses with CTB, the blots
were exposed to goat anti-mouse immunoglobulin horseradish
peroxidase conjugate (Bio-Rad Laboratories, Richmond, Calif.) for 2
h at 25.degree. C. Conjugate dilutions (1:2,000) were made in CTB.
The blots were again rinsed three times with CTB and exposed to
3-3'diaminobenzadine-4-hydrochloride in PBS, pH 7.2 (0.5 mg/ml),
with 0.003% H.sub.2O.sub.2 for 5 min at 25.degree. C. Reactivity
was expressed as a visible colored band on the nitrocellulose
paper. Low-molecular-mass protein standards (Bio-Rad) were used in
PAGE and immunoblotting. Rabbit antisera to the protein standards
were used to develop the standards (Carlone, G. M. (1986) Anal.
Biochem. 155:89-91). Molecular masses were calculated by the method
of Neville and Glossman (Neville, D. M., and H. Glossman (1974)
Methods Enzymol. 32:92-102) using appropriate molecular mass
standards.
IFA
A bacterial suspension containing approximately 400-500 CFU per
field (10 .mu.l) was allowed to dry at room temperature on each
well of acetone-resistant, 12-well (5 mm diameter), glass slides
(25.times.75 mm) (Cel-Line Associates, Newfield, N.J.). The slides
were then immersed in acetone for 10 min and air dried at room
temperature. MAbs were added to the slides, which were incubated
for 30 min at 37.degree. C. After incubation, the slides were
gently rinsed with PBS and soaked twice at 5-min intervals, blotted
on filter paper, and air dried at room temperature.
Fluorescein-labeled rabbit anti-mouse immunoglobulin (courtesy of
W.F.Bibb, CDC) was then added, and the slides were incubated for 30
min at 37.degree. C. They were then washed twice with PBS and
gently blotted on filter paper. Slides were covered with
carbonate-buffered mounting fluid, pH 9.0, and cover slips and were
then read with a Leitz Dialux 20 fluorescence microscope equipped
with a HBO-100 mercury incident light source, an I cube filter
system, a 40x dry objective lens, and 6.3x binoculars (E. Leitz,
Inc., Rockleigh, N.J.).
Immunoelectron Microscopy
Pneumococcal cells were washed two times with PBS and fixed in a
mixture of 1% paraformaldehyde-0.1% glutaraldehyde (freshly made)
for 20 min at 4.degree. C. The cells were dehydrated in a graded
alcohol series and then in a 1:1 mixture of absolute ethanol and
Lowicryl K4M (Ladd Research Industries, Inc.,Burlington, Vt.) for 1
h at 4.degree. C. The cells were pelleted and suspended in a 1:2
mixture of absolute ethanol and Lowicryl K4M for 1 h at 4.degree.
C. They were again pelleted and suspended in Lowicryl K4M
(undiluted) for 16 h at 4.degree. C.
The cells were transferred to fresh Lowicryl K4M two times during
the next 24-hour period. The Lowicryl K4M-treated cells were
imbedded in gelatin capsules, which were placed inside a box lined
with aluminum foil. The capsules were hardened by holding them, in
the box, 35 cm from a short-wave UV light source for 72 h at
-20.degree. C. The box was brought to room temperature, and the
capsules were allowed to continue hardening for up to 14 days.
Samples of the capsule were cut into 100-.mu.m thin sections and
picked up on nickel grids. Grids containing the sample were placed
on a droplet of ovalbumin solution in PBS containing sodium azide
(E.Y. Laboratories, Inc., San Mateo, Calif.) for 5 min. The grids
(wet) were transferred to a solution of primary MAbs diluted in a
solution of BSA reagent (1% BSA in PBS containing 0.1% Triton
X-100, Tween 20, and sodium azide) (E.Y. Laboratories) and
incubated for 1 h at room temperature or 18 to 48 h at 4.degree. C.
in a moist chamber. For antibody binding controls, other grids were
wetted with MAbs against Legionella pneumophila. The grids were
rinsed two times with PBS and incubated on droplets of goat
anti-mouse IgG-labeled colloidal gold particles (20 .mu.m) (E.Y.
Laboratories) for 1 h at room temperature. The grids were rinsed
two times and poststained with osmium tetroxide, uranyl acetate,
and lead citrate. The grids were examined with a Philips 410
transmission electron microscope.
EXAMPLE 1
Monoclonal Antibodies
Hybridoma clone 1E7A3D7C2 produced MAbs that reacted with a
37-kilodalton (kDa) protein antigen (pneumococcal fimbrial protein
A) found in S. pneumoniae. The MAbs reacted with an antigen
fractionated in SDS-PAGE, yielding a single immunoblot band. This
indicates that the MAb reacted with epitopes found only on the
37-kDa antigen (pneumococcal fimbrial protein A).
The MAbs produced by the immunization of mice with pneumococcal
cells reacted with all pneumococcal strains tested (24 serotypes)
to yield a sensitivity of 100%. For specificity, 55 different
nonpneumococcal strains of bacteria that can also cause respiratory
infections (Donowitz, G. R., and G. L. Mandell (1985) In:
Principles and practices in infectious diseases, 2nd ed. (G. L.
Mandell, R. G. Douglas, and J. E. Bennett, ed.) John Wiley &
Sons, Inc., New York, pp. 394-404) were tested for antigens
reacting with the MAbs. The latter strains represented 19 genera
and 36 species of bacteria. None of the strains tested reacted with
the pneumococcal MAbs, thus yielding a specificity of 100%
Of 44 patients known to have pneumococcus disease, 34 (77%) had
antibodies that reacted with the 37-kDa antigen (pneumococcal
fimbrial protein A) by Western immunoblot (FIG. 1).
The MAbs reacted with whole pneumococcal cells to yield a positive
test result in both the ELISA and IFA. FIG. 2 shows the bright
immunofluorescence of whole pneumococcus cells stained by the MAbs
and fluorescein-labeled anti-mouse immunoglobulin in the IFA.
Results from both the ELISA and the IFA indicate that the antigen
has exposed epitopes on the surface of the cell or that the
immunoglobulin and other immunologic reagents are able to penetrate
the pneumococcal cell walls.
Several strains of group A streptococci were tested for
immunofluorescence after reacting with the pneumococcus MAbs. None
of the heterologous bacterial cells fluoresced in this test,
indicating that the IFA reaction was specific for pneumococcus
cells.
To further determine the location on the cell of the 37-kDa antigen
(pneumococcal fimbrial protein A) epitopes reacting with the MAbs,
immunolabeling experiments were performed. FIG. 3 shows that the
cells were typical of gram-positive cocci in the process of
division. The figure also shows the reaction of MAbs and colloidal
gold-labeled anti-mouse immunoglobulin G with thin sections of
whole pneumococcal cells. A large portion of the antigen appears to
be intracellular since there is no coating or layering of the
labeled MAbs around the cell. The large patch of colloidal gold
staining indicates that the MAbs bound antigen located inside the
cell wall. There was no colloidal gold binding to control
pneumococci that were exposed to the MAbs against L.
pneumophila.
EXAMPLE 2
Cloning of the Pneumococcal Fimbrial Protein A Gene
Streptococcus pneumoniae DNA digested with restriction enzyme
Sau3A1 was ligated to BamHI digested pUC13 and transformed into E.
coli TB1. Recombinant clones were identified by colony immunoblot
using the 37-kDa monoclonal antibody. The plasmid pSTR3-1 is an
example of the pneumococcal fimbrial protein A gene cloned into
pUC13.
All publications mentioned hereinabove are hereby incorporated in
their entirety by reference. Additionally, Russell et al. (October
1990), J. of Clin. Microbiol. 28:2191-2195 is hereby incorporated
in its entirety by reference.
While the foregoing invention has been described in some detail for
purposes of clarity and understanding, it will be appreciated by
one skilled in the art from a reading of this disclosure that
various changes in form and detail can be made without departing
from the true scope of the invention and appended claims.
__________________________________________________________________________
SEQUENCE LISTING (1) GENERAL INFORMATION: (iii) NUMBER OF
SEQUENCES: 2 (2) INFORMATION FOR SEQ ID NO:1: (i) SEQUENCE
CHARACTERISTICS: (A) LENGTH: 1175 base pairs (B) TYPE: nucleic acid
(C) STRANDEDNESS: double (D) TOPOLOGY: linear (ix) FEATURE: (A)
NAME/KEY: CDS (B) LOCATION: 243..1172 (xi) SEQUENCE DESCRIPTION:
SEQ ID NO:1:
CTCATCACACCCGCTGCGACAGCCTATCTCTATGCCAATAGCCTCTGGTCCATGATGCTC60
CTTTCATCCGGATTAGGTGCCCTAGCCTCTATCCTAGGACTCTTTATCGGCTACAGTTTC120
AACATCGCCGTCGGGTCTTGTATC GTCCTCACTTCTGCCATCTTCTTTCTCATCAGCTTC180
TTTATCGCTCCTAAGCAGAGAAAGAATAAGCACGCTCTTTCACCTCATTAAAGGAGAAAC240
ACATGAAAAAAATCGCTTCTGTCCTCGCCCTCTTTGTGGCGCTCTTG287
MetLysLysIleAlaSerValLeuAlaLeuPheValAlaLeuLeu 151015
TTCGGCCTGTTGGCCTGCAGCAAAGGCACTTCTTCCAAGTCCTCATCC335
PheGlyLeuLeuAlaCysSerLysGlyThrSerSerLysSerSerSer 202530
GATAAATTGAAGGTGGTTACCACCAACTCCATCCTTGCCGATATCACC383
AspLysLeuLysValValThrThrAsnSerIleLeuAlaAspIleThr 354045
AAAAATATCGCTGGGGATAAAATCGAGCTCCACAGTATTGTACCTGTC431 L
ysAsnIleAlaGlyAspLysIleGluLeuHisSerIleValProVal 505560
GGTCAAGATCCCCACGAGTACGAACCGCTCCCAGAAGATGTCAAAAAA479 GlyGln
AspProHisGluTyrGluProLeuProGluAspValLysLys 657075
ACTTCACAAGCAGACCTGATCTTCTACAATGGGATCAACCTCGAAACG527 ThrSerGlnAlaAsp
LeuIlePheTyrAsnGlyIleAsnLeuGluThr 80859095
GGTGGCAATGCTTGGTTTACCAAATTGGTCAAAAATGCCAATAAAGTA575 GlyGlyAsnAl
aTrpPheThrLysLeuValLysAsnAlaAsnLysVal 100105110
GAAAACAAGGACTATTTCGCTGCCAGCGATGGCGTAGAGGTCATCTAC623 GluAsnLysA
spTyrPheAlaAlaSerAspGlyValGluValIleTyr 115120125
CTGGAAGGCCAAAACCAAGCTGGAAAAGAAGACCCTCACGCTTGGCTC671 LeuGluGlyGln
AsnGlnAlaGlyLysGluAspProHisAlaTrpLeu 130135140
AATCTCGAAAACGGGATTATCTACGCTAAAAACATTGCCAAACAATTA719
AsnLeuGluAsnGlyIle IleTyrAlaLysAsnIleAlaLysGlnLeu 145150155
ATCGCCAAAGATCCAAAAAATAAGGACTTCTACGAAAAAAATCTAGCA767
IleAlaLysAspProLysAsnLysAs pPheTyrGluLysAsnLeuAla 160165170175
GCCTACACTGAAAAACTCAGCAAGCTAGACCAAGAAGCCAAGCAAGCA815
AlaTyrThrGluLysLeuSerL ysLeuAspGlnGluAlaLysGlnAla 180185190
TTCAATAACATCCCAGCAGAGAAGAAGATGATCGTAACCAGCGAAGGT863
PheAsnAsnIleProAlaGlu LysLysMetIleValThrSerGluGly 195200205
TGCTTCAAGTACTTCTCCAAAGCCTACGGCGTCCCATCTGCCTATATC911
CysPheLysTyrPheSerLysAla TyrGlyValProSerAlaTyrIle 210215220
TGGGAAATCAACACTGAAGTAGAAGGGACACCTGAACAAATCAAAACG959
TrpGluIleAsnThrGluValGluGlyTh rProGluGlnIleLysThr 225230235
CTGCTAGAGAAATTGCGTCAAACCAAAGTACCGTCCCTCTTTGTCGAA1007
LeuLeuGluLysLeuArgGlnThrLysValProSerL euPheValGlu 240245250255
TCCAGTGTCGATGAGCGTCCTATGAAAACTGTGTCTAAGGATAGCAAT1055
SerSerValAspGluArgProMetLysThrVal SerLysAspSerAsn 260265270
ATCCCTATCTTTGCAAAGATCTTTACTGACTCGATTGCCAAAGAAGGC1103
IleProIlePheAlaLysIlePheThrAspSer IleAlaLysGluGly 275280285
GAAGAAGGCGACAGCTACTACAGCATGATGAAATGGAATTTGGAGAAA1151
GluGluGlyAspSerTyrTyrSerMetMetLysTr pAsnLeuGluLys 290295300
ATCGCAGAAGGTTTGAACAAATAA1175 IleAlaGluGlyLeuAsnLys 305 310 (2)
INFORMATION FOR SEQ ID NO:2: (i) SEQUENCE CHARACTERISTICS: (A)
LENGTH: 310 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear
(ii) MOLECULE TYPE: protein (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:
MetLysLysIleAlaSerValLeuAlaLeuPheValAlaLeuLeuPhe 15 1015
GlyLeuLeuAlaCysSerLysGlyThrSerSerLysSerSerSerAsp 202530
LysLeuLysValValThrThrAsnSer IleLeuAlaAspIleThrLys 354045
AsnIleAlaGlyAspLysIleGluLeuHisSerIleValProValGly 505560 G
lnAspProHisGluTyrGluProLeuProGluAspValLysLysThr 65707580
SerGlnAlaAspLeuIlePheTyrAsnGlyIleAsnLeuGluThrGly 859095
GlyAsnAlaTrpPheThrLysLeuValLysAsnAlaAsnLysValGlu 100105110
AsnLysAspTyrPhe AlaAlaSerAspGlyValGluValIleTyrLeu 115120125
GluGlyGlnAsnGlnAlaGlyLysGluAspProHisAlaTrpLeuAsn 130135 140
LeuGluAsnGlyIleIleTyrAlaLysAsnIleAlaLysGlnLeuIle 145150155160
AlaLysAspProLysAsnLysAspPheTyrGluLysAsnLeu AlaAla 165170175
TyrThrGluLysLeuSerLysLeuAspGlnGluAlaLysGlnAlaPhe 180185190 AsnA
snIleProAlaGluLysLysMetIleValThrSerGluGlyCys 195200205
PheLysTyrPheSerLysAlaTyrGlyValProSerAlaTyrIleTrp 210 215220
GluIleAsnThrGluValGluGlyThrProGluGlnIleLysThrLeu 225230235240
LeuGluLysLeuArgGlnThrLysValPro SerLeuPheValGluSer 245250255
SerValAspGluArgProMetLysThrValSerLysAspSerAsnIle 260265 270
ProIlePheAlaLysIlePheThrAspSerIleAlaLysGluGlyGlu 275280285
GluGlyAspSerTyrTyrSerMetMetLysTrpAsnLeuGluLysIle 29 0295300
AlaGluGlyLeuAsnLys 305310
* * * * *