U.S. patent application number 10/389679 was filed with the patent office on 2004-05-13 for use of a cd28 binding substance for making a pharmaceutical composition.
Invention is credited to Hunig, Thomas.
Application Number | 20040092718 10/389679 |
Document ID | / |
Family ID | 27797912 |
Filed Date | 2004-05-13 |
United States Patent
Application |
20040092718 |
Kind Code |
A1 |
Hunig, Thomas |
May 13, 2004 |
Use of a CD28 binding substance for making a pharmaceutical
composition
Abstract
The invention relates to the use of a CD28-specific
superagonistic monoclonal antibody (mAb) or of a mimicry compound
hereto for making a pharmaceutical composition for the induction
and/or multiplication of regulatory T cells.
Inventors: |
Hunig, Thomas; (Wurzburg,
DE) |
Correspondence
Address: |
Mark D. Wieczorek
P.O. Box 70072
San Diego
CA
92167
US
|
Family ID: |
27797912 |
Appl. No.: |
10/389679 |
Filed: |
March 13, 2003 |
Current U.S.
Class: |
530/387.1 ;
530/388.22 |
Current CPC
Class: |
A61K 35/17 20130101;
A61P 37/02 20180101; C07K 16/2818 20130101; A61K 2039/505 20130101;
C07K 2317/56 20130101; A61K 39/3955 20130101 |
Class at
Publication: |
530/387.1 ;
530/388.22 |
International
Class: |
C07K 016/28 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 13, 2002 |
DE |
DE 102 12 108.7 |
Claims
1. The use of a CD28-specific superagonistic monoclonal antibody
(mAb) or of a mimicry compound hereto for making a pharmaceutical
composition for the induction and/or multiplication of regulatory T
cells in vitro and/or in vivo.
2. The use in particular according to claim 1 for the treatment
and/or prophylaxis of autoimmune diseases and/or inflammatory
reactions.
3. The use in particular according to claim 1 for the treatment of
the Guillain-Barr{acute over (e )} syndrome (GBS) or of the chronic
demyelinating polyneuropathy (CDP).
4. The use according to one of claims 1 to 3, wherein the mAb can
be produced by that a non-human mammal is immunized with CD28 or a
partial sequence herefrom, in particular the C'-D loop, cells being
taken from the non-human mammal and hybridoma cells being produced
from the cells, and the thus obtained hybridoma cells being
selected such that in their culture supernatant there are mAbs
superagonistically binding to CD28.
5. The use according to one of claims 1 to 4, wherein the mimicry
compound is obtainable in a screening method, a prospective mimicry
compound or a mixture of prospective mimicry compounds being
subjected to a binding assay with CD28 or a partial sequence
herefrom, in particular the C'-D loop, and substances binding to
CD28 or to the partial sequence herefrom being selected, possibly
followed by an assay for testing for superagonistic stimulation of
several to all sub-groups of the T lymphocytes.
6. The use according to one of claims 1 to 5, wherein the mAb is
obtainable from hybridoma cells, as filed under the DSM numbers DSM
ACC2531 (mAb: 9D7 or 9D7G3H11) or DSM ACC2530 (mAb: 5.11A or
5.11A1C2H3).
7. The use according to one of claims 1 to 6, wherein the mAb or
the mimicry compound comprises one or more of the sequences Seq. ID
9, 11, 13 and/or 15, or one or more sequences Seq. ID 10, 12, 14,
16 or one or more of the sequences 18 and/or 19, or sequences being
homologous hereto.
8. A method for the treatment or prophylaxis of a disease according
to claim 2 or 3, wherein either to a patient is administered a
pharmaceutical composition comprising a CD28-specific
superagonistic monoclonal antibody or a mimicry compound hereto and
in a galenic preparation for a defined and suitable form of
administration, for instance IV injection, or from a patient is
taken a body liquid, in particular blood comprising T lymphocytes
or precursor cells hereto, and the body liquid, possibly after a
processing step, is reacted with a CD28-specific superagonistic
monoclonal antibody or a mimicry compound hereto, and the thus
treated body liquid is again administered to the patient, for
instance by IV injection.
Description
FIELD OF THE INVENTION
[0001] The invention relates to the use of a CD28 binding substance
for making a pharmaceutical composition.
DEFINITIONS
[0002] Monoclonal antibodies (mAbs) are antibodies which are
produced by hybrid cell lines (so-called hybridomas) which
typically have been generated by fusion of a B cell of animal or
human origin producing antibodies with a suitable myeloma tumor
cell.
[0003] The amino acid sequence of human CD28 is known under
accession No. NM.sub.--006139.
[0004] The C'-D loop of CD28 comprises the amino acids 52 to 66 of
the above CD28 sequence (for numbering see also Ostrov, D. A., et
al.; Science (2000), 290:816-819). The term C'-D loop will also
include in the following any partial sequences therefrom.
[0005] A loop or a binding site arranged therein is freely
accessible, if for a defined binding partner for the binding site
in the loop there is no steric hindrance by the sequences or
molecules following to the loop.
[0006] Regulatory T cells are CD4+ T cells inhibiting in a mixture
with naive CD4+ T cells the activation thereof. Hereto belong in
particular CD4+CD25+ T cells. Another feature of regulatory T cells
is, compared to other T cells, a low expression of the
high-molecular isoforms of CD45 (human: RA). For regulatory T
cells, the constitutive expression of CD152 is typical. CD4+CD8-SP
thymocytes are one of the essential sources for regulatory T cells.
For a further characterization of regulatory T cells, reference is
made to the document K. J. Maloy et al., Nature Immunology, Vol. 2,
No. 9, pages 816 ff., 2001.
[0007] The induction of regulatory T cells is the increase of the
metabolic activity, enlargement of the cell volume, synthesis of
immunologically important molecules and beginning of the cell
division (proliferation) upon an external stimulation. As a result,
after the induction there are more regulatory T cells than
before.
[0008] Homology is an at least 70%, preferably at least 80%, most
preferably at least 90% sequence identity on a protein level, a
homologous protein or peptide binding a defined binding partner
with at least identical affinity. Deviations in the sequence may be
deletions, substitutions, insertions and elongations.
[0009] A mimicry compound is a natural or synthetic chemical
structure behaving in a defined binding assay as a defined mAb
mimicrying the mimicry compound.
[0010] The term mAbs comprises, in addition to structures of the
conventional Fab/Fc type, also structures exclusively consisting of
the Fab fragment. It is also possible to use the variable region
only, the fragment of the heavy chains being connected with the
fragment of the light chain in a suitable manner, for instance also
by means of synthetic bridge molecules, such that the binding
regions of the chains form the antibody epitope. The term antibody
also comprises (possibly complete) chimeric and humanized
antibodies.
[0011] Superagonistic stimulation of the proliferation of
CD28-specific cells means that no costimulation, i.e. no further
binding event in addition to a binding of a mAb or of a mimicry
compound to CD28 is necessary for the stimulation or inhibition of
the proliferation.
BACKGROUND OF THE INVENTION AND PRIOR ART
[0012] For understanding the invention, firstly the following
technological background is important. The activation of resting T
cells for the proliferation and functional differentiation firstly
requires the occupation of two surface structures, so-called
receptors: 1. of the antigen receptor having a different
specificity from cell to cell and being necessary for the detection
of antigens, e.g. viral fission products; and 2. the CD28 molecule
expressed on all resting cells with the exception of a sub-group of
the human CD8 T cells, said CD28 molecule naturally binding to
ligands on the surface of other cells of the immune system. This is
called the costimulation of the antigen-specific immune reaction by
CD28. In a cell culture, these processes can be imitated by
occupation of the antigen receptor and of the CD28 molecule with
suitable mAbs. In the classic system of the costimulation, neither
the occupation of the antigen receptor nor that of the CD28
molecule alone will lead to the T cell proliferation, the
occupation of both receptors is however effective. This observation
has been made with T cells of man, mouse and rat.
[0013] There are however also known CD28-specific mAbs that can
initiate the T cell proliferation without costimulation. Such a
superagonistic, i.e. independent from the occupation of the antigen
receptor, activation of resting T lymphocytes by CD28-specific mAbs
is known in the art from the document Tacke et al., Eur. J.
Immunol., 1997, 27:239-247. According thereto, two types of
CD28-specific monoclonal antibodies having different functional
properties are described: costimulatory mAbs costimulating the
activation of resting T cells only with simultaneous occupation of
the antigen receptor; and superagonistic mAbs which can activate T
lymphocytes of all classes in vitro and in the test animal for
proliferation without occupation of the antigen receptor. Both in
so far known mAbs originate from an immunization with cells, on
which rat CD28 is expressed, and are obtainable by different
selections directed to their respective properties.
[0014] From the document DE-197 22 888 it is known in the art that
superagonistic mAbs are capable to effect an immune deviation TH1
to TH2 and are therefore suitable for use against adjuvant
arthritis. TH1 and TH2 cells are CD4-expressing T cells. TH1 cells
are also called pro-inflammatory T helper cells and secern the
cytokines IL-2, TNF and IFN-.gamma.. TH2 cells support the
activation of B cells and secern the cytokines IL-4, IL-5 and
IL-10. The differentiation of CD4 T cells from the above
functionally different subgroups is not only controlled by the
available cytokines, but it is also modulated by costimulation over
CD28. CD28-deficient mice show normal TH1, but reduced
TH2-dependent answers and the cytokine profile of TCR transgenic
CD4 cells is displaced by CD28 ligation in the direction TH2. On
the other hand, a strong TCR signal will prevent CD28-mediated TH2
differentiation.
[0015] From the primary literature summarized in the document K. J.
Maloy et al., Nature Immunology, vol. 2, No. 9, pages 816 ff.,
2001, it is known that regulatory T cells are important for
autoimmune reactions. For instance in experimental animal models of
the multiple sclerosis, of the type 1 diabetes and of inflammatory
intestinal diseases, the capability of these cells to suppress the
respective symptoms was shown.
[0016] The Guillain-Barr syndrome is an acute
autoimmune-inflammatory disease of the peripheral human nervous
system. The incidence of GBS is 1 to 2 per 100,000 inhabitants. The
chronic form is the chronic demyelinating polyneuropathy (CDP). The
incidence of CDP is 10 to 20 per 100,000 inhabitants. mAbs or
related substances for the prevention and/or treatment of these
diseases are not known.
TECHNICAL OBJECT OF THE INVENTION
[0017] The invention is based on the technical object to specify a
pharmaceutical composition, by means of which regulatory T cells
can be stimulated and which is particularly suited for the
prevention and/or treatment of the multiple sclerosis, type 1
diabetes, inflammatory intestinal diseases, GBS and/or CDP.
[0018] Basics of the Invention and Preferred Embodiments.
[0019] For achieving the above technical object, the invention
teaches the use of a CD28-specific superagonistic monoclonal
antibody (mAb) or of a mimicry compound thereto, for making a
pharmaceutical composition for the induction and/or multiplication
of regulatory T cells.
[0020] First of all, the invention is based on the finding that by
means of superagonistic CD28-specific substances, mAbs or mimicry
compounds hereto, CD4+CD25+ T cells can be induced, i.e. the number
thereof is, after treatment of an organism with the substance,
distinctly higher than in an organism that was not treated or was
treated with non-superagonistic substances.
[0021] Further, the invention is based on the finding that
substances according to the invention obviously are very good drugs
for the treatment of the Guillain-Barr syndrome and/or of the
chronic demyelinating polyneuropathy and other autoimmune-related
diseases. Therefore, the invention further teaches the use for
treating these diseases.
[0022] Superagonistic CD28-specific substances used according to
the invention, i.e. mAbs or mimicry compounds thereto, are those
which activate independently from the occupation of the antigen
receptor several to all sub-groups of the T lymphocytes.
[0023] The substance binds to CD28 or to a partial sequence
thereof. The partial sequence may for instance include an amino
acid sequence Seq. ID 1 or 2-7 or 17, which lie at least partially
in the region of the C'-D loop of CD28. To one of the sequences
with val at the 5' end, one or more amino acids of the sequence 8
may be connected in the order defined there. The loop is in the
region with the sequence GNYSQQLQVYSKTGF. Mimicry compounds
according to the invention can be identified in a screening method,
a prospective mimicry compound or a mixture of prospective mimicry
compounds being subjected to a binding assay with CD28 or a partial
sequence herefrom, in particular the C'-D loop, and substances
binding to CD28 or to the partial sequence herefrom being selected,
possibly followed by an assay for testing for superagonistic
stimulation of several to all sub-groups of the T lymphocytes. In
the case of a mixture it will be suitable to perform a
deconvolution. Among the selected mimicry compounds so to speak a
ranking according to the selectivity and/or affinity may be
established, highly affinitive substances being preferred. In
addition to or in lieu of such a ranking, a ranking may be
performed according to a quantification of the induction of the
regulatory T cells or according to the inhibition of the disease
for instance in an animal test by using disease models.
[0024] An example of a substance used according to the invention is
a superagonistic CD28-specific mAb. It can for instance be made by
that a non-human mammal is immunized with CD28 or a peptide
comprising a partial sequence herefrom, for instance as mentioned
above or homologues hereto, cells being taken from the non-human
mammal cells and hybridoma cells being produced from the cells, and
the thus obtained hybridoma cells being selected such that in their
culture supernatant there are mAbs binding to CD28. A humanization
can be performed with conventional methods. Suitable mAbs can
alternatively be made by selecting B lymphocytes binding to the
loop, and by cloning their expressed immunoglobulin genes. An
isolation of suitable mAbs from phages libraries is also
possible.
[0025] In detail, this may be a mAb being obtainable from hybridoma
cells, as filed under the DSM numbers DSM ACC2531 (mAb: 9D7 or
9D7G3H11) or DSM ACC2530 (mAb: 5.11A or 5.11A1C2H3). The mAb may
comprise one or more of the sequences Seq. ID 9, 11, 13 and/or 15,
or one or more of the sequences Seq. ID 10, 12, 14, 16, 18 and/or
19, or sequences being homologous hereto or being (partially) coded
thereby. In Seq. ID 13 the nucleic acid sequence of the variable
region of the heavy chain of a mAb 5.11A according to the invention
is represented. Seq. ID 14 shows the peptide coded thereby. Seq. ID
15 shows the nucleic acid sequence of the variable region of the
light chain of this mAb. Seq. ID 16 is the peptide coded hereby. In
Seq. ID 9 the nucleic acid sequence of the variable region of the
light chain of a mAb 9D7 according to the invention is represented.
Seq. ID 10 shows the peptide coded hereby. Seq. ID 11 shows the
nucleic acid sequence of the variable region of the heavy chain of
this mAb. Seq. ID 12 is the peptide coded hereby. Seq. ID 18 and 19
show the amino acid sequences of the variable region of a humanized
mAb 5.11A of the light chain and of the heavy chain,
respectively.
[0026] The invention finally also relates to treatments, wherein to
a person suffering from a disease caused by low regulator T cell
counts or high T lymphocytes infiltration in organs or tissues, for
instance GBS and/or CDP, a pharmaceutical composition according to
the invention is administered in a pharmacologically effective dose
and in a galenic preparation suitable for the administration.
[0027] In the following, the invention is explained in more detail,
based on examples representing embodiments only. Herein, in FIGS. 1
to 9 and the text sections belonging hereto, methods and results
are shown that represent on the one hand target structures for
finding suitable substances and that describe on the other hand
substances which can be used according to the invention. In FIGS.
10 to 15 are represented results that prove the induction of
regulatory T cells by substances used according to the invention.
FIGS. 16 to 21 show results hat prove the effect of substances
according to the invention in an animal model, the experimental
allergic neuritis of the LEW rat (EAN). The EAN is a model for the
human GBS and the CDP (also called CIDP or chronic inflammatory
demyelinating poly-radiculoneuropathy). There are:
[0028] FIG. 1 the stimulation of T lymphocytes of the rat with
different CD28-specific mAbs (a: costimulation, b: superagonistic
stimulation),
[0029] FIG. 2 a sequence comparison between mouse, rat and human
CD28 in the region of the C'-D loop (in box),
[0030] FIG. 3 experimental results for localizing the binding site
of superagonistic mAb at the CD28 molecule of the rat,
[0031] FIG. 4 the binding of different human CD28-specific mAbs at
CD28 (a) and costimulatory (b) and superagonistic (c) activity of
the mAbs of FIG. 4a,
[0032] FIG. 5 binding tests that show that superagonistic mAbs
specifically bind to the C'-D loop,
[0033] FIG. 6 a three-dimensional representation of CD28 with
marking of the C'-D loop,
[0034] FIG. 7 experiments for the activation of cells by means of
mAbs according to the invention,
[0035] FIG. 8 the representation of the sequences Seq.-ID 9-16
(a-h) and of the humanized variable domain of the antibody 5.11A
(light chain: VLC5.11, i; heavy chain: VHC5.11, j), Seq.-ID
18-19,
[0036] FIG. 9 the frequency of the CD4+CD25+ cells in the total
population of the CD4 cells of a rat, in comparison to after a
treatment with a superagonistic CD28-specific mAb and a
costimulatory mAb,
[0037] FIG. 10 the phenotypic characterization of CD4+CD25+ cells
induced by superagonistic CD28-specific mAbs and the comparison
with CD4+CD25- and CD4+CD25+ cells from untreated control
animals,
[0038] FIG. 11 the induction of the proliferation of CD4+CD25+
cells by superagonistic CD28-specific mAbs in a cell culture,
[0039] FIG. 12 another phenotype of the CD4+CD25+ cells obtained
according to FIG. 11,
[0040] FIG. 13 the inhibitory function of the regulatory T
cells,
[0041] FIG. 14 the experiments according to FIG. 11 with human T
cells and the use of superagonistic human-CD28-specific mAbs,
[0042] FIG. 15 the course of the active EAN disease under treatment
with superagonistic CD28-specific mAbs in comparison with
costimulatory mAbs,
[0043] FIG. 16 the effect against ENA by administration of
superagonistic CD28-specific mAbs before the immunization with the
autoantigen inducing EAN,
[0044] FIG. 17 the treatment according to FIG. 15, however with a
different treatment plan,
[0045] FIG. 18 the treatment according to FIG. 15, however for the
case of the passive or adoptive transfer EAN,
[0046] FIG. 19 the sorting of human CD4+ cells in CD4+CD25+++ and
CD4+CD25- cells,
[0047] FIG. 20 the growth curves of T cells expanded by monoclonal
antibodies and IL-2 according to the invention of FIG. 19
(sorted),
[0048] FIG. 21 the CTLA-4 expression of the expanded T cells of
FIG. 20, and
[0049] FIG. 22 the functional analysis of the expanded T cells of
FIG. 20 by means of a suppression assay, A: proliferation of the
indicator cells without and with stimulation (CD3/anti CD28), B:
suppression of the proliferation of the indicator cells in presence
of expanded CD4+CD25+++ cells.
[0050] FIG. 1 shows the stimulation of freshly isolated T
lymphocytes of the rat in the form of a 3H thymidine incorporation.
The method corresponds to the one described in the document
WO98/54225, to which here and in the following explicitly reference
is made and its disclosure contents are herewith incorporated in
the present text. In FIG. 1a is shown the costimulation, i.e. T
cell receptor (TCR) specific mAbs were bound to the plastic surface
in all wells. Because of lacking costimulation, the negative
control (uppermost bar) does not show any incorporation.
Costimulation is then given by the addition of CD28-specific mAbs
in a dissolved form. The complete shown range of CD28-specific mAbs
was used. This series of different CD28-specific mAbs originates
from an approach of the immunization and preparation of hybridoma
cell lines described in WO98/54225. These are culture supernatants
containing enough CD28-specific mAbs for a saturating binding to
2.multidot.10.sup.5 T cells. From FIG. 1a can be taken that all of
these mAbs are able to activate in a costimulating manner, i.e. to
excite the thymidine incorporation in presence of the anti-TCR
mAbs. In FIG. 1b is shown the stimulation in absence of
TCR-specific mAbs. This experiment, too, was performed as described
in WO98/54225. It can be seen that only two mAbs are able to
stimulate the T lymphocytes in absence of a TCR signal. These mAbs
have thus a superagonistic activity.
[0051] Further, it was investigated whether costimulatory and
superagonistic CD28-specific mAbs bind to different regions of the
CD28 molecule. The mAbs were prepared by immunization of mice with
CD28 of the rat; as expected, they all do not react with mouse CD28
(not shown). Since the mAbs can thus detect only such regions of
the rat CD28 molecule which are different from the mouse, first a
sequence comparison between the CD28 of the mouse and of the rat
was made (see FIG. 2, upper section). The differences between the
two species are highlighted. For identifying the amino acids, a
one-letter code was used. As prototypes for a conventional rat
CD28-specific mAb JJ319 was used, for a superagonistic mAb JJ316
was used (see WO98/54225).
[0052] In FIG. 3 is shown the mapping of the binding. Expression
plasmids were constructed, wherein a part of the extracellular
domain of CD28 originates from the mouse, another one from the rat.
This is symbolically shown by bars or lines; on the right hand
thereof is shown the binding of the mAbs JJ316 and JJ319 to mouse
fibroblasts (L929 cells) transfected with these expression
plasmids. In the first two lines of FIG. 3 (m/r and r/m 1-37) the
binding of the two antibodies to the "right-hand" half of the
sequence is mapped. Both bind, when the latter originates from the
rat. In the reversed construct (m/r CD28 1-37, left hand rat, right
hand mouse) there is no binding. In the third line (m/r CD28 1-66)
it is shown that JJ316 does not bind anymore, whereas the still
present part of the rat sequences ("right-hand") sill suffices for
the detection by JJ319. According thereto, the two mAbs detect
different epitopes on the CD28 molecule, and the binding of the
superagonist JJ316 is therefore to be searched in the region which
originated in the construct of the first line, not however in the
construct of the third line from the rat. A clear candidate herefor
is the region in the box in FIG. 2.
[0053] In lines 4 and 5 of FIG. 3, therefore firstly two and then
three amino acids in this region of the mouse CD28 molecule were
modified such that they now represent the rat sequence. By this
"transplantation" of three amino acids only, the binding capability
for mAb JJ316, not however (as expected) that of JJ319 could be
transferred. In Table 1 are summarized the binding data for the
complete range of CD28-specific mAbs. There results a clear
correlation: the two mAbs which function even without TCR
stimulation (superagonists) detect said epitope (in box in FIG. 2),
the conventional mAbs (only costimulatory) however do not. A
costimulatory mAb (5S35) detects the epitope in box very weakly and
binds very strongly to the "conventional" epitope.
[0054] The next two figures deal with superagonistic human-specific
mAbs. These, too, were prepared in mice, thus do not react with the
CD28 molecule of the mouse. The mice were immunized with
human-CD28-transfected A20/J mouse B lymphoma cells (see
WO98/54225) and in addition boostered prior to the fusion with
commercially available human-CD28 FC fusion protein (bought from R
and D Systems). In a series of fusion experiments, from several
thousand cell lines, approx. 20 were identified producing
human-CD28-specific mAbs (binding to mouse L929 cells expressing
human-CD28, but not to untransfected L929 cells), analogously to
the screen in document WO98/54225. Two of these showed the searched
superagonistic activity (9D7 and 5.11A), whereas all new mAbs have
the conventional costimulatory activity. In the following, in
particular the two superagonistic mAbs are described. As an example
for a conventional human-CD28-specific mAb, the also newly
generated mAb 7.3B6 was used.
[0055] FIG. 4a shows that the used preparations of the three new
mAbs bind comparatively well and also with a comparative titer to
human T lymphocytes. It is shown an experiment wherein freshly
isolated mononuclear cells from the human blood (so-called PBMC)
firstly were treated with different dilution steps of the used mAbs
on ice; then they were washed, and the bound mAb was made visible
by a secondary antibody marked with a fluorescence dye, said
antibody specifically detecting the bound mouse mAb. By the use of
another mAb which detects human CD4 cells and to which was bound a
second fluorescence dye, the binding of the titrated mAbs could be
determined by electronic gating selectively for the CD4 T
lymphocytes. "MFI" is the median fluorescence intensity being a
measure for the amount of the bound CD28-specific mAb. The
concentrations are 1:3 dilutions of a standardized original
preparation. It is fully normal that in this test the highest
concentration provides a weaker signal than the following titration
steps; this has to do with the avidity (bivalent binding) of mAbs
and does not play a role in the contexts discussed here.
[0056] FIGS. 4b and c compare the capabilities of superagonistic
human-CD28-specific mAbs to those of conventional CD28-specific
mAbs--in presence and in absence of a TCR signal--to stimulate
freshly isolated human T cells to growth. Again a 3H thymidine
incorporation is shown, as described before for the rat. For FIG.
4b, the wells were coated with a mAb reacting with the human
TCR/CD3 complex. Thus costimulation was measured. It can be seen
that the proliferation does not occur without a costimulation with
one of the mAbs (negative control), all three antibodies are
however able to stimulate the cell division. For FIG. 4c, the
procedure took place in absence of a TCR/CD3-specific mAb. Only the
antibodies 9D7 and 5.11A could stimulate in a superagonistic
manner.
[0057] After the epitope for superagonistic mAbs for the rat is
defined, and two new superagonistic mAbs with specificity for human
CD28 have been isolated, it was verified whether these mAbs bind to
the corresponding position of the human CD28 molecule. As can be
seen in FIG. 2, the CD28 molecules of mouse and man differ in
numerous positions. On the basis of the mapping of the
superagonistic epitope for the rat, it was therefore directly
verified whether the binding site for the superagonistic epitope on
human CD28 to the CD28 molecule of the mouse can be achieved by a
"transplantation" of the five amino acids of this homologous
region. The results are shown in FIG. 5. With the background of the
homogeneously represented mouse sequence for the extracellular
domain of the CD28 molecule (center), the exchanged (mouse to
human) amino acid positions are shown as lines (bottom). The
numbers at the sides in addition indicate the individual positions
and mutations (F60V means for instance that at position 60 the
phenylalanine of the mouse was replaced by a valine of the human
sequence). Moreover, the binding of the three investigated mAbs is
represented. As the figure shows, all three mAbs do detect human
CD28, however only the two mAbs 9D7 and 5.11A react with the mouse
CD28 molecule to which were transplanted the five amino acids of
the human CD28 at the decisive position. In view of the variety of
differences, this specific preparation of the reactivity is
surprising and confirms to a full extent the finding derived from
the experiments with rat CD28, namely that superagonistic mAbs must
bind to a defined, namely this position of the molecule.
[0058] FIG. 6 is a three-dimensional model of the CD28 molecule.
The newly defined binding region is highlighted. It corresponds to
the sequence in the box in FIG. 2. The extracellular domain of CD28
structurally belongs to the immunoglobulin superfamily being
characterized by two superimposed .beta.-pleated sheets as a basic
structure. The labeling of these bands follows a pattern given in
the literature. It is important for the representation shown here
that the region identified as an epitope for superagonistic
CD28-specific mAbs in rat and mouse are designated "C'-D loop".
Thus it was shown that mAbs with specificity for the C'-D loop of
the CD28 molecule have superagonistic activity, that is, in the
meaning of the document WO98/54225, can be used for the activation
of T lymphocytes. The superagonistic activity of C'-D loop-specific
mAbs in rat and man shows that not the sequence of the epitope, but
its position or shape is important.
[0059] In the experiments of FIG. 7, it was investigated whether
mAbs do not only bind (see FIGS. 3 and 5), but whether there is
really an activation. For this purpose, T tumor cells of the mouse,
BW, were transfected either with the construct of FIG. 3, line 5
(rat C'-D loop transfer) or with the construct of FIG. 5, line 3
(human C'-D loop). The activation of these cells is not measured by
cell division (they proliferate anyway) , but by the production of
the cytokine IL-2. FIG. 7 shows that without stimulation there is
no IL-2 production (negative control). The stimulation with a T
cell receptor-specific mAb induces IL-2 production (positive
control). FIG. 7a shows the results when using the superagonistic
mAb JJ316 of the rat, whereas FIG. 7b shows the results for the
human C'-D loop-specific mAb 5.11A. In either case the respective
cell lines are stimulated to IL-2 production. As expected, the
stimulation did however not take place by means of "conventional"
CD28-specific mAbs, since they do not only bind to the C'-D loop,
but cannot detect at all the construct, because they are specific
for the rat or human-specific sequences which are not included in
the construct.
[0060] In FIG. 9 are shown dot plots, wherein every measured cell
is represented by a dot. The phenotypic characterization of the
regulatory T cells takes place by the combination of the cell
surface molecules CD4 and CD25. For this purpose, the cell
suspensions were incubated with correspondingly fluorescence dye
marked monoclonal antibodies against CD4 and CD25, washed and
examined in a flow cytophotometer for the binding of these
antibodies. The shown results were obtained three days after IP
injection of a costimulatory (FIG. 9a, JJ319) or superagonistic
CD28-specific mAb (FIG. 9b, JJ316). In the case of JJ319, approx.
7% of the CD4 T cells are also CD25-positive(4/(50+4)), which
corresponds to not shown results in untreated animals. However,
after treatment with JJ316, approx. 20% are CD4+CD25+ (10/(10+40)).
Further, the level of the CD25 expression is by far higher than in
the control animal. Such a high level is characteristic for
regulatory T cells.
[0061] FIG. 10 shows a phenotypic characterization in a
representation as a histogram. In FIGS. 10a to 10c, the marker
CD45RC was detected, a high-molecular isoform of the CD45 molecule
being expressed strongly on naive CD4 T cells, however weakly on
stimulated CD4 T cells. A weak expression is typical for regulatory
T cells. FIG. 10a shows that most CD4+C25- cells from untreated
animals strongly express CD45RC. However, in the case of CD4+CD25+
cells from untreated animals, a strong expression takes place in a
clear minority of all cells (FIG. 10b). In the case of the
treatment with the superagonistic CD28-specific mAb (FIG. 10c), the
downward regulation of CD45CD45RC is even more distinct than in the
case of FIG. 10b. In the case of FIGS. 10d to 10e, the CD152
(CTLA-4) constitutively expressed by regulatory T cells is detected
by staining. This staining must be performed, because of the
intracellular localization of CD152, after permeabilization of
fixed cells, and is therefore provided with an unspecific
background. For verifying this, a so-called isotype control was
performed, i.e. an intracellular staining with a mAb of the same
immunoglobulin class, which however cannot detect anything
specifically. The specific CD152 proof is obtained by a
displacement of the CD152 histogram with regard to the isotype
control histogram. In FIG. 10d cannot be seen a displacement and
thus no CD152 expression in the CD4+CD25- cells. In the untreated
CD4+CD25+ cells there is a weak displacement (FIG. 10e) and in the
JJ316 (superagonistic CD28-specific mAb) treated cells there is a
stronger displacement, in agreement with the results of FIGS. 10a
to 10c.
[0062] As a result, it is phenotypically shown, with FIGS. 9 and
10, how regulatory cells can be identified, and that superagonistic
CD28-specific mAbs preferentially multiply or induce in vivo
regulatory T cells.
[0063] In FIG. 11, CD4+CD25+ cells are isolated by electronic cell
sorting either from untreated rats (FIG. 11a) or from rats treated
with JJ316 (FIG. 11b) and cultivated in 96 well plates according to
the state of the art. The cell multiplication was measured by 3H
thymidine incorporation between day 2 and 3 of the cultivation.
"(-) " means no stimulation, costimulation means stimulation with a
non-superagonistic CD28-specific mAb (JJ319) and with the
TCR-specific R73, and JJ316 shows the superagonistic stimulation.
FIG. 11a as well as 11b show that regulatory cells do not react
well upon costimulation, however well upon stimulation with a
superagonistic CD28-specific mAb. Stimulation with mAbs used
according to the invention shows also in a cell culture a
considerable multiplication of regulatory T cells.
[0064] FIG. 13 shows a representation according to FIG. 10f,
however after in vitro stimulation with superagonistic
CD28-specific mAbs (JJ316). An even stronger detectable CD152
expression can be seen.
[0065] In FIG. 13 is shown the inhibitory function of regulatory T
cells on Cd4+CD25- T cells serving as indicator cells for the
suppression effect. As a stimulus for the CD4+CD25- T cells,
costimulation (R73+JJ319) was used. The 3H thymidine incorporation
between day 2 and 3 of the cultivation was measured. CD25+ means
electronically sorted CD4+CD25+ T cells from animals treated three
days before with superagonistic CD28-specific mAbs (JJ316). CD25-
represents the indicator cells. CD25+/CD25- means in FIG. 13a that
both cell populations were mixed with one another in identical
parts. It can be seen that upon costimulation the CD25+ cells do
not react with proliferation. Further, the proliferation of
indicator cells is in addition suppressed. In FIG. 13b is
represented a titration of the regulatory T cells by a mixture with
indicator cells in different quantities. It can be seen that even
with a ratio of regulatory to indicator cells of 1:16, suppression
can still be observed. This shows the high effectivity of the
regulatory cells stimulated with mAbs used according to the
invention.
[0066] FIG. 14 shows a comparison of the reactions of human
CD4+CD25- T cells (naive cells) to CD4+CD25+ T cells (regulatory
cells) in response to costimulation (anti-CD3+conventional
anti-CD28 mAb) or to human-specific superagonistic CD28-specific
mAbs (9D7 and 5.11A). The experiments correspond to those described
above for the rat. Beginning at the left-hand side, the first three
groups show unstimulated controls (no 3H thymidine incorporation).
These are all CD4+ T cells, then the CD25- fraction gained by
sorting and finally the CD25+ fraction gained by sorting. "med"
means medium. Then follow two groups wherein a superagonistic
stimulation was made (9D7 and 5.11A). It can be seen that the
regulatory T cells react in a better way on the stimulation with
superagonistic CD28-specific mAbs, compared to the total population
of the CD4+ cells and their CD25- fraction. The last group of three
shows the results of the conventional costimulation. Here, however,
the reaction of the unseparated T cells and of the CD25- fraction
is rather better.
[0067] As a result, it is proven for rat T cells as well as in the
human system that superagonistic CD28-specific mAbs induce or
multiply regulatory T cells in a better way than conventional
costimulation. Further, it is proven that this can also be verified
in the intact organism.
[0068] In FIG. 15 is represented the course of the active EAN
disease under treatment with various mAbs. 7-8 weeks old female LEW
rats (obtainable from Charles River Laboratories, Sulzfeld,
Germany) were used. The animals were immunized with a synthetic
peptide corresponding to a part of the myelin protein P2 wrapping
peripheral nerve fibers (amino acids 53-78 of the bovine P2
protein, 50 .mu.l of a 0.5 mg/ml solution, inoculation in the foot
balls). After approx. 10 days a progressive paralysis develops
which can be quantified according to a standardized scoring (King
et al., Exp. Neurol., 87:9-19 (1985)). FIG. 15a shows a preparative
therapy with superagonistic CD28-specific mAbs (JJ316) and FIG. 15b
a treatment with conventional mAbs (JJ319). The application took
place in 1 mg/animal doses IP either on the day of the P2
immunization (D0), at day 12 (D12), i.e. after beginning of the
symptoms, or on both days. The various groups comprises 3 to 6
animals. A comparison of FIGS. 15a and 15b shows that the treatment
with superagonistic CD28-specific is distinctly more effective than
the treatment with conventional mAbs.
[0069] FIG. 16 shows the results according to FIG. 15, however with
a prophylactic treatment. d-7 is a treatment 7 days before the
immunization, d-21 21 days before the immunization. It can be seen
that a resistant state can be achieved by multiplication of
regulatory T cells with a treatment within one week before the
immunization, not however with a treatment 3 weeks before the
immunization.
[0070] FIG. 17 is based on an approach identical to FIG. 15,
however treatment with JJ316 at day 0 and 4. FIG. 17a shows the
course of the disease corresponding to the representation of FIG.
15a. FIG. 17b shows electro-physical properties, namely speed of
the stimulus transmission as a direct clinical parameter for the
damage of the sciatic nerve. The measurements were performed
according to the documents Adlkofer et al., Nat. Genet., 11:274-280
(1995) and Heininger et al., Ann. Neurol., 19:44-49 (1986). The
pathological results can be seen by means of control groups in
particular in the extension of the N1 and F latencies (see days 0
and 12, open symbols). In contrast, the latencies in the case of
the animals treated with superagonistic CD28-specific mAbs (JJ316)
remain nearly unchanged between day 0 and day 12 (full
symbols).
[0071] Not shown are supplementing examinations with a histological
proof of the T cell infiltration in thin layers of the nerves. The
detection of the cells took place with a mAb being suitable for
this technology, namely B115 and coloration of the T lymphocytes.
The cell nuclei were counter-colored in a different color. In
comparative experiments it was found that in the not treated
control group, a higher number of T cells were infiltrated than in
the group treated with a superagonistic CD28-specific mAb (JJ316),
which indicates a suppression by regulatory T cells by using mAbs
according to the invention.
[0072] Further experiments are not shown wherein the isolating
myelin sheaths were colored. The treatment with superagonistic
CD28-specific mAbs showed a healthy picture, whereas the control
group showed demyelinization, i.e. destruction of the isolating
sheaths.
[0073] In FIG. 18 are shown the results of a therapy of the passive
or active adoptive transfer EAN (AT-EAN). This is not induced by
immunization with the nerve antigen, as described above, but takes
place by intravenous injection of an autoreactive CD4+ T cell clone
with specificity for the P2 myelin antigen (8.multidot.10.sup.6,
cell line G7) according to the document Stienekemeier et al.,
Brain, 122:523-535 (1999). FIG. 18a shows the course of the disease
of a control group, under treatment with JJ316 at day 1 (d1) and
treatment at day 3 (d3). It is notable that even after the
beginning of the disease symptoms, i.e. treatment at day 3, the
disease can be stopped. In FIG. 18b the infiltration of the nerves
with T cells has been quantified for the three groups, and it can
be seen that in the control group this leads to a damage to the
nerves. In contrast, the T cell counts are considerably lower in
case of a treatment with mAbs used according to the invention
because of the induction of regulatory T cells.
[0074] In the experiments of FIGS. 19 to 22, it is finally proven
that CD4+CD25+++ T cells expanded by means of monoclonal antibodies
according to the invention can even after expansion maintain their
functional properties, e.g. the suppression of the proliferation of
"conventional" T cells. For this purpose, the CD4+ T cells from
human peripheral mononuclear cells (PBMC) were purified by means of
magnetic separation (negative depletion of CD8+, CD11b+, CD16+,
CD19+, CD36+ and CD56+ cells; purity 95%). These cells were then
loaded with a CD28-specific antibody and then with a PE-conjugated
secondary antibody, sorted into CD4+CD25+++ and CD4+CD25- T cells
(see FIG. 19) and cultivated after addition of monoclonal
antibodies according to the invention coupled to Dynabeads (hulG4)
and Interleukin 2 (IL-2) (day 0). On day 5, a coloration of the
expanded cells with anti-CD4 and anti-CD25 at the cell surface took
place, and intracellularly with anti-CTLA-4 and Ki-67. On day 6,
the separation of the beads from the cultivated cells and removal
of the IL-2 by repeated washing was performed, followed by a 2-day
culture in medium alone. The two subpopulations multiplied tenfold
within 8 days (see FIG. 20). The increased expression of the
protein CTLA-4 in the expanded CD4+CD25+++ cells (see FIG. 21) is
an indication that these cells have kept their regulatory
phenotype. This was then verified as follows by a functional
characterization.
[0075] Syngeneic peripheral mononuclear cells from heparinized
whole blood were gained and marked with the fluorescence dye CFSE
(carboxy fluorescencein diacetate succinimidyl ester). These cells
served as indicators cells. Firstly, they were stimulated with
anti-CD3 and anti-CD28 antibodies for three days. With every cell
division, the intensity of the marking measurement values of these
indicator cells were halved (see FIG. 22a). In independent
approaches, on day 8 expanded CD4+CD25+++ or CD4+CD25- T cells,
resp., were mixed with the CFSE-marked indicator cells in a ratio
1:1 or 1:5, resp., and were cultivated (stimulation with anti-CD3
mAb, clone HIT3a, final concentration 0.1 .mu.g/ml and anti-CD28
mAb, clone CD28.2, final concentration 0.05 .mu.g/ml). FIG. 22b
shows that the number of cell divisions in the indicator cells was
strongly reduced by the presence of the expanded CD4+CD25+++ T
cells, whereas the CD4+CD25- T cells showed a weak effect only.
Thus it is proven that the regulatory CD4+CD25+++ T cells expanded
with monoclonal antibodies according to the invention were still
able to suppress the proliferation of other "normal" T cells.
1TABLE I Binding of anti-rat CD28 mAbs to mouse and rat CD28 and
different CD28 mutants mouse rat mcD28, S62P m/rCD28 mAb CD28 CD28
A64V, E65G Mva1269I Contr. - - - - JJ316 - +++ +++ - JJ319 - +++ -
+++ 5S28 - ++ - ++ 5S38.17 - +++ +++ - 5S247 - +++ - +++ 5G40/3 -
+++ - +++ 5G87 - ++ - ++ 5G111 - ++ - ++ 5S35 - +++ + +++
[0076]
Sequence CWU 1
1
19 1 6 PRT homo sapiens 1 Val Tyr Ser Lys Thr Gly 1 5 2 4 PRT homo
sapiens 2 Tyr Ser Lys Thr 1 3 5 PRT homo sapiens 3 Tyr Ser Lys Thr
Gly 1 5 4 5 PRT homo sapiens 4 Val Tyr Ser Lys Thr 1 5 5 6 PRT homo
sapiens 5 Tyr Ser Lys Thr Gly Phe 1 5 6 7 PRT homo sapiens 6 Val
Tyr Ser Lys Thr Gly Phe 1 5 7 5 PRT homo sapiens 7 Ser Lys Thr Gly
Phe 1 5 8 8 PRT homo sapiens 8 Gly Asn Tyr Ser Gln Gln Leu Gln 1 5
9 321 DNA artificial msic_feature (1)..(321) mab 9 gatatccaga
cgacacagac tacatcctcc cgttctgcct ctctgggaga cagagtcacc 60
atcagttgca gggcaggtca ggacattagt aattatttaa actggtatca gcagaaacca
120 gatggaactg ttaagctcct gatctactac acatcaagat tacactcagg
agtcccatca 180 aggttcagtg gcagtgggtc tggaacagat tattctctca
ccattagcaa cctggagcaa 240 gaagatattg ccacttactt ttgccaacag
ggtcatacgc ttccgtggac gttcggtgga 300 ggcaccaagc tggaaatcaa a 321 10
107 PRT artificial misc_feature (1)..(107) mab 10 Asp Ile Gln Thr
Thr Gln Thr Thr Ser Ser Leu Ser Ala Ser Leu Gly 1 5 10 15 Asp Arg
Val Thr Ile Ser Cys Arg Ala Gly Gln Asp Ile Ser Asn Tyr 20 25 30
Leu Asn Trp Tyr Gln Gln Lys Pro Asp Gly Thr Val Lys Leu Leu Ile 35
40 45 Tyr Tyr Thr Ser Arg Leu His Ser Gly Val Pro Ser Arg Phe Ser
Gly 50 55 60 Ser Gly Ser Gly Thr Asp Tyr Ser Leu Thr Ile Ser Asn
Leu Glu Gln 65 70 75 80 Glu Asp Ile Ala Thr Tyr Phe Cys Gln Gln Gly
His Thr Leu Pro Trp 85 90 95 Thr Phe Gly Gly Gly Thr Lys Leu Glu
Ile Lys 100 105 11 363 DNA artificial misc_feature (1)..(363) mab
11 gatgtgcagc ttcaggagtc gggacctggc ctggtgaaac cttctcagtc
tctgtccctc 60 acctgcactg tcactggcta ctcaatcacc agtgattatg
cctggaactg gatccggcag 120 tttccaggaa acaaactgga gtggatgggc
tacataagat acagtggtag tactagctac 180 aatccatctc tcaaaagtcg
aatctctatc actcgagaca catccaagaa ccagttcttc 240 ctgcagttga
attctgtgac tactgaggac acagccacat attactgtgc aagagattgg 300
ccgcgaccga gctactggta cttcgatgtc tggggcgcag ggaccacggt caccgtctcc
360 tca 363 12 121 PRT artificial misc_feature (1)..(121) mab 12
Asp Val Gln Leu Gln Glu Ser Gly Pro Gly Leu Val Lys Pro Ser Gln 1 5
10 15 Ser Leu Ser Leu Thr Cys Thr Val Thr Gly Tyr Ser Ile Thr Ser
Asp 20 25 30 Tyr Ala Trp Asn Trp Ile Arg Gln Phe Pro Gly Asn Lys
Leu Glu Trp 35 40 45 Met Gly Tyr Ile Arg Tyr Ser Gly Ser Thr Ser
Tyr Asn Pro Ser Leu 50 55 60 Lys Ser Arg Ile Ser Ile Thr Arg Asp
Thr Ser Lys Asn Gln Phe Phe 65 70 75 80 Leu Gln Leu Asn Ser Val Thr
Thr Glu Asp Thr Ala Thr Tyr Tyr Cys 85 90 95 Ala Arg Asp Trp Pro
Arg Pro Ser Tyr Trp Tyr Phe Asp Val Trp Gly 100 105 110 Ala Gly Thr
Thr Val Thr Val Ser Ser 115 120 13 360 DNA artificial misc_feature
(1)..(360) mab 13 caggtccaac tgcagcagtc cggacctgag ctggtgaagc
cggggacttc agtgaggatt 60 tcctgcgagg cttctggcta caccttcaca
agctactata tacactgggt gaaacagagg 120 cctggacagg gacttgagtg
gattggatgt atttatcctg gaaatgtcaa tactaactat 180 aatgagaagt
tcaaggacaa ggccacactg attgtagaca catcctccaa cactgcctac 240
atgcagctca gcagaatgac ctctgaggac tctgcggtct atttctgtac aagatcacac
300 tacggcctcg actggaactt cgatgtctgg ggcgcaggga ccacggtcac
cgtctcctca 360 14 120 PRT artificial misc_feature (1)..(120) mab 14
Gln Val Gln Leu Gln Gln Ser Gly Pro Glu Leu Val Lys Pro Gly Thr 1 5
10 15 Ser Val Arg Ile Ser Cys Glu Ala Ser Gly Tyr Thr Phe Thr Ser
Tyr 20 25 30 Tyr Ile His Trp Val Lys Gln Arg Pro Gly Gln Gly Leu
Glu Trp Ile 35 40 45 Gly Cys Ile Tyr Pro Gly Asn Val Asn Thr Asn
Tyr Asn Glu Lys Phe 50 55 60 Lys Asp Lys Ala Thr Leu Ile Val Asp
Thr Ser Ser Asn Thr Ala Tyr 65 70 75 80 Met Gln Leu Ser Arg Met Thr
Ser Glu Asp Ser Ala Val Tyr Phe Cys 85 90 95 Thr Arg Ser His Tyr
Gly Leu Asp Trp Asn Phe Asp Val Trp Gly Ala 100 105 110 Gly Thr Thr
Val Thr Val Ser Ser 115 120 15 321 DNA artificial misc_feature
(1)..(321) mab 15 gacatccaga tgaaccagtc tccatccagt ctgtctgcat
cccttggaga cacaattacc 60 atcacttgcc atgccagtca aaacatttat
gtttggttaa actggtacca gcagaaacca 120 ggaaatattc ctaaactctt
gatctataag gcttccaacc tgcacacagg cgtcccatca 180 aggtttagtg
gcagtggatc tggaacaggc ttcacattaa ccatcagcag cctgcagcct 240
gaagacattg ccacttacta ctgtcaacag ggtcaaactt atccgtacac gttcggaggg
300 gggaccaagc tggaaataaa a 321 16 107 PRT artificial misc_feature
(1)..(107) mab 16 Asp Ile Gln Met Asn Gln Ser Pro Ser Ser Leu Ser
Ala Ser Leu Gly 1 5 10 15 Asp Thr Ile Thr Ile Thr Cys His Ala Ser
Gln Asn Ile Tyr Val Trp 20 25 30 Leu Asn Trp Tyr Gln Gln Lys Pro
Gly Asn Ile Pro Lys Leu Leu Ile 35 40 45 Tyr Lys Ala Ser Asn Leu
His Thr Gly Val Pro Ser Arg Phe Ser Gly 50 55 60 Ser Gly Ser Gly
Thr Gly Phe Thr Leu Thr Ile Ser Ser Leu Gln Pro 65 70 75 80 Glu Asp
Ile Ala Thr Tyr Tyr Cys Gln Gln Gly Gln Thr Tyr Pro Tyr 85 90 95
Thr Phe Gly Gly Gly Thr Lys Leu Glu Ile Lys 100 105 17 15 PRT homo
sapiens 17 Gly Asn Tyr Ser Gln Gln Leu Gln Val Tyr Ser Lys Thr Gly
Phe 1 5 10 15 18 107 PRT artificial misc_feature (1)..(107) mab 18
Asp 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 His Ala Ser Gln Asn Ile Tyr Val
Trp 20 25 30 Leu Asn Trp Tyr Gln Gln Lys Pro Gly Lys Ala Pro Lys
Leu Leu Ile 35 40 45 Tyr Lys Ala Ser Asn Leu His Thr 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 Gly Gln Thr Tyr Pro Tyr 85 90 95 Thr Phe Gly Gly Gly
Thr Lys Val Glu Ile Lys 100 105 19 120 PRT artificial misc_feature
(1)..(120) mab 19 Gln Val Gln Leu Val Gln Ser Gly Ala Glu Val Lys
Lys Pro Gly Ala 1 5 10 15 Ser Val Lys Val Ser Cys Lys Ala Ser Gly
Tyr Thr Phe Thr Ser Tyr 20 25 30 Tyr Ile His Trp Val Arg Gln Ala
Pro Gly Gln Gly Leu Glu Trp Ile 35 40 45 Gly Cys Ile Tyr Pro Gly
Asn Val Asn Thr Asn Tyr Asn Glu Lys Phe 50 55 60 Lys Asp Arg Ala
Thr Leu Thr Val Asp Thr Ser Ile Ser Thr Ala Tyr 65 70 75 80 Met Glu
Leu Ser Arg Leu Arg Ser Asp Asp Thr Ala Val Tyr Phe Cys 85 90 95
Thr Arg Ser His Tyr Gly Leu Asp Trp Asn Phe Asp Val Trp Gly Gln 100
105 110 Gly Thr Thr Val Thr Val Ser Ser 115 120
* * * * *