U.S. patent application number 10/020648 was filed with the patent office on 2002-12-12 for lysing or blocking unwanted cells with il-2 receptor-specific binding substance.
Invention is credited to Strom, Terry B..
Application Number | 20020187145 10/020648 |
Document ID | / |
Family ID | 25096555 |
Filed Date | 2002-12-12 |
United States Patent
Application |
20020187145 |
Kind Code |
A1 |
Strom, Terry B. |
December 12, 2002 |
Lysing or blocking unwanted cells with IL-2 receptor-specific
binding substance
Abstract
A method of lysing unwanted, non-malignant cells in a mammal,
the cells having on their surfaces a receptor for a growth factor,
and the method including administering to the mammal a cell-lysing
amount of a substance characterized in that it has specific
affinity for the receptor of the growth factor and has the ability
to effect the lysis of the cells.
Inventors: |
Strom, Terry B.; (Brookline,
MA) |
Correspondence
Address: |
LERNER, DAVID, LITTENBERG,
KRUMHOLZ & MENTLIK
600 SOUTH AVENUE WEST
WESTFIELD
NJ
07090
US
|
Family ID: |
25096555 |
Appl. No.: |
10/020648 |
Filed: |
December 12, 2001 |
Related U.S. Patent Documents
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Application
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10020648 |
Dec 12, 2001 |
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09517851 |
Mar 2, 2000 |
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09517851 |
Mar 2, 2000 |
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08975563 |
Nov 21, 1997 |
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6113900 |
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08975563 |
Nov 21, 1997 |
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08761975 |
Dec 11, 1996 |
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5916559 |
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08761975 |
Dec 11, 1996 |
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08469538 |
Jun 6, 1995 |
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5607675 |
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08469538 |
Jun 6, 1995 |
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08275010 |
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5510105 |
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08275010 |
Jul 8, 1994 |
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07842463 |
Feb 27, 1992 |
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5336489 |
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07842463 |
Feb 27, 1992 |
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07692830 |
Apr 26, 1991 |
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07692830 |
Apr 26, 1991 |
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07492616 |
Mar 12, 1990 |
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07492616 |
Mar 12, 1990 |
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06772893 |
Sep 5, 1985 |
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5011684 |
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Current U.S.
Class: |
424/143.1 ;
424/178.1 |
Current CPC
Class: |
A61K 2039/505 20130101;
C07K 16/2866 20130101; A61P 37/06 20180101; Y10S 514/885 20130101;
A61P 35/00 20180101; A61K 38/00 20130101 |
Class at
Publication: |
424/143.1 ;
424/178.1 |
International
Class: |
A61K 039/395 |
Goverment Interests
[0002] Funding for the work described herein was provided by the
Federal government, which has certain rights in the invention.
Claims
1. A method of lysing unwanted, non-malignant cells in a mammal,
said cells having on their surfaces a receptor for a growth factor,
and said method comprising administering to said mammal a
cell-lysing amount of a substance characterized in that it has
specific affinity for said receptor of said growth factor and has
the ability to effect said lysis of said cells.
2. The method of claim 1 wherein said cells are lymphocytes.
3. The method of claim 2 wherein said lymphocytes are
T-lymphocytes.
4. The method of claim 2 wherein said lymphocytes are
B-lymphocytes.
5. The method of claim 1 wherein said receptor is an IL-2
receptor.
6. The method of claim 1 wherein said substance comprises an
antibody to said receptor.
7. The method of claim 1 wherein said substance comprises said
growth factor or an analog thereof, linked to a cytotoxin.
8. A method of inhibiting the T-lymphocyte-induced rejection of an
allograft in a mammal comprising administering to said mammal,
following said allograft, a substance characterized in that it has
specific affinity for IL-2 receptors on said T-lymphocytes and has
the ability either to effect the lysis of said T-lymphocytes, or to
interfere with the binding of IL-2 to said T-lymphocytes.
9. The method of claim 8 wherein said substance has the ability to
effect the lysis of said T-lymphocytes.
10. The method of claim 8 wherein said substance is administered
when said T-lymphocytes are undergoing, in response to said
allograft, a proliferative burst characterized by the presence of
said IL-2 receptors on the surfaces of said T-lymphocytes.
11. The method of claim 8 wherein said substance comprises an
antibody to said IL-2 receptor.
12. The method of claim 11 wherein said antibody is a monoclonal
antibody.
13. The method of claim 11 wherein said antibody is of the IgG or
IgM isotype.
14. The method of claim 9 wherein said substance comprises IL-2 or
an IL-2 receptor-specific analog thereof linked to a cytotoxin.
15. A method of treating a patient having an acute autoimmune
disease characterized by the presence of lymphocytes bearing IL-2
receptors, said method comprising administering to said patient a
substance characterized in that it has specific affinity for IL-2
receptors on said lymphocytes and has the ability either to effect
the lysis of said lymphocytes, or to interfere with the binding of
IL-2 to said lymphocytes.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No.
07/692,830, filed Apr. 26, 1991, which is a continuation of U.S.
Ser. No. 07/492,616, filed Mar. 12, 1990, now abandoned, which is a
continuation of U.S. Serial No. 06/772,893, filed Sep. 5, 1985, now
U.S. Pat. No. 5,011,684.
BACKGROUND OF THE INVENTION
[0003] This invention relates to the lysis of unwanted,
non-malignant cells, e.g., lymphocytes involved in the rejection of
allografts such as transplanted organs.
[0004] Allograft rejection is an immune response, involving
activated T-lymphocytes. Currently used immunosuppressive protocols
designed to inhibit rejection involve the administration of drugs
such as asathioprine, cyclosporine, and coritcosteroids, all of
which cause toxic side effects to non-lymphoid tissues. The recent
development of pan-T-lymphocyte monoclonal antibodies represents an
important refinement in therapy, since only T-lymphocytes are
targeted by the administration of such antibodies. However, this
therapy has the disadvantage of destroying, along with the
T-lymphocytes involved in allograft rejection, those required for
normal immune surveillance.
SUMMARY OF THE INVENTION
[0005] In general, the invention features a method of lysing
unwanted, non-malignant cells in a mammal, which cells have on
their surfaces a receptor for a growth factor; the method substance
characterized in that it has specific affinity for the growth
factor receptor and has the ability to effect lysis of the cells.
(As used herein, "malignant" cells refers to cancerous cells, e.g.,
primary or metastatic solid tumor cells, or leukemia cells; the
non-malignant cells targeted according to the invention are
unwanted cells which are not cancerous. "Growth factor" refers to a
substance which, when taken into a cell after binding to a growth
factor receptor on the surface of the cell, facilitates
proliferation of the cell. "Specific affinity" refers to the
ability of a substance to bind virtually exclusively to a
particular growth factor receptor, e.g., the interleukin-2 ("IL-2")
receptor, and not to other cell surface receptor proteins, e.g.,
insulin receptors.)
[0006] In preferred embodiments, the unwanted cells are
lymphocytes, i.e., T-lymphocytes or B-lymphocytes, and the growth
factor receptor-specific substance includes either an antibody
(preferably a monoclonal antibody of the lytic IgC or IgM isotypes)
or the growth factor itself (or a receptor-specific analog thereof)
linked to a cytotoxin, e.g., diptheria toxin or ricin, via either a
covalent linkage such as a disulfide linkage or, more preferably,
via a peptide linkage.
[0007] The unwanted, non-malignant cells most preferred to be lysed
by the method of the invention are T-lymphocytes, which are the
cell type primarily responsible for causing rejection of allografts
(e.g., transplanted organs such as the heart). T-lymphocytes
(killer and helper) respond to allografts by undergoing a
proliferative burse characterized by the transitory presence on the
T-lymphocyte surfaces of IL2 receptors. Killing these cells by the
administration, during the proliferative burst, of a lytic, IL-2
receptor-specific substance inhibits allograft rejection, and also
advantageously fails to adversely affect other cells (including
resting or long-term memory T-lymphocytes needed for fighting
infections), since these other cells do not bear IL-2 receptors and
are therefore not recognized by the IL-2 receptor-specific
substance. In addition, cell lysis according to the invention is
efficient because the IL-2 receptor binds top IL-2
receptor-specific substances so that the cytotoxin, if one is
involved, is internalized in a way which results in cell death.
[0008] Where the lytic substance is an antibody of the
complement-fixing IgG or IgM isotypes, it is not necessary that the
antibody compete with IL-2 for the IL-2 receptor; i.e., the
antibody can be one which binds to the receptor in a way which
permits IL-2 to bind as well. Competitive binding is, however,
important, for non-lytic IL-2 receptor-specific substances, as is
discussed below.
[0009] The concept that allograft rejection can be inhibited by
taking advantage of the proliferative burst of attacking
T-lymphocytes which is characterized by the transient presence of
IL-2 receptors on the surfaces of the T-lymphocytes can also form
the basis for inhibiting allograft rejection using an IL-2
receptor-specific substance which, by virtue of its binding to the
IL-2 receptors of the T-lymphocytes which would otherwise attack
the allograft, impairs their ability to cause rejection of the
allograft, but does not lyse them via complement fixation. Such
substances, (e.g., non-complement fixing IgA antibodies), to be
effective, must compete with IL-2 for the IL-2 receptor, so that
their administration will prevent IL-2 from binding to the
T-lymphocytes.
[0010] This preventing of the binding of IL-2 to T-lymphocytes can
result in several important phenomena which contribute to rejection
inhibition. First, the T-lymphocytes, newly activated by the
presence of the allograft, fail to proliferate, and eventually die,
due to the lack of the essential anabolic stimulus IL-2. In
addition, the T-lymphocytes, deprived of IL-2, fail to release at
least three lymphokines which play important roles in organ
rejection. One of these, gamma interferon, normally activates
allograft-attacking macrophages, and also stimulates the allograft
to produce additional antigen, marking the allograft for more
vigorous attack by the immune system. A second of these lymphokines
is B-cell differentiation factor II, which ordinarily would
stimulate the differentiation of B-cells, which in turn would
produce allograft-attacking antibodies. A third lymphokine is IL-3,
a hematopoietic stem cell growth factor also believed to play an
important role in allograft rejection.
[0011] The method of the invention inhibits allograft rejection in
a manner which does not cause general immune suppression, with its
resulting risk of life-threatening infections. In addition, the
method spares donor-specific T suppressor cells, which can thus
proliferate and aid in prolonging allograft survival. Furthermore,
antibodies do not need to be tailored to individual patients; a
single antibody can be used as a universal allograft rejection
inhibiting agent for every donor-recipient combination. In
addition, therapy need not be continuous following the allograft,
but can be discontinued after a course of treatment.
[0012] Other features and advantages of the invention will be
apparent from the following description of the preferred
embodiments thereof, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In the drawing, the FIGURE is a graph showing skin allograft
survival following treatment with an antibody according to the
invention (open circles with dashed line, n=9) and untreated
controls (closed circles with solid line, n=7).
ANTIBODY THERAPY
[0014] One embodiment of the invention employs, as the IL-2
receptor-specific substance, an antibody (preferably monoclonal)
which is specific for the IL-2 receptor on T-lymphocytes and which
is preferably capable of effecting in vivo lysis of T-lymphocytes
to whose IL-2 receptors it binds. Antibodies specific for the IL-2
receptor on T-lymphocytes can be made using standard techniques, or
can be purchased, e.g., from Becton Dickenson Company (mouse-human
monoclonal anti-IL2 receptor antibodies, packaged in azide, which
would need to be removed prior to use). The antibody can be used
alone, or it can be coupled to a toxin to increase its lytic
capacity. The antibody can be monoclonal or polyclonal, and can be
derived from any suitable animals. Where the antibody is monoclonal
and the mammal being treated is human, mouse-human anti-IL-2
receptor antibodies are preferred.
[0015] Production and initial screening of monoclonal antibodies to
yield those specific for the IL-2 receptor can be carried out as
described in Uchiyama et al., J. Immunol. 126(4):1393 (1981); this
method, briefly, is as follows. Human cultured T-lymphocytes are
injected into mammals, e.g., mice, and the spleens of the immunized
animals are removed and the spleen cells separated and then fused
with immortal cells, e.g., mouse or human myeloma cells, to form
hybridomas.
[0016] The antibody-containing supernatants from the cultured
supernatants are then screened for those specific for the IL-2
receptor, using a complement-dependent cytotoxicity test, as
follows. Human T-lymphocytes and EBV transformed B-lymphocytes are
labeled with .sup.51Cr sodium chromate and used as target cells;
these cells are incubated with hybridoma culture supernatants and
with complement, and then the supernatants are collected and
counted with a gamma counter. Those supernatants exhibiting
toxicity against activated T-lymphocytes, but not resting T- or
B-lymphocytes, are selected, and then subjected to a further
screening step to select those supernatants containing antibody
which precipitates (i.e., is specifically reactive with) the 50
kilodalton glycoprotein IL-2 receptor (described in detail in
Leonard et al. P.N.A.S. USA 80:6957 (1983). The desired anti-IL-2
receptor antibody is purified from the supernatants using
conventional methods.
[0017] Graft rejection inhibition employing anti-IL-2 receptor
monoclonal antibodies has been carried out using two different
mammalian species, mice and rats, as described below.
[0018] Mice
[0019] Animals and Operative Techniques
[0020] Inbred male mice weighing 20-25 grams of strains C57B1/10,
B10.BR, and BLO.AKM (Jackson Laboratory, Bar Harbor, ME) were used
throughout. These strains are completely mismatched for the H-2
locus, but share the same genetic background.
[0021] Vascularized, heterotopic heart allografts were performed as
originally described by Corry et al. Transplantation 16:343 (1973).
The aorta was anastomosed to the abdominal aorta, and the pulmonary
artery to the adjacent vena cava using standard microvascular
techniques with 10-0 nylon suture (Ethicon, Inc., Somerville, N.J.)
under 20.times. magnification. With completion of the anastomoses
and warming of the heart with Ringer's lactate solution at
37.degree. C., normal sinus rhythm was resumed. Function of the
transplant heart was assessed by daily palpation of ventricular
contractions through the abdominal wall. Rejection was defined as
the cessation of all mycardial contractions, which was confirmed at
laparotomy under ether anesthesia.
[0022] To perform skin grafts, full thickness tail skin was removed
from a donor sacrificed by cervical dislocation. The recipient was
anesthetized with ether, shaven, and a graft bed prepared on the
posterior flank by removing a 0.5.times.0.5 cm portion of skin,
with care taken not to injure the underlying panniculus or its
blood vessels. The graft was shaped to fit the graft bed,
positioned, and covered with baseline gauze. A bandage was then
wrapped circumferentially around the chest to protect the graft.
The grafts were inspected daily beginning on day 6 or 7, and
considered rejected when greater than 50% of the epiuthelium was
non-viable.
[0023] Preparation and Administration of Monoclonal Antibody
[0024] The monoclonal antibody employed was antibody M7/20, which
is described in Gaulton et al. (1985) Clin. Immunol. and
Immunopath. M7/20 is a monoclonal rat anti-mouse k, u, Ig antibody
specific for the IL-2 receptor. M7/20 was purified from the culture
supernatants of cells grown in serum free media (Hanna Labs,
Berkeley, Calif.). Supernatants were precipitated with 40-50%
saturated ammonium sulfate, dialyzed, passed over DEAE Affi-Gel
Blue (Bio-Rad, Richmond, Va.) in 20 mM NcCl, and the eluate
fractionated on Sephadex G-200 (Pharmacia, Piscataway, N.J.), run
in 20 mM Tris (pH 7.2), 250 mM NaCl, 0.5% n-butanol. Antibody
purity was assessed by SDS-Page gel electropheresis. There was also
employed a control monoclonal antibody, RA3-2C2, which binds to
pre-B cells and to some mature B cells, was obtained from the
American Type Culture Collection (Rockville, Md.), and the antibody
purified by the procedure described above for M7/20.
[0025] Both antibodies were diluted to a final concentration of 25
.mu.g/ml in phosphate buffered saline. Treated recipients of heart
or skin allografts received 0.2 ml (5 .mu.g) by intraperitoneal
injection daily for 10 days, usually beginning the day of
transplant. In a small number of heart graft recipients, the onset
of treatment was delayed until day 3 or 6, then given for a total
of 10 daily doses.
[0026] Histology
[0027] Separate groups of treated and untreated C57B1/10 recipients
of B10.BR heart allografts were sacrificed at intervals
post-transplant for histologic studies. Hearts were removed from
two animals in each group at days 3, 6, and 9 following
transplantation, fixed in formalin, sectioned, and stained with
hematoxylin and eosin. Results
[0028] The results, given in Table I, below, demonstrate the
ability of M7/20 to prevent rejection of vascularized heart
allografts in two strain combinations of inbred mice. Control
C57B1/10 heart allografts in untreated B10.AKM recipients were
rejected with a median survival of 8 days. However, when treatment
with M7/20 was begun on the day of transplant and continued for 10
days at a dose of 5 .mu.g daily, 4 of 6 grafts survived
indefinitely (>90 days), with two rejecting at 20 and 31 days.
This survival is significantly longer than control (p<0.01).
Similar results were obtained in C57B1/10 recipients of B10.BR
heart allografts. Control grafts were rejected at 10-20 days, while
treated grafts were not rejected until 20, 27, 34, 38 days, with
two grafts functioning for more than sixty days (p<0.01).
Treatment with RA3-2C2 did not prolong graft survival.
1TABLE 1 The Effect of M7/20 on Survival of Murine Heart Allografts
Recipient Donor Treatment Allograft Survival in Days B10AKM
C57B1/10 none 8, 8, 8, 8, 16, 29 B10AKM C57B1/10 M7/20.sup.2 20,
31, >90, >90, >90, >90 B10AKM C57B1/10 RA3-2C2.sup.A 6,
9, 9, 10, >90 C5731/10 B10.BR none 9, 10, 10, 10, 14, 16, 20, 20
C5731/10 B10.BR M7/20.sup.a 20, 27, 34, 38, >60, >60 C5731/10
B10.BR M7/20 day.sup.b 11, 15, 19, >30 C5731/10 B10.BR M7/20
day6.sup.c 19, >30, >30 .sup.a5 .mu.g i.p. daily for 10 days
.sup.b5 .mu.g i.p. daily for 10 days beginning day 3 .sup.c5 .mu.g
i.p. daily for 10 days beginning day 6
[0029] The effect of M7/20 on graft rejection was confirmed
histologically in separate groups of C57B/10 recipients of B10.BR
heart allografts sacrificed at intervals following transplantation.
By three days post-transplant control grafts were heavily
infiltrated by mononuclear cells. Treatment with M7/20 prevented
this graft infiltration. Treated grafts at days 6 and 9 had some
areas of mononuclear cell infiltration, but markedly less than in
control grafts. Both treated and control grafts contained
considerable myocyte necrosis, evident even at three days
post-transplant. This necrosis appeared unrelated to the rejection
process, and may represent ischemic damage sustained during
transplantation.
[0030] The efficacy of M7/20 in reversing established rejection was
examined in a small number of C57B1/10 recipients of B10.BR
allografts (Table 1). In four animals the onset of treatment was
delayed until day 3, by which time rejection was ongoing, and
continued through day 12. Three grafts were rejected on days 11,
15, and 18, while the fourth was still functioning at 30 days. When
treatment was given on days 6-15, one graft was rejected at 19
days, while two were still functioning at 30 days.
[0031] The influence of M7/20 on skin allograft survival was
studied in the same strain combinations used for heart allografts.
As seen in the Figure, when C57B1/10 skin was placed on B10.AKM
recipients, M7/20 at a dose of 5.mu. daily for 10 days
significantly prolonged graft survival when compared with controls
(p<0.01). However, none of the skin grafts survived
indefinitely. M7/20 was ineffective in prolonging the survival of
B10.BR skin on C57B1/10 recipients.
[0032] Rats
[0033] Animals and Operative Techniques
[0034] Inbred male rats weighing 200-250 g were used throughout
(Microbiological Assoc., Walkersville, Md.). Unmodified Lewis rats
acted as organ recipients and Lewis-Brown Norway F1 hybrids served
as heart donors. Wistar Furth rats were used as heart donors for
specificity studies.
[0035] Heterotopic cardiac grafts were anastomosed to the abdominal
great vessels according to the method of Ono et al., J. Thorac.
Cardiovasc. Surg. 57:225 (1969). The size and ventricular activity
were assessed daily by palpation through the recipient flank.
Rejection was taken as the time of complete cessation of myocardial
contractions.
[0036] Preparation and Administration of Monoclonal Antibody
[0037] A mouse anti-rat IgG, anti-IL-2 receptor monoclonal antibody
was obtained from cultured hybridoma cells (designated ART 18) made
according to the method of Kohler and Milstein, Nature 256:495
(1975), as modified by Lemke et al., Nature 271:249 (1978), and
described in detail in Osowa et al., J. Immunol. 30:51 (1983) (the
mice were primed with phorbol myristate activated rat
T-lymphoblasts). The antibody recognizes the rat 50-kilodalton
glycoprotein IL-2 receptor molecule; binds to rat T-lymphoblasts at
a rate of 7.5.times.10.sup.4 binding sites per cell; does not bind
to mature, resting T-lymphocytes not bearing IL-2 receptors.
[0038] Antibody (protein concentration 10 mg/ml, 5 mg/ml of pure
antibody) was diluted in medium and administered to experimental
animals intravenously at a dose of 25-300 ug of antibody/kg/day for
5 or 10 consecutive days. Alzet osmotic pumps (Model 2 ML1, Alza
Corp., Palo Alto, Calif.) were inserted into the external jugular
vein of some recipients to give a constant infusion of antibody
(10.5 ul/hr for 10 days), as is described in further detail
below.
[0039] Allograft recipients received anti-IL-2 receptor antibody
therapy according to arbitrarily chosen doses and durations of
treatment. Antibody administered intravenously in doses of 25, 100,
or 300 ug/kg/day for 10 consecutive days beginning on the day of
grafting increased the mean allograft survival (compared to the
untreated 8-day survival rate) in a dose dependent fashion to
MST.+-.SD=13.+-.1 days, 14.+-.3 days, and 21.+-.1 days,
respectively. Limiting the period of treatment to the first five
post-transplant days was less effective and resulted in a
significant graft prolongation only when antibody was given at a
dose of 300 ug/kg/day (14.+-.2 days, p 0.005).
[0040] The efficacy of antibody therapy in reversing well
established allograft rejection was also tested. Treatment was
initiated at 5 days after transplantation, at which time the grafts
were grossly enlarged and heavily infiltrated with lymphocytes.
Significantly, antibody therapy started day 5 after transplantation
and continued for 5 days at a dose of 300 ug/kg/day improved
allograft survival to 18.+-.4 days, a result comparable to the
effect produced by 10 consecutive injections. In addition, the
dense cellular noted histologically in acute rejection at day 5 had
virtually disappeared after the antibody therapy. Intermittent
antibody administration (5-9 and 15-19 days, with no treatment on
days 20-14) extended graft survival even further, to 26-28 days,
while lower antibody doses were ineffectual in reversing ongoing
rejection.
[0041] To demonstrate that the results of antibody treatment were
not unique to one strain combination, Wistar Furth rat recipients
of Lewis cardiac grafts underwent antibody treatment (300
ug/kg/daily) for 10 days beginning the day of transplantation.
Allograft survival was prolonged to 16.+-.1 days.
[0042] In the next series of experiments, antibody was administered
(300 ug/kg/day over ten days) intravenously in a constant infusion
of 10.5 ul/hr using an Alzet osmotic pump. Such treatment was
significantly less effective than the above-described "pulse"
treatment in preventing rejection (graft survival=12-13 days, n=3,
p<0.005).
[0043] Non-Competition with IL-2
[0044] The potentially offsetting effects of exogenously supplied
anti-IL-2 receptor antibody and IL-2 itself were studied in vivo
within the microenvironment of unmodified graft recipients. As
shown above, sole therapy with the antibody directed at the rat
IL-2 receptor increases cardiac allograft survival to about 3
weeks. In contrast, it has been previously shown that a course of
IL-2 accelerates immune responsiveness. To test the effects of the
two together, the optimal doses of each (300 ug/kg of antibody and
100 ul of IL-2) were mixed and delivered in daily intravenous
injections for a period of 10 days. Interestingly, this combined
treatment produced the same effect as if antibody had been
administered alone (graft survival=20.+-.2 days, n+4), suggesting
that an excess of IL-2 does not prevent in vivo binding of antibody
to IL-2 receptor-bearing cells. Moreover, these results suggest
that, in the case of this particular antibody, treatment prolongs
engraftment by destroying IL-2 receptor positive cells rather than
by pharmacological blocking of the IL-2 receptor.
[0045] Effect of Antibody Therapy on T Suppressor Cells
[0046] Spleen cells were harvested at day 10 from heart grafted
hosts after the dose regimen of anti-IL-2 receptor antibody had
been completed, and transferred intravenously
(40-50.times.10.sup.4) into normal recipients which received test
cardiac allografts 24 hrs later. Such adoptive transfer prolonged
donor-specific (Lewis-Brown Norway F1 hybrids) but not third-party
(Wistar Furth) test graft survival (15.+-.1 days and 8.+-.1 days,
respectively, n=5, p 0.001). Thus, potent antigen specific
suppressor, but little alloaggressive activity, was demonstrated in
animals maintaining well-functioning cardiac allografts following
antibody therapy. In other words, the antibody advantageously lysed
most (but not all) receptor-bearing T-lymphocytes, but spared the
T-suppressor cells, which are important in inhibiting
rejection.
[0047] Human Dosage and Administration
[0048] Dosages of anti-rejection substances will vary, depending on
factors such as whether or not the substance is lytic, and the
condition of the patient. Generally, lytic monoclonal anti-IL-2
receptor antibodies will be administered in a series (e.g., two to
fifteen, more preferably five to ten intravenous doses, given e.g.,
once or twice daily or every two or three days, or in regular
courses interrupted by periods of cessation of treatment), begun on
the day of the transplant; each dose preferably will be in the
range of about 50-1000 ug/kg. In some instances, treatment
initiation can be delayed one or more days following the allograft,
since therapy not only can prevent rejection, but can reverse it as
well.
[0049] Other Embodiments
[0050] Other embodiments are within the following claims. For
example, the cell-lysing substance can be specific for a growth
factor receptor other than the IL-2 receptor, provided that the
growth factor is present primarily on the surfaces of unwanted
target cells during a proliferative burst, and is not found on the
surfaces of normal cells to an extent which would result in their
lysis to an unacceptable extent upon administration of the
substance. In the case of the IL-2 receptor, the target cells can
be unwanted B-lymphocytes, which, like T-lymphocytes, bear IL-2
receptors on their surfaces during proliferative bursts associated,
e.g., with acute stages of autoimmune diseases such as systemic
lupus erythmatosus. In addition, acute stages of autoimmune
diseases such as multiple sclerosis apparently, like allograft
rejection, involve T-lymphocytes which undergo proliferative bursts
associated with the transient appearance of IL-2 receptors, and
patients with such an acute disease can be treated by administering
an effective amount of an IL-2 receptor-specific affinity substance
capable of lysing the lymphocytes or interfering with IL-2 binding
to them. The lytic substance, rather than an antibody, can be the
growth factor itself (which is highly specific for the growth
factor receptor) linked to a toxin, e.g., ricin or diptheria
toxin.
[0051] Although the invention herein has been described with
reference to particular embodiments, it is to be understood that
these embodiments are merely illustrative of the principles and
applications of the present invention. It is therefore to be
understood that numerous modifications may be made to the
illustrative embodiments and that other arrangements may be devised
without departing from the spirit and scope of the present
invention as defined by the appended claims.
* * * * *