WO1992004896A1

WO1992004896A1 - Method of treating auto-immune diseases using gallium compounds

Info

Publication number: WO1992004896A1
Application number: PCT/US1991/006802
Authority: WO
Inventors: Nicholas Gerber; Velimir Matkovic
Original assignee: The Ohio State University
Priority date: 1990-09-21
Filing date: 1991-09-19
Publication date: 1992-04-02
Also published as: AU8752991A; CA2069111A1

Abstract

Gallium is utilized in methods of treating macrophage mediated autoimmune diseases and in the treatment and prevention of resistance to transplantation.

Description

METHOD OF TREATING AUTO-IMMUNE DISEASES USING GALLIUM COMPOUNDS

This application is a continuation-in-part application of United States Serial No. 586,491, filed September 21, 1990. Field of the Invention

This invention relates generally to methods of treating autoimmune diseases, and a method of treatment and prevention of resistance to transplantation by the use of gallium or a pharmaceutically acceptable salt thereof. Background of the Invention

Immunosuppressive agents activate or inhibit lymphocyte proliferation. Lymphocyte proliferation is due to the .interaction between antigens, macrophages, T- and B- ly phocytes as well as certain chemicals. The presence of certain antigens may activate a particular T- or B- lymphocyte. Further, certain B-lymphocytes can be activated by active T-lymphocytes while others are independent of the T-lymphocytes and are activated only by antigens. Activated T-lymphocytes can cause macrophages to produce a molecule known as interleukin-1 which in turn activates both T- and B-lymphocytes. Activated T-lymphocytes can also produce a molecule known as interleukin-2 which further induces T- lymphocyte activation. Additionally, chemicals can trigger activity in T- or B-lymphocytes. Immunosuppressive agents affect the complex interactions between the components of the immune system.

The immune system defends against substances which can cause disease, however, i cannot distinguish between helpful and < armful foreign substances and destroys both. Often times the immunological mechanisms become sensitized to some part of an individual's own body causing interference with or even destruction of that part. The ability to distinguish between the body's own and antigens not from the body becomes impaired and the body begins to 1 06802

destroy itself. The result is an autoimmune disease. Some autoimmune diseases in man are multiple sclerosis, type I diabetes mellitus, lupus erythematosus, and Graves disease. Suppression of the immune system in autoimmune diseases is desirable in minimizing or limiting the affects of the disease.

Circulating antibodies and cellular immune responses are involved in the rejection of transplanted tissues and organs. Unless the donor is the identical twin of the recipient or is the individual himself, the recipient's lymphocytes recognize the transplant as not being its own and immediately responds to destroy it. The exceptions to this situation are transplants to non-vascularized areas, such as the cornea of the eye, where lymphocytes do not circulate and therefore are not sensitized and do not prompt an immune response. It is difficult to suppress the immune reaction to prevent rejection of the transplant without severely damaging the patient in other ways.

It has been found that gallium, and gallium nitrate, in particular, are effective in treating diseases mediated by macrophage cell lines, including macrophage/T cell/B cell interactions and for the treatment and prevention of resistance to transplantation.

Gallium has been known for many years to be useful in the treatment of calcium bone disorders. Gallium is a metal which belongs to the Group III A Elements of the Periodic Table. The metallic compounds used, have, of course, a low order of toxicity and are pharmaceutically acceptable.

Prior U.S. Patents 4,529,593 issued July 16, 1985 to • arrell et al; 4,686,104 issued August 11, 1987 to Bockman et al.; and 4,704,277 issued November 3, 1987 to Bockman et al. describe methods of preventing excessive loss of calcium from human bone by the administration of pharmaceutically acceptable gallium-containing compounds. The '593 patent teaches the use of pharmaceutically acceptable gallium salts to reduce the excessive loss of bone calcium. The patent specifically teaches the use of gallium to prevent or treat disorders associated with extensive loss of calcium from bone in humans by administering to the individual a pharmaceutically acceptable gallium compound. Of special importance among the disorders which, may be thus treated are hypercalcemia, osteopenia, osteoporosis, bone destruction due to metastasis from malignant tumors and hyperparathyroidism. Gallium salts which are disclosed to be of use include nitrate, citrate, and halide, preferably the chloride, carbon, acetate, tartrate, oxylate, oxide or hydrated oxide.

Loss of bone mass from increased bone resorption results in accelerated transfer of calcium into the blood. This is the major cause of hypercalcemia. Diseases result when significant depletion of bone calcium occurs and the serum calcium level exercises dangerously. The therapeutic agent of choice, according to the aforementioned patents, for treating this and many other bone disorders is gallium, which decreases bone resorption and thereby maintains bone tissue calcium content_*

U.S. Patent 4,303,363 discloses a method of cancer treatment which uses radioactive 67-gallium as a cytotoxic agent.

Heretofore, there has been no link between the treatment of bone disorders and cancer by the use of gallium and the treatment of autoimmune and immunosuppressant diseases.

Summary of the Invention

The present invention relates to methods of treating macrophage mediated autoimmune diseases, and a method of treatment and prevention of resistance to transplantation by *-.he use of gallium or a pharmaceutically acceptable salt thereof. Detailed Description of the Drawings

Figures 1(a) and 1(b) graphically represent the effect of gallium administration following experimental allergic encephalitis (EAE) induction; Figure 2 graphically represents the effects of gallium to PEAT-specific T line cells during stimulation with PEAT or Concanavalin A and antigen-presenting cells;

Figure 3 graphically represents a decline in the expression of I-A in macrophages of BALB/c mice with and without gallium; and

Figure 4 graphically represents the prevention of diabetes by the administration of gallium. Detailed Description of the Invention

In accordance with the present invention, it is believed that gallium is effective in the treatment of autoimmune diseases involving various body systems: central nervous, cardiopulmonary, gastrointestinal, dermatological, endocrine, renal, reproductive, skeletal and the hepato-biliary systems. The wide reaching functionality of gallium indicate that it has promise as a therapeutic agent for many conditions and diseases heretofore not associated with gallium.

More specifically, the present invention relates to the use of gallium compounds in the treatment of autoimmune diseases which are mediated by macrophage cell lines including macrophage/T cell/B cell interaction. These diseases include multiple sclerosis, thyroiditis, type I diabetes mellituε, Hashimoto's Disease, Graves Disease, lupus erythematosus, rheumatoid arthritis, sarcoidosis, Wegner's granulomatosis and leprosy. In the past, gallium compounds have been employed in the treatment of disorders associated with bone tissue, and as a cytotoxic agent, but have not been administered for the treatment of the aforementioned autoimmune diseases. Further, in the present invention, gallium is utilized in the suppression of T-cell proliferation.

The following experiments were designed to show the administration and use of gallium for preventing and/or treating autoimmune diseases and to show the efficacy of gallium in the resistance to transplantation. The experiments are shown in examples which are illustrative of _r._^ ,, _^

PCT/US91/06802

the present invention. The examples are not intended to limit the scope of the invention in any way.

Example 1 Effect of gallium administration on experimental allergic encephalomvelitis (EAE) .

This study demonstrates that the administration of gallium prevents the development of EAE and results in an antigen-εpecific suppression of the lyphocyte proliferative response. The animal model screens compounds for efficacy against multiple sclerosis.

Materials and Methods Rats. Male Lewis rats (8-12 weeks of age) were purchased from Harland Sprague-Dawley (Indianapolis, IN) . The rats were divided into five groups. antigens. Guinea pig MBP myelin basic protein (GPMEP) and rat MBP (RMBP) were prepared from spinal cords (Rockland, Inc. , Gilbertsville, PA) by cholorform/methanol extraction. Human MBP (HuMBP)- was prepared from cerebral cortex by cholorform/methanol extraction. The control antigen ovalbumin (OVA) was obtained from Sigma (St. Louis, MO) , and purified protein derivative (PEAT) was from Parke- Davis (Detroit, MI) .

Gallium Nitrate. Ben Venue Laboratories, Bedford, Ohio was the source of a citrated solution of gallium nitrate, 500 mg/20 ml. Rats received injections of gallium as described in Figure la on days 1, 6, 13 and 20 relative to the induction of EAE. Group 1 animals received only saline; all others received weekly injections of gallium as noted. Groups 3 and 5 received saline rather than gallium on day -1.

Induction of EAE. Rats received an intradermal injection into one hind footpad of guinea pig MBP (25 ug) , combined with complete Freund's adjuvant (CFA) on day 0. All rats were monitored daily for clinical neurologic signs, which were scored as follows: limp tail, 1+; ataxia, 2+; early or partial paralysis, 3+; full hind limb paralysis, 4+ 5 deaths. Rats were sacrificed at the time of severe paralysis or 21-38 days after sensitization if no clinical signs appeared.

Histopatholoqic evaluation. Brains and spinal cords were removed and fixed in 10% formalin, and 7-μ transverse sections of the thalamus, meεencephalon, and cerebellum-pons and longitudinal sections of the entire spinal cord were processed for hematoxylin and eosin staining. Histologic slides were assessed for the presence of perivascular mononuclear infiltrates and sqored as follows: 1-10 lesions, 1+; 11*30 lesions, 2+; and greater than 30 lesions, 3+.

Results

Figures 1(a) and 1(b) graphically represent the effect of gallium administration prior to or following experimental allergic encephalitis (EAE) induction.

Clinical signs of EAE were scored as described in Figure 1(a). Rats who received 30 mg per kg on day 6 had the lowest clinical scores, irrespective of day -1.

CNS Histological Evaluations were performed on all rats as reported in Bitar et al. Cell. Immunol. 112:364-370 (1988).

The rats received subcutaneous injections of 30 g/kg gallium in the form of gallium nitrate beginning six days after induction of EAE with maintenance doses of 10 mg/kg on days 13 and 20. Controlled untreated rats progressed to maximum paralysis by day 13 as shown in Figure 1(a), whereas gallium treated rats exhibited either no signs or minimal disease (partial left tail) . Studies were subsequently undertaken to determine the effects of dosages and timing of administration gallium on EAE. Gallium totaling 0-80 mg/kg was administered at weekly intervals beginning either before or after induction of EAE as shown in Table 1. Marked suppression of EAE was demonstrated in all gallium treated (30-80 mg/kg) animals. Maximum inhibition of clinical disease was achieved when 30 mg/kg was given on day 6, and maximal suppression of histopathologic changes occurred at the largest dose of gallium. No demonstrable adverse clinical effects of gallium were noted in any of the in. vivo studies.

The optimum timing for administration of gallium following induction of EAE was determined by injecting 30 mg/kg as a single dose to the rats on day 3, 6, 9, or 12 after induction. Figure 1(b) shows that gallium exerts its maximal εuppreεsive effect when given on day 6, with a significant inhibitory effect also observable when administered on day 3 or 9. Following complete recovery, rats from each group were reinjected with myelin basic protein (MEP) on day 28 and none developed EAE.

Example 2

In vitro Study of the Effect of gallium upon Lymphoid Cells

Materials and Method

Rats. Thirty-eight male Lewis rats (135-195 g) were purchased from Charles River Laboratories (Portage, MI) for use in this experiment.

Establishment of a purified protein derivative (PEAT) specific T lymphocyte line. A specific PEAT-reactive T-cell line was prepared by conventional techniques. Cells (8xl0⁶/ml) from lymph nodes of CFA-immunized Lewis rats were incubated for 3 days in tissue culture Petri dishes in RPMI 1640 (Whittaker M.A. Bioproductε, alkersville, MD) containing 50 U/ml penicillin, 50 μg/ml streptomycin, 50 μM 2-mercaptoethanol, 2 mM glutamine, 26 mM Hepes, 1% fresh autologous rat serum, and 40 μg/ml PEAT. Lymphoblasts were obtained by centrifugation, using lymphocyte-separating medium (Organon Teknika, Durham, NC) (240 g, 25 min) , and the ΓPIIS wer° washed and cultured in medium containing 10% fetal bovine serum (Whittaker M.A. Bioproducts) and 10% (v/v) rat T-cell growth factor (24-hr supernatant from rat spleen cells stimulated with Concanavalin A) . After 4-8 days in culture, the cells were restimulated for 3 days with PEAT (20 μg/ml) in the presence of synergic γ-irradiated (3300 r) thymocytes (10⁷/ml) as a source of antigen presenting cells. The T-line cells were alternately expanded in rat growth factor or restimulated with antigen and irradiated thymocytes. After the second round of antigen restimulation, in vitro lymphocyte proliferative assays revealed a PEAT-specific response. After establishment of the T-cell line, restimulation with antigen was performed at approximately two-week intervals.

Procedure

To measure the effect of Ga on the PEAT-specific T-cell line, a lymphocyte proliferative aεεay was used with [³H]thymidine incorporation as the endpoint. T cells (2xl0/well) were cultured in 150 μl of RPMI complete medium together with 10⁴/well) were cultured in 150 μl of RPMI complete medium together with 10⁶ irradiated (3300 r) thymocytes and 20 μg/ml PD or 2 μg/ml Concanavalin A in 96- well round-bottomed plates (Flow, Maclean, VA) . Cultures were incubated for a total of 72 hr in 7% C0₂ at 37°C in a humidified atmosphere and pulsed with ['HJthymidine (1 lμCi/well) (Amersham, .Arlington Heights, IL) during the final 18 hr of culture. Cells were harvested using a semi¬ automatic sample harvester (Skatron, Sterling, VA) and counted by liquid scintillation. Cultures contained either no Ga or Ga nitrate at 1.0 mg/ l. In order to control for nonspecific toxicity of the Ga preparation, an aliquot of T cells was incubated with Ga (1.0 mg/ml) for 1 hr and washed prior to culture.

Results

Figure 2 shows the effects of addition of gallium to'

PEAT-εpecific T line cells during stimulation with PEAT or

Concanavalin A and antigen-presenting cells.

Example 3

Expression of Major Histocompatibility Complex Class II Glvcoproteins.

Sixty-four male BALB/c mice received an i.p. injection of 2 ml of 3% thioglycolate medium in sterile water to induce migration of macrophages to the peritoneum. After 3- 5 days, the mice were euthanized and 15-20 x 10* cells collected from the peritoneum of each by lavage with Hanks' balanced salt solution (Whittaker M.A. Bioproducts) . Viability, determined by trypan blue excluεion, was always greater than 95%. The cells were added to Dulbecco's modified Eagle's medium, supplemented with 10% fetal bovine serum (Hyclone Laboratories, Logan, UT) , 2 mM glutamine, 100 U of penicillin, and 100 μg of streptomycin, to a final concentration of 2 x 10⁵ cells/ml for each mouse. One-half milliliter of each cell suspenεion was added to chambers of multichambered Lab-Tek slides (Nunc, Inc. , Naperville, IL) . Macrophages were allowed to adhere to the slideε for 24 hr; then nonadherent cells were removed by washing with Hanks' balanced salt solution. The macrophages were incubated for 48 hr with 100 U/well of murine reco binant 7-interferon (.Amgen, Thouεand Oaks, CA) . A macrophage-activating factor, γ-interferon stimulates the expresεion of I-A (an MHC class II glycoprotein) and enhances the cell's ability to kill microorganisms and tumor cells. Gallium nitrate (0 (A), 05- (B) , 1.0 (C) , or 2.5 g (D) ) was subsequently added to each well, and the percentage of cells expressing I-A was determined at 1, 4, 8, and 16 hr by indirect fluorescence, using a UV microscope (Zeiss, Oberkochen, W. Germany) . Specifically, the macrophages were treated with 5% rabbit serum at 4°C to block Fc receptor binding. After 30 minutes the cells were washed and then incubated with 0.5 μg of monoclonal anti I-A^a (MKD-6, American Type Culture Collection, Rockville, MD) , grown in the same medium as the macrophages. MKD-6 is a cell line which produces cytotoxic monoclonal antibodies wr.ich react with mur..ne I-A^d antigen. After 40 rain (a+- 4°C) the cells were washed with Hanks', and FITC-conjugated goat anti ouse F(ab')₂ immunoglobulin (Organon Teknika) was added for 40 min. This was subsequently washed off, the tops of the slides removed, a coverslip placed over the cellε, and the number of fluorescent cells asεeεsed in a blinded fashion.

Results

Figure 3 shows a decline in the expresεion of I-A when peritoneal macrophages of BALB/c mice were incubated with gallium. This inhibition of expression diminished with time, ranging from approximately 45% at 1 hr to 0% (full recovery) by 16 hr. Cells remained viable throughout the study.

Example

Treatment of Pre-Diabetic Non-Obese (NOD) Mice with Gallium Nitrate Prevents Development of Diabeteε.

Diabetogenesiε in NOD/mice is an immune mediated diseaεe, with generation of auto-immune reactivity against pancreatic β cells requiring participation of macrophages and T lymphocytes. In the specific pathogen-free NOD/LT colony, untreated virgin females exhibited a 79% diabetes incidence by eight months of age. compared to a 45% incidence in virgin males. Diabetes in NOD mice can be circumvented by a variety of i munomodulatory procedures initiated shortly after weaning. These include immunoεuppreεsive treatments impairing viability and/or function of either macrophages or T cells. In this Example, gallium nitrate is used to circumvent diabetes.

Materials and Methods

NOD mice. 24 NOD/Lt female mice from litters born between 12-1-90 and 12-6-90 from Jackson Laboratories, Bar Harbour, Maine were randomly sorted into two groups of twelve. Mice were caged three/side in double penned plastic boxes with a natural ingredient diet (old Guilford 96 w) and Libitum.

Gallium Nitrate. A citrated solution of gallium nitrate per 500 mg/20 ml was obtained from Ben Venue Laboratories, Bedford, Ohio. Lot No. 89/215 was used in this experiment. At six weeks of age, twelve females received an injection i.p. of 45 mg/kg body weight followed by once weekly injections i.p. of 45 mg/kg body weight. The controlled group of twelve females received an injection of vehicle (citrated saline solution) at the same times. Mice were weighed and checked for glycosuria using TES-tape diagnostic tapes supplied by Eli Lilly and Company at weekly intervals. A diagnosis of diabetes was made if the mice remained glycosuria for three consecutive weeks and lost weight. Diabetic mice were euthanized without further analysis. At the end of 20 weeks, weekly injections of gallium nitrate in vehicle were discontinued; the mice were aged at 30 weeks to determine whether absence of disease would persist without treatment.

Results NOD/LT females after 14 weeks of gallium injections did not show reduced body weights compared to vehicle controls (mean ± SEM = 23.0 ± 0.7 g (n *= 10) for gallium recipients versus 23.0 ± 0.5 (n = 8) for vehicle controls. Two females in the gallium treatment group had to be deleted from the experiment due to development of malocculsions and subsequent weight loss. Malocculsionε are detected sporadically in the NOD/Lt colony and are not considered to be direct effectε of the gallium treatment.

Figure 4 depicts the diabetes incidence in the mice. The ability of gallium nitrate injections to circumvent development of clinical diabetes is unequivocal. There are no cases of overt diabetes in the group during the period of weekly gallium administration. Further, there was no " reakthiou h" o£ diabetes within a 5 week pexiod alter cessation of gallium injections. In distinction, a sharp increase in diabetes incidence occurred in vehicle controls during the same period (21-25 weeks) . .

Exa ple 5

Transplantation of a Mouse Heart The heart of a DBA/2 from Harland mouse was removed. The abdomen of a C57/BL/6 mouse from Sprague Dawley, Indianapolis, IN. was opened and the abdominal aorta displayed. The donor heart was transplanted by attaching the donor aorta to the recipient abdominal aorta and the donor pulmonary artery to the recipient vena cava. A single dose of 45 mg/kg of elemental gallium was administered subcutaneouεly after the εurgical procedure waε completed. The transplanted heart remained viable for eleven days. A controlled experiment in a mouse from the same strain and source using the foregoing procedure without the administration of gallium nitrate allowed the heart to remain viable for only five days.

As used herein, the term "patient" refers to a warm - blooded animal such as a mammal which is affected with a disease, such as an autoimmune disease, or is in danger of rejection of a transplanted tiεεue or organ. It is understood that humans are included within the scope of the term "patient." Based on εtandard clinical and laboratory tests and procedures, an attending diagnostician, as a perεon skilled in the art, can readily identify thoεe patientε who are in need of treatment with immunoεuppreεεive agents.

According to the present invention, in order to obtain the beneficial effects of gallium in treating autoimmune diseases and resistance to transplantation, pharmaceutically acceptable gallium containing compounds are administered to the patient in an amount sufficient to provide therapeutic levels of gallium. Therapeutic levels are obtained when gallium is preεent in a εteady state concentration in blood. Typically, the amount of elemental gallium administered is from about 0.05 to about 50 mg/per kg per day of body weight. Preferably, thiε amount rangeε from about 0.05 to about .5 mg/per kg of body weight. Gallium containing compounds, effective with this invention, may be any gallium containing compounds in non- nephrotoxic amounts to inhibit or treat autoimmune diseases, and resistance to transplantation, in patients suffering from the aforementioned conditions by administering to a patient a therapeutically effective amount of such a compound. Preferably, the compounds may be selected from the group consisting of gallium nitrate, gallium citrate, gallium chloride, gallium carbonate, gallium acetate, gallium lactate, gallium tartrate, gallium oxalate, gallium oxide and hydrated gallium oxide.

Gallium containing compounds are useful in formulations having a variety of routes of administration. The route(ε) of administration useful in a particular application for the treatment of autoimmune diseases, immunosuppression and resistance to transplantation is apparent to one skilled in the art. Routes of administration include but not limited to topical, transdermal, parenteral, transbronchial and transalveolar.

Formulations of gallium containing compounds suitable for topical application include, but are not limited to, implants, ointments, creams, resins and gels. Formulations suitable for transdermal application include, but are not limited to, suspensions, oils, creams and ointments applied directly or attached to a protective carrier such as a patch. Formulations suitable for parenteral administration include, but are not limited to, sterile solutions for intravenous, intramuscular or subcutaneous injection. Formulations suitable for transbronchial and transalveolar administration include, but are not limited to, various ^pci cf aerostls for inhalation. Th above-mentioned formulations are meant to describe but not limit the methods of administering gallium containing compounds. The methods of making the various formulations are within the ability of one skilled in the art and need not be described in detail. The terms and expressions which had been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the feature shown and described or portions thereof, it being recognized that various modifications are possible within the scope of the invention.

Claims

What is Claimed Is: ^~15~

1. A method of treating macrophage mediated autoimmune diseases comprising administering an effective amount of pharmaceutically acceptable gallium-containing compound suitable to provide therapeutic levels of gallium to a patient in need thereof.

2. A method according to claim 1 wherein the autoimmune disease is selected from the group consisting of autoimmune diseases involving various body systems including central nervous, cardiopulmonary, gastrointestinal, dermatological, endocrine, renal, reproductive and the hepato-biliary systems.

3. A method according to claim 1 wherein the gallium- containing compound is selected from the group consisting of gallium nitrate, gallium citrate, gallium chloride, gallium carbonate, gallium acetate, gallium lactate, gallium tartrate, gallium oxalate, gallium oxide and hydrated gallium oxide.

4. A method according to claim 3 wherein the gallium containing compound is gallium nitrate.

5. The method according to claim 1 wherein the gallium-containing compound is administered via a route selected from the group consiεting of topical, tranεdermal, parenteral, transbronchial and transalveolar.

6. The method according to claim 4 wherein the amount of elemental gallium administered is about .05 mg/kg to about 50 mg/kg of body weight.

7. A method of preventing transplantation rejection which comprises administering an effective amount of a pharmaceutically acceptable gallium containing compound suitable to provide therapeutic levels of gallium to a patient in need thereof.

8. A method according to claim 7 wherein the gallium- containing compound is selected from the group consisting of gallium nitrate, gallium citrate, gallium chloride, gallium fluoride, gallium carbonate, gallium acetate, gallium lactate, gallium tartrate, gallium oxalate, gallium oxide and hydrated gallium oxide. 9. A method according to claim 7 wherein the gallium containing compound is gallium nitrate.

10. The method according to claim 7 wherein the gallium-containing compound is administered via a route selected from the group consisting of topical, transdermal, parenteral, transbronchial and transalveolar.

11. The method according to claim 7 wherein the amount of elemental gallium administered is about .05 mg/kg to about 50 mg/kg of body weight.

12. A method of treating diseases beneficially treated by administration of compounds having immunosuppressive activity in a patient in need thereof, which comprises administering to such patient an effective amount of a pharmaceutically acceptable gallium containing compound suitable to provide therapeutic levels of gallium.

13. A method according to claim 12 wherein the gallium-containing compound is selected from the group consisting of gallium nitrate, gallium citrate, gallium chloride, gallium carbonate, gallium acetate, gallium lactate, gallium tartrate, gallium oxalate, gallium oxide and hydrated gallium oxide.

14. A method according to claim 12 wherein the gallium containing compound is gallium nitrate.

15. The method according to claim 12 wherein the gallium-containing compound is administered via a route selected from the group consisting of topical, transdermal, parenteral, transbronchial and transalveolar.

16. The method according to claim 13 wherein the amount of elemental gallium administered is about .05 mg/kg to about 50 mg/kg of body weight.

17. A method of suppressing T-cell proliferation comprising administering an effective amount of pharmaceutically acceptable gallium-containing compound suitable to provide therapeutic levels of gallium to a patient in need thereof.

18. A method according to claim 17 wherein the gallium-containing compound is selected from the group consisting of gallium nitrate, gallium citrate, gallium chloride, gallium carbonate, gallium acetate, gallium lactate, gallium tartrate, gallium oxalate, gallium oxide and hydrated gallium oxide.

19. A method according to claim 18 wherein the gallium containing compound is gallium nitrate.

20. A method according to claim 17 wherein the gallium- containing compound is administered via a route selected from the group consisting of topical, transdermal, parenteral, transbronchial and transalveolar.

21. The method according to claim 19 wherein the amount of elemental gallium administered is about .05 mg/kg to about 50 mg/kg of body weight.

22. A method of treating multiple sclerosis comprising administering an effective amount of pharmaceutically acceptable gallium-containing compound suitable to provide therapeutic levels of gallium to a patient in need thereof.

23. A method according to claim 22 wherein the gallium- containing compound is selected from the group consisting of gallium nitrate, gallium citrate, gallium chloride, gallium carbonate, gallium acetate, gallium lactate, gallium tartrate, gallium oxalate, gallium oxide and hydrated gallium oxide.

24. A method according to claim 22 wherein the gallium containing compound is gallium nitrate.

25. A method according to claim 22 wherein the gallium- containing compound is administered via a route selected from the group consisting of topical, transdermal, parenteral, transbronchial and transalveolar.

26. The method according to claim 22 wherein the amount of elemental gallium administered is about .05 mg/kg to about 50 mg/kg of body weight. 7. Λ methoi of treating heumatoid arthritis comprising administering an effective amount of a pharmaceutically acceptable gallium containing compound suitable to provide therapeutic levels of gallium to a patient in need thereof.

28. A method according to claim 27 wherein the gallium- containing compound is selected from the group consisting of gallium nitrate, gallium citrate, gallium chloride, gallium carbonate, gallium acetate, gallium lactate, gallium tartrate, gallium oxalate, gallium oxide and hydrated gallium oxide. —id—

29. A method according to claim 27 wherein the gallium containing compound is gallium nitrate.

30. A method according to claim 27 wherein the gallium- containing compound is administered via a route selected from the group consisting of topical, transdermal, parenteral, transbronchial and transalveolar.

31. The method according to claim 27 wherein the amount of elemental gallium administered is about .05 mg/kg to about 50 mg/kg of body weight.