T Cell Regulation

Abstract

Regulatory T cells (Treg) limit autoimmunity but can also attenuate the magnitude of anti-pathogen and anti-tumor immunity. Understanding the mechanism of Treg function and therapeutic manipulation of Treg in vivo requires identification of Treg selective receptors. A comparative analysis of gene expression arrays from antigen specific CD4+ T cells differentiating to either an effector/memory or a regulatory phenotype revealed Treg selective expression of LAG-3 (CD223), a CD4-related molecule that binds MHC class II. LAG-3 expression on CD4+ T cells correlates with the cells' in vitro suppressor activity, and ectopic expression of LAG-3 on CD4 T cells confers suppressor activity on the T cells. Antibodies to LAG-3 inhibit suppression both in vitro and in vivo. LAG-3 marks regulatory T cell populations and contributes to their suppressor activity.

We claim: 
     
         1 . A method of treating a patient suffering from an autoimmune disease, comprising:
 transfecting in vitro auto-immune T cells isolated from the patient with an expression construct comprising a coding sequence for CD223;   reinfusing the transfected auto-immune T cells to the patient.   
     
     
         2 . The method of  claim 1  wherein the patient suffers from multiple sclerosis. 
     
     
         3 . A composition, comprising:
 antibodies which specifically bind to CD223; and   an anti-cancer vaccine.   
     
     
         4 . The composition of  claim 3  which is a pharmaceutical composition. 
     
     
         5 . The composition of  claim 3  wherein the antibodies are monoclonal antibodies. 
     
     
         6 . The composition of  claim 3  wherein the composition is formed in vivo after administration to a patient. 
     
     
         7 . A kit comprising:
 antibodies which specifically bind to CD223; and   an anti-cancer vaccine.   
     
     
         8 . The kit of  claim 7  wherein said antibodies and vaccine are in separate containers. 
     
     
         9 . The kit of  claim 7  further comprising instructions for administration of components of the kit to a cancer patient. 
     
     
         10 . An improved method of treating a cancer patient with an anti-cancer vaccine, comprising:
 administering to the cancer patient an antibody which specifically binds to CD223;   administering to the cancer patient an anti-cancer vaccine, wherein the antibody increases magnitude of anti-cancer response of the cancer patient to the anti-cancer vaccine.   
     
     
         11 . A method to overcome suppression of an immune response to an anti-cancer vaccine, comprising:
 administering an antibody which specifically binds to CD223 to a cancer patient with regulatory T-cells which suppress an immune response to an anti-cancer vaccine;   administering to the cancer patient an anti-cancer vaccine, whereby the antibody increases the response of the cancer patient to the anti-cancer vaccine.   
     
     
         12 . The method of  claim 11  wherein the antibody is monoclonal. 
     
     
         13 . A method for increasing number of T cells in a mammal, comprising:
 administering to the mammal an inhibitory agent which binds to CD223 protein or CD223 mRNA.   
     
     
         14 . The method of  claim 13  wherein the inhibitory agent is an antibody which specifically binds to CD223 protein. 
     
     
         15 . The method of  claim 13  wherein the inhibitory agent is an antisense construct which expresses an antisense RNA molecule which is complementary to at least 7 nucleotides of CD223 mRNA. 
     
     
         16 . The method of  claim 13  wherein the inhibitory agent is an antisense oligonucleotide which is complementary to at least 7 nucleotides of CD223 mRNA. 
     
     
         17 . The method of  claim 13  wherein the inhibitory agent is a ribozyme which specifically binds to CD223 mRNA. 
     
     
         18 . The method of  claim 13  wherein the inhibitory agent is an RNA interference molecule which specifically binds to CD223 mRNA. 
     
     
         19 . The method of  claim 13  wherein the mammal is a cancer patient. 
     
     
         20 . The method of  claim 13  wherein the mammal is bone marrow transplantation recipient. 
     
     
         21 . The method of  claim 19  further comprising the step of vaccinating the cancer patient with anti-tumor vaccine. 
     
     
         22 . The method of  claim 19  further comprising the step of transferring a tumor-specific T cell population to the cancer patient. 
     
     
         23 . The method of  claim 19  further comprising the step of administering an anti-cancer chemotherapeutic drug to the patient. 
     
     
         24 . The method of  claim 19  further comprising the step of administering anti-cancer antibodies to the patient. 
     
     
         25 . The method of  claim 13  wherein the mammal has a chronic viral infection. 
     
     
         26 . The method of  claim 25  further comprising the step of administering an anti-viral vaccine to the mammal. 
     
     
         27 . The method of  claim 13  wherein the mammal has a chronic bacterial infection. 
     
     
         28 . The method of  claim 27  further comprising the step of administering an anti-bacterial vaccine to the mammal. 
     
     
         29 . The method of  claim 25  wherein the chronic viral infection is HIV. 
     
     
         30 . A method for increasing number of T cells in a population of T cells, comprising:
 administering to a population of T cells in vitro an inhibitory agent which binds to CD223 protein or CD223 mRNA.   
     
     
         31 . The method of  claim 30  wherein the inhibitory agent is an antibody which specifically binds to CD223 protein. 
     
     
         32 . The method of  claim 30  wherein the inhibitory agent is an antisense construct which expresses an antisense RNA molecule which is complementary to at least 7 nucleotides of CD223 mRNA. 
     
     
         33 . The method of  claim 30  wherein the inhibitory agent is an antisense oligonucleotide which is complementary to at least 7 nucleotides of CD223 mRNA. 
     
     
         34 . The method of  claim 30  wherein the inhibitory agent is a ribozyme which specifically binds to CD223 mRNA. 
     
     
         35 . The method of  claim 30  wherein the inhibitory agent is an RNA interference molecule which specifically binds to CD223 mRNA. 
     
     
         36 . A method for decreasing number of T cells in a mammal, comprising:
 administering to the mammal an expression construct which encodes CD223, whereby CD223 is expressed from the expression construct and concentration of CD223 in the mammal is increased, and the number of T cells in the mammal is decreased.   
     
     
         37 . The method of  claim 36  wherein the mammal is an autoimmune disease patient. 
     
     
         38 . A method for decreasing number of T cells in a mammal, comprising:
 administering to the mammal a population of CD223 +  T cells, whereby the concentration of CD223 in the mammal is increased and the number of T cells in the mammal is decreased.   
     
     
         39 . The method of  claim 38  wherein the mammal is an autoimmune disease patient. 
     
     
         40 . The method of  claim 39  wherein the CD223 +  T cells are CD4 +  T cells which have been transduced with an expression construct which encodes CD223. 
     
     
         41 . The method of  claim 39  wherein the CD223 +  T cells are auto-antigen specific T cells which have been transduced with an expression construct which encodes CD223. 
     
     
         42 . A polypeptide consisting of 50 or less contiguous amino acid residues of CD223, wherein the polypeptide comprises an amino acid sequence KIEELE as shown in SEQ ID NO: 5. 
     
     
         43 . A fusion polypeptide which comprises at least two segments, wherein a first segment consists of 50 or less contiguous amino acid residues of CD223, wherein the first segment comprises an amino acid sequence KIELLE as shown in SEQ ID NO: 5, wherein a second segment comprises an amino acid sequence which is not found in CD223 as shown in SEQ ID NO: 2 or 4. 
     
     
         44 . A method of testing substances for potential activity as a drug for treating cancer, autoimmune disease, chronic infections, AIDS, bone marrow transplantation recipients, comprising:
 contacting a test substance with a CD223 protein or CD223 protein fragment comprising an amino acid sequence KIELLE as shown in SEQ ID NO: 5;   determining whether the test substance bound to the CD223 protein or CD223 protein fragment;   identifying the test substance as a potential drug for treating cancer, autoimmune disease, chronic infections, AIDS, or bone marrow transplantation recipients if the test substance bound to the CD223 protein or CD223 protein fragment.   
     
     
         45 . A method of testing substances for potential activity as a drug for treating cancer, chronic infections, AIDS, and bone marrow transplantation recipients, comprising:
 contacting a test substance with a CD223 protein;   determining CD223 activity in the presence and absence of the test substance;   identifying a test substance as a potential drug for treating cancer, chronic infections, AIDS, and bone marrow transplantation recipients if the test substance inhibits the CD223 activity.   
     
     
         46 . A method of testing substances for potential activity as a drug for treating autoimmune disease, comprising:
 contacting a test substance with a CD223 protein; determining CD223 activity in the presence and absence of the test substance;   identifying a test substance as a potential drug for treating autoimmune disease if the test substance increases the CD223 activity.   
     
     
         47 . A method of testing substances for potential activity as a drug for treating cancer, chronic infections, AIDS, and bone marrow transplantation recipients, comprising:
 contacting a CD223 +  T cell with a test substance;   determining CD223 expression in the cell in the presence and absence of the test substance;   identifying a test substance as a potential drug for treating cancer, chronic infections, AIDS, and bone marrow transplantation recipients if the test substance inhibits the CD223 expression in the T cell.   
     
     
         48 . A method of testing substances for potential activity as a drug for treating autoimmune disease, comprising:
 contacting a test substance with a CD223 +  T cell;   determining CD223 expression in the cell in the presence and absence of the test substance;   identifying a test substance as a potential drug for treating autoimmune disease if the test substance increases the CD223 expression in the T cell.   
     
     
         49 . A method of isolating CD223 +  T cells or CD223 −  T cells, comprising:
 contacting a mixed population of T cells with an antibody which specifically binds to CD223 according to SEQ ID NO: 2 or 4; 
 separating T cells which are bound to the antibody from T cells which are not bound to the antibody, thereby forming a population of CD223 +  T cells and a population of CD223 −  T cells. 
 
     
     
         50 . The method of  claim 49  further comprising the step of transferring the population of CD223 +  T cells to an autoimmune disease patient. 
     
     
         51 . The method of  claim 49  wherein prior to the step of transferring the population to an autoimmune disease patient, the population is activated in vitro with an auto-antigen. 
     
     
         52 . The method of  claim 49  wherein the mixed population of T cells is a sample of donor lymphocytes. 
     
     
         53 . The method of  claim 52  further comprising the step of transferring the population of CD223 −  T cells to a cancer patient. 
     
     
         54 . The method of  claim 49  wherein the mixed population of T cells is tumor-specific. 
     
     
         55 . The method of  claim 54  further comprising the step of transferring the population of CD223 −  T cells to a cancer patient. 
     
     
         56 . An isolated soluble murine CD223 protein comprising residues 1 to 431 and lacking residues 467 to 521. 
     
     
         57 . The isolated soluble CD223 protein of  claim 56  which is produced by a protease on the surface of CD223 +  T cells. 
     
     
         58 . The isolated soluble CD223 protein of  claim 56  which is free of other serum proteins. 
     
     
         59 . An isolated soluble human CD223 protein comprising residues 1 to 440 and lacking residues 475 to 525. 
     
     
         60 . The isolated soluble CD223 protein of  claim 59  which is produced by a protease on the surface of CD223 +  T cells. 
     
     
         61 . The isolated soluble CD223 protein of  claim 59  which is free of other serum proteins. 
     
     
         62 . A method for decreasing number of T cells in a mammal, comprising:
 administering to the mammal a soluble CD223 protein whereby MHC class II-restricted/CD4+ T cell responses in the mammal are modulated.   
     
     
         63 . The method of  claim 62  wherein the mammal is an autoimmune disease patient. 
     
     
         64 . The method of  claim 62  wherein the mammal is an allergy patient. 
     
     
         65 . The method of  claim 62  wherein the mammal is an asthma patient.