Peptides associated with hla-dr mhc class ii molecule and involved in rheumatoid arthritis

Abstract

Antigenic peptides that bind to MHC Class II molecules with the shared epitope referred to as HLA-DR molecules are disclosed. More specifically, are citrullinated antigenic peptides having an increased affinity for HLA-DR molecules and associated with rheumatoid arthritis. These novel peptides provide the basis for new methods of diagnosis and treatment of rheumatoid arthritis.

1 . An isolated citrullinated peptide, said peptide binding with a high or increased affinity to a MHC class II molecule having the shared epitope compared with a non-citrullinated peptide, wherein said binding to said shared epitope evokes a T cell response in the blood of a patient with an autoimmune disorder, and wherein said peptide is of 8 to 55 amino acids in length. 
     
     
         2 . The peptide of  claim 1 , wherein said peptide is selected from the group consisting of citrullinated fibrinogen peptides and citrullinated vimentin peptides. 
     
     
         3 . The peptide of  claim 1 , wherein said peptide comprises at least one amino acid sequence selected from the group consisting of: SAVRACitSSVPGVR (SEQ ID NO. 1); FSMCitIVCLV (SEQ ID NO. 2); VVECitHQSAC (SEQ ID NO. 3); FTNCitINKLK (SEQ ID NO. 4); LRSCitIEVLK (SEQ ID NO. 5); VLKCitKVIEK (SEQ ID NO. 6); IKICitSCRGS (SEQ ID NO. 7); LPSCitDRQHL (SEQ ID NO. 8); FRHCitHPDEA (SEQ ID NO. 9); FPSCitGKSSS (SEQ ID NO. 10); IQQCitMDGSL (SEQ ID NO. 11); LTQCitGSVLR (SEQ ID NO. 12); YHFCitVGSEA (SEQ ID NO. 13); YDPCitNNSPY (SEQ ID NO. 14); VSFCitGADYS (SEQ. ID NO. 15); YSLCitAVRMK (SEQ ID NO. 16); MKICitPLVTQ (SEQ ID NO. 17); YRACitPAKAA (SEQ ID NO. 18); WQKCitQKQVK (SEQ ID NO. 19); IQNCitQDGSV (SEQ ID NO. 20); WYNCitCHAAN (SEQ ID NO. 21); YSMCitKMSMK (SEQ ID NO. 22); MKICitPFFPQ (SEQ ID NO. 23); LHPCitNLILY (SEQ ID NO. 24); VATCitDNCCI (SEQ ID NO. 25); LDECitFGSYC (SEQ ID NO. 26); LKSCitIMLEE (SEQ ID NO. 27); FQKCitLDGSV (SEQ ID NO. 28); YALCitVELED (SEQ ID NO. 29); WNGCitTSTA (SEQ ID NO. 30); WKTCitWYSMK (SEQ ID NO. 31); YATCitSSAVR (SEQ ID NO. 32); VRLCitSSVPG (SEQ ID NO. 33); LNDCitFANYI (SEQ ID NO. 34); MLQCitEEAEN (SEQ ID NO. 35); LNLCitETNLD (SEQ ID NO. 36); VETCitDGQVI (SEQ ID NO. 37). 
     
     
         4 . The peptide of  claim 1 , wherein said autoimmune disorder is rheumatoid arthritis. 
     
     
         5 . The peptide of  claim 1 , wherein said T cell is a CD4+ T cell. 
     
     
         6 . The peptide of  claim 3 , wherein said peptide has an amino acid sequence that differs from SEQ ID Nos. 1-37 by one or more conservative amino acid substitutions. 
     
     
         7 . The peptide of  claim 6 , wherein said peptide has an amino acid sequence that differs from SEQ ID Nos. 1-37 by a single mutation, wherein said single mutation represents a single amino acid deletion, insertion or substitution. 
     
     
         8 . A pharmaceutical composition comprising an effective amount of one or more of the peptides of  claim 3 , and a pharmaceutically acceptable carrier. 
     
     
         9 . A method of diagnosing rheumatoid arthritis, said method comprising;
 (a) contacting a blood sample from a subject with a citrullinated peptide of  claim 1 ;   (b) determining whether T cells in said sample are activated and/or determining whether a complex is formed between said citrullinated peptide and said MHC class II molecule having a shared epitope.   
     
     
         10 . A method of diagnosing rheumatoid arthritis, or susceptibility to rheumatoid arthritis in a subject, the method comprising:
 determining whether T cells of said subject recognize a citrullinated peptide antigen of  claim 1  bound to a MHC class II molecule having a shared epitope on an antigen presenting cell of said subject, wherein recognition by said T cells indicates that said subject has, or is susceptible to, rheumatoid arthritis.   
     
     
         11 . A diagnostic method for the detection of autoreactive T cells which are reactive with a citrullinated peptide antigen bound to an MHC class II molecule having a shared epitope, said method comprising;
 incubating an isolated sample of peripheral blood mononuclear cells from a subject with one or more citrullinated peptides of  claim 1 ;   detecting the response of T cells, indicating the presence of activated autoreactive T cells in said subject.   
     
     
         12 . The method of  claim 11 , wherein said T cells are CD4+. 
     
     
         13 . The method of  claim 12 , wherein activated T cells indicating that said subject has or is susceptible to an autoimmune disorder. 
     
     
         14 . The method of  claim 13 , wherein said citrullinated peptide comprises at least one amino acid sequence selected from the group consisting of: SAVRACitSSVPGVR (SEQ ID NO. 1); FSMCitIVCLV (SEQ ID NO. 2); VVECitHQSAC (SEQ ID NO. 3); FTNCitINKLK (SEQ ID NO. 4); LRSCitIEVLK (SEQ ID NO. 5); VLKCitKVIEK (SEQ ID NO. 6); IKICitSCRGS (SEQ ID NO. 7); LPSCitDRQHL (SEQ ID NO. 8); FRHCitHPDEA (SEQ ID NO. 9); FPSCitGKSSS (SEQ ID NO. 10); IQQCitMDGSL (SEQ ID NO. 11); LTQCitGSVLR (SEQ ID NO. 12); YHFCitVGSEA (SEQ ID NO. 13); YDPCitNNSPY (SEQ ID NO. 14); VSFCitGADYS (SEQ ID NO. 15); YSLCitAVRMK (SEQ ID NO. 16); MKICitPLVTQ (SEQ ID NO. 17); YRACitPAKAA (SEQ ID NO. 18); WQKCitQKQVK (SEQ ID NO. 19); IQNCitQDGSV (SEQ ID NO. 20); WYNCitCHAAN (SEQ ID NO. 21); YSMCitKMSMK (SEQ ID NO. 22); MKICitPFFPQ (SEQ ID NO. 23); LHPCitNLILY (SEQ ID NO. 24); VATCitDNCCI (SEQ ID NO. 25); LDECitFGSYC (SEQ ID NO. 26); LKSCitIMLEE (SEQ ID NO. 27); FQKCitLDGSV (SEQ ID NO. 28); YALCitVELED (SEQ ID NO. 29); WNGCitTSTA (SEQ ID NO. 30); WKTCitWYSMK (SEQ ID NO. 31); YATCitSSAVR (SEQ ID NO. 32); VRLCitSSVPG (SEQ ID NO. 33); LNDCitFANYI (SEQ ID NO. 34); MLQCitEEAEN (SEQ ID NO. 35); LNLCitETNLD (SEQ ID NO. 36); and VETCitDGQVI (SEQ ID NO. 37). 
     
     
         15 . A test kit for the detection of activated autoreactive T cells which are reactive with a citrullinated peptide antigen bound to an MHC class II shared epitope positive cell, said test kit comprising a peptide of  claim 3 . 
     
     
         16 . A method for treating a subject suffering from rheumatoid arthritis evoked by the binding of a citrullinated peptide to MHC class II molecules with the shared epitope leading to T cell activation and an inflammatory response, said method comprising;
 administering a T cell tolerance inducing amount of a composition comprising a citrullinated peptide comprising the peptide of  claim 3 .   
     
     
         17 . The method of  claim 16  wherein said pharmaceutically acceptable carrier is a soluble MHC class II molecule. 
     
     
         18 . A method of inducing rheumatoid arthritis in an animal to provide an animal model for the study of rheumatoid arthritis, said method comprising administering to said animal a rheumatoid arthritis inducing amount of a composition comprising one or more citrullinated peptides of  claim 1  together with a pharmaceutically acceptable carrier. 
     
     
         19 . The method of  claim 18 , wherein said peptide comprises citrullinated vimentin. 
     
     
         20 . The method of  claim 19 , wherein said peptide comprises citrullinated fibrinogen.