Use of cd31 peptides in the treatment of thrombotic and autoimmune disorders

Abstract

The present invention stems from the finding that the extracellular domain of CD31 proteins present on blood leukocytes is shed and released in the circulation as a soluble form of CD31. The invention relates to peptides corresponding to fragments of CD31 that inhibit T-cell response, and to their use in the treatment of thrombotic disorders such as atherothrombosis and autoimmune disorders.

1 - 18 . (canceled) 
     
     
         19 . An isolated peptide consisting of:
 a) a fragment of at least 6 amino acids of the sequence defined by amino acids 579 to 601 of SEQ ID NO: 1;   b) a fragment of at least 6 amino acids of the sequence corresponding to (a) in a non-human mammalian CD31; or   c) a fragment consisting of a sequence at least 80% identical to (a),   
       wherein said peptide exerts a dose-dependent inhibition of T-cell proliferation in vitro and does not consist of an amino acid sequence of SEQ ID NO: 5 or 6 and wherein said peptide optionally comprises at least one chemical modification improving its stability and/or its bioavailability selected from the group consisting of:
 (a) modification to the N-terminal and/or C-terminal end of the peptide by N-terminal acylation or deamination; 
 (b) modification of the C-terminal carboxyl group into an amide or an alcohol group; 
 (c) modification at the amide bond between two amino acids by acylation or alkylation at the nitrogen atom or the alpha carbon of the amide bond linking said two amino acids; 
 (d) modification at the alpha carbon of the amide bond linking two amino acids by acylation or alkylation at the alpha carbon of the amide bond linking said two amino acids; 
 (e) replacement of one or more naturally occurring L-enantiomeric amino acids with a corresponding D-enantiomer; 
 (f) retro-inversion, in which one or more naturally occurring L-enantiomeric amino acids is replaced with a corresponding D-enantiomer, together with inversion of the amino acid chain; 
 (g) replacement of one or more alpha carbons with nitrogen atoms; and 
 (h) binding of the amino group of one or more amino acid to the β carbon instead of the α carbon. 
 
     
     
         20 . The peptide according to  claim 19 , wherein said peptide consists of:
 a) a fragment of 6 to 15 amino acids of the sequence defined by amino acids 579 to 601 of SEQ ID NO: 1;   b) a fragment of 6 to 15 amino acids of the sequence corresponding to (a) in a non-human mammalian CD31;   c) a fragment consisting of a sequence at least 80% identical to (a), or   d) a peptide as defined in a), b) or c) comprising at least one chemical modification improving its stability and/or its bioavailability selected from the group consisting of:
 (a) modification to the N-terminal and/or C-terminal end of the peptide by N-terminal acylation or deamination; 
 (b) modification of the C-terminal carboxyl group into an amide or an alcohol group; 
 (c) modification at the amide bond between two amino acids by acylation or alkylation at the nitrogen atom or the alpha carbon of the amide bond linking said two amino acids; 
 (d) modification at the alpha carbon of the amide bond linking two amino acids by acylation or alkylation at the alpha carbon of the amide bond linking said two amino acids; 
 (e) replacement of one or more naturally occurring L-enantiomeric amino acids with a corresponding D-enantiomer; 
 (f) retro-inversion, in which one or more naturally occurring L-enantiomeric amino acids is replaced with a corresponding D-enantiomer, together with inversion of the amino acid chain; 
 (g) replacement of one or more alpha carbons with nitrogen atoms; and 
 (h) binding of the amino group of one or more amino acid to the β carbon instead of the α carbon; 
   wherein said peptide exerts a dose-dependent inhibition of T-cell proliferation in vitro.   
     
     
         21 . The peptide according to  claim 19 , wherein said peptide comprises an amino acid sequence at least 80% identical to SEQ ID NO: 2, 3 or 4. 
     
     
         22 . A pharmaceutical composition comprising one or more of:
 a peptide consisting of:
 a) a fragment of at least 6 amino acids of the sequence defined by amino acids 579 to 601 of SEQ ID NO: 1; 
 b) a fragment of at least 6 amino acids of the sequence corresponding to (a) in a non-human mammalian CD31; or 
 c) a fragment consisting of a sequence at least 80% identical to (a), wherein said peptide exerts a dose-dependent inhibition of T-cell proliferation in vitro and does not consist of an amino acid sequence of SEQ ID NO: 5 or 6 
 and wherein said peptide optionally comprises at least one chemical modification improving its stability and/or its bioavailability selected from the group consisting of:
 (a) modification to the N-terminal and/or C-terminal end of the peptide by N-terminal acylation or deamination; 
 (b) modification of the C-terminal carboxyl group into an amide or an alcohol group; 
 (c) modification at the amide bond between two amino acids by acylation or alkylation at the nitrogen atom or the alpha carbon of the amide bond linking said two amino acids; 
 (d) modification at the alpha carbon of the amide bond linking two amino acids by acylation or alkylation at the alpha carbon of the amide bond linking said two amino acids; 
 (e) replacement of one or more naturally occurring L-enantiomeric amino acids with a corresponding D-enantiomer; 
 (f) retro-inversion, in which one or more naturally occurring L-enantiomeric amino acids is replaced with a corresponding D-enantiomer, together with inversion of the amino acid chain; 
 (g) replacement of one or more alpha carbons with nitrogen atoms; and 
 (h) binding of the amino group of one or more amino acid to the β carbon instead of the α carbon, and 
 
 a nucleic acid encoding said peptide; 
   and a physiologically acceptable carrier.   
     
     
         23 . The pharmaceutical composition according to  claim 22 , wherein said peptide consists of:
 a) a fragment of 6 to 15 amino acids of the sequence defined by amino acids 579 to 601 of SEQ ID NO: 1;   b) a fragment of 6 to 15 amino acids of the sequence corresponding to (a) in a non-human mammalian CD31;   c) a fragment consisting of a sequence at least 80% identical to (a), or   d) a peptide as defined in a), b) or c) comprising at least one chemical modification improving its stability and/or its bioavailability selected from the group consisting of:
 (a) modification to the N-terminal and/or C-terminal end of the peptide by N-terminal acylation or deamination; 
 (b) modification of the C-terminal carboxyl group into an amide or an alcohol group; 
 (c) modification at the amide bond between two amino acids by acylation or alkylation at the nitrogen atom or the alpha carbon of the amide bond linking said two amino acids; 
 (d) modification at the alpha carbon of the amide bond linking two amino acids by acylation or alkylation at the alpha carbon of the amide bond linking said two amino acids; 
 (e) replacement of one or more naturally occurring L-enantiomeric amino acids with a corresponding D-enantiomer; 
 (f) retro-inversion, in which one or more naturally occurring L-enantiomeric amino acids is replaced with a corresponding D-enantiomer, together with inversion of the amino acid chain; 
 (g) replacement of one or more alpha carbons with nitrogen atoms; and 
 (h) binding of the amino group of one or more amino acid to the β carbon instead of the α carbon; 
 wherein said peptide exerts a dose-dependent inhibition of T-cell proliferation in vitro. 
   
     
     
         24 . The pharmaceutical composition according to  claim 22 , wherein said peptide comprises an amino acid sequence at least 80% identical to SEQ ID NO: 2, 3 or 4. 
     
     
         25 . A method of activating CD31-mediated signaling in an individual in need thereof, comprising administering to the individual a peptide comprising or consisting of:
 a) amino acids 579 to 601 of SEQ ID NO: 1;   b) the amino acids corresponding to (a) in a non-human mammalian CD31;   c) a fragment of at least 6 amino acids of (a);   d) a fragment of at least 6 amino acids of (b); or   e) a sequence at least 80% identical to (a) or (c),   
       wherein said peptide exerts a dose-dependent inhibition of T-cell proliferation in vitro and wherein said peptide optionally comprises at least one chemical modification improving its stability and/or its bioavailability selected from the group consisting of:
 (a) modification to the N-terminal and/or C-terminal end of the peptide by N-terminal acylation or deamination; 
 (b) modification of the C-terminal carboxyl group into an amide or an alcohol group; 
 (c) modification at the amide bond between two amino acids by acylation or alkylation at the nitrogen atom or the alpha carbon of the amide bond linking said two amino acids; 
 (d) modification at the alpha carbon of the amide bond linking two amino acids by acylation or alkylation at the alpha carbon of the amide bond linking said two amino acids; 
 (e) replacement of one or more naturally occurring L-enantiomeric amino acids with a corresponding D-enantiomer; 
 (f) retro-inversion, in which one or more naturally occurring L-enantiomeric amino acids is replaced with a corresponding D-enantiomer, together with inversion of the amino acid chain; 
 (g) replacement of one or more alpha carbons with nitrogen atoms; and 
 (h) binding of the amino group of one or more amino acid to the β carbon instead of the α carbon. 
 
     
     
         26 . The method according to  claim 25 , wherein said peptide has a length of at most 30 amino acids. 
     
     
         27 . The method according to  claim 25 , wherein said individual has a CD31 shed  T lymphocytes phenotype. 
     
     
         28 . The method according to  claim 25 , wherein said peptide consists of:
 a) a peptide according to  claim 19 ;   b) a peptide comprising an amino acid sequence at least 80% identical to SEQ ID NO: 5 or 6; or   c) a peptide comprising an amino acid sequence of SEQ ID NO: 5 or 6.   
     
     
         29 . The method according to  claim 25 , wherein said peptide consists of:
 a) a fragment of 6 to 15 amino acids of the sequence defined by amino acids 579 to 601 of SEQ ID NO: 1;   b) a fragment of 6 to 15 amino acids of the sequence corresponding to (a) in a non-human mammalian CD31;   c) a fragment consisting of a sequence at least 80% identical to (a), or   d) a peptide as defined in a), b) or c) comprising at least one chemical modification improving its stability and/or its bioavailability selected from the group consisting of:
 (a) modification to the N-terminal and/or C-terminal end of the peptide by N-terminal acylation or deamination; 
 (b) modification of the C-terminal carboxyl group into an amide or an alcohol group; 
 (c) modification at the amide bond between two amino acids by acylation or alkylation at the nitrogen atom or the alpha carbon of the amide bond linking said two amino acids; 
 (d) modification at the alpha carbon of the amide bond linking two amino acids by acylation or alkylation at the alpha carbon of the amide bond linking said two amino acids; 
 (e) replacement of one or more naturally occurring L-enantiomeric amino acids with a corresponding D-enantiomer; 
 (f) retro-inversion, in which one or more naturally occurring L-enantiomeric amino acids is replaced with a corresponding D-enantiomer, together with inversion of the amino acid chain; 
 (g) replacement of one or more alpha carbons with nitrogen atoms; and 
 (h) binding of the amino group of one or more amino acid to the β carbon instead of the α carbon; 
 wherein said peptide exerts a dose-dependent inhibition of T-cell proliferation in vitro. 
   
     
     
         30 . The method according to  claim 25 , wherein said peptide comprises an amino acid sequence at least 80% identical to SEQ ID NO: 2, 3 or 4. 
     
     
         31 . The method according to  claim 25 , wherein said method is a method for treating a thrombotic or an autoimmune disorder. 
     
     
         32 . The method according to  claim 25 , wherein said method is a method for treating a thrombotic disorder selected from the group consisting of atherothrombosis, atherosclerosis, acute coronary syndrome, ischemic stroke, peripheral arterial disease, abdominal aortic aneurysm, deep vein thrombosis, myocardial infarction, and pulmonary embolism. 
     
     
         33 . The method according to  claim 25 , wherein said method is a method for treating an autoimmune disorder selected from the group consisting of rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease, systemic lupus erythematosus, Graves' disease and diabetes mellitus.