Il-2 chimeric proteins for immunosuppression

Abstract

Methods of increasing regulatory T cells in a subject by administering an IL-2 chimeric molecule with increased serum half-life as compared to wild-type Il-2 are provided. Methods of treating inflammatory and autoimmune disease are also provided.

1 . A method of increasing regulatory T cell (T reg ) number in a subject in need thereof, the method comprising administering to said subject an interleukin-2 (IL-2) chimeric molecule characterized by increased serum half-life as compared to a wild-type IL-2 molecule and wherein said IL-2 chimeric molecule lacks an immunoglobulin moiety, thereby increasing T reg  proliferation in a subject. 
     
     
         2 . The method of  claim 1 , wherein said administering comprises administering a low dose of said IL-2 chimeric molecule, wherein said low dose is a dose that does not activate CD8 +  cell proliferation, natural killer (NK) cell proliferation, or both. 
     
     
         3 . The method of  claim 1 , wherein said increasing T reg  number comprises increasing T reg  proliferation, treating inflammation or both. 
     
     
         4 . The method of  claim 3 , wherein said method further comprises at least one of: increasing CD4+/CD25+ cell number in said subject, increasing CD8+/CD25+ cell number in said subject, increasing CD8+/CD25+/FoxP3+ cell number in said subject and not increasing CD69 positive immune cells in said subject. 
     
     
         5 . (canceled) 
     
     
         6 . The method of  claim 3 , wherein said increasing T reg  number comprises treating inflammation, and said inflammation is an inflammatory disease or an autoimmune disease. 
     
     
         7 . The method of  claim 6 , wherein said autoimmune disease is selected from inflammatory bowel disease (IBD), and arthritis. 
     
     
         8 . The method of  claim 1 , wherein said increased serum half-life comprises at least a 10 times longer clearance half-life as compared to wild-type IL-2. 
     
     
         9 . The method of  claim 1 , wherein said chimeric molecule is further characterized by increased signaling through IL-2 receptor (IL-2R) upon binding as compared to wild-type IL-2, increased proliferation induction of CTLL-2 cells upon binding as compared to wild-type IL-2, increased binding to CD25 as compared to wild-type IL-2, or a combination thereof. 
     
     
         10 . The method of  claim 1 , wherein said IL-2 is selected from wild-type IL-2 comprising SEQ ID NO: 13, IL-2 mutated to increase binding to T regs , IL-2 mutated to decrease binding to CD8 +  T-cells and natural killer cells, IL-2 mutated to increase binding to IL-2R gamma (IL-2Rγ) and IL-2 mutated to decrease binding to IL-2R beta (IL-2Rβ). 
     
     
         11 . The method of  claim 10 , wherein said IL-2 is mutated IL-2 and wherein said mutated IL-2 comprises SEQ ID NO: 8. 
     
     
         12 . (canceled) 
     
     
         13 . The method of  claim 1 , wherein said chimeric molecule comprises a NKp44 hinge region moiety. 
     
     
         14 . The method of  claim 13 , wherein said NKp44 hinge region moiety is
 a. selected from SEQ ID NO: 2 and SEQ ID NO: 3;   b. attached to an N-terminus, C-terminus or both of said IL-2;   c. glycosylated; or   d. a combination thereof.   
     
     
         15 . (canceled) 
     
     
         16 . The method of  claim 13 , wherein said chimeric molecule comprises a NKp44 moiety attached to an N-terminus and a C-terminus of said IL-2. 
     
     
         17 . (canceled) 
     
     
         18 . The method of  claim 10 , wherein said chimeric molecule comprises an amino acid sequence selected from SEQ ID NO: 4, 5, 6, 7, 14, 15, 16, and 17. 
     
     
         19 . The method of  claim 18 , wherein said chimeric molecule comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 6 and SEQ ID NO: 14. 
     
     
         20 . (canceled) 
     
     
         21 . The method of  claim 1 , wherein said administering is administering a low dose of said IL-2 chimeric molecule, wherein said low dose is
 a. the equivalent number of international units (IU)/day of said IL-2 chimeric molecule as the IU/day for low dose wild-type IL-2 therapy;   b. a dose below 5×10{circumflex over ( )}6 IU/day; or   c. both.   
     
     
         22 . (canceled) 
     
     
         23 . The method of  claim 1 , wherein said administering is administering a reduced dosing regimen as compared to wild-type IL-2 therapy, and wherein said reduced dosing regimen comprises
 a. dosing less frequently that daily;   b. dosing every 2-4 days; or   c. both.   
     
     
         24 . (canceled) 
     
     
         25 . A chimeric molecule comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 14-18. 
     
     
         26 . The chimeric molecule of  claim 21 , consisting of the amino acid sequence of SEQ ID NO: 14. 
     
     
         27 . A pharmaceutical composition comprising a chimeric molecule of  claim 25  and a pharmaceutically acceptable carrier, excipient or adjuvant. 
     
     
         28 . (canceled)