Polypeptides

Abstract

Disclosed are a polypeptide (including that in soluble form) as receptor for a novel cytokine, i.e., interleukin-18, a DNA encoding the polypeptide, and the uses of the polypeptide including pharmaceutical and neutralizer to interleukin-18. Pharmaceuticals with the polypeptide is useful to treat and prevent autoimmune and allergic disease because it suppresses and regulates excessive immunoreaction.

What is claimed is:  
     
         1 . A method for treating diseases associated with excessive IL-18 induced immunoreaction, comprising: 
 transforming effector cells with an isolated DNA comprising a nucleotide sequence encoding an IL-18 binding polypeptide capable of binding IL-18; and    introducing the transformed effector cells into a subject to provide adoptive immunogene therapy to treat diseases associated with excessive IL-18 induced immunoreaction.    
     
     
         2 . The method according to  claim 1 , further comprising proliferating the transformed effector cells in vitro prior to introducing the transformed effector cells into a subject.  
     
     
         3 . The method according to  claim 2 , wherein the effector cells are tumor cells collected from the subject to be treated.  
     
     
         4 . The method according to  claim 2 , wherein the effector cells are lymphocytes collected from the subject to be treated.  
     
     
         5 . A method for treating diseases associated with excessive IL-18 induced immunoreaction, comprising administering to a subject in need thereof an isolated DNA comprising a nucleotide sequence encoding an IL-18 binding polypeptide capable of binding IL-18.  
     
     
         6 . An isolated DNA comprising a nucleotide sequence encoding an IL-18 binding polypeptide derived from an IL-18 receptor, wherein said IL-18 receptor comprises the amino acid sequence of SEQ ID NO: 21.  
     
     
         7 . The isolated DNA according to  claim 6 , wherein said nucleotide sequence encoding said IL-18 binding polypeptide comprises a part or a whole of the nucleotide sequence of SEQ ID NO: 4 or a complementary sequence thereto.  
     
     
         8 . The isolated DNA according to  claim 7 , wherein said nucleotide sequence encoding said IL-18 binding polypeptide is selected from the group consisting of SEQ ID NO: 2, SEQ ID NO: 11, and complementary sequences thereto.