Chemokine-cytokine fusion proteins and their applications

Abstract

The present invention provides a fusion protein, comprising a chemokine polypeptide, which is a chemokine or a receptor binding domain thereof; and a cytokine polypeptide connected to said chemokine polypeptide, which is an interleukin, a TNF-superfamily cytokine or a receptor-binding domain thereof; wherein the chemokine polypeptide and the cytokine polypeptide have a common target cell, and the fusion protein has an improved chemokine activity as compared to the chemokine polypeptide, and an improved cytokine activity as compared to the cytokine polypeptide.

1 . A fusion protein, comprising:
 a chemokine polypeptide, the chemokine polypeptide being a stromal cell-derived factor-1 (SDF-1) or a receptor binding domain thereof; and   a cytokine polypeptide connected to the chemokine polypeptide, the cytokine polypeptide being interleukin-2 (IL-2) or a receptor binding domain thereof;   wherein   the chemokine polypeptide and the cytokine polypeptide have a common target cell, and the fusion protein has an improved chemokine activity as compared to the chemokine polypeptide, and an improved cytokine activity as compared to the cytokine polypeptide.   
     
     
         2 . The fusion protein according to  claim 1 , wherein the chemokine polypeptide and the cytokine are connected by a peptide linker. 
     
     
         3 . The fusion protein according to  claim 2 , wherein the peptide linker is a flexible peptide linker of (Gly-Gly-Gly-Gly-Ser) n  where n is less than 6, or a hydrophilic helical peptide linker of (Glu-Ala-Ala-Ala-Lys) n  where n is less than 6. 
     
     
         4 . The fusion protein according to  claim 1 , wherein the chemokine polypeptide has an amino acid sequence selected from the group consisting of: SEQ ID NO: 10, 12, 14, 16, 18, a homolog thereof, and an analog thereof. 
     
     
         5 . The fusion protein according to  claim 1 , wherein the cytokine polypeptide has an amino acid sequence selected from the group consisting of: SEQ ID NO: 30, 32, 34, 36, 38, a homolog thereof, and an analog thereof. 
     
     
         6 . The fusion protein according to  claim 1 , which has an amino acid sequence of SEQ ID NO: 44. 
     
     
         7 . An isolated nucleic acid molecule encoding a fusion protein according to  claim 1 . 
     
     
         8 . The isolated nucleic acid molecule according to  claim 7 , which comprises a nucleotide sequence encoding a chemokine polypeptide, selected from the group consisting of: SEQ ID NO: 9, 11, 13, 15, 17, a homolog thereof, and an analog thereof. 
     
     
         9 . The isolated nucleic acid molecule according to  claim 7 , which comprises a nucleotide sequence encoding a chemokine polypeptide, selected from the group consisting of: SEQ ID NO: 31, 33, 35, 37, a homolog thereof, and an analog thereof. 
     
     
         10 . The isolated nucleic acid molecule according to  claim 7 , which has a sequence of SEQ ID NO: 43. 
     
     
         11 . The isolated nucleic acid molecule according to  claim 7 , which is an expression vector. 
     
     
         12 . A host cell comprising a nucleic acid molecule according to  claim 7 . 
     
     
         13 . The host cell according to  claim 12 , wherein the nucleic acid molecule is an expression vector.