Hybrid cytokine of IL-7 and beta-chain of hepatocyte growth factor

Abstract

A hybrid cytokine comprising the B-chain of hepatocyte growth factor and IL-7, linked by a linker molecule, having pre-pro-B growth stimulating activity.

We claim:  
     
         1 . A hybrid cytokine comprising: 
 a) a polypeptide which has greater than about 40% sequence identity with interleukin-7;    b) a polypeptide which has greater than about 40% sequence identity with the beta chain of HGF; and    wherein the hybrid cytokine complex is not isolated from a natural source.    
     
     
         2 . The hybrid cytokine of  claim 1  further comprising an oligosaccharide linker between a) and b).  
     
     
         3 . The hybrid cytokine of  claim 2  wherein the oligosaccharide linker is a low molecular weight form of heparan sulfate.  
     
     
         4 . The hybrid cytokine of  claim 3  wherein the low molecular weight of heparan sulfate has a molecular weight less that about 3000 kD.  
     
     
         5 . A hybrid cytokine complex comprising: 
 a) a cytokine or biologically-active variant thereof;    b) a growth factor, or biologically-active variant therof; and    c) a flexible linking moiety adjoining a) and b)    wherein the hybrid cytokine complex is not isolated from a natural source.    
     
     
         6 . The hybrid cytokine complex of  claim 5  wherein the flexible linking moiety is an oligosaccharide.  
     
     
         7 . The hybrid cytokine of  claim 6  wherein the oligosaccharide linker is a low molecular form of heparan sulfate.  
     
     
         8 . The hybrid cytokine of  claim 7  wherein the low molecular weight form of heparan sulfate has a molecular weight of less than about 3000 kD.  
     
     
         9 . A biological preparation in which at least 95% by weight of the proteinaceous matter in the preparation comprises the complex of  claim 5 .  
     
     
         10 . A biological preparation in which at least 60% by weight of the proteinaceous matter in the preparation comprises the complex of  claim 5 .  
     
     
         11 . A biological preparation in which at least 30% by weight of the proteinaceous matter in the preparation comprises the complex of  claim 5 .  
     
     
         12 . A method of treating lymphocyte-related disorders, comprising administering to a host in need for such treatment an effective amount of the complex of  claim 5 .  
     
     
         13 . A method of treating lymphocyte-related disorders, comprising administering to a host in need for such treatment an effective amount of the complex of  claim 9 .  
     
     
         14 . A method of treating lymphocyte-related disorders, comprising administering to a host in need for such treatment an effective amount of the complex of  claim 10 .  
     
     
         15 . A method of treating lymphocyte-related disorders, comprising administering to a host in need for such treatment an effective amount of the complex of  claim 11 .  
     
     
         16 . The complex of  claim 9 , furthered characterized in that it is free from protease activity.  
     
     
         17 . A process for producing a hybrid cytokine comprising the β-chain of hepatocyte growth factor (HGF) and rIL7, said method comprising: 
 (a) obtaining recombinantly-derived β-chain of hepatocyte growth factor (HGF) by: 
 (1) cloning HGFβ cDNA into mammalian or prokoryotic expression vectors and transfecting or transforming the vectors into mammalian or prokoryotic cells;  
 (2) growing the transfected or transformed cells in vitro;  
 (3) isolating purified β-chain of hepatocyte growth factor (HGF) by extraction from the cell culture; and  
 
 (b) obtaining IL-7 from a recombinant or natural source;  
 (c) linking the recombinantly-derived β-chain of hepatocyte growth factor (HGF) of step (a) with the IL-7 of step (b) by way of a linker molecule.  
 
     
     
         18 . A hybrid cytokine complex comprising: 
 a) interleukin-7;    b) the beta chain of HGF;    c) a flexible linking moiety adjoining a) and b);    wherein the hybrid cytokine complex is not isolated from a natural source.    
     
     
         19 . The hybrid cytokine complex of  claim 12  wherein the flexible linking moiety is an oligosaccharide linker.  
     
     
         20 . The hybrid cytokine complex of  claim 19  wherein the oligosaccharide linker is a low molecular weight form of heparan sulfate.  
     
     
         21 . The hybrid cytokine complex of  claim 20  wherein the molecular weight form of heparan sulfate has a molecular weight less than about 3000 kD.  
     
     
         22 . A bimolecular protein complex comprising: 
 a) a polypeptide which has greater than about 40% sequence identity with interleukin-7;    b) a polypeptide which has greater than about 40% sequence identity with the beta chain of HGF; and    wherein the bimolecular protein complex supports the proliferation and differentiation of pre-pro-B-cells.    
     
     
         23 . The biomolecular protein of  claim 22  further comprising an oligosaccharide linker between a) and b).  
     
     
         24 . The biomolecular protein of  claim 23  wherein the oligosaccharide linker is a low molecular weight form of heparan sulfate.  
     
     
         25 . The biomolecular protein of  claim 24  wherein the low molecular weight form of heparan sulfate has a molecular weight less than 3000 kD.  
     
     
         26 . A purified hybrid cytokine complex preparation comprising: 
 a) a hybrid cytokine complex comprising interleukin-7 and the beta claim of HGF;    b) excipient; and    wherein the hybrid cytokine complex preparation is more than about 40% hybrid cytokine complex.    
     
     
         27 . A method for forming a hybrid cytokine complex supporting the proliferation and differentiation of pre-pro-B-cells, said method comprising: 
 a) obtaining a cytokine or biologically-active variant thereof;    b) obtaining a growth factor or a biologically-active variant thereof, and    c) linking the cytokine of step (a) to the growth factor of step (b) using an oligosaccharide linker.    
     
     
         28 . An expression vector containing the cDNA sequence for the B-chain component of hepatocyte growth factor.  
     
     
         29 . A cell transformed by the expression vector of  claim 28 .  
     
     
         30 . The cell of  claim 29  comprising a Chinese hamster ovary cell.  
     
     
         31 . The cell of  claim 29  comprising  E. coli.