Activation of HCV-specific T cells

Abstract

The invention provides a method of activating hepatitis C virus (HCV)-specific T cells, including CD4 + and CD8 + T cells. HCV-specific T cells are activated using fusion proteins comprising HCV NS3, NS4, NS5a, and NS5b polypeptides, polynucleotides encoding such fusion proteins, or polypeptide or polynucleotide compositions containing the individual components of these fusions. The method can be used in model systems to develop HCV-specific immunogenic compositions, as well as to immunize a mammal against HCV.

We claim:  
     
         1 . A fusion protein consisting essentially of an NS3, an NS4, and an NS5a polypeptide of a hepatitis C virus (HCV).  
     
     
         2 . A fusion protein consisting essentially of an NS3, an NS4, an NS5a, and NS5b polypeptide of an HCV.  
     
     
         3 . A fusion protein according to either of claims  1  or  2 , wherein one of the HCV polypeptides is derived from a different strain of HCV than the other HCV polypeptides.  
     
     
         4 . The fusion protein of  claim 3  wherein each of the HCV polypeptides is derived from a different strain of HCV.  
     
     
         5 . A composition comprising: 
 (a) a fusion protein according to either of claims  1  or  2 ; and    (b) a pharmaceutically acceptable excipient.    
     
     
         6 . A composition comprising: 
 (a) a fusion protein according to  claim 4;  and    (b) a pharmaceutically acceptable excipient.    
     
     
         7 . A composition consisting essentially of: 
 (a) an isolated and purified NS3 polypeptide of a hepatitis C virus (HCV);    (b) an isolated and purified NS4 polypeptide of a HCV;    (c) an isolated and purified NS5a polypeptide of a HCV; and    (d) a pharmaceutically acceptable excipient and optionally an adjuvant.    
     
     
         8 . A composition consisting essentially of: 
 (a) an isolated and purified NS3 polypeptide of a hepatitis C virus (HCV);    (b) an isolated and purified NS4 polypeptide of a HCV;    (c) an isolated and purified NS5a polypeptide of a HCV;    (d) an isolated and purified NS5b polypeptide of a HCV; and    (e) a pharmaceutically acceptable excipient and optionally an adjuvant.    
     
     
         9 . An isolated and purified polynucleotide which encodes a fusion protein according to either of claims  1  or  2 .  
     
     
         10 . An isolated and purified polynucleotide which encodes the fusion protein of  claim 4 .  
     
     
         11 . A composition comprising: 
 (a) the isolated and purified polynucleotide of  claim 9;  and    (b) a pharmaceutically acceptable excipient.    
     
     
         12 . The composition of  claim 11  wherein the polynucleotide is DNA.  
     
     
         13 . The composition of  claim 12  wherein the polynucleotide is in a plasmid.  
     
     
         14 . A composition comprising: 
 (a) an isolated and purified polynucleotide according to  claim 10;  and    (b) a pharmaceutically acceptable excipient.    
     
     
         15 . The composition of  claim 14  wherein the polynucleotide is DNA.  
     
     
         16 . The composition of  claim 15  wherein the polynucleotide is in a plasmid.  
     
     
         17 . A composition consisting essentially of: 
 (a) an isolated and purified polynucleotide encoding an NS3 polypeptide of a hepatitis C virus (HCV);    (b) an isolated and purified polynucleotide encoding an NS4 polypeptide of a HCV;    (c) an isolated and purified polynucleotide encoding an NS5a polypeptide of a HCV; and    (d) a pharmaceutically acceptable excipient and optionally an adjuvant.    
     
     
         18 . The composition of  claim 17  wherein the polynucleotide is DNA.  
     
     
         19 . The composition of  claim 18  wherein the polynucleotide is in a plasmid.  
     
     
         20 . A composition consisting essentially of: 
 (a) an isolated and purified polynucleotide encoding an NS3 polypeptide of a hepatitis C virus (HCV);    (b) an isolated and purified polynucleotide encoding an NS4 polypeptide of a HCV;    (c) an isolated and purified polynucleotide encoding an NS5a polypeptide of a HCV;    (d) an isolated and purified polynucleotide encoding an NS5b polypeptide of a HCV; and    (e) a pharmaceutically acceptable excipient and optionally an adjuvant.    
     
     
         21 . The composition of  claim 20  wherein the polynucleotide is DNA.  
     
     
         22 . The composition of  claim 21  wherein the polynucleotide is in a plasmid.  
     
     
         23 . A method of activating T cells which recognize an epitope of an HCV polypeptide, comprising the step of: 
 contacting T cells with a fusion protein of either of claims  1  or  2 , whereby a population of activated T cells recognizes an epitope of the NS3, NS4, NS5a, or NS5b polypeptides.    
     
     
         24 . The method of  claim 23  wherein the T cells are obtained from a mammal selected from the group consisting of a mouse, a baboon, a chimpanzee, and a human.  
     
     
         25 . The method of  claim 24  wherein the mammal is infected with an HCV.  
     
     
         26 . The method of  claim 24  wherein the mammal is not infected with an HCV.  
     
     
         27 . The method of  claim 23  wherein the population of T cells comprises CD4 +  T cells.  
     
     
         28 . The method of  claim 23  wherein the population of T cells comprises CD8 +  T cells.  
     
     
         29 . The method of  claim 28  wherein the CD8 +  T cells express interferon-γ.  
     
     
         30 . The method of  claim 28  wherein the CD8 +  T cells specifically recognize an epitope of an NS5a polypeptide.  
     
     
         31 . The method of  claim 30  wherein the epitope is selected from the group consisting of the epitopes shown in SEQ ID NO:1 and SEQ ID NO:2.  
     
     
         32 . The method of  claim 23  wherein the T cells comprise CD8 +  and CD4 +  T cells.  
     
     
         33 . The method of  claim 23  wherein the step of contacting further comprises contacting the T cells with an adjuvant.  
     
     
         34 . The method of  claim 23  wherein the fusion protein is provided by a polynucleotide encoding the fusion protein.  
     
     
         35 . The method of  claim 34  wherein the polynucleotide is DNA.  
     
     
         36 . The method of  claim 34  wherein the polynucleotide is RNA.  
     
     
         37 . The method of  claim 23  wherein the T cells are in a mammal.  
     
     
         38 . The method of  claim 37  wherein the mammal is selected from the group consisting of a mouse, a baboon, a chimpanzee, and a human.  
     
     
         39 . The method of  claim 37  wherein the mammal is infected with an HCV.  
     
     
         40 . The method of  claim 37  wherein the mammal is not infected with an HCV.  
     
     
         41 . A method of activating T cells which recognize an epitope of an HCV polypeptide, comprising the step of: 
 contacting T cells with a composition according to  claim 7 , whereby a population of activated T cells recognizes an epitope of the NS3, NS4, NS5a, or NS5b polypeptides.    
     
     
         42 . A method of activating T cells which recognize an epitope of an HCV polypeptide, comprising the step of: 
 contacting T cells with a composition according to  claim 8 , whereby a population of activated T cells recognizes an epitope of the NS3, NS4, NS5a, or NS5b polypeptides.    
     
     
         43 . A method of activating T cells which recognize an epitope of an HCV polypeptide, comprising the step of: 
 contacting T cells with a composition according to  claim 17 , whereby a population of activated T cells recognizes an epitope of the NS3, NS4, NS5a, or NS5b polypeptides.    
     
     
         44 . A method of activating T cells which recognize an epitope of an HCV polypeptide, comprising the step of: 
 contacting T cells with a composition according to  claim 20 , whereby a population of activated T cells recognizes an epitope of the NS3, NS4, NS5a, or NS5b polypeptides.