Tuberculosis vaccine

Abstract

A method of detecting an anti-mycobacterial CD8 T cell response comprising contacting a population of CD8 T cells of an individual with one or more peptides selected from the peptides represented by SEQ ID NO: 3, 4, 7, 8, 9, 10, 11 or 12, and, optionally, one or two further peptides represented by SEQ ID NO: 1 and/or 2, wherein one or more of said peptides may be substituted by an analogue which binds a T cell receptor which recognises the corresponding substituted peptide, and determining whether CD8 T cells of the CD8 T cell population recognize the peptide(s). The invention also provides a method of vaccinating against infection by a mycobacterium, wherein the vaccination leads to a CD8 T cell response, comprising administering (i) a CD8 T cell epitope of a mycobacterium protein, (ii) an analogue of the epitope which is capable of inhibiting the binding of the epitope to a T cell receptor, (iii) a precursor or (i) or (ii) which is capable of being processed to provide (i) or (ii), or (iv) a polynucleotide which is capable of being expressed to provide (i), (ii) or (iii).

1 . A method of detecting an anti-mycobacterial CD8 T cell response comprising contacting a population of CD8 T cells of an individual with one or more peptides selected from the peptides represented by SEQ D NO: 3, 4, 7, 8, 9, 10, 11 or 12, and, optionally, one or two further peptides represented by SEQ ID NO 1 and/or 2, wherein one or more of said peptides may be substituted by an analogue which binds a T cell receptor that recognises the corresponding substituted peptide, and determining whether CD8 T cells of the CDS T cell population recognize the peptide(s)  
     
     
         2 . A method according to  claim 1  wherein a peptide panel is employed consisting of the peptides represented by SEQ ID NO's 3, 4, 8, 9 and 10, wherein one or more of these peptides may be substituted by said corresponding analogue  
     
     
         3  A method according to  claim 1  wherein a peptide panel is employed consisting of the peptides represented by SEQ ID NO's 1, 2, 3, 4, 8, 9 and 10, wherein one or more of these peptides may be substituted by said corresponding analogue  
     
     
         4  A method according to  claim 1  wherein any analogue which is used is (i) at least 70% homologous, preferably at least 80% homologous, more preferably at least 90% homologous, to the entire corresponding substituted peptide, and/or (ii) has one or more deletions at the N-terminus and/or C-terminus in comparison to the corresponding substituted peptide, and/or (iii) has one or more conservative substitutions compared to the corresponding substituted peptide.  
     
     
         5  A method according  claim 1  in which the recognition of the peptide(s) by the CD8 T cells is determined by measuring secretion of a cytokine from the CD8 T cells  
     
     
         6  A method according to  claim 5  in which IFN-γ secretion from the T cells is measured.  
     
     
         7  A method according to  claim 6  in which IFN-γ secretion from the CD8 T cells is determined by allowing secreted IFN-γ to bind an immobilised antibody specific to the cytokine and then determining the presence of antibody/cytokine complex  
     
     
         8  A method according to  claim 1  in which the CD8 T cells are freshly isolated ex vivo cells from peripheral blood.  
     
     
         9  A method according to  claim 1  in which CD8 T cells are pre-cultured in vitro with the peptide(s).  
     
     
         10  A method according to  claim 1  in which the mycobacterium is  M. tuberculosis    
     
     
         11  A method according to  claim 1  wherein the population of CD8 T cells is from an individual to whom an anti-mycobacterial vaccine has been administered.  
     
     
         12  A method according to  claim 1  which s carried out in vitro.  
     
     
         13  A method according to  claim 1  comprising administering one or more polynucleotides capable of expressing in human cells peptides and/or analogues as defined in  claim 1   
     
     
         14  A kit for carrying out a method according to  claim 1  comprising one or more peptides selected from the peptides represented by SEQ ID NO 3, 4, 7, 8, 9, 10, 11 or 12, and, optionally, one or two further peptides represented by SEQ ID NO 1 and/or 2, wherein one or more of said peptides may be substituted by an analogue which binds a T cell receptor which recognises the corresponding substituted peptide, and optionally a means to detect recognition of the peptide(s) by CD8 T cells.  
     
     
         15  A kit according to  claim 14  consisting of the peptides represented by SEQ ID NO's 3, 4, 8, 9 and 10, wherein one or more of these peptides may be substituted by said corresponding analogue  
     
     
         16  A kit according to  claim 14  consisting of the peptides represented by SEQ ID NO's 1, 2, 3, 4, 8, 9 and 10, wherein one or more of these peptides may be substituted by said corresponding analogue.  
     
     
         17  A kit according to  claim 14  which includes an antibody to IFN-γ.  
     
     
         18  A kit according to  claim 17  wherein said antibody is immobilised on a solid support and which optionally also includes a means to detect any antibody/IFN-γ complex  
     
     
         19  A kit for carrying out a method according to  claim 13  comprising one or more polynucleotides capable of expressing in human cells one or more peptides selected from the peptides represented by SEQ ID NO. 3, 4, 7, 8, 9, 10, 11 or 12, and, optionally, one or two further peptides represented by SEQ ID NO 1 and/or 2, wherein one or more of said peptides may be substituted by an analogue which binds a T cell receptor which recognises the corresponding substituted peptide  
     
     
         20  A peptide whose sequence is represented by any one of SEQ ID NO's 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12; or an analogue which binds a T cell receptor which recognises any one of SEQ ID NO's 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12  
     
     
         21  A pharmaceutical composition a peptide or analogue as defined in  claim 20   
     
     
         22  A method of vaccinating against infection by a mycobacterium, wherein the vaccination leads to a CD8 T cell response, comprising administering (i) a CD8 T cell epitope of a mycobacterium protein, (ii) an analogue of the epitope which is capable of inhibiting the binding of the epitope to a T cell receptor, (iii) a precursor of (i) or (ii) which is capable of being processed to provide (i) or (ii), or (iv) a polynucleotide which is capable of being expressed to provide (i), (ii) or (iii)  
     
     
         23 . A method according to  claim 22  in which the mycobacterial protein is from  M tuberculosis.    
     
     
         24  A method according to  claim 22  wherein ESAT-6 or a fragment of ESAT-6 is employed  
     
     
         25  A method of vaccination which leads to a CD8 T cell response, the CD8 T cells of which are specific for a CD8 T cell epitope which is represented by any one of SEQ ID NO's 1, 2, 3, 4, 8, 9, 10, 11 or 12, or which epitope is present in the sequence represented by SEQ ID NO 7, said method comprising administering (i) a CD8 T cell epitope which is represented by any one of SEQ ID NO's 1, 2, 3, 4, 8, 9, 10, 11 or 12, or which is present in the sequence represented by SEQ ID NO. 7, (ii) an analogue of the epitope which is capable of inhibiting the binding of the epitope to a T cell receptor, (iii) a precursor of (i) or (ii) which is capable of being processed to provide (i) or (ii) excluding ESAT-6 or fragments of ESAT-6, or (iv) a polynucleotide which is capable of being expressed to provide (i), (ii) or (iii).  
     
     
         26  A pharmaceutical composition comprising an epitope, analogue, precursor or polynucleotide as defined in  claim 25  and a pharmaceutically acceptable carrier or diluent.  
     
     
         27  A vaccine comprising an adjuvant which stimulates a CD8 T cell response and (i), (ii), (iii) or (iv) as defined in claims  22 , or a vaccine comprising (ii), (ii), (iii) or (iv) as defined in  claim 22  associated with a delivery system capable of stimulating a CD8 T cell response