Herpesvirus preparations and their uses

Abstract

Herpesviral particle preparations, e.g. a preparation of herpesviral particles isolated from the cell culture in which such particles were produced, can have at least part of the VP22 tegument protein present in the form of a recombinant mutant form of VP22, e.g. as a recombinant fusion polypeptide comprising a VP22-active sequence and a non-VP22 peptide or polypeptide sequence such as a fluorescent GFP sequence: corresponding DNA preparations are described. The use of virus particles containing fluorescent fusion protein to detect the progress of cell infection by virus and to screen for neutralising antibody or inhibitors of infection is also described. Vaccine uses of modified herpesvirus particles are described.

1 . A preparation of herpesviral particles (e.g. a preparation of herpesviral particles isolated from the cell culture in which such particles were produced), in which at least part of the VP22 tegument protein is present as a recombinant fusion polypeptide comprising a VP22-active sequence and a non-VP22 peptide or polypeptide sequence selected from sequences providing a detectable gene product, e.g. as a fusion with a gene encoding green fluorescent protein (GFP).  
     
     
         2 . A preparation of herpesviral particles according to  claim 1  wherein the fusion polypeptide is detectable by fluorescence.  
     
     
         3 . A rpeparation according to  claim 1  wherein the whole of the VP22 component of the virion is said fusion polypeptide, e.g. a fusion protein of VP22 with GFP.  
     
     
         4 . A preparation according to  claim 1  wherein the virus is a herpesviral mutant which is deleted in respect of an essential viral gene.  
     
     
         5 . A process of using a preparation of herpesviral particles according to  claim 1  where the fusion polypeptide sequence comprises a sequence providing a detectable VP22 fusion protein, to detect the progress of herpesviral infection of cells, which process comprises (i) contacting said particles with said cells and (ii) detecting said fusion protein within said cells.  
     
     
         6 . A process according to  claim 5 , wherein the protein is a fluorescent fusion protein and said detection step comprises detecting the fluorescence of said fusion protein within said cells, e.g. fluorescence of GFP-VP22 fusion protein.  
     
     
         7 . A process according to  claim 6 , wherein said virus particles containing fluorescent fusion protein are used to detect the progress of cell infection by virus and/or to screen for neutralising antibody or inhibitors of infection of cells by virus.