The bovine herpesvirus type 1 major tegument protein VP8 expressed in recombinant vaccinia virus does not induce significant immunity in mice.
We previously reported the characterization of the gene encoding the bovine herpesvirus type 1 (BHV-1) major tegument protein VP8. With the aim of defining the immunological properties of this protein, we constructed a recombinant vaccinia virus (VV-VP8) in which expression of the VP8 gene was regulated by the P7.5 early/late promoter. Since the sequence of the VP8 gene contained a TTTTTNT motif known to serve as a transcription termination signal of vaccinia virus genes of the early class, a second recombinant (VV-VP8-Mut) in which this signal was modified by site-directed mutagenesis was created. Characterization of the recombinant viruses revealed that truncated VP8 mRNA and protein (69 kDa) were synthesized in VV-VP8 infected cells, whereas cells infected with VV-VP8-Mut produced a protein which was undistinguishable from that of the BHV-1 encoded protein (92-94 kDa). Immunization of BALB/c mice (H-2d) with VV-VP8-Mut induced a low VP8-specific antibody response whereas no specific response was induced in VV-VP8 inoculated mice. The low humoral response elicited was similar in C57BL/6 (H-2b) and C3H (H-2k) mice. Furthermore, immunization of mice with VV-VP8-Mut did not induce a BHV-1-specific lymphoproliferation in the three mice strains examined. Our results contrast with a recent study showing that immunization of calves with purified VP8 stimulated both T cell proliferation and antibody production.
LaBoissière
S
S
Centre de Recherche en Virologie, Institut Armand-Frappier, Université du Québec, Laval, Canada.
Trudel
M
M
Simard
C
C
D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D002213:Capsid / Q000235:genetics / Q000276:immunology*; D036022:Capsid Proteins; D002417:Cattle; D015870:Gene Expression; D005822:Genetic Vectors / Q000235:genetics; D007242:Herpesvirus 1, Bovine / Q000276:immunology*; D006801:Humans; D007109:Immunity; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D011994:Recombinant Proteins / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D014407:Tumor Cells, Cultured; D014616:Vaccinia virus / Q000235:genetics
D000914:Antibodies, Viral; D036022:Capsid Proteins; D011994:Recombinant Proteins; C442561:VP8 protein, Bovine herpesvirus 1