title: A chimeric protein comprised of bovine herpesvirus type 1 glycoprotein D and bovine interleukin-6 is secreted by yeast and possesses biological activities of both molecules.
abstract: Bovine herpesvirus type 1 (BHV-1) glycoprotein D (gD) engenders mucosal and systemic immunity and protects cattle from viral infection. Chimerization of cytokines with gD is being explored to confer intrinsic adjuvanticity on gD. Addition of the appropriate cytokine may convert gD into an antigen that specifically engenders protective mucosal immunity. Here DNA coding for the mature bovine interleukin-6 (IL-6) protein was fused through a synthetic glycine linker to the 3' end of DNA coding for the mature BHV-1 gD (tgD) external domain. It was cloned behind the yeast alpha prepro signal sequence and transfected into Pichia pastoris which secreted the chimeric protein (tgD-IL-6) as a 100 kDa molecule. This chimera combined the immunogenic properties of native gD and the in vitro biological activity of bovine IL-6 based on the following observations. A panel of BHV-1 gD-specific monoclonal antibodies recognizing five neutralizing epitopes on native gD reacted with tgD-IL-6. Sera from yeast tgD-IL-6-immunized mice neutralized BHV-1 infection in vitro. The chimeric protein enhanced total bovine immunoglobulin production 16-fold above tgD alone in pokeweed-stimulated bovine peripheral blood mononuclear cells (P < 0.05). This chimeric protein may be a potent mucosal immunogen.
authors.affiliation: Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison 53706, USA.
authors.forename: X
authors.initials: X
authors.lastname: Zhu
authors.forename: S
authors.initials: S
authors.lastname: Wu
authors.forename: G J
authors.initials: GJ
authors.lastname: Letchworth
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000917:Antibody Formation; D001483:Base Sequence; D002417:Cattle; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000302:isolation & purification; D006023:Glycoproteins / Q000276:immunology* / Q000378:metabolism; D006031:Glycosylation; D007242:Herpesvirus 1, Bovine / Q000276:immunology*; D007111:Immunity, Cellular; D015850:Interleukin-6 / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009092:Mucous Membrane / Q000276:immunology; D010843:Pichia / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000276:immunology* / Q000378:metabolism