title: Targeting with bovine CD154 enhances humoral immune responses induced by a DNA vaccine in sheep.
abstract: CD40-CD154 interactions play an important role in regulating humoral and cell-mediated immune responses. Recently, these interactions have been exploited for the development of therapeutic and preventive treatments. The objective of this study was to test the ability of bovine CD154 to target a plasmid-encoded Ag to CD40-expressing APCs. To achieve this, a plasmid coding for bovine CD154 fused to a truncated secreted form of bovine herpesvirus 1 glycoprotein D (tgD), pSLIAtgD-CD154, was constructed. The chimeric tgD-CD154 was expressed in vitro in COS-7 cells and reacted with both glycoprotein D- and CD154-specific Abs. Both tgD and tgD-CD154 were capable of binding to epithelial cells, whereas only tgD-CD154 bound to B cells. Furthermore, dual-labeling of ovine PBMCs revealed that tgD-CD154 was bound by primarily B cells. The functional integrity of the tgD-CD154 chimera was confirmed by the induction of both IL-4-dependent B cell proliferation and tgD-specific lymphoproliferative responses in vitro. Finally, sheep immunized with pSLIAtgD-CD154 developed a more rapid primary tgD-specific Ab response and a significantly stronger tgD-specific secondary response when compared with animals immunized with pSLIAtgD and control animals. Similarly, virus-neutralizing Ab titers were significantly higher after secondary immunization with pSLIAtgD-CD154. These results demonstrate that using CD154 to target plasmid-expressed Ag can significantly enhance immune responses induced by a DNA vaccine.
authors.affiliation: Veterinary Infectious Disease Organization, University of Saskatchewan, Saskatoon, Canada.
authors.forename: Sharmila
authors.initials: S
authors.lastname: Manoj
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Griebel
authors.forename: Lorne A
authors.initials: LA
authors.lastname: Babiuk
authors.forename: Sylvia
authors.initials: S
authors.lastname: van Drunen Littel-van den Hurk
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis*; D000918:Antibody Specificity / Q000235:genetics; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism; D023201:CD40 Ligand / Q000008:administration & dosage / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D019556:COS Cells; D002417:Cattle; D002460:Cell Line; D019281:Dimerization; D004285:Dogs; D004847:Epithelial Cells / Q000276:immunology / Q000378:metabolism; D018985:Epitopes, B-Lymphocyte / Q000276:immunology; D005260:Female; D018390:Gene Targeting / Q000379:methods*; D006566:Herpesviridae Infections / Q000276:immunology / Q000517:prevention & control; D007242:Herpesvirus 1, Bovine / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D010957:Plasmids / Q000008:administration & dosage / Q000276:immunology; D011485:Protein Binding / Q000235:genetics / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000096:biosynthesis / Q000276:immunology / Q000378:metabolism; D012756:Sheep; D014162:Transfection; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014764:Viral Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
chemical_list: D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D018985:Epitopes, B-Lymphocyte; D011993:Recombinant Fusion Proteins; D019444:Vaccines, DNA; D014764:Viral Proteins; C046998:bovine herpesvirus type-1 glycoproteins; D023201:CD40 Ligand