DIFFERENTIAL T-CELL RESPONSE INDUCED BY CERTAIN RECOMBINANT OLIGOPEPTIDES OF HERPES-SIMPLEX VIRUS GLYCOPROTEIN-B IN MICE

Much attention is presently focused on the quality of the immune respo nse produced by helper T or regulatory cells because of its implicatio ns for vaccine development and immunomodulation. Glycoprotein B (gB) o f herpes simplex virus (HSV) has been shown to induce a protective T c ell response. To further characterize the nature of the T cell respons e, oligopeptides were expressed from the open reading frame of gB from HSV-2 (gB-2) as fusion proteins with beta-galactosidase (GZ) in E. co li. After immunopurification using an anti-GZ affinity column, oligope ptides p59 and p65, spanning amino acid residues 339-394 and 424-484 o f gB-2 respectively, were examined for immunogenic response by delayed type hypersensitivity (DTH) in vivo and for antigenic response by T c ell proliferation in vitro. p59 but not p65 was able to prime for both DTH and proliferative T cell response to whole HSV-2 and protect agai nst challenge infection. However, when mice were pretreated with cyclo -phosphamide, p65 primed for a strong DTH response to a level similar to that induced by p59 in mice either pretreated or not treated with c yclo-phosphamide. This suggests that p65 contains epitopes capable of inducing both DTH and immunosuppression. Thus, when mice were primed w ith p65 before immunizing with HSV-2, their in vitro HSV-specific prol iferative response was suppressed. Therefore, p59 is a good immunogen able to induce significant, though incomplete, protection. It could be considered for inclusion in a cocktail of subunit vaccines against HS V-2 whereas p65 or parts thereof should be excluded for this purpose.