Topological distribution of virus-specific and cross-reactive antigenic determinants on the gB glycoprotein of the herpes simplex viruses.

The antigenic properties and relations between the herpes simplex virus type 1 and 2 (HSV1, HSV2) gB glycoproteins were investigated. Using several assay systems to analyze the virus-specific reactivity of polyclonal monospecific rabbit anti-gB sera, it was demonstrated that most of the antigenic determinants of the gB glycoproteins exposed at the surface of both virions and infected cells are virus-specific rather than cross-reactive. Comparative examination of the reactivity of human immune sera with HSV1 and HSV2 antigens by immunoblotting also revealed differences in the ability of HSV1 and HSV2 immune sera to recognize homologous vs. heterologous gB antigens. These results indicate that despite the high degree of amino acid sequence homology which exists between the HSV1 and HSV2 gB glycoproteins many of the immunologically relevant antigenic determinants of the gB glycoproteins probably reside in regions of the molecule which are not so highly conserved between the two HSV serotypes.