Serologic specificity of antibodies to herpes simplex virus glycoprotein B present in human sera. Analysis by transient expression of glycoprotein B-derivatives.

Glycoprotein B (gB) is an essential glycoprotein of herpes simplex virus (HSV) and a major target for cellular and humoral immune response in the infected host. In the present study, we have analyzed the pattern of reactivity of a panel of 23 HSV-seropositive patient sera using as test antigens gB derivatives made in COS cells in a transient expression assay. Our results show that nearly all the sera tested, reacted with wild-type gB or tgB (772) (that lacks 102 amino acids cytoplasmic domain). However, when tgB (477 amino acids) or gBdl (an inframe deletion between amino acids 477-772) were used as test antigens only 12 out of 23 sera tested positive. Further analysis using competition assays revealed that these sera can be classified into at least two groups: (i) that contain gB-reactive antibodies reactive to intact gB or tgB (772); (ii) that contain antibodies that recognize all forms of gB-derivatives tested. The results presented here underscore the potential limitations in using certain truncated forms of gB as antigens for subunit vaccine or in the serodiagnosis of HSV infection.