Common antigenic epitopes are present on heat-labile oligomers of MDV glycoprotein B and on HSV glycoprotein B.

The antigenic cross-reactivity between the Marek's disease virus glycoprotein B (MDV gB) and glycoprotein B (gB) of herpes simplex virus type 1 and 2 (HSV1 and HSV2) was analysed by the immunoblotting method. We studied cell lysates in both denatured and in undenatured form (i.e., unheated) and reacted them with convalescent sera from chickens infected with the RBIB MDV strain and with human anti-HSV1 gB. Both sera detected the heat-labile MDV gB and the HSV gB oligomers. In addition, monospecific antibodies to the MDV gB 230 kDa oligomer (strain CVI988) were immunoaffinity purified from both the chicken and the human sera. The chicken and human monospecific antibodies detected the homologous and the heterologous gB oligomers in native MDV- and HSV1-infected cell lysates. 15 human sera were tested by immunoblotting and by immunofluorescence on HSV1-, CVI988-and herpes virus of turkeys (HVT)-infected cells. By both assays about half of the human sera reacted with MDV-infected cells. This study demonstrates that the MDV gB heat-labile oligomers possess conformational epitopes shared with the human alpha-herpes virus HSV1 and HSV2 gB heat-labile oligomers.