Monospecific antibodies to Marek's disease virus antigen B dimer (200 kDa) and monomer (130 and 60 kDa) glycoproteins neutralize virus infectivity and detect the antigen B proteins in infected cell membranes.
Monospecific antibodies were prepared by nitrocellulose blot immunoaffinity to 3 polypeptide components of the host-membrane associated B antigen of Marek's disease herpesvirus (MDV) and to its soluble A antigen. The B antigen comprised a 200 kDa dimer which is 2-mercaptoethanol (2-ME) labile, a monomer of 130 kDa and a 60 kDa protein, both of which are 2-ME resistant. Cross-immunoblotting studies showed that the anti-dimer antibody recognized the dimer protein as well as the 130 and 60 kDa components. In contrast, the anti-130 kDa antibody gave the strongest signal on blots of reducing gels indicating that the monomer is largely formed by in vitro reduction with 2-ME. All four antibodies recognized membrane antigens on chicken embryo fibroblasts infected with MDV vaccine viruses representative of the three serotypes and in addition, neutralized the homologous MDV isolate. The anti-dimer antibody was greatest, the anti-monomer antibody was the weakest and the anti-60 kDa antibody intermediate in neutralizing efficacy to all four viruses. We conclude from these studies that the B antigen presents at least two classes of neutralizing epitopes: one is discontinuous and of broad specificity on the intact dimer molecule and the other, on the 130 and 60 kDa proteins, is continuous and of lower avidity.
Davidson
I
I
Department of Avian Diseases, Kimron Veterinary Institute, Bet Dagan, Israel.
Becker
Y
Y
Malkinson
M
M
D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D000918:Antibody Specificity; D000956:Antigens, Viral / Q000276:immunology*; D002460:Cell Line; D002462:Cell Membrane / Q000382:microbiology; D002642:Chick Embryo; D003429:Cross Reactions; D005455:Fluorescent Antibody Technique; D008381:Herpesvirus 2, Gallid / Q000276:immunology* / Q000502:physiology; D015151:Immunoblotting; D009500:Neutralization Tests; D014779:Virus Replication
D000914:Antibodies, Viral; D000956:Antigens, Viral; C056151:Marek's disease herpesvirus gp57-65