Abstract
Nuclear DNA-binding proteins were extracted from lymphoblastoid cell lines transformed with Epstein-Barr virus (EBV) or with the related lymphotropic herpesviruses of gorilla (Herpesvirus gorilla), chimpanzee (H. pan), baboon (H. papio) or orang-utan (H. pongo). They were immunoblotted with the sera of all four simian species in comparison with EBV antibody-positive human sera. Eight nuclear proteins were identified, and were designated GONA-1 and GONA-2 for H. gorilla-determined nuclear antigens, PANA-1A, PANA-1B and PANA-2 for H. pan, PONA-2 for H. pongo and HUPNA-1 and HUPNA-2 for H. papio-determined nuclear antigens. One of two tested HUPNA-2-positive baboon sera and one PONA-2-positive orang-utan serum also reacted with EBNA-2 in EBV-transformed cells. A human serum that contained antibodies to all five EBNA proteins cross-reacted only with PANA-2 and PONA-2. Monospecific anti-peptide antibodies against EBNA-2, type A, also reacted with PONA-2, but not with the other simian nuclear antigens. The data provide evidence that EBV-like simian lymphotropic herpesviruses induce EBNA-like nuclear antigens and that EBNA-2 and some simian EBNA-related proteins contain an epitope that has been conserved during the evolution of the EBV family of viruses.