Comparisons of nuclear antigens of Epstein-Barr virus (EBV) and EBV-like simian viruses

Nuclear antigens (NA) of EBV (EBNA), Herpesvirus gorilla, H. papio, H. pongo and H. pan were tested with sera of human, gorilla, chimpanzee, orangutan, gibbon and baboon origins. Both conventional anticomplement immunofluorescence (ACIF) and acid-fixed nuclear binding of antigen followed by ACIF (AFNB) procedures were used. Comparisons of antibody titres by ACIF and AFNB suggested that human sera detected the same antigenic determinants on EBNA by the two procedures but gorilla sera measured different determinants on H. gorilla NA. Asymmetric cross-reactions were found with gorilla, chimpanzee and baboon sera but individual human and orangutan sera were found which had extensive cross-reactivities. Absorption experiments with these broadly reactive sera with H. gorilla NA and comparisons of antibody titres of human sera with EBNA, H. gorilla and H. papio NA suggested the presence of an EBV-specific determinant as well as a broadly reactive determinant on EBNA.