Abstract
Three lymphoblastoid cell lines were established from splenic lymphocytes of a lymphomatous baboon (Papio hamadryas) by co‐cultivation of the lymphocytes with X‐irradiated cells of marmoset or baboon lymphoblastoid cell cultures; the baboon splenic lymphocytes failed to grow when cultured alone. A herpesvirus, associated with each cell line, was identified by immunofluorescence, molecular hybridization and electron microscopy. Antigenic comparison with Epstein‐Barr virus (EBV) showed that the baboon herpesvirus and EBV shared cross‐reacting viral capsid antigens (VCA): 20 of 20 (100%) anti‐VCA(EBV)‐positive human sera and 55 of 62 (89%) baboon sera reacted with the baboon lymphoblastoid cells and baboon sera stained EBV VCA in P3HR‐1 and EB‐3 cells. No nuclear antigen, as assayed by anti‐complement immunofluorescence tests, was detected in baboon lymphoblastoid cells when human or baboon anti‐VCA positive sera were used. Baboon anti‐VCA‐positive sera also failed to stain EBV nuclear antigens (EBNA) in Raji or P3HR‐1 cells. Preliminary molecular hybridization studies showed only approximately 40% homology between viral DNA of baboon cell lines and DNA of EBV derived from P3HR‐1 cells.