Abstract
The pathogenesis of nasopharyngeal carcinoma caused by the Epstein-Barr virus (EBV) has been studied experimentally by infecting monolayer cells derived from human normal nasopharynx with the B-lymphotropic EBV. Direct EBV infection of the cell sheets derived from the human nasopharynx resulted in the appearance of EBV-associated nuclear antigen-positive floating cells, suggesting that the monolayer cells have been transformed. Since these cells seemed to be of the B-type lymphocyte, it may be assumed that there must have been B lymphocytes among the cells of the monolayer which have undergone transformation by the virus. EBV infection of fused human epithelial cells (Ad-AH and D98-AH cells) and B-lymphoblastoid cells (BJAB cells) showed that the EBV receptors had been maintained for no longer than 24 h even when heterokaryons and hybrid cells were formed.