Effect of activation of the Epstein-Barr virus genome on expression of B cell differentiation antigens of Burkitt's lymphoma lines

Using anti-human B cell monoclonal antibodies prepared against B1 (CD20), B2 (CD21), B4 (CD19), and BB-1 (B lymphoblast antigen-1), we compared the expression of B cell differentiation antigens on a Jijoye-P3HR-1 cell line family of Burkitt's lymphomas. The expression of BB-1 and B2 antigens was faint on P3HR-1 K cell line which is an Epstein-Barr virus (EBV) high producer. On the other hand, B1 and B4 antigens were strongly expressed on it. It was also found that BB-1 expression decreased on P3HR-1 cells after activation of intracellular EBV genes by treating chemically with tumor-promoting agent (TPA) and n-butyrate, or on Raji cells on superinfection with EBV. This decrease of BB-1 was blocked by the additional treatment with retinoic acid, an inhibitor of virus replication. Dual immunofluorescence staining analysis showed that the individual cell expressing EBV-associated antigens expressed BB-1 antigen only marginally. The relationship between the change in phenotypes of host B cells and the activation of the EBV genome is discussed.