AFRICAN BURKITTS-LYMPHOMA - A PLANT, EUPHORBIA-TIRUCALLI, REDUCES EPSTEIN-BARR VIRUS-SPECIFIC CELLULAR-IMMUNITY

Endemicity of Burkitt's lymphoma (BL) coincides with profusion of a pl ant Euphorbia tirucalli in tropical Africa. E. tirucalli contains 4-de oxyphorbol ester that enhances Epstein-Barr virus (EBV) infection of B lymphocytes. In this study, we found that 4-deoxyphorbol ester reduce d EBV-specific cytotoxic T-cell function. Furthermore, the B lymphocyt es dually exposed to EBV and 4-deoxyphorbol ester were resistant to EB V-specific T cell cytotoxicity, through down-regulation of latent memb rane protein 1 (LMP1), the major target to EBV-specific cytotoxic T-ce lls. These immunologic findings strengthen the notion that E. tirucall i may be an important environmental risk factor for the genesis of Afr ican BL.