VARIATION IN THE SEQUENCE OF EPSTEIN-BARR-VIRUS NUCLEAR ANTIGEN-1 IN NORMAL PERIPHERAL-BLOOD LYMPHOCYTES AND IN BURKITTS-LYMPHOMAS

We have examined sequence variations in the EBNA-1 protein of EBV in n ormal peripheral blood lymphocytes (PBL) and Burkitt's lymphomas (BL), We find two EBNA-1 strains P (prototype) and V (variant) which differ by 15 amino acids, Each strain has two subtypes defined by the amino acid at position 487 (P-ala, P-thr, V-pro and V-leu), In PBLs from 32 normal individuals, up to three of these subtypes were found in each s ample, but the V strain did not occur in the absence of P strain virus es, nor was the V-leu subtype ever observed in normal PBL, In BLs only a single subtype was observed in each tumor, The P-thr and V-leu subt ypes were more frequently seen than the P-ala and V-pro subtypes, whic h occurred in only two and one of the 36 tumor samples respectively, T he P-thr was the most commonly observed peripheral blood of both Ameri can and as well as in African tumors, However, in 11 of 12 American tu mors, the EBNA-1 subtype was V-leu, These data indicate that some EBNA -1 subtypes are more likely to lead to oncogenesis, and one subtype, V -leu, appears only to occur in tumors.