BAMHI DNA fragment H-polymorphism of Epstein-Barr virus is associated with the mutations present in an 89 BP sequence localized in EBNA2 gene

To characterize the genotypes of Epstein-Barr virus (EBV) isolate present in North Africa, viruses were isolated from B-lymphoblastoid cell lines established from the saliva of both Algerian Nasopharyngeal Carcinoma (NPC) patients and EBV-positive normal individuals, Algerian Burkitt's lymphoma cell lines, and NPC biopsies. By nucleotide sequence analysis, we showed that there were two specific missense mutations in an 89 bp region of EBNA2 gene at position 49390-49479 of the EBV genome: a mutation at 49449 (C-->A) and another mutation at 49444 (T-->C), changing their amino acid sequence. The first mutation was found in all B cell lines established from the saliva and 50% of BL cell lines, as well as the W91 cell line, while the second mutation was found in EBV isolates from NPC biopsies, BL cell lines and the M-ABA isolate. A PCR-RFLP analysis on the BamHI DNA fragment H showed that the Hl-H2-polymorphism was specifically associated with M-ABA-like mutation, while H-polymorphism was linked with W91-like mutation. The latter was not identified in NPC biopsies, but was found rather in saliva from NPC patients, normal individuals and BL cell lines. The M-ABA-like mutation, on the other hand, was found in 100% of NPC biopsies and some BL cell lines. This suggests that EBV with H1-H2-polymorphism is tightly implicated in NPC development in North Africa rather than EBV with H-polymorphism.