GEOGRAPHIC SEQUENCE VARIATION OF LATENT MEMBRANE-PROTEIN-1 GENE OF EPSTEIN-BARR-VIRUS IN HODGKINS LYMPHOMAS

To assess the role of the Epstein-Barr virus (EBV) latent membrane pro tein 1 (LMP1) gene in the development of Hodgkin's lymphoma (HL), the polymorphism of this gene in EBV isolates from different geographic lo cations was analyzed. A 497 bp fragment spanning LMP1 gene exons 1 and 2 was amplified by polymerase chain reaction (PCR), using a primer pa ir bracketing a Xhol restriction site. PCR products were subjected to Xhol digestion and to DNA sequencing analysis. Twenty-five HL biopsy s pecimens from the United States and five HL and four non-Hodgkin's lym phoma (NHL) biopsy specimens from Italy were examined. Eighty percent of LMP1-positive samples (12 of 15) from the United States maintained the Xhol restriction site and the remaining 20% partially lost the Xho l site. One of four EBV-positive HL and one of the three EBV-positive NHL specimens from Italy lost the restriction site. The other three EB V-positive HL DNAs were partially cut by Xhol. Direct DNA sequencing a nalysis revealed that those Italian samples not digested by Xhol were due to a G to C transversion at the first base of codon 18, resulting in the change of glycine to arginine. Those DNA samples partially cut by Xhol were due to a mixture of G/C at the same location. In contrast , those partially digested American HL DNAs had a mixture of GTT at th e second base of codon 17. The sequence variation found in the Italian samples differs from that of Asian EBV strains, in which G to T trans version was detected at codon 17, resulting in the substitution of arg inine by leucine. Among the 72% (18 of 25) EBV-positive American HL sa mples, 67% (12 of 18) were associated with type A virus, 17% (3 of 18) with type B, and 17% (3 of 18) with dual viral sequences. EBV DNA was detected in 80% (four of five) of Italian HL biopsy specimens, in whi ch 50% (two of four) were associated with type A and 50% (two of four) with type B. Despite these sequence variations at the Xhol recognitio n site between EBV isolates of different geographic locations, no dire ct correlation with a specific genotype was observed. These results, t o our knowledge, represent the first observation of a specific point m utation at codon 18 of LMP1 gene associated with a particular geograph ic location. It appears that the Xhol polymorphism may be a useful mol ecular marker for epidemiologic study, and the alteration in the LMP1 gene may have functional significance in the development of HL in cert ain geographic areas. (C) 1995 Wiley-Liss, Inc.