A novel recombinant variant of latent membrane protein 1 from Epstein Barr virus in Argentina denotes phylogeographical association

Epstein Barr virus (EBV) infection in Argentina occurs at an early age and occasionally develops infectious mononucleosis (IM). EBV is also related with lymphomas. LMP1, the viral oncoprotein is polymorphic and is used to define viral variants. AIM: To study LMP1 variants distribution among children with EBV+ malignant and benign conditions as well as in healthy carriers. METHODS: Oral secretions and blood cells from 31 children with IM, and biopsies from 14 EBV+ reactive lymphoid hyperplasia and 33 EBV+ lymphomas were included. LMP1 was amplified by nested PCR and sequenced. Phylogenetic reconstructions were made under Maximun Likelihood, Bayesian and coalescent algorithms. RESULTS: Six clades were defined (China1, China2, Med-, Alaskan, B95.8 and Argentine). Argentine variants, the most prevalent (46%), harbored 3 distinctive mutations and were a recombination between Raji and China1. Despite no pathology or compartment associations were observed for LMP1, the Argentine clade showed a phylogeographic association with our region. LMP1 estimated evolution rate was 8.591x10(-5)s/s/y and the estimated tMRCA for Raji and Argentine was 136ybp. CONCLUSIONS: An LMP1 Argentine clade was defined. LMP1 evolutionary rate was higher than expected for herpesviruses. The tMRCA for Raji and the Argentine agrees with African immigration and could explain the recombinant nature of the Argentine variant.