Genomic characterization of genealogically related Junin virus strains, XJ#44 and the attenuated vaccine strain, Candid #1

GOÑI, S. E; ISERTE, J.A.; AMBROSIO, A.M.; ROMANOWSKI, V.; GHIRINGHELLI, P. D.; LOZANO, M. E.

Salvador de Bahía, Brasil

Congreso; XVI Encontro Nacional de Virología; 2005

Sociedad Brasilera de Virologia

Arenaviridae comprises 20 recognized virus species with a bipartite ssRNA genome and an ambisense coding strategy. The virions are enveloped and include non-equimolar amounts of each genomic RNA species, designated L (ca. 7200 nt) and S (ca. 3500 nt). Some arenaviruses have been recognized as ethiological agents for serious human diseases. In Argentina, three native arenaviruses have been described, including Junín virus -the ethiological agent of Argentine hemorrhagic fever (AHF), an acute disease with high mortality rate. In the ´80s, the Junín virus Candid#1 strain was developed as a live attenuated vaccine for AHF. Although the attenuated phenotype of this strain was confirmed in clinical trials, the molecular basis of virulence attenuation is still unknown. Molecular characterization of the vaccine strain, Candid #1, and of its more virulent ancestors, XJ 13 (prototype) and XJ#44, permits a systematic approach aimed at studying the basis of Junín virus virulence. Here we describe sequence information of both genomic RNAs, determined for Junín virus strain Candid #1 and XJ#44 and compared them to XJ 13 wild-type strain and other closely and distantly related arenaviruses. Furthermore we analyzed the secondary structure predicted for the complete set of proteins coded by the viral genome. Our results revealed twelve amino acid changes among proteins deduced for Candid#1 and the wild-type strains. Some of these changes are associated with the prediction of important secondary structure changes, and can be provisionally associated with the attenuated phenotype.