A clustering phenomenon among HCV-1a strains characterized among HIV-coinfected patients from Buenos Aires, Argentina

Abstract

The Human Immunodeficiency Virus (HIV) and Hepatitis C Virus (HCV) share the same transmission routes which lead to high coinfection rates. Among HIV-infected individuals such rates reached 21% in Argentina, being HCV-1a the most predominant subtype. In this work, twenty-five HCV subtype 1a (HCV-1a) strains from Argentinean patients that were coinfected with HIV were studied based on E2 and NS5A sequences. Phylogenetic analyses indicated that 12 strains were highly related to each other, constituting a highly supported (posterior probability = 0.95) monophyletic group that we called ?Argentinean Cluster?. The remaining HCV strains (?Other Argentinean Strains?) were interspersed along the phylogenetic trees. When comparing both groups of HCV-1a, 10 amino acid differences were located in functional domains of E2 and NS5A proteins related with the mechanisms underlying HCV resistance to IFN as well as appear to affect the peptides binding to MHC-I molecules thus favoring the immuno-surveillance and contributing to the divergence of the HCV genotypes.