Construction and Characterization of Infectious Molecular Clones of HIV-1 CRF63_02A6.

Currently, HIV-1 CRF63_02A6 is the prevalent genetic variant of the HIV-infected subjects in the major part of the Siberian Federal District (Russia). The HIV-1 CRF63_02A6 R5-tropic pT11.17 and X4-tropic pMtBs.18 infectious molecular clones (IMCs) were constructed using the virus isolates recovered in 2015 and 2017 of male HIV-infected Russian residents (from Tomsk and Novosibirsk, respectively). Near full-length proviral HIV-1 sequences (9,644 and 9,748 bp) were subcloned in pBluescript II KS(-). The CRF63_02A6 IMC virions were obtained by transfecting HEK293T cells with the constructed plasmids and demonstrated a stable growth in peripheral blood mononuclear cell culture (p24 concentration increased >1,000-fold and the virus protein accumulation in culture liquid exceeded 100,000 pg/mL). The tropism of CRF63_02A6 IMCs was determined genotypically (using Geno2pheno) and phenotypically by cultivating the IMC virions in MT-2, U87-CD4-CCR5, and U87-CD4-CXCR4 cell cultures. The obtained HIV-1 CRF63_02A6 IMCs may be useful in basic and applied research.