Short communicationVirological characterization of HIV-2 vpx gene mutants in various cell systems

Requirement of intrinsically disordered protein Vpx for HIV-2 replication is cell-type dependent. To define Vpx-dependent conditions, replication ability of HIV-2 vpx mutants was analyzed in various cell lines that differ in cellular type, differentiation state and/or expression level of anti-HIV-1 SAMHD1 degraded by Vpx. Induction of Vpx-sensitive anti-HIV-2 state was not always associated with SAMHD1 expression. Compared with our previous data in lymphocytic cells, growth-defectiveness of the vpx mutants in differentiated THP-1 cells, a newly established multi-cycle infection system, was considerably different. Taken together, our results suggest that Vpx plays cell-type dependent role through its undetermined structure and/or function.