The human immunodeficiency virus type 1 (HIV-1) vif protein is located in the cytoplasm of infected cells and its effect on viral replication is equivalent in HIV-2

The human immunodeficiency virus type 1 (HIV-1) vif gene (viral infectivity gene) plays an important role in viral replication in vitro. We demonstrated that the Vif protein is membrane associated in HIV-1-infected cells and have investigated the role in viral replication of the equivalent gene in HIV-2. We constructed an HIV-2 vif minus mutant and studied its virulence and cellular tropism in vitro. Parallel experiments were also performed with an HIV-1 vif mutant to ascertain whether the two distantly related HIV-2 and HIV-1 genes might exert the same effect on viral replication. The results indicated that both HIV-1 and HIV-2 vif minus cell-free infection was not impaired when the SupT-1 cell line was used. However, differential degrees of impairment in viral replication were observed when other cell lines were used (Molt-3, U-937). Nevertheless, when viral production could not be detected, rescue experiments by coculture with the permissive cell line SupT-1 were generally positive, indicating that the...