Analysis of vif-defective human immunodeficiency virus type 1 (HIV-1) virions synthesized in 'non-permissive' T lymphoid cells stably infected with selectable HIV-1.

In order to facilitate analyses of the molecular function of the human immunodeficiency virus type 1 (HIV-1) Vif protein, we have developed a cell culture model-system which allows permanent production of genotypically and phenotypically vif-defective HIV-1 virions in 'non-permissive' H9 cells. Using recombinant, replication-competent HIV-1 proviruses coding for a selectable marker gene (gpt) instead of nef, two stably infected H9 subclones named M2 (vif-mutant) and WX (wild-type), respectively, were generated. Virions released from cell line M2--displaying the expected vif-defective phenotype--are produced permanently, and in an at least 50 times higher amount than virus particles from acutely vif-negative HIV-1-infected H9 cells. Analysis of viral protein composition and the electron-microscopic morphology of vif-mutant virions did not reveal any detectable differences in comparison to wild-type virions.