FIG. 2.

Producer cell CypB has no effect on HIV-1 virion infectivity. Pools of HeLa cells transduced with an shRNA expression construct specific for CypB mRNA or specific for luciferase (Luc), as a control, were normalized by cell number and subjected to immunoblotting with antibodies for CypB and actin (A). Virions were produced by transfection of CypB KD or Luc KD HeLa cells with pNL4-3 in the presence of 10 μM CsA, as indicated (B). Virions were enriched by ultracentrifugation as described in the legend to Fig. 1, normalized by RT activity, and used to infect Jurkat T cells in drug-free medium. Infected cells were identified by flow cytometry after being immunostained for HIV-1 CA. Infectivity is reported relative to the number of virions produced from the control cells in the absence of CsA.