CypA promotes HIV-1 reverse transcription in both HeLa and Jurkat T cells, but inhibits nuclear entry in HeLa cells. HIV-1 reporter viruses bearing wild-type (WT) CA or the indicated CA mutants, were used to challenge HeLa (left) or Jurkat T (right) cells, treated with 5 μM CsA or DMSO as control. 72 hours later GFP expression was assessed by flow cytometry (A). 24 hrs later, late reverse transcription (B) and 2-LTR circles (C) were assayed by quantitative PCR. Data represent one of at least three independent experiments. Error bars represent ± SEM (n = 3).