An additional mechanism of growth restriction in T cell line H9 of human immunodeficiency virus type 1 isolates from asymptomatic homosexual men.

The replicative properties of human immunodeficiency virus type 1 (HIV-1) isolates from asymptomatic carriers (asymptomatic isolates) and AIDS patients (AIDS isolates) were examined in the human T lymphocyte cell line H9. In agreement with earlier reports the replication of asymptomatic isolates was restricted whereas AIDS isolates replicate well in H9 cells. PCR analysis of H9 cells infected with asymptomatic isolates showed transient gag DNA synthesis for up to 48 h post-infection. This transient DNA synthesis was much lower than the amount of DNA synthesized by the AIDS isolates. The reduction in DNA synthesis reflects a restriction during virus entry. We further analysed transient DNA synthesis by the asymptomatic isolates to investigate possible post-entry restriction mechanisms. The transiently synthesized DNA was present only in the unintegrated form and was not transported in to the nucleus, suggesting an additional restriction mechanism for asymptomatic isolates in H9 cell lines at a step post-DNA synthesis and prior to or during nuclear translocation of newly synthesized viral DNA.