(melle-4)cyclosporin and HIV-Infections

SDZ NIM 811 is a cyclosporin A (CsA) analogue that is completely devoid of immunosuppressive capacity but exhibits potent and selective anti-human immunodeficiency virus type 1 (HIV-1) activity. Binding to cyclophilin A, the intracellular receptor for cyclosporins, is a prerequisite for HIV-1 inhibition by cyclosporins. Cyclophilin A was demonstrated to bind to HIV-1 p24gag and this cyclophilin-Gag interaction leads to the incorporation of cyclophilin A into HIV-1 virions. SDZ NIM 811 inhibits this protein interaction, and this is likely to be the molecular basis for its antiviral activity. Here, we show that in activated primary T cells SDZ NIM 811 interferes with two stages of the virus replication cycle: (i) translocation of pre-integration complexes into the nucleus and (ii) production of infectious virus particles. SDZ NIM 811 not only inhibits translocation of HIV-1 pre-integration complexes in primary T cells, but also in a growth-arrested T cell line. In vivo, most T lymphocytes are quiescent, but serve nevertheless as a major and inducible HIV-1 reservoir in infected individuals. Significant amounts of cyclophilin A were found to be associated with virus particles propagated in primary T cells. SDZ NIM 811 caused a strong reduction in the amount of incorporated cyclophilin A, thereby reducing infectivity. Thus, cyclophilin A seems to be necessary for HIV-1 replication in primary T cells.

Topics: Anti-HIV Agents; Cell Division; Cyclosporine; Drug Interactions; HIV Infections; HIV-1; Humans; T-Lymphocytes; Virion; Virus Replication