Inhibition of human immunodeficiency virus replication by nonimmunosuppressive analogs of cyclosporin A

Analogs of the immunosuppressive cyclic undecapeptide cyclosporin A (CsA) with substitutions in positions 1, 4, 6, and/or 11 were rationally designed to possess substantially diminished or no immunosuppressive activity. When these compounds were assayed for their capacity to interfere with the replication of human immunodeficiency virus, some displayed a potent antiviral activity in newly infected cells. However, only CsA could interfere with virus replication in persistently infected cells. One CsA analog with antiviral activity costimulated the phytohemagglutinin-induced production of interleukin 2 by human lymphocytes. Human immunodeficiency virus particles from drug-exposed cells showed lower infectivity than virions from untreated cells. Thus, these nonimmunosuppressive analogs of CsA constitute a promising class of lead compounds to develop drugs for effective treatment of the acquired immunodeficiency syndrome.