LIGANDS OF THE ANTIESTROGEN-BINDING SITE ARE ABLE TO INHIBIT VIRION PRODUCTION OF HUMAN-IMMUNODEFICIENCY-VIRUS 1-INFECTED LYMPHOCYTES

Since the discovery of human immunodeficiency retrovirus, the drug ars enal against retrovirus has rapidly increased. Concomitantly, new chal lenges in the therapy of acquired immune deficiency syndrome have aris en, including drug toxicities, drug resistance, and the development of various cancers as effective therapies prolong survival. Tamoxifen, a nonsteroidal antiestrogen with a low incidence of side effects, is wi dely used in cancer therapy; it is known to exert pleiotropic activiti es by binding essentially to the estrogen receptor and other unidentif ied proteins. In the present work, quantification of the p24 core prot ein of human immunodeficiency virus 1 produced by infected lymphocytes shows an inhibitory effect of tamoxifen on virion production, Moreove r, we assume that this effect is not mediated by the estrogen receptor because antiestrogen ligands interacting with the antiestrogen-bindin g site exhibit efficacy related to their affinity for this site, altho ugh specific antiestrogens of the estrogen receptor are ineffective.