[HIV entry into the cells--mechanisms and therapeutic possibilities].

Human immunodeficiency virus (HIV) entry into cells is the first step in the viral replication cycle, which has been explored as a new therapeutic target. A better knowledge of the mechanisms involved in the entry process has led to the development of agents, which may inhibit each of the different steps of the viral entry process: attachment of the gp120 to the CD4 cell receptor; binding of the gp120 to CCR5 or CXCR4 coreceptors; and the fusion of viral and cell membranes. Entry inhibitors are the latest family of antiretroviral compounds, being enfuvirtide, a fusion inhibitor, the first approved. Several other entry inhibitors are currently in clinical development and hopefully soon will be part of the therapeutic armamentarium against HIV.