Inhibition of HIV-1 Entry into Cells

Treatments for HIV-1 include drugs which act to inhibit specific steps in the virus life cycle such as reverse transcription and viral maturation. In 1995 breakthroughs were made in our understanding of the entry of HIV-1 into cells. HIV-1 was shown to use, in addition to the CD4 receptor, chemokine co-receptors, primarily CCR5 and CXCR4, for entry into CD4+ T cells and macrophages. These discoveries have provided another target for the treatment of HIV-1 infection. Drugs developed to block HIV-1 entry include CD4 receptor inhibitors, chemokine receptor inhibitors and inhibitors of attachment and membrane fusion. These drugs may add a further treatment for HIV-1 infection along with protease inhibitors and reverse transcription inhibitors. Several of the entry inhibitors are currently being used in clinical trials and demonstrate efficacy in vivo. In this review, the entry blocking drugs that have recently been patented, their mode of action in inhibiting HIV-1 and their efficacy in clinical trials will be discussed.