Discovery of VIRIP – a Natural HIV Entry Inhibitor

Preventing entry of HIV into host cells is a key strategyfor controlling viral replication. To date, there isonly one approved HIV entry inhibitor drug, enfuvirtide(Fuzeon®; T-20), although several others are in development.German researchers have recently reportedthe identification of a naturally occurring peptide inhuman blood that blocks HIV entry (Kirchhoff, et al.Cell 2007;129:263-75). The investigators screened acomprehensive library of more than one million smallpeptides generated from human blood filtrate, theresidue left after kidney dialysis. They found that a20-residue peptide sequence designated “virus inhibitorypeptide,â€? or VIRIP, a fragment of alpha-1-antitrypsin,which is the most abundant circulating serineprotease inhibitor, reduced cellular HIV infection by99%, and inhibited multiple strains of HIV-1, includingthose resistant to current antiretroviral drugs.