Circle of protection against HIV
New in vitro research suggests that HIV infection can be prevented by inducing the endogenous production of θ-defensins, a class of cyclic antimicrobial peptides whose expression is thought to be blocked in the vast majority of humans.1 The use of aminoglycoside-based vaginal microbicides to induce the peptides is being tested for safety in macaques.
θ-Defensins are a class of cyclic 18-amino-acid peptides that contain 3 disulfide bonds and target HIV entry into cells. The compounds were first identified in rhesus macaques in 1999,2 but thus far nobody has found them to be expressed in humans. A 2002 study by a University of California, Los Angeles (UCLA) team found that humans have defensin-θ (DEFT) genes, but premature termination