Defensins inhibit HIV-1 replication

CD8 T lymphocytes from immunologically stable HIV-1-infected secrete a soluble factor — termed CAF —, which suppresses HIV-1 replication, but the exact identity of CAF has been unclear. In September 26 Sciencexpress, Linqi Zhang and colleagues at The Rockefeller University, New York, USA, show that human α-defensins-1, -2 and -3 collectively account for the anti-HIV-1 activity of CAF not attributable to β-chemokines (Sciencexpress, 10.1126/science.1076185, September 26, 2002).

Zhang et al. stimulated CD8 T cells from long-term non-progressors with HIV-1 infection and, using protein-chip technology, isolated a cluster of proteins secreted after stimulation. They identified these proteins as α-defensins-1, -2 and -3 on the basis of specific antibody recognition and amino-acid sequence. In addition, they showed that a human α-defensin antibody neutralized CAF activity and α-defensin preparations inhibited the replication of HIV-1 isolates in vitro.

"Additional studies are necessary to define the true antiviral potency of α-defensins, which...