Chemokines and defensins as HIV suppressive factors: an evolving story

When attacked by HIV, the immune system counteracts infection with elicitation of HIV-specific antibodies and cytotoxic T lymphocytes. In most cases however, these defenses are unable to resolve HIV infection, which progresses, if left untreated, ravaging the immune system and leading to AIDS and, eventually, to death. Nonetheless, there are additional components of the immune system, from both the innate and the adaptive components, that are associated with improved clinical status and, in some cases, even with protection from infection. Two distinct families of such factors have been studied in depth: chemokines and beta-defensins. CCR5 chemokines, which are involved in adaptive immunity, are molecules produced by lymphocytes, and thus are likely to play a role in controlling HIV systemically. beta-defensins are instead produced by epithelial cells, and thus are important in controlling infection at mucosal sites. Both of these families of molecules, therefore, are involved in crucial battlegrounds for fighting HIV infection. Here, we review the evidence that argues for their importance in AIDS pathogenesis and in preventive and therapeutic approaches to combat HIV infection.