Early Cytotoxic T-Cell Responses May Be Key To Development.(Brief Article)

2001 NOV 7 - (NewsRx.com & NewsRx.net) -- by Michael Greer, senior medical writer - Vaccines for HIV should harness the powerful cytotoxic T-lymphocyte (CTL) responses to the virus seen in the acute stages of infection, researchers in Wisconsin report.

David I. Watkins and colleagues at the Wisconsin Regional Primate Center at the University of Wisconsin in Madison described a "a novel approach to HIV vaccine design that is, as yet, unproven and still in preliminary development" in the November 2001 issue of the journal Immunology Letters.

Vaccines may be able to use viral escape mutations to hasten early immune responses, so that HIV mutation cannot outpace CTL destruction of the virus, Watkins and coauthors suggested.

"Conventional wisdom suggests that regions of the virus that are structurally and functionally important will generally be well-conserved both among clades and within an infected host," they said. Many vaccines currently being developed, including several already being tested in human studies, target these conserved genetic regions because escape mutations there would presumably cripple viral function.

However, Watkins and coworkers found in rhesus macaques several specific CTL responses to acute SIV infection that resulted in genetically altered viral populations. The appearance of these mutated viruses suggests that cells infected by wild-type viruses were successfully negated by CTL activity, they noted.

The researchers hypothesized that vaccines using epitopes from viruses ...