Epimmune: There's no denying tat

Epimmune Inc. and colleagues last week published in Nature that cytotoxic T lymphocytes specific for the HIV tat protein are key during the first few weeks of the immune response to infection, and that HIV escapes immune clearance by rapid mutation of tat. The finding, which is consistent with previous observations that individual progression to AIDS correlates with the strength of the initial CTL response, could suggest that early HIV proteins such as tat, rev and nef might make useful vaccine candidates.

However, tat and other early proteins already have been tested - unsuccessfully - as HIV vaccines. But EPMN (San Diego, Calif.) believes an epitope-based vaccine designed to induce a broad CTL response will have better luck by limiting the virus' ability to escape immune response through mutation...