Broadly targeted CD8 + T cell responses restricted by major histocompatibility complex E

Abstract

An unconventional route to protection One promising approach toward an HIV-1 vaccine involves infecting people with cytomegalovirus engineered to express proteins from HIV-1. This approach, which works by eliciting virus-killing CD8 + T cells, provides robust protection in nonhuman primate models. Hansen et al. have found out why this approach is so effective. Normally, peptide antigens presented by major histocompatibility complex-1a (MHC-Ia) activate CD8 + T cells. In vaccinated monkeys, however, CD8 + T cells reacted to peptide antigens presented by MHC-E molecules instead. Moreover, MHC-E could present a much wider range of peptides than MHC-Ia. Science , this issue p. 714