Since Jules Freund reported that crude mycobacterial extracts greatly promoted immune responses to antigens (1), the use of adjuvants has become a widespread, but poorly understood practice to promote T and B cell responses (2). Recent studies have begun to identify the chemical nature of several adjuvants and the cellular and molecular mechanisms of their long-elusive immunological effects. For example, conserved microbial structures are recognized by innate immunity receptors such as Toll-like receptors (TLRs) and the complement system, eliciting specific signaling cascades which, ultimately, result in enhancing and guiding T and B cell responses (for reviews, see references 3 and 4).
Despite these considerable advances, the task of enhancing CD8 T cell priming to nonliving antigens, a major goal of vaccines against a range of infectious and cancer diseases, has eluded immunologists. In this issue, Gonzalez-Aseguinolaza and colleagues report that...
