The synthetic peptide Trp-Lys-Tyr-Met-Val-d-Met as a novel adjuvant for DNA vaccine

Trp-Lys-Tyr-Met-Val-d-Met (WKYMVm) is a synthetic peptide known to activate human neutrophils, monocytes and dendritic cells, resulting in the enhancement of superoxide generation, bactericidal activity, chemotactic migration and survival. In this study, we demonstrated that WKYMVm enhanced the surface expression of CD80, but not that of CD40, CD86 and MHC class II, on mouse bone marrow-derived dendritic cells which is one of the essential costimulatory signals for the induction of immune responses. Furthermore, when WKYMVm was codelivered with HIV, HBV and Influenza DNA vaccines, WKYMVm selectively enhanced the vaccine-induced CD8+ T cell responses in a dose-dependent manner, in terms of IFN-γ secretion and cytolytic activity. Our results indicate that a synthetic peptide, WKYMVm can function as a novel adjuvant for DNA vaccine.