Exosomes act as potent cell-free peptide-based vaccines.

2004 APR 21 - (NewsRx.com & NewsRx.net) -- Exosomes act as potent cell-free peptide-based vaccines.

According to a study from an international team of researchers, "Ideal vaccines should be stable, safe, molecularly defined, and off-the-shelf reagents efficient at triggering effector and memory antigen-specific T cell-based immune responses. Dendritic cell-derived exosomes could be considered as novel peptide-based vaccines because exosomes harbor a discrete set of proteins, bear functional MHC class I and 11 molecules that can be loaded with synthetic peptides of choice, and are stable reagents that were safely used in pioneering phase I studies. However, we showed in part I that exosomes are efficient to promote primary MHC class I-restricted effector CD8+ T cell responses only when transferred onto mature DC in vivo."

"In this work, we bring evidence that among the clinically available reagents, Toll-like receptor 3 and 9 ligands are elective adjuvants capable of triggering efficient MHC-restricted CD8+ T cell responses when combined to exosomes," stated Nathalie Chaput at the Institut Gustave Roussy in France and collaborators in France, the U.S., the Netherlands, Italy, and England. "Exosome immunogenicity across species allowed to verify the ...