Mini-chaperones: potential immuno-stimulators in vaccine design.

The immunogenic properties of heat shock proteins (HSPs) have prompted investigations into their application as immuno-modulatory agents. HSPs have been used as potent adjuvants in immunotherapy of cancer and infectious diseases. Some studies showed that immune activities reside within N- or C-terminal fragments of HSPs. These small fragments are sufficient to link peptides, to bind and be taken up by the receptors CD91 and scavenger receptor type A on antigen presenting cells (APCs). Thus, these mini-chaperones can be used in immunotherapy of tumors and vaccine development. The data clearly demonstrated the potential of using HSP fragments as a possible adjuvant to augment CTL response against infectious diseases. Some HSP domains have been shown to inhibit endothelial cell growth, angiogenesis or tumor growth. In this review, we describe the immuno-stimulatory activities of various mini-chaperones in development of different vaccine strategies (DNA-based vaccine and protein/peptide-based vaccines).