Abstract
Enhanced expression of intracellular heat shock proteins (HSP) primarily promotes protein chaperoning, transport and folding of naïve, aberrantly folded, or mutated proteins, resulting in cytoprotection during variety of stressful stimuli. In contrast, exposure of immunocompetent cells to extracellular HSP activates antigen presenting cell-mediated effectors functions; including enhanced pro-inflammatory and anti-inflammatory responses, chemokine and costimulatory molecule expression and in anti-tumor surveillance. In addition, extracellular HSP has been shown to play a role in situations of both acute psychological stress and exercise. This chapter covers recent advances in understanding the complex nature of the chaperokine activity of HSP and briefly discusses the biological significance of circulating serum HSPA1A (Hsp70) to host physiology and includes recent application of HSPA1A (Hsp70)-based immunotherapies.
