title: The role of heat shock proteins in antigen cross presentation.
abstract: Heat shock proteins (HSPs) are molecular chaperones that bind tumor antigens and mediate their uptake into antigen presenting cells. HSP-antigen complexes are then directed toward either the MHC class I pathway through antigen cross presentation or the conventional class II pathway, leading to activation of T cell subsets. Uptake of HSP-chaperoned polypeptides can involve both receptor-mediated and receptor-independent routes, and mechanisms of antigen sorting between the Class I and II pathways after uptake are currently under investigation. The processes involved in internalization of HSP-antigen complexes differ somewhat from the mechanisms previously determined for (unchaperoned) particulate and free soluble antigens. A number of studies show that HSP-facilitated antigen cross presentation requires uptake of the complexes by scavenger receptors (SR) followed by processing in the proteasome, and loading onto MHC class I molecules. In this review we have examined the roles of HSPs and SR in antigen uptake, sorting, processing, cell signaling, and activation of innate and adaptive immunity.
authors.affiliation: Molecular and Cellular Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School Boston, MA, USA.
authors.forename: Ayesha
authors.initials: A
authors.lastname: Murshid
authors.forename: Jianlin
authors.initials: J
authors.lastname: Gong
authors.forename: Stuart K
authors.initials: SK
authors.lastname: Calderwood