Heat shock protein gp96 and cancer immunotherapy.

Heat shock protein gp96 is a highly conserved and monomorphic glycoprotein in the endoplasmic reticulum. It functions as molecular chaperone and can associate with a variety of antigenic peptides noncovalently in vivo and in vitro. Recent studies have indicated that gp96 molecules participate in major histocompatibility complex class I-restricted antigen presentation pathway. Immunization of mice with gp96 preparations isolated from cancer cells can elicit a cancer-specific protective T cell immune response that is recallable, which is a prerequisite for gp96 as a therapeutic vaccine against cancers. The immunogenicity of gp96 molecules has been attributed to the antigenic peptides associated with them. These phenomena provide a new pathway for cancer immunotherapy. The mechanism that the gp96-peptide complex induces specific immune response and the explorations for gp96-peptide complex as a therapeutic cancer vaccine are reviewed.