Summary

Heat shock protein (HSP) preparations derived from cancer cells and virus-infected cells have been shown previously to elicit cancer-specific or virus-specific immunity. The immunogenic-ity of HSP preparations has been attributed to peptides associated with the HSPs. The studies reported here demonstrate that immunogenic HSP–peptide complexes can also be reconsti-tuted in vitro. The studies show that ( a) complexes of hsp70 or gp96 HSP molecules with a va-riety of synthetic peptides can be generated in vitro; ( b) the binding of HSPs with peptides is specific in that a number of other proteins tested do not bind synthetic peptides under the con-ditions in which gp96 molecules do; ( c) HSP–peptide complexes reconstituted in vitro are im-munologically active, as tested by their ability to elicit antitumor immunity and specific CD8