Pharmaceutical compositions comprising a stress protein complex and related molecules encoding or cells presenting such a complex are provided. The stress protein complex comprises an hsp110 or grp170 polypeptide complexed with an immunogenic polypeptide. The immunogenic polypeptide of the stress protein complex can be associated with a cancer or an infectious disease. Preferred immunogenic polypeptides include gp100, her2/neu ECD-PD, ICD and M. tuberculosis antigens. The pharmaceutical compositions of the invention can be used for the treatment or prevention of cancer or infectious disease.