Adaptive immune responses against tumors are routinely detected in hosts bearing the tumor due to immunosurveillance mechanisms. How the immune response to tumors is initially primed remains unclear, given the limited amount of tumor antigen available for cross-priming and lack of classical Pathogen Associated Molecular Patterns (PAMPs). We demonstrate that specific ablation of CD91 in Antigen Presenting Cells (APCs) prevented the establishment of anti-tumor immunity. Anti-tumor immunity was also inhibited when transfer of tumor-derived Heat Shock Proteins (HSPs) to APCs was prevented using an endogenous inhibitor of CD91. Inhibition was manifested in a reduction of cross-presentation of tumor-derived antigenic peptides in lymph nodes. Our findings demonstrate that early in tumor development, the HSP-CD91 pathway is critical for establishment of anti-tumor immunity.
- Received August 23, 2013.
- Revision received December 16, 2013.
- Accepted December 17, 2013.
- Copyright © 2013, American Association for Cancer Research.