ERADICATION OF ESTABLISHED MURINE TUMORS USING A NOVEL CELL-FREE VACCINE - DENDRITIC CELL-DERIVED EXOSOMES

Dendritic cells (DCs) are professional antigen presenting cells with t he unique capacity to Induce primary and secondary immune responses in vivo. Here, we show that DCs secrete antigen presenting vesicles, cal led exosomes, which express functional Major Histocompatibility Comple x class I and class II, and T-cell costimulatory molecules. Tumor pept ide-pulsed DC-derived exosomes prime specific cytotoxic T lymphocytes in vivo and eradicate or suppress growth of established murine tumors in a T cell-dependent manner. Exosome-based cell-free vaccines represe nt an alternative to DC adoptive therapy for suppressing tumor growth.