Comparative analysis of necrotic and apoptotic tumor cells as a source of antigen(s) in dendritic cell-based immunization

There is considerable controversy as to whether necrotic (lysate) or apopto tic tumor cells serve as the superior source of multiple tumor-associated a ntigens (TAAs) to pulse dendritic cells (DCs) for immunotherapeutic applica tions. Here, we show that standard procedures to induce apoptosis by UVB ir radiation unequivocally result in a mixed population of viable, apoptotic, and necrotic tumor cells, necessitating additional purification. We used hi ghly enriched apoptotic versus lysate of B16 melanoma cells to examine whet her or not there are important distinctions between these two sources of TA As for loading of DCs. Our results demonstrate that although some differenc es exist between the two forms of TAAs in expression of heat shock proteins , as well as production of interleukin-12 by pulsed DCs, their respective c apacities to mature DCs phenotypically, as well as to elicit both effective immune priming and antitumor therapeutic efficacy in vivo when presented b y DCs, are equivalent.