OBJECTIVETo investigate whether the exosomes derived from Tca8113 could induce production of tumor-specific T cells when pulsed onto dendritic cells.

METHODSTca8113 cell was cultured with RPIM1640, isolated and purified the tumor-derived exosomes from the culture supernatants by ultrafiltration with Millipore centrifual filter devices; frozen and thawed Tca8113 cells to get frozen tumor antigens (FTA). The exosomes and FTA was pulsed onto DC generated from normal human peripheral blood mononuclear cell (PBMC) in vitro. The DC pulsed with FAP or exosomes cocultured with the peripheral blood lymphocytes to transform T cell into specific CTL. To observe the killing and wounding activity of CTL, the CTL and Tca8113 cells were mixed at a ratio of 20 to 1, SPCA-1 cells and 95-D cells was evaluated as control group.

RESULTSThe CTL induced by DC pulsed with FAP or exosomes had significant activity killing Tca8113 (P < 0.01); Moreover the CTL induced by DC pulsed with exosomes could also kill SPCA-1 cells (P < 0.05), but the CTL induced by DC pulsed with FTA had not this function.

CONCLUSIONExosomes derived from tumour accumulate in culture supernatants. Exosomes are a natural and new source of tumour-rejection antigens, opening up new avenues for immunotherapy against oral cancers. The exosome-specific CTL could kill another kind of tumor, so tumor-derived exosomes may contain shared tumor-rejection antigens.