OBJECTIVETo investigate the specific antitumor immune response induced by idiotype protein (Id)-pulsed dendritic cells (DC) in vitro.

METHODSDC was generated from peripheral blood monocytes of the multiple myeloma (MM) patients using GM-CSF, IL-4, and TNF-alpha. The DCs were pulsed with idiotypic fragment, the F(ab')2 fragment of M protein from MM patient at the immature stage. The morphologic characteristics of the cells were observed with light and electron microscopes. The phenotypic features were analyzed with FACS, MTT assay was employed to evaluate the proliferation of autologous T cells and the inhibition rate of MM cells.

RESULTSDC precursors in peripheral blood could be induced to typical mature DC in medium containing GM-CSF, IL-4 and TNF-alpha. Mature DC with Id could increase the proliferation of the autologous T cells and activate naive T cells to become tumor specialized cytotoxic T lymphocytes (CTL). The CTL at different doses showed significant inhibition on or killing ability to autologous MM cells in vitro.

CONCLUSIONSIn a suitable cytokine environment, the DC precursors from peripheral blood of MM patients could be induced to functional DC, and vaccination of Id-pulsed DC could induce active antitumor immune response.