Constructing of PSA-specific dendritic cell vaccine and its in vitro immune activity / 第二军医大学学报

ABSTRACT

Objective: To construct of PSA-specific dendritic cell (DC) vaccine and to observe its in vitro anti-tumour activity, so as to pave a way for future study. Methods: Bone marrow precursors were isolated and bone marrow derived DCs were prepared. Mature DCs were pulsed by PSA, Lysate of cancer cells, OVA and PBS to yield PSA-DC, Lys- DC, Ova-DC, and Non DC, respectively. After primed by antigen, the changes of IL-12 p70 and IL-1β in the supernatant of dendritic cells were assessed by ELISA. The antigen-specific proliferation and cytotoxicity activity of T cell-primed by PSA-pulsed DCS were observed and the results were compared with those by Lys-, Ova- and PBS-pulsed DCs. Results: Mature DCs were successfully derived from bone marrow cells with a purity higher than 95%. ELISA assay showed PSA-DC, Lys-DC and Ova-DC group secreted high levels of IL-12 p70 and IL-1β than Non-DC group (P < 0.05). In addition, PSA-DCs and Lys-DCs had significantly stronger ability to stimulate the proliferation of CD4+ T cells in 3-day classic mixed lymphocyte reaction (MLR) compared with Ova-DCs and Non-DCs (P<0.01). Higher levels of IFN-γ and IL-2 were detected in PSA-DCs and Lys-DCs groups compared with the other two groups (P<0.01), whereas the levels of IL-10 and IL-4 were lower than the other two groups (P<0.05). Moreover, PSA-DCs and Lys DCs enhanced DTH responses of C57BL/6 mice after antigen immunization; the third antigen and control did not show the enhancement effect (P<0.05). To observe the in vitro anti-PSA CTL reactions induced by PSA-DCs and Lys-DCs, the LNCaP cell line (PSA specific) was used as syngeneic target and the E. G7 cell line (H-2b) was used as Ova-specific target cells. Compared with Ova-DCs and Non-DCs, CTL cells induced by PSA DCs, Lys-DCs had significantly enhanced antigen-specific CTL activity to LNCall cells (P<0.05). Conclusion: DC-based PSA-epitope vaccine can be prepared by pulsing DCs with PSA protein; the prepared vaccine has strong in vitro immune activity and can kill LNCaP cells.