Study inhibition and apoptosis of peripheral blood dendritic cells hybridize tumor vaccine induced systematic immune effector cells to the BxPC-3 in vitro

Abstract

Objective To observe the inhibition and apoptosis effects of systematic immune effector cells (SIECs) induced by increased expansion of normal human peripheral venous blood dendritic cells (DCs) hybridoma vaccine on orthotopic pancreatic cancer cell line (BxPC-3) in vitro. Methods The peripheral blood mononuclear cells (PBMCs) of healthy human were obtained by gradient centrifugation of lymphocyte separation fluid, and DCs and DCs derived monocytes cells (SIECs) were obtained by adherent method. DCs and SIECs were respectively cultured with granulocyte macrophage-colony stimulating factor (GM-CSF), interleukin (IL)-4, tumor necrosis factor-α (TNF-α), IL-2, BxPC-3 tumor specific antigen (pc-3tsa). After five days, DCs were collected and counted. BxPC-3TAA-sensitized DCs (referred to as sensitive DCs), and DCs were fused with BxPC-3 by PEG+ 10% dimethylsurfoxide (DMSO) with 10∶1, 5∶1, 1∶5 to obtain sensitive DCs-BxPC-3 and DCs-BxPC-3 fusion tumor vaccines. On the 7th day, SIECs were respectively mixed with sensitive DCs-BxPC-3, DCs-BxPC-3, sensitive DCs, and DCs for 1 days in a 40∶1 mixture. The mixed cultured cells were collected, and the Annexin V-fluoresceine isothiocyanate (FITC)/propidium iodide (PI) apoptosis assay and cell counting kit-8 (CCK-8) toxicity assay were performed on BxPC-3 in the mixed target SIECs∶BxPC3=10∶1. Results The sensitives DCs, DCs and BxPC-3 were fused, and the fusion effect was the best when the ratio was 1∶1, and the fusion rate was 40.0%. The CCK-8 assay showed that the inhibition rates of BxPC-3 induced by SIECs and SIECs by sensitive DCs-BxPC-3, DCs-BxPC-3, sensitive DCs and DCs were 53.1%, 45.3% and 78.8%, respectively. The Annexin V-FITC/PI assay showed that apoptosis rates of sensitive DCs-BxPC-3, DCs-BxPC-3, sensitive DCs, DCs and SIECs were 24.17%, 11.43%, 85.87% and 29.94%. Conclusion Tumor antigen sequential sensitization DCs have a superimposed effect on antigen acquisition, which can play a better anti-tumor effect. Early DCs fusion tumor vaccine can induce SIECs to inhibit tumor cells to a certain extent. Key words: Dendritic cells; Sequential sensitization; Pancreatic cancer; Tumor vaccine; Cell inhibition; Apoptosis