OBJECTIVETo observe the role of interleukin (IL) 21 alone, IL12 alone, and IL21 plus IL12 for inducing the antitumor activity of peripheral blood mononuclear cells (PBMCs) in patients with endometrial cancer.

METHODSPBMCs were isolated from peripheral blood in patients with endometrial cancer in vitro, and kept the culture with low-level IL2. IL2-stimulated PBMCs were cocultured under different conditions (with anti-IL21 antibody, IL21 alone, IL12 alone, or IL21 plus IL12) for 72 h. The cytotoxicity of PBMCs was then examined by lactate dehydrogenase(LDH) released assay. CD4(+) CD25(+) FOXP3(+) regulatory (Treg) cell and CD4(+) IL17A(+) T-helper (Th17) cell proportion were determined with flow cytometry. Cell proliferation and apoptosis were measured by cell counting kit-8(CCK-8)assay and flow cytometry, respectively.

RESULTSIn comparison to control group, both IL21 and IL12 significantly enhanced the cytotoxicity of PBMCs. The IL21 plus IL12 group had superior effect to IL21 alone and IL12 alone. IL21 and IL12 significantly decreased the percentages of Treg cells and the rate of PBMCs apoptosis. IL21 or IL12 had no significant effect on the differentiation of Th17 cells and the proliferation of PBMCs.

CONCLUSIONSIL21 and IL12 can enhance the cytotoxicity of PBMCs in patients with endometrial cancer, which can be further strengthened with treatment of IL21 plus IL12. Such effects may be achieved by inhibiting the differentiation of Treg cells and the apoptosis of PBMCs, but not by the differentiation of Th17 cell.