[IL-33 enhances cytokine secretion and killing function of peripheral blood mononuclear cells in vitro]

To investigate whether interleukin 33 (IL-33) can enhance cytokine secretion and killing activity of peripheral blood mononuclear cells (PBMCs) in vitro.

PBMCs were harvested from healthy volunteers and stimulated with different combination of cytokines (CD3 mAb/CD28 mAb/IL-2, CD3 mAb/CD28 mAb/IL-2/IL-12, CD3 mAb/CD28 mAb/IL-2/IL-12/IL-33) in vitro. The cells of each group were collected after 72 hours. Total RNA were extracted and assayed by real-time quantitative PCR (qRT-PCR) for the levels of interferon γ (IFN-γ) and granzyme B. The cytotoxic activity of the cells targeting A549 human lung adenocarcinoma cells was detected by CCK-8 assay. The levels of programmed death-1 (PD-1) and IFN-γ were determined by flow cytometry.

There was no significant difference in cell morphology observed by microscope among the three groups. In the cells stimulated in the presence of IL-33, the levels of IFN-γ and granzyme B mRNAs were significantly elevated, cell killing ability was strengthened, and the level of IFN-γ increased significantly, PD-1 level decreased when compared with the other two groups.

IL-33 might enhance the function of PBMCs and then promote adaptive anti-tumor immune response.