Matrine regulates immune functions to inhibit the proliferation of leukemic cells.

Aims: To investigate the roles of matrine in regulating immune functions and its effect on the proliferation of leukemic cells. Methods: Human leukemia K562, OUN-1, HL-60, U937, K562/AO2 cell lines and primary leukemic cells were used to detect the NKG2D ligands (NKG2DL) expression such as MICA/B, ULBP-1, ULBP-2, ULBP-3, and NK cells receptor NKG2D, CD158a, CD158b were detected by flow cytometry. Cell cytotoxic activity of human NK cells and CIK cells against K562 leukemia cells was detected using CFSE/PI double staining. Pro-inflammatory cytokines and adhesion molecules in K562 or NK cells supernatant after matrine treatment were detected. Results: Matrine could upregulate the expression of NKG2DL on leukemic cell lines, and primary leukemic cells and enhance the NK and CIK cytotoxicity targeted to K562 cells. After matrine treatment, pro-inflammatory cytokines and adhesion molecular such as IL-6, IL-1, IL-2, IL-4, IL-5, GRO and TNF-α in K562 cells supernatant were significantly decreased (P < 0.05). Flow cytometry analysis showed that the NKG2D expression was up-regulated significantly as well as the CD158a and CD158b expression decreased after treatment with different concentration of matrine in a dose-dependent manner in K562 cells. A significant decrease of supernatant concentrations of IL-1α, IL-5, IL-6, IL-10, IFN-γ, GRO and TNF-α in NK cells was also observed after exposure to the matrine. Conclusion: Matrine regulates immune functions to inhibit the proliferation of leukemic cells.