Effects of Yupingfeng Powder on PD-L1 expression and T cell function in lung cancer cells
AIM To explore the effects of Yupingfeng Powder on the binding of programmed death receptor 1(PD-1)and programmed death ligand 1(PD-L1),and the growth of lung cancer cells in vitro and in vivo.METHODS Yupingfeng Powder extract had its effect on the growth of Lewis lung carcinoma(LLC)cells in mice detected by MTT assay;its effect on eliminating target cells in the co-culture of T cells and LCC cells detected by lactate dehydrogenase(LDH)release test;its effect on blocking the combination of PD-1 and PD-L1,and its influence on the levels of interferon-γ(IFN-γ)and tumor necrosis factor-α(TNF-α)release detected by enzyme-linked immunosorbent assay(ELISA);its inhibitory effect on the growth of LLC cells in vivo analyzed by homologous tumor model;its effect on the infiltration of CD4+T cells and CD8+T cells in tumor tissues investigated by immunohistochemical staining.RESULTS Yupingfeng Powder inhibited the growth of LLC cells and the expression of endogenous PD-L1 protein in a dose-dependent manner(P<0.05,P<0.01),competitively blocked the combination of PD-1 and PD-L1(P<0.05,P<0.01),and promoted the release of IFN-γ and TNF-α from T cells(P<0.05,P<0.01).Yupingfeng Powder inhibited the growth of LLC tumor(P<0.01),and increased the infiltration of CD4+T and CD8+T cells(P<0.01).CONCLUSION Yupingfeng Powder exhibits its in vitro capability in blocking the PD-L1 inhibition on T cells,and its in vivo anti-tumor effect in terms of the improvement of CD4+T cells and CD8+T cells in this homologous mouse tumor model.