〔Abstract〕 Objective To investigate the regulatory effect of artemisinin derivative dihydroartemisinin(DHA) on anti-tumor immune function of CD8+T cells induced by non-small cell lung cancer(NSCLC) cells.Methods NSCLC A549 cells were divided into DMSO control group and DHA treatment group.A549 cells were treated with DMSO and DHA at different concentrations(25,50 and 100 μmol/L),and the optimal concentration of DHA was selected to treat A549 cells for 0,24,48 and 72 h according to half maximal inhibitory concentrate(IC50).CCK-8 method and colony formation test were used to detect the effect of DHA on the proliferation and colony formation ability of A549 cells.Peripheral blood mononuclear cells(PBMCs) of healthy individuals were isolated by density gradient centrifugation.After monocytes were removed by adhesion method,A549 cells pretreated with mitomycin C were co-cultured with PBMCs at 10:1 ratio.After 2 weeks,flow cytometry was used to detect the proportion of CD8+T cells and the expression levels of perforin and granzyme B.Results Compared with the control group,the proliferation inhibition rates of A549 cells increased after treatment with 25,50 and 100 μmol/L DHA for 24 h(P<0.01).The IC50of DHA on A549 cells was 46.26 μmol/L.According to IC50concentration analysis,the inhibition rates of A549 cells treated with 50 μmol/L DHA for 0,24,48 and 72h were 1.53%,53.50%,63.84% and69.91%,and the cells inhibition rates of A548 cells increased compared with the previous observation time point,namely 0,24 and 48 h(P<0.01).The colony formation assay showed that the colony formation number of A549cells in DHA treated group decreased compared with the control group(P<0.01).Flow cytometry results showed that compared with the control group,the proportion of CD8+T cells induced by A549 cells in the co-culture system and the proportion of CD8+T cells expressing perforin and granzyme B were higher in DHA pretreatment group(P<0.01).Conclusion DHA inhibits the growth of NSCLC cells and promotes anti-tumor immune response of CD8+T cells induced by NSCLC cells.