To explore the mechanism of Feiliuping Ointment in improving lipid accumulation and reversing the function of tumor-related dendritic cells(TDCs) by simulating tumor microenvironment in vitro and constructing TDCs model.Methods:Serum with and without Feiliuping Ointment was prepared,and lung TDCs were obtained by isolation,induction and co-culture with Lewis lung cancer cells.Flow cytometry was used to detect the lipid content and phenotypic changes of TDCs under the intervention of Feiliuping Ointment.Luminex technology was employed to quantitatively detect the secretion of TDCs cytokines IL-12p70 and IFN-γ.The co-culture system of TDCs and T cells was constructed to explore the effects of Feiliuping Ointment on TDCs' regulation of mixed lymphocyte proliferation and T cell subsets.Results:The lipid content in the TDCs treated with Feiliuping Ointment was lower(P<0.01),and the expression levels of CD80 and CD86 and the secretion of IL-12P70 and IFN-γ were higher(P<0.05,P<0.05) than those of the blank serum control group.In addition,compared with the conditions in the blank serum,the proliferation ability of mixed cells and the expression proportion of CD4+ and CD8+ in the co-culture of TDCs and T cells were enhanced(P<0.05,P<0.05),and the expression of Tregs cells was reduced(P<0.05) after treatment with serum containing Feiliuping Ointment.Conclusion:Feiliuping Ointment could reduce the lipid accumulation in TDCs and promote the maturation and antigen presentation ability of TDCs.