Abstract： Objective:To observe the effect of hepatitis B virus(HBV)infection on the immune function associated with interferon(IFN)-γ and to study the therapeutic effect of Bushen Jianpi Formula(补肾健脾方).Methods:First,chronic HBV-infected patients and healthy volunteers were recruited and assigned into experimental and control groups.Peripheral blood was collected for the separation of the serum,and the ser-um levels of IFN-γ,IFN-α,interleukin(IL)-2,IL-12,and tumor necrosis factor(TNF)-α in both groups were measured by enzyme-linked immunosorbent assay(ELISA).Peripheral blood mononuclear cells(PBMCs)were separated by density gradient centrifugation,and flow cy-tometry(FCM)was employed to examine the number of natural killer(NK)cells,T helper 1(Th1)cells,and cytotoxic T lymphocytes(CTLs).The intracellular protein levels of IFN-γ,IFN-α,IL-2,IL-12,TNF-α,stimulator of interferon genes(STING),T-box expressed in T cell(T-BET),and signal transducer and activator of transcription 4(STAT4)were determined.Second,the drug(Bushen Jianpi Formula)-containing serum of rats was prepared,and the safe dose of the drug-containing serum for PBMC intervention was screened by the WST-1 method and cytotoxicity assay kit.The PBMCs from HBV-infected patients were classified into 3 groups,control,blank serum,and drug-con-taining serum groups.After 48 h of intervention,ELISA was employed to measure the levels of IFN-γ,IFN-α,IL-2,IL-12,and TNF-α in the cell culture supernatant.FCM was employed to count CTLs,Th1 cells,and NK cells and examine the cytokine levels in PBMCs of each group.RT-qPCR was performed to determine the mRNA levels of cytokines in each group.Results:Compared with healthy volunteers,the HBV-in-fected patients showed lowered serum levels of IFN-γ and IL-12,decreased CTLs,Th1 cells,and NK cells,and reduced synthesis of intracellu-lar IFN-γ,IL-12,TNF-α,STAT4,and T-BET(P＜0.05).Compared with the blank serum,the drug-containing drug serum elevated the levels of IFN-γ and IL-12 in the PBMC culture supernatant,increased CTLs,Th1 cells,and NK cells,up-regulated the intracellular protein level of IFN-γ and the mRNA levels of Ifn-γ,Il-2,Il-12,and Tnf-α genes(P＜0.05).Conclusion:By increasing CTLs,Th1 cells,and NK cells and promoting the secretion of IL-12 and the synthesis and secretion of IFN-γ,Bushen Jianpi Formula can restore the immune function of PBMCs in HBV-infected patients.