Abstract: OBJECTIVE To explore the effect of silencing PD-1 gene on adeno-associated virus（AAV）8-mediated T cell immune response in HBV-infected rats. METHODS A total of 40 normal rats were randomly selected, 10 of which left untreated to be the normal group, and the remaining 30 rats were established to AAV8-mediated HBV infection models.After successful modeling, 10 rats were randomly selected and left untreated to be the model group, and the remaining 20 model rats were divided into the silencing PD-1 group and the overexpression PD-group.Among them, the silencing PD-1 group underwent the silencing programmed death cell receptor-1（PD-1） intervention, and the overexpressing PD-1 group underwent the overexpression PD-1 intervention.The levels of HBsAg and HBeAg of the rats were measured and compared, the HBV DNA of the rats from each group was detected by RT-PCR, and the expression of PD-1 molecules on surfaces of CD₈⁺ cells and T cells were detected by means of flow cytometry, and the positive rates of cells of tumor necrosis factor-α（TNF-α）, interferon γ（IFN-γ） and Tim3 were observed. RESULTS The levels of HBsAg and HBeAg of the model group, the overexpression PD-1 group and the silencing PD-1 group were significantly higher than those of the normal group; the levels of HBsAg and HBeAg of the overexpressing PD-1 group were significantly higher than those of the model group, while the levels of HBsAg and HBeAg of the silencing PD-1 group were significantly lower than those of the model group（P＜0.05）.The positive rates of cells of IFN-γ and TNF-α in livers of the model group, the overexpression PD-1 group and the silencing PD-1 group were significantly lower than those of the normal group, the positive rate of cells of Tim was higher; the positive rates of cells of IFN-γ and TNF-α of the overexpressing PD-1 group were significantly lower than those of the model group, the positive rate of cells of Tim3 was significantly higher, the positive rates of cells of IFN-γ and TNF-α of the silencing PD-1 group were significantly higher than those of the model group, and the positive rate of cells of Tim3 was lower（P＜ 0.05）.As compared with the normal group, the percentage of CD₈⁺ lymphocytes of the model group, the overexpression PD-1 group and the silencing PD-1 group was lower, while the expression level of PD-1 on surfaces of T cells was significantly higher.As compared with the model group, the percentage of CD₈⁺ lymphocytes of the overexpression PD-1 group was lower, and the expression level of PD-1 on surfaces of T cells was higher; the percentage of CD₈⁺ lymphocytes of the silencing PD-1 group was significantly higher, and the expression level of PD-1 on surfaces of T cells was lower（P＜0.05）. CONCLUSION The intervention to silencing PD-1 gene in the AAV8-mediated rats with HBV infection can significantly improve the progression of liver fibrosis, enhance the relevant activity of T cells, regulate the immune metabolic function in the body, boost the body's antiviral ability, improve the prognosis, enhance the body's immune response ability, and inhibit the progress of hepatitis B virus.