[Effects of Shufeng Jiedu Capsules on lung injury repair and T cell subset proportions during recovery period in mice with influenza A H1N1 pneumonia].

This study investigated the effects of Shufeng Jiedu Capsules(SFJD) on pharmacodynamics, T helper cell(Th) proportions, and CD8~+T-cell immune memory formation during the recovery phase in mice infected with influenza A H1N1 virus. A non-lethal pneumonia mouse model was established by intranasal inoculation with influenza A virus A/PR/8/34(PR8) strain. Mice were randomly divided into three time-point groups: 7, 10, and 13 days post-infection(dpi), with 30 mice in each group. At each time point, mice were further randomly divided into a normal group, PR8 model group, positive drug group(oseltamivir phosphate, 0.027 5 g·kg~(-1)·d~(-1)), and high-and low-dose SFJD groups(2.558 and 1.279 g·kg~(-1)·d~(-1)), with six mice in each subgroup. From 0 dpi until the day of sample collection(7, 10, or 13 dpi), mice were administered the corresponding drugs by gavage, while the normal and PR8 model groups received equal volumes of deionized water. At the indicated time points, mice were sacrificed for sample collection. Lung and body weights were measured to calculate the lung index. At 10 dpi, Micro-CT was used to observe lung imaging changes. Viral load in lung tissue was detected by qRT-PCR. Flow cytometry was used to determine the proportions of CD4~+T cells and CD8~+T cells in peripheral blood and lung tissue at the three time points. Based on preliminary experimental results, 10 dpi was selected for further analysis of T-cell subsets in lung tissue by flow cytometry, including Th1 and Th2, as well as naive CD8~+T cells, central memory CD8~+T cells, effector CD8~+T cells, and memory precursor effector CD8~+T cells. The results showed that SFJD increased body weight and reduced lung index at all three time points, improved lung morphology at 10 dpi, and reduced viral load in lung tissue. SFJD also increased the proportion of CD8~+T cells in peripheral blood at 7 dpi, increased the proportion of CD4~+T cells in lung tissue at 7 dpi, and reduced the proportion of CD8~+T cells in lung tissue at 7, 10, and 13 dpi. Based on analyses of lung index and the proportions of CD4~+ and CD8~+T cells in peripheral blood and lung tissue at the three time points, 10 dpi was selected to investigate the effects of SFJD on T-cell subsets in lung tissue. SFJD promoted recovery from mild influenza A H1N1 viral pneumonia by inhibiting differentiation of Th1 cells and effector CD8~+T cells, while promoting the generation of naive CD8~+T cells, central memory CD8~+T cells, and memory precursor effector CD8~+T cells, thereby preventing persistent inflammation and facilitating immune memory formation.