动物造模,巨噬细胞 z-bio 2021-09-14 220

　　Objective: To use functional PD-L1 monoclonal antibody to block the macrophage-mediated PD1/PD-L1 pathway, and to study its immune intervention effect and mechanism on the recurrence of tuberculosis in mice after treatment.

　　Methods: 106CFU H37Rv was infected with C57BL/6 female mice through the tail vein to obtain acute tuberculosis infection. Two weeks later, isoniazid (10mg/kg) and isoniazid combined with PD-L1 monoclonal antibody (50μg each) were given continuous treatment. Four weeks, latent infection was obtained, and TNF-α antibody (50μg each) was used to induce recurrence for four weeks during the incubation period. Through the quantitative analysis of lung, spleen and liver tissue pathology and bacterial load at each time point, the PD-L1 single Anti-intervention effect on active tuberculosis and tuberculosis recurrence in mice. In vitro experiments were used to further clarify the effect of knockdown of PD-L1 on the apoptosis of macrophages infected by tuberculosis.

　　Results: In the first two weeks after the infection, the lung, spleen and liver had a higher bacterial load (3~4LgCFU/mL), and the granulomatous lesions were heavier, manifested as active tuberculosis, isoniazid and isoniazid combined with PD- After four weeks of L1 monoclonal antibody treatment, the lung, spleen, and liver bacterial counts were significantly reduced compared with the model control group, and the granulomatous lesions were also significantly reduced, but there was no significant difference between the two treatment groups. Compared with the isoniazid treatment group, the isoniazid combined with PD-L1 monoclonal antibody treatment group can significantly reduce the amount of bacteria in the tissues during the recurrence period and alleviate pathological changes. In vitro experiments have confirmed: use PD-L1 antibody or siRNA to knock down PD-L1 on the phages, and it was found that both can promote the apoptosis of macrophages infected by tuberculosis.

　　Conclusion: Functional PD-L1 antibody can inhibit tuberculosis recurrence, knocking down PD-L1 on macrophages or blocking PD1/PD-L1 pathway can promote macrophage apoptosis, suggesting that blocking PD-L1 can effectively assist Isoniazid treats tuberculosis and significantly inhibits the recurrence of tuberculosis.