动物造模,巨噬细胞 z-bio 2022-01-18 419

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

　　Methods: C57BL/6 female mice were infected with 106CFU H37Rv via the tail vein to acquire acute tuberculosis infection. Two weeks later, they were given isoniazid (10 mg/kg) and isoniazid combined with PD-L1 monoclonal antibody (50 μg each) for continuous treatment. After four weeks, the latent infection was acquired, and TNF-α antibody (50 μg each) was used to induce the relapse for four weeks during the incubation period. Through the quantitative analysis of lung, spleen and liver histopathology and bacterial load at each time point, the expression of PD-L1 monocytogenes was investigated. The effect of antagonism on active tuberculosis and tuberculosis recurrence in mice. In vitro experiments were used to further clarify the effect of PD-L1 knockdown on the apoptosis of macrophages infected with Mycobacterium tuberculosis.

　　Results: In the first two weeks after infection, the amount of bacteria in the lung, spleen and liver of the mice was higher (3-4 LgCFU/mL), and the granuloma lesions were more severe, which manifested as active tuberculosis, isoniazid and isoniazid combined with PD- After L1 monoclonal antibody treatment for four weeks, the amount of bacteria in the lung, spleen and liver 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 relapsed tissue and reduce the pathological lesions. In vitro experiments confirmed that PD-L1 antibody or siRNA knockdown giant PD-L1 on phagocytes, and it was found that both can promote the apoptosis of tuberculosis-infected macrophages.

　　Conclusion: Functional PD-L1 antibody can inhibit the recurrence of tuberculosis, knockdown of 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.