结核分枝杆菌感染对BALB/c小鼠B细胞发育分化的影响

目的 探讨结核分枝杆菌感染对小鼠B淋巴细胞分化发育的影响。方法 建立Mtb感染BALB/c小鼠模型,在感染早期(4周)及晚期(8周)分别取小鼠骨髓细胞及脾脏细胞,或经培养后,荧光抗体染色,用流式细胞术对感染早期及晚期小鼠的B细胞表型进行分析,设生理盐水处理的小鼠作为对照。结果 Mtb感染组与对照组比较,pro-B细胞(CD45R⁺CD43⁺)(4周:t=2.886,P<0.05)、未成熟B细胞(CD45R⁺IgM⁺IgD^-)(4周:t=4.760,P<0.05)减少,骨髓成熟B细胞(CD45R⁺IgM^+/-IgD⁺)(4周:t=-3.485,P<0.05;8周:t=-2.594,P<0.05)与脾脏成熟B细胞(CD45R⁺IgMlowIgDhi)(4周:t=-2.275,P<0.05;8周:t=-2.97,P<0.05)增多;小鼠脾脏B细胞活化分子CD69表达升高(4周:t=-2.271,P<0.05;8周:t=-2.052,P<0.05);小鼠脾脏记忆性B细胞 (CD45R⁺CD27⁺IgD^+/-)升高(4周:t=-4.203,P<0.05;8周:t=-5.280,P<0.05)。结论 Mtb感染能影响B细胞的分化发育,促使B细胞向成熟细胞分化,并能促使B细胞活化,使机体更有利于抗结核的感染。

Influencing on development and differentiation of B cells in Mycobacterium tuberculosis infected BALB/c Mice

To explore the impact on development and differentiation of B cell in BALB/c mice infected with Mycobacterium tuberculosis (Mtb), mice infected models were established with Mtb of Dali clinical isolates. After 4 weeks and 8 weeks of infected with Mtb, the bone marrow cells and splenic cells were collected from the mice, separately. The cells or cultured cells were stained by specific antibodies conjugated fluorescein. The phenotype of B cells was analyzed by flow cytometer. At the same time, mice injected with normal saline were set as control. Compared with the control group, pro-B cell(CD45R⁺CD43⁺)(4 week: t=2.886, P<0.05), immature B cell (CD45R⁺IgM⁺IgD^-)(4 week: t=4.760, P<0.05) were decreased at both of the early and late stage infected with Mtb, and the mature B cells in bone marrow(CD45R⁺IgM^+/-IgD⁺)(4 week: t=-3.485,P<0.05; 8 week: t=-2.594,P<0.05) and spleen (CD45R⁺IgMlow IgDhi) (4 week: t=-2.27,P<0.055; 8 week: t=-2.97,P<0.05)increased. Compared with the control group, expression of CD69 on murine splenic B cells increased (4 week: t=-2.271,P<0.05; 8 week: t=-2.052,P<0.05). In addition, The memory B cell (CD45R⁺CD27⁺IgD^+/-)(4 week: t=-4.203,P<0.05; 8 week: t=-5.280.P<0.05) increased in the infection mice. The infection of Mtb can affect the development and differentiation of B cell, inducing differentiation of B cells into mature cells and activation of B cells, so that the body is more conducive to Mtb infection.