重组MBD2体内抗不可分型流感嗜血杆菌机制的初步研究

Study on antibacterial mechanism of recombinant MBD2 against NTHi in vivo

目的观察实验小鼠体内注射重组鼠β防御素2(MBD2)后细胞因子的变化,评价重组MBD2对不可分型流感嗜血杆菌(NTHi)感染小鼠的治疗效果,并对其抗感染机制进行初步探讨。方法重组MBD2蛋白注射实验小鼠,利用PCR半定量检测小鼠肺组织中TLR2、IL-1β、TNF-α、MBD2和β-Actine mRNA的表达;重组MBD2治疗NTHi肺部感染小鼠,通过肺指数、肺组织病理切片及肺部荷菌数检测,对其治疗效果进行评价。结果体内注射重组MBD2可显著提高实验小鼠肺组织TLR2、IL-1β、TNF-α及MBD2等细胞因子的表达量;重组MBD2的应用能显著降低NTHi肺部感染小鼠的肺指数及肺组织内的NTHi荷菌数,并能减轻感染小鼠肺组织的炎性浸润程度,明显改善其肺部病变。结论重组MBD2在体内对NTHi感染有较好的治疗效果,其作用机制可能与重组MBD2对机体特异性免疫应答的诱导密切相关,为防御素抗感染机制的进一步完善奠定了良好的实验基础。

Objective To observe the changes of cytokines after injection of recombinant MBD2 in vivo,and evaluate its treatment effect.Methods Recombinant MBD2 protein was purified and injected into C57BL/6 female mice.mRNA expression of mice lung tissue TLR2,IL-1β,TNF-α,MBD2 and β-Actine were semi-quantitative analysis with PCR.NTHi lung infection model were established and treated with recombinant MBD2,which was evaluated through mouse lung index,bacteria detection of lung and the pathological change of lung tissue.Results The expression of TLR2,IL-1β,TNF-α,and MBD2 with injection of recombinant MBD2 in experimental mice were increased.The lung index and quantity of NTHi in lung of the experimental mice infected by NTHi were obviously reduced with injection of recombinant MBD2,and the inflammatory exudation and pathological change of lung tissue of infected mice were significantly relieved with its usage.Conclusion Recombinant MBD2 had good ability of anti-NTHi infection in vivo.Its antibacterial mechanism maybe relate with induction of specific immune response by recombinant MBD2.