Objective To study the activation of TLRs/NF-κB signal pathway and production of different functional cytokines during invasive pulmonary aspergillosis( IPA) , in order to probe the pathogene-sis of IPA. Methods Mouse were randomly divided into normal, normal + inoculated with Aspergillus fumigatus( normal inoculation group), and immune suppression + inoculation with Aspergillus fumigatus (IPAmodel group) , the mouse were killed at different time points after inhaling Aspergillus fumigatus spores by nose. Removing the lung tissue in a sterile manner and making pathological section respectively, counting Aspergillus fumigatus colony, dynamiclly detecting the expression of TLR2, TLR4 mRNA, variation of NF-κB p65 protein, pro-inflammatory cytokines TNF-α, IL-1β and anti-inflammatory cytokines IL-10 levels in the lung tissue by RT-PCR and Western blot method during Aspergillus fumigatus infection in mouse. Results (1) When it's 72 h after inhaling Aspergillus fumigatus by nose, IPA model emerged severe lung tissue inflammation, and generated a large number of hyphae, meanwhile, burthen of Aspergillus fumigatus was higher than normal inoculation group at each time point. (2)Compared with the normal inoculation group, IPA group whose TLR2 mRNA was low expression at early stage of infection (24 h), and emerged high expression at late stage of infection (120 h, 144 h); and TLR4 mRNA has been at a state of low expression in the infection process; NF-κB p65 suddenly increased at early stage of infection(24 h) and then continued to decline. (3) After infected by Aspergillus fumigatus in normal mouse, proinflammatory cytokine TNF-α, IL-1β in lung exhibited high expression at the early stages of infection, and the highest expression levels appeared at 48 h or 72 h, then decreased and recovered to normal level. And the expression level of anti-inflammatory cytokine IL-10 rised at late stage of infection; The IP A mouse released a lot of anti-inflammatory cytokine IL-10 at early stage of infection, which significantly reduced at late stage, and released pro-inflammatory cyto-kines TNF-α, IL-1β at slow and low level. Conclusion The abnormal activation of TLRs/NF-β signaling pathway caused the loss of dynamic balance between pro-inflammatory cytokines and anti-inflammatory cytokines, leading to the occurrence and development of IPA.%目的 研究小鼠侵袭性肺曲霉病(IPA)发生过程中TLRs/NF-κB信号通路的激活和不同功能细胞因子的产生情况,探讨IPA的发病机制.方法 小鼠随机分为正常组、正常+接种烟曲霉菌组(正常接菌组)和免疫抑制+接种烟曲霉菌组(IPA模型组),经鼻吸入烟曲霉孢子后在不同时相点处死小鼠,无菌取肺组织分别进行病理切片,烟曲霉菌落计数,RT-PCR法、Western blot法动态检测小鼠感染烟曲霉菌过程中肺组织TLR2、TLR4 mRNA表达、NF-κB p65蛋白、促炎细胞因子TNF-α、IL-1β及抗炎细胞凶子IL-10含量的变化规律.结果 (1)鼻吸入烟曲霉菌后72 h,IPA模型组肺组织出现严重炎症反应,并有大昔的菌丝生成,同时各时相点的烟曲霉菌负倚均高于正常接菌组;(2)与正常接菌组比较,IPA组TLR2 mRNA感染早期(24 h)低表达,感染后期(120 h、144 h)高表达;而TLR4mRNA则在感染过程中一直处于低表达状态;NF-κB p65感染早期(24 h)骤然升高后持续下降.(3)正常小鼠感染烟曲霉菌后,肺组织巾促炎细胞因子TNF-α、IL-1β在感染早期皆呈高表达,且最高表达量均出现在48 h或72 h,随后下降并恢复至正常水平.同时感染后期抗炎细胞因子IL-10表达水平升高;而IPA小鼠在感染甲.期抗炎症细胞因子IL-10大量释放,后期显著降低,促炎症细胞因子TNF-α、IL-1β缓慢且低水平释放.结论 TLRs/NF-κB信号通路的异常激活,引起促炎细胞因子和抗炎细胞因子之间失去动态平衡,可能是导致侵袭性肺曲霉病发生发展的原因之一.
展开▼
