摘 要: 目的 探讨白细胞介素-12(IL-12)在哮喘小鼠发病机制中的作用及对气道炎症的影响。方法 65只小鼠随机分为对照组(A组)、哮喘组(B组)、重组白细胞介素-12(rm IL-12)组(C组)和IL-12基因敲除组(D组),以卵白蛋白(OVA)致敏和激发制备哮喘模型。C组在每次激发前30 min给予rm IL-12腹腔注射,D组在激发前1 d给小鼠植入含有抗IL-12多克隆抗体的缓释泵,A组小鼠在末次激发后24 h处死,其余三组小鼠在末次激发后的1 d、2 d、4 d、7 d分别处死。摘眼球取血进行血浆一氧化氮(NO)和免疫球蛋白E(Ig E)的检测。收集各组小鼠的支气管肺泡灌洗液(BALF),ELISA法检测其上清中白细胞介素-10(IL-10)、IL-12、肿瘤坏死因子-α(TNF-α)含量。离心后的细胞沉淀行白细胞总数和嗜酸性粒细胞(EOS)分类计数;剪下结扎右肺下叶用于HE染色。结果 (1)细胞计数:小鼠BALF中的细胞总数和EOS百分比,B组明显高于A组(P<0.05),C组明显低于B组(P<0.05),D组较B组明显升高(P<0.05)。(2)ELISA检测: 与A组相比,B组小鼠BALF中IL-10、IL-12水平明显降低(P<0.05),TNF-α、NO、Ig E水平明显升高(P<0.05)。与B组相比,C组小鼠BALF中IL-10、IL-12水平明显升高,TNF-α、NO、Ig E水平明显降低;D组小鼠TNF-α、NO、Ig E水平明显升高,IL-10、IL-12水平明显降低;于1 d、2 d、4 d、7 d差异均有统计学意义(P<0.05)。(3)肺组织病理改变:A组小鼠HE染色未见异常;B组小鼠肺泡间隔及小血管周围可见大量炎性细胞浸润;C组小鼠的炎性细胞浸润较B组缓解;D组小鼠部分可见小气道管腔完全闭塞,炎性细胞浸润较B组明显加重。结论 rm IL-12能够明显抑制哮喘小鼠炎症细胞的浸润,同时降低炎症因子TNF-α、NO和Ig E的表达,促进抑炎因子IL-10的表达,从而在哮喘发病过程中起到保护作用。 |
关键词: 小鼠哮喘模型 白细胞介素-12(IL-12) 功能性基因敲除 肿瘤坏死因子-α(TNF-α) 白细胞介素-10(IL-10) 一氧化氮(NO) |
中图分类号: R-332
文献标识码:
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基金项目: 河北省自然科学基金资助项目(编号:2010001788) |
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Role of cytokine IL-12 in pathogenesis of asthma in mice |
Wang Yuan,Wang Hongyang,Liu Heliang,Wang Hongli,Hao Xiaohui
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Affiliated Hospital of North China University of Science and Technology,Tangshan 063000,China
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Abstract: Objective To explore the role of IL-12 in the pathogenesis of asthma in mice and its effect on airway inflammation. Methods Sixty-five mice were randomly divided into 4 groups: control group (group A),asthma group (group B),recombinant
interleukin 12 (rmIL-12) group (group C) and IL-12 knockout group (group D), mice were sensitized and challenged by ovalbumin. Mice of group C were given intraperitoneal injection of rmIL-12 30 minutes before each inhalation of ovalbumin. Mice of group D were implanted with sustained-release pump containing anti IL-12 antibodies one day before each challenge. Except the mice of group A were sacrificed 24 hours after last challenge, mice in other three groups were sacrificed at 1 d,2 d,4 d and 7 d after the last challenge, respectively. Enzyme linked immunosorbent assay (ELISA) was used to detect the levels of IL-10, IL-12,TNF-αin BALF and NO, IgE in plasma; the BALF precipitations were collected for counting of leucocytes and EOS; the right lung lower lobes were taken and stained with HE for observation of inflammatory changes. Results (1) Cell count results: the total number of leucocytes and EOS percentage in group B were higher than those in group A and group C (P<0. 05),however, lower than those in group D (P<0.05). (2)ELISA detection results: the levels of TNF-α,NO and IgE in group B were higher than those in group A,while the levels of IL-10 and IL-12 were lower(P<0.05); the leves of TNF-α,NO and IgE in group C were lower than those in group B,while the levels of IL-10 and IL-12 were higher (P<0.05); compared with group B, the levels of TNF-α,NO and IgE in group D were higher and the levels of IL-10 and IL-12 were lower (P<0.05).(3)The pathological change in lung: no abnormality was revealed in mice of group A; a large number of inflammatory cell infiltration was seen surrounding alveolar septum and small blood vessels in mice of group B; the inflammatory infiltration in group C also could be seen but less than that in group B; meanwhile, the inflammatory infiltration in group D was obviously aggravated than that in group B, the small airway even entirely shuted.Conclusion The results suggest that IL-12 may significantly inhibit inflammatory cell infiltration in airway, reduce expression of such inflammatory cytokines as TNF-α,NO and IgE and promote the expression of anti-inflammatory cytokine IL-10 in asthmatic mice, thereby play a protective role in the pathogenesis
of asthma. |
Keywords: mice asthma model interleukin-12(IL-12) functional knockout tumor necrosis factor-α(TNF-α) interleukin-10(IL-10) nitric oxide(NO) |