糖皮质激素对肺孢子菌肺炎宿主免疫反应影响的转录组研究

发布时间：2018-04-12 16:55

本文选题：肺孢子菌肺炎 + 转录组分析　；参考：《首都医科大学》2017年博士论文

【摘要】：研究背景:肺孢子菌肺炎(pneumocystis pneumonia,PCP)为常见于免疫抑制患者的机会性真菌感染,在过去普遍认为与HIV感染有关。但近20年以来,HIV群体发生PCP的病例数减少,与之相反,HIV阴性的PCP患者有增多趋势。糖皮质激素治疗是HIV阴性患者发生PCP的重要危险因素,然而目前糖皮质激素为何造成患者对PCP易感机制不明。研究方法:我们使用小鼠全转录组表达谱芯片Affymetrix Mouse Genome 430 2.0Array对野生型及使用糖皮质激素的PCP小鼠的肺组织进行转录组分析,比较两者在肺孢子菌感染免疫中的基因表达差异并进行生物信息学分析,以此阐述两者在免疫防御过程中的差异。我们对于表达谱芯片发现的差异基因(differentially expressed genes,DEGs)在小鼠肺组织及临床PCP患者的外周血中进行了q PCR的验证。同时通过流式细胞学分析对关键基因的蛋白表达进行了检测。研究结果:表达谱芯片结果显示与固有免疫包括抗原处理递呈、炎症反应、吞噬以及T、B淋巴细胞免疫相关的基因均存在表达下调。其中与B细胞免疫反应相关的基因受到明显抑制,涉及B细胞信号转导、B细胞稳态及抗体生成。在PCP患者的外周血及小鼠肺组织中所做的实时定量PCR证实了使用激素的小鼠及患者存在B细胞表达相关的基因表达下调。流式细胞学结果进一步显示B细胞及相关受体在给予激素的PCP小鼠肺组织及外周血中均存在明显下降。研究结论:根据现有研究,B淋巴细胞在肺孢子菌的免疫防御过程中具有重要作用。鉴于此,糖皮质激素对B细胞的抑制作用部分解释了使用糖皮质激素患者对肺孢子菌易感的原因,这很可能是激素促进PCP发生发展的重要机制之一。
[Abstract]:Background: pneumocystis pneumocystis pneumoniae (HIV) is a common opportunistic fungal infection in immunosuppressive patients.However, in recent 20 years, the number of PCP cases in HIV-negative population decreased, and the number of HIV-negative PCP patients increased.Glucocorticoid therapy is an important risk factor for PCP in HIV negative patients. However, it is unclear why glucocorticoid causes susceptibility to PCP.Methods: we used Affymetrix Mouse Genome 430 2.0Array to analyze the lung tissues of wild type and PCP mice using glucocorticoid.The difference of gene expression in Pneumocystis infection immunity was compared and bioinformatics analysis was carried out to explain the difference between them in the process of immune defense.At the same time, the protein expression of key genes was detected by flow cytometry.Results: the results of expression microarray showed that the expression of genes related to innate immunity including antigen presentation inflammatory reaction phagocytosis and T lymphocyte immunity were down-regulated.The genes associated with B cell immune response were significantly inhibited and involved in B cell signal transduction of B cell homeostasis and antibody production.Real-time quantitative PCR in peripheral blood and lung tissues of patients with PCP confirmed the down-regulation of gene expression related to B cell expression in steroid treated mice and patients.Flow cytometry further showed that B cells and related receptors were significantly decreased in the lung tissues and peripheral blood of PCP mice treated with hormones.Conclusion: B lymphocytes play an important role in the immune defense of Pneumocystis.Therefore, the inhibitory effect of glucocorticoids on B cells partly explains the susceptibility of patients with glucocorticoid to Pneumocystis, which may be one of the important mechanisms of hormone promoting the development of PCP.
【学位授予单位】：首都医科大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R519

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