Background &Aims: The intestinal lamina propria has traditionally been viewed as the effector site of mucosal immune responses. However, this view has been challenged with the identification, in the murine lamina ...Background &Aims: The intestinal lamina propria has traditionally been viewed as the effector site of mucosal immune responses. However, this view has been challenged with the identification, in the murine lamina propria, of an in situ class switch DNA recombination pathway to IgA. In this study, we tested the hypothesis that in situ class switching occurs in the human lamina propria. Methods: Immunohistochemistry was used to analyze tissue microenvironments and RT-PCR to look for molecular evidence of Ig class switching and to track clonally related cells of B lineage. Results: We found no evidence of proliferation of either lamina propria CD20+or CD19+cells or evidence of activation-induced cytidine deaminase mRNA expression outside the organized gut-associated lymphoid tissue, although Iα-Cαimmunoglobulin germ-line gene transcript expression could be identified in the lamina propria. We identified clonally related cells, including IgA and IgM isotype-switched variants, in multiple samples known to be free of activation-induced cytidine deaminase, organized lymphoid tissue, or cellular proliferation. For 4 groups of cells, the patterns of somatic mutations on the rearranged IgVH5 gene segment were more similar between cells from distant sites than from their immediate neighbors, implying dissemination of cells from a common set of precursors. Conclusions: Our data are inconsistent with a model in which precursors of human IgA-secreting plasma cells are induced or expanded in the lamina propria. The human lamina propria is therefore likely to solely be an effector site of intestinal secretory IgA responses that originate from the organized gut-associated lymphoid tissues.展开更多
目的从单细胞水平探究多房棘球蚴感染小鼠晚期阶段肝脏组织微环境细胞组成及其转录谱特征。方法收集2只多房棘球蚴感染BALB/c小鼠(6~8周龄)肝脏病灶旁组织和配对远端肝组织进行单细胞转录组测序。利用R软件Seurat包对获得的数据进行质...目的从单细胞水平探究多房棘球蚴感染小鼠晚期阶段肝脏组织微环境细胞组成及其转录谱特征。方法收集2只多房棘球蚴感染BALB/c小鼠(6~8周龄)肝脏病灶旁组织和配对远端肝组织进行单细胞转录组测序。利用R软件Seurat包对获得的数据进行质量控制、多样本整合和批次效应校正,应用统一流形逼近与投影(uniform manifold ap⁃proximation and projection,UMAP)算法进行细胞聚类,根据经典标记基因注释细胞类型。通过差异基因表达分析筛选各细胞类型的差异表达基因,进行基因本体论(Gene Ontology,GO)和京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)功能富集分析,预测细胞生物学作用。结果对来自多房棘球蚴感染小鼠肝脏病灶旁和远端肝组织的43710个细胞进行了分析,归类为11种细胞类型:中性粒细胞、T细胞、巨噬细胞、粒细胞⁃单核细胞祖细胞、B细胞、浆细胞、嗜碱性粒细胞、肝星状细胞、内皮细胞、肝细胞、血小板。T细胞是组织微环境中占比最高的免疫细胞,包括5种CD4+T细胞、2种CD8+T细胞和磷酸抗原反应γδT细胞。与病灶远端肝组织相比,病灶旁肝组织中的CD4+辅助性T细胞和CD4+细胞毒性T细胞比例降低、辅助性T细胞2(Th2细胞)比例明显增高。Th2细胞差异表达基因主要与免疫系统负调控过程相关,CD4+细胞毒性T细胞高表达基因与免疫系统激活相关。结论通过单细胞转录组测序揭示了多房棘球蚴感染小鼠肝组织微环境中的细胞组成和分布差异,病灶旁肝组织中Th2细胞升高可能与免疫抑制性微环境形成有关。展开更多
文摘Background &Aims: The intestinal lamina propria has traditionally been viewed as the effector site of mucosal immune responses. However, this view has been challenged with the identification, in the murine lamina propria, of an in situ class switch DNA recombination pathway to IgA. In this study, we tested the hypothesis that in situ class switching occurs in the human lamina propria. Methods: Immunohistochemistry was used to analyze tissue microenvironments and RT-PCR to look for molecular evidence of Ig class switching and to track clonally related cells of B lineage. Results: We found no evidence of proliferation of either lamina propria CD20+or CD19+cells or evidence of activation-induced cytidine deaminase mRNA expression outside the organized gut-associated lymphoid tissue, although Iα-Cαimmunoglobulin germ-line gene transcript expression could be identified in the lamina propria. We identified clonally related cells, including IgA and IgM isotype-switched variants, in multiple samples known to be free of activation-induced cytidine deaminase, organized lymphoid tissue, or cellular proliferation. For 4 groups of cells, the patterns of somatic mutations on the rearranged IgVH5 gene segment were more similar between cells from distant sites than from their immediate neighbors, implying dissemination of cells from a common set of precursors. Conclusions: Our data are inconsistent with a model in which precursors of human IgA-secreting plasma cells are induced or expanded in the lamina propria. The human lamina propria is therefore likely to solely be an effector site of intestinal secretory IgA responses that originate from the organized gut-associated lymphoid tissues.
文摘目的从单细胞水平探究多房棘球蚴感染小鼠晚期阶段肝脏组织微环境细胞组成及其转录谱特征。方法收集2只多房棘球蚴感染BALB/c小鼠(6~8周龄)肝脏病灶旁组织和配对远端肝组织进行单细胞转录组测序。利用R软件Seurat包对获得的数据进行质量控制、多样本整合和批次效应校正,应用统一流形逼近与投影(uniform manifold ap⁃proximation and projection,UMAP)算法进行细胞聚类,根据经典标记基因注释细胞类型。通过差异基因表达分析筛选各细胞类型的差异表达基因,进行基因本体论(Gene Ontology,GO)和京都基因与基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)功能富集分析,预测细胞生物学作用。结果对来自多房棘球蚴感染小鼠肝脏病灶旁和远端肝组织的43710个细胞进行了分析,归类为11种细胞类型:中性粒细胞、T细胞、巨噬细胞、粒细胞⁃单核细胞祖细胞、B细胞、浆细胞、嗜碱性粒细胞、肝星状细胞、内皮细胞、肝细胞、血小板。T细胞是组织微环境中占比最高的免疫细胞,包括5种CD4+T细胞、2种CD8+T细胞和磷酸抗原反应γδT细胞。与病灶远端肝组织相比,病灶旁肝组织中的CD4+辅助性T细胞和CD4+细胞毒性T细胞比例降低、辅助性T细胞2(Th2细胞)比例明显增高。Th2细胞差异表达基因主要与免疫系统负调控过程相关,CD4+细胞毒性T细胞高表达基因与免疫系统激活相关。结论通过单细胞转录组测序揭示了多房棘球蚴感染小鼠肝组织微环境中的细胞组成和分布差异,病灶旁肝组织中Th2细胞升高可能与免疫抑制性微环境形成有关。
