Tracking Mucosal T cells to Commensal Microbes in Vivo

追踪粘膜 T 细胞与体内共生微生物

• 批准号: 6845376
• 负责人: MASSIMO COSTALONGA
• 金额: $ 25.99万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-02-01 至 2007-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6845376
• 关键词: Lactobacillus; T lymphocyte; cell differentiation; cell proliferation; cell type; cellular immunity; confocal scanning microscopy; cytokine; enteric bacteria; flow cytometry; host organism interaction; humoral immunity; immune response; immunoglobulin A; immunologic memory; immunoregulation; laboratory mouse; leukocyte activation /transformation; molecular shape; mucosal immunity; oral bacteria; protein localization; secretory immune system; virulence

DESCRIPTION: IgA antibodies provide an important first line of defense against mucosal pathogens. The induction of immunoglobulins against T cell-dependent antigens is subordinate to T cell activation, T/B cell interaction and cytokines. Our long-range goal is to learn how the mucosal immune system responds to protein antigens of the virulent and commensal microbiota. Our current objective is to determine, in vivo, which type of T cell response is induced by the commensal Lactobacillus murinus, while transiting the intestine. We hypothesize that intestinal commensal microorganisms transmucosally induce a T cell-dependent humoral response, while suppressing the cell-mediated response. Testing this hypothesis can lead to the design of effective microbial delivery systems. We will test this hypothesis by determining 1) how a commensal microbe primes naive T cells in the intestine and 2) the type of cytokines elicited in memory T cells. We engineered L. murinus to expresses an ovalbumin epitope that induces ovalbumin-specific T cell proliferation when injected subcutaneously. We inject a small population of ovalbumin-specific T cells into recipient mice and feed L. murinus in high numbers. Ovalbumin-specific T cells are tracked by staining cell suspensions or tissues of the recipients with anti-CD4 and an anti-T cell receptor monoclonal antibody. Four-color flow cytometry and confocal immunohistology will establish in vivo that commensal microorganisms transiting the intestine activate T cells to induce CD69 expression. In an antigen-specific manner we will test the phenotype and kinetics of transmucosal T cell activation, proliferation and differentiation into cytokine-producing memory cells. Collectively, this research will elucidate the missing link between the oral antigen delivery and the production of secretory antibodies. The data will be important to human health, establishing a framework to study in vivo mucosal infectious agents and oral vaccines.

描述：IgA抗体为粘膜病原体提供了重要的第一道防线。免疫球蛋白对T细胞依赖性抗原的诱导是T细胞激活，T/B细胞相互作用和细胞因子的下属。我们的远程目标是了解粘膜免疫系统如何应对毒物和共生微生物群的蛋白质抗原。我们目前的目的是确定体内，在传播肠道的同时，由共生乳杆菌诱导哪种类型的T细胞反应。 我们假设肠道共生微生物传播会诱导T细胞依赖性体液反应，同时抑制细胞介导的反应。检验该假设可以导致有效的微生物输送系统的设计。我们将通过确定1）在肠道中幼稚T细胞和2）记忆T细胞中引起的细胞因子类型来检验这一假设。我们设计了L. murinus，以表达卵巢蛋白表位，该表位在皮下注射时诱导卵蛋白特异性T细胞增殖。我们将少量的卵蛋白特异性T细胞注入受体小鼠中，并以高数量喂食叶乳杆菌。通过用抗CD4和抗T细胞受体单克隆抗体染色细胞悬浮液或组织，跟踪卵蛋白特异性T细胞。四色流式细胞术和共聚焦免疫组织学将在体内建立，使肠道传播肠子激活T细胞以诱导CD69的表达的微生物。 以抗原特异性的方式，我们将测试传播T细胞激活，增殖和分化为细胞因子产生的记忆细胞的表型和动力学。总的来说，这项研究将阐明口服抗原递送与分泌抗体的产生之间的缺失联系。这些数据对人类健康很重要，建立一个研究体内粘膜感染剂和口服疫苗的框架。