Defining modes of helper T cell motility within inflamed tissues

定义发炎组织内辅助 T 细胞的运动模式

• 批准号: 8060788
• 负责人: Michael Glen Overstreet
• 金额: $ 4.84万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-02-14 至 2014-02-13
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8060788
• 关键词: Antibodies; Antigen-Presenting Cells; Architecture; Behavior; CD4 Positive T Lymphocytes; Cell Adhesion Molecules; Cell physiology; Cells; Chronic; Data; Dendritic Cells; Dermis; Disease; Effector Cell; Environment; Event; Extracellular Matrix; Feedback; Foundations; Genetic; Goals; Helper-Inducer T-Lymphocyte; Image; Immune; Immune response; Immunology; In Vitro; Infection; Inflammation; Integrins; Interleukin-13; Interleukin-4; Interleukin-5; Laboratories; Leishmania; Leishmania major; Leukocytes; Life; Location; Lymphocyte; Lymphoid Tissue; Mediating; Mesenchymal; Microscopy; Modeling; Molecular; Movement; Mus; Myosin Type II; Nature; Parasites; Parasitic infection; Pathology; Pathway interactions; Pattern; Peripheral; Phenotype; Photons; Population; Research Training; Residencies; Selectins; Signal Transduction; Site; Small Interfering RNA; Solid; Stream; Surface; System; T-Cell Activation; T-Lymphocyte; T-Lymphocyte Subsets; Testing; Th1 Cells; Th2 Cells; Therapeutic; Tissues; Tumor Necrosis Factor-Beta; Work; antibody inhibitor; base; cell motility; chemokine; cytokine; design; in vivo; interstitial; intravital microscopy; lymph nodes; novel; pathogen; receptor; response; small molecule; therapeutic target; tumor

DESCRIPTION (provided by applicant): Leukocytes have been shown to utilize different modes of motility in vitro, depending on the nature of their surrounding environment. Using a system of intravital 2-photon microscopy to image live T cells within the inflamed dermis of a mouse, we have observed two distinct interstitial crawling phenotypes that were displayed by functionally discrete CD4+ T cell populations. Th1 cells moved rapidly with amoeboid-like motility while Th2 cells crawled with mesenchymal-like motility. These two modes suggest the mechanisms underlying movement of these functionally distinct T cells are distinct. Given the feedback between the extracellular matrix and intracellular signaling through surface receptors (such as integrins), these observations have relevance in a model of Leishmania major, in which our previous data has suggests that there are functional alterations to T cells in the locally infected tissue that may restrict Th1 accumulation. Thus, we will test the hypotheses that 1) Th1 and Th2 effectors T cells utilize different molecular machinery for motility during in vivo interstitial crawling and 2) motility is modified during parasitic L. major infection. Specific Aim 1: Do effector Th1 and Th2 cells utilize distinct mechanisms to crawl in sites of inflammation? Currently, two main modes of interstitial crawling have been described by cell biologists; integrin-dependent (mesenchymal) and integrin-independent, myosin II-dependent (amoeboid) motility. The objective of this aim is to determine the molecular means by which distinct helper T cell populations crawl within the interstitial space of the inflamed dermis. Candidate molecular pathways will be disrupted by antibody-blockade, genetic deletion and siRNA and the effects on motility determined by intravital 2-photon microscopy. Specific Aim 2: Can the migratory and crawling patterns of helper T cells be modulated by local changes induced by a pathogen? In addition to the immunological responses that accompany chronic infection, pathogens such as L. major can induce significant changes in the local milieu. L. major could modulate T cell motility in trans through pathogen-driven changes in architecture and composition of the ECM of the local tissue and in cis through modulating the chemokines and adhesion molecules expressed by the infected host cells. These changes can result local microenvironments that are dramatically different from steady state and even non-parasitized inflamed tissue. The goal of this aim is to evaluate the effects of the L. major-infected tissue microenvironment on Th1 and Th2 cell crawling, as well as the ability of parasitized antigen presenting cells to interact with the different effector T cells subsets. PUBLIC HEALTH RELEVANCE: Using a system of intravital microscopy to image live T cells within the inflamed dermis of a mouse, we have observed two unique crawling phenotypes that were displayed by functionally distinct CD4+ T cell populations. In the current research training plan, we will test whether the different crawling phenotypes observed utilize unique molecular mechanisms in vivo. An understanding of mechanisms employed by functionally distinct effector T cells could present means of preferentially manipulating subsets of tissue-resident effector cells, potentially offering great therapeutic potential for many disease states.

描述（由申请人提供）：已显示白细胞在体外利用不同的运动模式，这取决于其周围环境的性质。使用活体2-光子显微镜系统成像小鼠发炎真皮内的活T细胞，我们观察到两种不同的间质爬行表型，由功能离散的CD 4 + T细胞群体显示。Th 1细胞以阿米巴样运动迅速移动，而Th 2细胞以间充质样运动爬行。这两种模式表明这些功能不同的T细胞的运动机制是不同的。鉴于细胞外基质和细胞内信号之间的反馈，通过表面受体（如整合素），这些观察结果在利什曼原虫模型的相关性，其中我们以前的数据表明，有功能的改变，T细胞在局部感染的组织，可能会限制Th 1积累。因此，我们将测试以下假设：1）Th 1和Th 2效应T细胞在体内间质爬行期间利用不同的分子机制进行运动，以及2）在寄生性L.严重感染具体目标1：效应Th 1和Th 2细胞是否利用不同的机制在炎症部位爬行？目前，细胞生物学家已经描述了两种主要的间质爬行模式：整合素依赖性（间充质）和整合素非依赖性，肌球蛋白II依赖性（变形虫）运动。本研究的目的是确定不同的辅助性T细胞群在发炎真皮的间质空间内爬行的分子方式。候选分子通路将被抗体阻断、基因缺失和siRNA破坏，并通过活体双光子显微镜测定对运动性的影响。特异性目标2：病原体诱导的局部变化能否调节辅助性T细胞的迁移和爬行模式？除了伴随慢性感染的免疫反应外，病原体如L. major可以引起当地环境的重大变化。L. major可以通过病原体驱动的局部组织ECM的结构和组成的变化来反式调节T细胞运动性，并且通过调节由感染的宿主细胞表达的趋化因子和粘附分子来顺式调节T细胞运动性。这些变化可能导致局部微环境与稳态甚至非寄生的发炎组织显著不同。目的是评价L.主要感染的组织微环境对Th 1和Th 2细胞爬行的影响，以及寄生的抗原呈递细胞与不同效应T细胞亚群相互作用的能力。 公共卫生相关性：使用活体显微镜系统对小鼠发炎真皮内的活T细胞进行成像，我们观察到功能不同的CD 4 + T细胞群体显示的两种独特的爬行表型。在目前的研究培训计划中，我们将测试观察到的不同爬行表型是否利用体内独特的分子机制。对功能不同的效应T细胞所采用的机制的了解可以提供优先操纵组织驻留效应细胞子集的方法，从而可能为许多疾病状态提供巨大的治疗潜力。