Expression and function of the TLRs on T cells

T 细胞上 TLR 的表达和功能

• 批准号: 7162068
• 负责人: Laurence A Turka
• 金额: $ 40.17万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7162068
• 关键词: Adaptor Signaling Protein; Adoptive Transfer; Alloantigen; Backcrossings; Binding; Bone Marrow; CD4 Positive T Lymphocytes; Cell Survival; Cells; Chimera organism; Complex; Coupled; Cytokine Signaling; DNA; Data; Goals; Immune; Immune response; Immune system; Immunity; Immunologic Monitoring; In Vitro; Individual; Inflammatory; Interleukin-12; Interleukin-2; Knockout Mice; Laboratories; Ligands; Ligation; MAP Kinase Gene; MAPK14 gene; MAPK8 gene; MHC Class II Genes; Mammals; Mediating; Mediator of activation protein; Memory; Microbe; Modeling; Molecular; Mus; Mutate; NF-kappa B; Pathway interactions; Pattern; Pattern recognition receptor; Phagocytosis; Play; Production; Proteins; Reagent; Receptor Activation; Receptor Signaling; Reporting; Research; Rest; Retroviral Vector; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Stimulus; System; T-Cell Activation; T-Lymphocyte; TLR3 gene; TLR9 gene; TNFRSF5 gene; Tissues; Toll-Like Receptor 5; Toll-like receptors; Toxoplasma gondii; Transgenes; Transgenic Mice; Transgenic Organisms; Transplantation; Up-Regulation; Work; base; cytokine; eosinophil; in vivo; in vivo Model; macrophage; mast cell; neutrophil; pathogen; programs; receptor binding; receptor expression; receptor function; reconstitution; response

DESCRIPTION (provided by applicant): Toll-like receptors (TLRs) play an integral role in innate and adaptive immunity. Ligation of TLRs activates cells of the innate immune system, inducing functions such as phagocytosis and IFN-a and IFN-b secretion. TLR-ligation also serves as a bridge between the innate and adaptive immune systems. TLR stimulation of DCs and macrophages induces the production of inflammatory cytokines such as IL-12, and upregulation of MHC class II and costimulatory ligands such as CD40 and CD86, and most of these responses require signals delivered through the adaptor signaling molecule MyD88. While roles for TLRs and MyD88 on APCs are well-established, surprisingly little is known about their expression and potential function on T cells. Studies from our laboratory show that several TLRs are expressed following activation of naive CD4+CD25 T cells. Ligation of these TLRs activates, via MyD88, several downstream signaling pathways, including NF- kB, p38 JNK, and ERK. Functionally, this leads to enhanced T cell survival and provides costimulation with sub-optimal TCR ligation. New data also indicates that in vivo expression of MyD88 in T cells may be required for a protective immune response to the pathogen Toxoplasma gondii. Our working hypothesis is that TLR and MyD88 signaling on T cells are important contributors to cellular immune responses. To this end, the long-term goals of this research program are to define the expression and function of TLRs on T cells. In specific aim #1 we will characterize the signals which govern the expression and upregulation of TLRs on T cells, and the downstream signaling pathways which TLRs and MyD88 use to mediate their effects. Specific aim #2 will use cells from TCR transgenic mice coupled with in vitro and in vivo adoptive transfer systems to conduct a detailed examination of the effects of TLR and MyD88 activation of T cells on induction of activation and costimulatory molecules, cytokine production or skewing, and effector/memory differentiation and responsiveness. This approach will allow for precise definition of what TLR stimulation of T cells can do. In specific aim #3 we will then ask which of the functions identified for TLRs and MyD88 in aim #2 are operative during in vivo immune responses. To do so, we will use MyD88 knockout mice and bone-marrow chimeras and adoptive transfer systems to create in vivo models in which only T cells are deficient in MyD88. Based on our preliminary data, we will use these models to assess responses to Toxoplasma gondii, and will also backcross the MyD88-deficient mice onto TCR transgenic backgrounds to enable us to track the fate of individual T cells as they respond to alloantigen in vivo in transplantation models.

描述（由申请人提供）：Toll 样受体（TLR）在先天性和适应性免疫中发挥着不可或缺的作用。 TLR 的连接可激活先天免疫系统的细胞，诱导吞噬作用以及 IFN-a 和 IFN-b 分泌等功能。 TLR 连接还充当先天性免疫系统和适应性免疫系统之间的桥梁。 DC 和巨噬细胞的 TLR 刺激诱导炎症细胞因子（如 IL-12）的产生，以及 MHC II 类和共刺激配体（如 CD40 和 CD86）的上调，并且大多数这些反应需要通过接头信号分子 MyD88 传递信号。虽然 TLR 和 MyD88 在 APC 上的作用已得到充分证实，但令人惊讶的是，人们对它们在 T 细胞上的表达和潜在功能知之甚少。我们实验室的研究表明，初始 CD4+CD25 T 细胞激活后会表达多种 TLR。这些 TLR 的连接通过 MyD88 激活多个下游信号传导途径，包括 NF-kB、p38 JNK 和 ERK。从功能上讲，这会增强 T 细胞的存活率，并通过次优 TCR 连接提供共刺激。新数据还表明，T 细胞中 MyD88 的体内表达可能是针对病原体弓形虫的保护性免疫反应所必需的。我们的工作假设是 T 细胞上的 TLR 和 MyD88 信号传导是细胞免疫反应的重要贡献者。为此，该研究计划的长期目标是明确TLRs在T细胞上的表达和功能。在具体目标#1中，我们将描述控制T细胞上TLR表达和上调的信号，以及TLR和MyD88用来介导其作用的下游信号通路。具体目标#2 将使用来自 TCR 转基因小鼠的细胞与体外和体内过继转移系统相结合，详细检查 T 细胞的 TLR 和 MyD88 激活对激活和共刺激分子的诱导、细胞因子的产生或偏差以及效应器/记忆分化和反应性的影响。这种方法将能够精确定义 TLR 刺激 T 细胞的作用。在具体目标#3 中，我们将询问目标#2 中为TLR 和MyD88 确定的哪些功能在体内免疫反应期间起作用。为此，我们将使用 MyD88 敲除小鼠、骨髓嵌合体和过继转移系统来创建体内模型，其中只有 T 细胞缺乏 MyD88。根据我们的初步数据，我们将使用这些模型来评估对弓形虫的反应，并将 MyD88 缺陷小鼠回交到 TCR 转基因背景上，以便我们能够跟踪单个 T 细胞在移植模型中对体内同种异体抗原作出反应时的命运。