Mechanisms of initiation of T-cell signaling by the TCR-CD3 complex

TCR-CD3 复合物启动 T 细胞信号传导的机制

• 批准号: 10193621
• 负责人: MICHELLE KROGSGAARD
• 金额: $ 2.48万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-05-01 至 2022-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10193621
• 关键词: Adaptor Signaling Protein; Affect; Affinity; Agonist; Amino Acids; Antibodies; Antigens; Apical; Autoimmune Process; Autoimmunity; Binding; Binding Proteins; Biological Assay; Biophysics; Biosensor; CD3 Antigens; CD8B1 gene; Cell Surface Receptors; Cell physiology; Cell surface; Cells; Cellular biology; Chemicals; Complex; Cytoplasmic Tail; Data; Derivation procedure; Development; Disease; Docking; Engineering; Environment; Event; Extracellular Structure; Feedback; Fluorescence Resonance Energy Transfer; Goals; Health; Human; ITAM; Image; Immune; Immune response; Immunology; Immunotherapy; In Situ; Individual; Infection; Inflammation; Inflammatory; Interdisciplinary Study; Interleukin-2; Kinetics; Label; Lead; Ligand Binding; Ligands; Ligation; Major Histocompatibility Complex; Malignant Neoplasms; Maps; Measurement; Mediating; Membrane; Modeling; Molecular; Molecular Conformation; Molecular Target; Mutate; NMR Spectroscopy; Outcome; Peptide/MHC Complex; Peptides; Phospholipids; Phosphorylation; Phosphotransferases; Play; Process; Production; Protein Tyrosine Kinase; Proteins; Public Health; Publications; Publishing; Receptor Signaling; Regulation; Relaxation; Resolution; Role; Signal Transduction; Signaling Protein; Site; Structural Models; Structure; Structure-Activity Relationship; T cell response; T-Cell Activation; T-Cell Receptor; T-Lymphocyte; Testing; Therapeutic; Visualization; Work; ZAP-70 Gene; adaptive immune response; base; biophysical techniques; chimeric antigen receptor; crosslink; design; experimental study; extracellular; functional outcomes; immune activation; improved; interdisciplinary approach; real time monitoring; response; small molecule; three dimensional structure; treatment strategy

PROJECT SUMMARY The T cell receptor (TCR)-CD3 complex plays an important role in antigen recognition in cell mediated adaptive immune responses. A fundamental unanswered question in immunology is how ligand engagement of TCR mediates critical information transfer from the antigen recognition site in the external environment to the intracellular compartment via the CD3 signaling complex, resulting in signal initiation. A complete understanding the molecular organization and function of the TCR-CD3 signaling complex has wide significance for development of new strategies for immune therapeutic intervention focusing on the very earliest stages of immune activation. The overall goal of this project is to understand how antigen recognition leads to molecular changes in the extracellular TCR-CD3 complex that further propagates molecular changes in intracellular immunoreceptor tyrosine-based activation motifs (ITAM) to result in functional outcomes. Our hypothesis is that force-induced or spontaneous reorientations and/or conformational changes in the extracellular TCR-CD3 complex and intracellular ITAMs upon agonist ligand binding are necessary for sufficient binding of protein tyrosine kinases (Lck, ZAP-70) to initiate proximal signaling events. Based on our recently published work that generated a structural model of the extracellular assembly of the TCR-CD3 complex and our preliminary data demonstrating that there is feedback mechanism through Lck mediated CD8 binding to agonist pMHC that prolongs TCR-pMHC catch-bonds we propose the following three aims to test our hypothesis. In the first aim, we will use paramagnetic relaxation enhancement, biomembrane force probe (BFP) assay and photo-crosslinking to determine how extracellular arrangements in the TCR-CD3 complex influence intracellular signaling. In the second aim, we will use NMR chemical shift perturbation analysis and BFP to study the interaction of intracellular CD3 with Lck/ZAP-70 to determine how structural changes in CD3 cytoplasmic domains influence protein tyrosine kinases interaction. In the third aim, we will employ BFP combined with concurrent FRET based imaging of proximal signaling components to determine how changes in TCR-CD3 extracellular interaction influence CD3-Lck /ZAP-70 interactions, TCR-pMHC binding and TCR- pMHC-CD8 interactions. By undertaking these aims we expect to determine the mechanistic basis of the signal transduction process through the TCR-CD3 complex during T cell recognition. Providing a detailed understanding of the involvement of force and specifics of these molecular interactions will allow for a more complete understanding of the molecular basis of signal transduction process during T cell antigen recognition. The relevance of this work to public health is in the potential to improve the response rate and overall outcomes of immunotherapies. Potential treatment strategies could include the use of antibodies, modified T cells, chimeric antigen receptors or small molecules which would allow for manipulation of immune responses to cancer, infections, inflammation and autoimmunity, which remains a significant problem in human health.

项目摘要 T细胞受体（TCR）-CD 3复合物在细胞介导的免疫应答中的抗原识别中起重要作用。 适应性免疫反应免疫学中一个基本的未回答的问题是， TCR介导关键信息从外部环境中的抗原识别位点转移到免疫系统中。 通过CD 3信号传导复合物进入细胞内区室，导致信号起始。一个完整 了解TCR-CD 3信号复合物的分子组织和功能具有广泛的意义。 免疫治疗干预新策略的发展意义， 免疫激活的最早阶段这个项目的总体目标是了解抗原识别 导致细胞外TCR-CD 3复合物的分子变化， 细胞内免疫受体酪氨酸激活基序（ITAM）导致功能结果。我们 假设是力诱导的或自发的重定向和/或构象变化， 激动剂配体结合后的细胞外TCR-CD 3复合物和细胞内ITAM是必需的， 充分结合蛋白酪氨酸激酶（Lck，ZAP-70）以启动近端信号传导事件。基于我们 最近发表的工作产生了TCR-CD 3细胞外组装的结构模型， 我们的初步数据表明，存在通过Lck介导的CD 8 我们提出了以下三个目的来测试与抑制TCR-pMHC捕获键的激动剂pMHC的结合 我们的假设在第一个目标中，我们将使用顺磁弛豫增强，生物膜力探针 (BFP)测定和光交联以确定TCR-CD 3复合物中细胞外排列如何 影响细胞内信号传导。在第二个目标中，我们将使用NMR化学位移微扰分析， BFP研究细胞内CD 3与Lck/ZAP-70的相互作用，以确定CD 3 胞质结构域影响蛋白酪氨酸激酶的相互作用。在第三个目标中，我们将采用BFP 与同时进行的基于FRET的近端信号传导成分成像相结合，以确定如何改变 在TCR-CD 3细胞外相互作用影响CD 3-Lck /ZAP-70相互作用中，TCR-pMHC结合和TCR-CD 3-Lck /ZAP-70相互作用影响TCR-CD 3-Lck/ZAP-70相互作用影响TCR-pMHC结合和TCR-CD 3-Lck/ZAP-70相互作用。 pMHC-CD 8相互作用。通过承担这些目标，我们期望确定信号的机械基础 在T细胞识别过程中通过TCR-CD 3复合物的转导过程。提供详细的 理解力的参与和这些分子相互作用的细节将允许更多的 全面了解T细胞抗原识别过程中信号转导过程的分子基础。 这项工作与公共卫生的相关性在于有可能提高答复率， 免疫疗法的结果。潜在的治疗策略可能包括使用抗体，修饰的T 细胞、嵌合抗原受体或小分子 癌症、感染、炎症和自身免疫，这仍然是人类健康中的一个重要问题。