DC-HIL in Cutaneous Immunity

DC-HIL 在皮肤免疫中的应用

基本信息

批准号：
7336753
负责人：
Kiyoshi Ariizumi
金额：
$ 32.65万
依托单位：
UT SOUTHWESTERN MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-04-01 至 2009-07-14
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7336753
关键词：
Agonist Antibodies Antigen-Presenting Cells Antigens Appendix Attenuated Binding Biochemical Biological Assay Cell physiology Cells Cloning Complementary DNA Contact hypersensitivity Cutaneous Dendritic Cells Down-Regulation Event Functional disorder Genes Haptens Immunity Immunologics In Vitro Infectious Agent Inflammation Integral Membrane Protein Interleukin-2 Kinetics Knockout Mice Langerhans cell Lead Ligands Measures Methods Mixed Lymphocyte Culture Test Modeling Molecular Profiling Molecular Weight Mus Northern Blotting Numbers Organ Pathway interactions Play RNase protection assay Regulatory Pathway Relative (related person)Research Personnel Reverse Transcriptase Polymerase Chain Reaction Role Signal Transduction Skin Small Interfering RNA Subfamily lentivirinae Systemic disease T-Cell Activation T-Cell Proliferation T-Cell Receptor T-Lymphocyte Technology Time Translations cellular engineering cytokine expression cloning in vivo inhibitor/antagonist lymph nodes mRNA Expression novel research study response therapeutic target tumor growth

项目摘要

Because T cell activation is a highly regulated event with crucial consequences to the host, it is important to understand mechanisms that promote as well as down-regulate it. We discovered DC-HIL, a type I transmembrane protein expressed constitutively at high levels by epidermal Langerhans cells and dendritic cells (DC). Soluble DC-HIL bound to activated (but not naive) T cells, indicating that expression of its T cell ligand (DC-HIL-L) requires activation. In T cell activation assays, immobilized DC-HIL acted as a negative agonist, markedly attenuating T cell proliferation and IL-2 secretion triggered by signaling via the T cell receptor. By contrast, soluble DC-HIL augmented the mixed lymphocyte reaction and exacerbated contact hypersensitivity (CH) when injected intraperitoneally into mice during hapten-challenge (but not during hapten-priming); herein, DC-HIL acted as an antagonist interfering with binding of DC-HIL to DC-HIL-L. We hypothesize that the DC-HIL/DC-HIL-L pathway transmits a potent inhibitory signal to activated T cells and plays an important role in down-regulating effector T cell responses. Our specific aims are to: (1) Determine whether DC-HIL expression on DC modulates antigen presenting cell function in vitro. We will examine the ability of DC engineered genetically to over-express or silence DC-HIL, to activate T cells. (2) Characterize the inhibitory function of DC-HIL/DC-HIL-L pathway in vivo using the CHmodel. We will: identify DC-HIL- or DC-HIL-L-expressing cells in skin and lymph nodes (LN) of hapten-sensitized mice; characterize LN T cells in sensitized mice treated with soluble DC-HIL; compare DC-HIL/DC-HIL-L and PD-1/PD-L pathways for potency, synergy, and kinetics of down-regulated T cell activation; and examine DC-HIL knockout mice for phenotypic and functional changes including CH responses. (3) Identify DC-HIL-L on activated T cells by biochemical methods and an expression cloning strategy. Our results are likely to show great promise for DC-HIL and DC-HIL-L as potential therapeutic targets for immunologic or pharmacologic modulation.

由于T细胞激活是一个高度调节的事件，对宿主产生了至关重要的后果，因此了解促进和下调的机制很重要。我们发现了DC-HIL，这是一种I型跨膜蛋白，由表皮Langerhans细胞和树突状细胞（DC）在高水平上的组成型表达。可溶性DC-HIL与激活（但不是天真的）T细胞结合，表明其T细胞配体（DC-HIL-L）的表达需要激活。在T细胞激活测定中，固定的DC-HIL充当负激动剂，显着衰减T细胞增殖和通过T细胞受体信号触发的IL-2分泌。相比之下，可溶性DC-HIL增强了混合淋巴细胞反应和加剧的接触性超敏反应（CH），当时将腹膜内注射到hapen-challenge期间（但没有在期间） Hapen-Priming）;本文中，DC-HIL充当拮抗剂，干扰了DC-HIL与DC-HIL-L的结合。我们假设DC-HIL/DC-HIL-L途径将有效的抑制信号传递到激活的T细胞中，并在下调效应T细胞反应中起重要作用。我们的具体目的是：（1）确定DC上的DC-HIL表达是否在体外调节抗原呈现细胞功能。我们将检查DC工程在遗传上过表达或沉默DC-HIL激活T细胞的能力。（2）表征使用Chmodel在体内DC-HIL/DC-HIL-L途径的抑制功能。我们将：鉴定皮肤敏感小鼠的皮肤和淋巴结（LN）中表达DC-HIL或DC-HIL-L-L-L-L-L-L-表达细胞；在用可溶性DC-HIL处理的敏化小鼠中表征Ln T细胞；比较DC-HIL/DC-HIL-L和PD-1/PD-L途径，以进行下调T细胞激活的效力，协同和动力学；并检查DC-HIL基因敲除小鼠是否有表型和功能变化，包括CH反应。（3）通过生化方法和表达克隆策略鉴定激活的T细胞上的DC-HIL-L。我们的结果可能会显示出DC-HIL和DC-HIL-L作为免疫或药理调节的潜在治疗靶标。