Role of immune receptor clustering in controlling efficacy of antibody-dependent FcγRIIIa-mediated cytotoxicity by NK cells

免疫受体簇在控制 NK 细胞抗体依赖性 FcγRIIIa 介导的细胞毒性中的作用

基本信息

批准号：
10078249
负责人：
Kerry S Campbell
金额：
$ 51.02万
依托单位：
THOMAS JEFFERSON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-01-01 至 2024-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10078249
关键词：
Affect Affinity Antibodies Antigens Autoimmune Diseases Avidity Binding CD8-Positive T-Lymphocytes CD8B1 gene Cell Adhesion Molecules Cell Degranulation Cell Maturation Cell surface Cells Cellular immunotherapy Communicable Diseases Cytolysis Cytoplasmic Granules Cytotoxic T-Lymphocytes Data Development Diffuse Disease Dissociation Effector Cell Environment FCGR3B gene Fab Immunoglobulins Fc Immunoglobulins Fc Receptor Goals Host Defense Human IgG1 IgG3 Immunoglobulin G Immunologic Receptors Immunotherapeutic agent Immunotherapy Infection Integrins Intercellular adhesion molecule 1 Kinetics Ligands Ligation Light Lipid Bilayers Lymphocyte MHC Interaction MS4A1 gene Malignant Neoplasms Mediating Membrane Modeling Molecular NK Cell Activation Names Natural Killer Cell toxicity Natural Killer Cells Nature Peptide/MHC Complex Play Positioning Attribute Production Proteins Receptor Cell Role Signal Transduction Structure Surface Synapses System T cell response T-Lymphocyte Testing Therapeutic Variant Virus Virus Diseases antibody-dependent cell cytotoxicity base cancer cell cell killing crosslink cytokine cytotoxic cytotoxicity density design immune function immunological synapse formation improved kinetic model membrane model nanocluster nanolipoprotein particles nanoparticle nanoscale novel strategies pathogen receptor receptor-mediated signaling response rituximab synaptic function synaptogenesis tool tumor

项目摘要

Project Summary NK cells are capable of killing virus-infected and cancer cells and, therefore, play an important role in innate host defense. Unlike cytotoxic T lymphocytes (CTL), whose cytolytic activity is induced by productive TCR engagement with cognate pMHC ligands, activation of NK cells is regulated by a set of activating and inhibitory receptors. The net result of the signals induced by these receptors determines the extent of NK cell effector activities such as INF- production and granule-mediated cytotoxicity. One of the main mechanisms of NK cell- mediated cytolytic activity depends on antibodies and is termed antibody-dependent cell-mediated cytotoxicity (ADCC). ADCC is induced by FcRIIIa (CD16) receptors that do not directly recognize antigens on the target cells, but interact with Fc fragments of IgG antibodies specifically bound to the antigens on the surface of target cells. Available evidence, including ours, strongly suggests that ligand-mediated clustering of activating receptors on cytotoxic lymphocytes regulates kinetics of intracellular signaling, formation of a highly ordered synaptic interface, kinetics of granule delivery, and efficiency of target cell lysis (1-6). The receptor clustering can be further modulated by antigen co-clustering with other membrane ligands on target cells, which interact with inhibitory receptors or adhesion molecules on the surface of NK cells. We hypothesize that differences in FcRIIIa (CD16) clustering/co-clustering could have significant impact on receptor-mediated signaling influencing efficiency of ADCC. Thus, the goal of this project is to study how homotypic and heterotypic ligand clustering regulates ability of the ligands to cooperate in the engagement of CD16, inhibitory receptors and adhesion molecules to modulate efficiency of ADCC. We will use well-characterized CD16.NK92 cells that we have developed to model functions of NK cells (7-12) and freshly activated human NK cells to investigate the role of CD16 clustering/co-clustering with other receptors. To achieve this goal, we will exploit fluorescent nanoparticles (NiNLPs) that can be loaded with ligands for CD16, adhesion molecules, and inhibitory receptors at various ratios and densities, and will examine the binding kinetics of these model membrane clusters to NK cells as well as the kinetics of induced intracellular Ca2+ signaling. We will also utilize planar lipid bilayers presenting the same ligands, either dispersed in the bilayers or co-localized by cross-linking with the iDimerize system, and will analyze how cross-linking of the ligands will influence structure of the synaptic interface and the kinetics of NK cell degranulation. The expected results will provide significantly improved understanding of the mechanisms controlling cytolytic activity of primary and activated human NK cells to design new NK cell-based immunotherapeutic strategies to improve efficiency of ADCC to treat viral infections, autoimmune diseases, and cancer.

项目摘要 NK细胞能够杀死感染病毒和癌细胞，因此在先天性中起着重要作用主持人防御。与细胞毒性T淋巴细胞（CTL）不同，其细胞溶解活性是由生产性TCR诱导的与同源PMHC配体的接合，NK细胞的激活受到一组激活和抑制作用调节受体。这些受体诱导的信号的最终结果决定了NK细胞效应子的程度诸如INF-产生和颗粒介导的细胞毒性之类的活性。 NK细胞的主要机制之一介导的细胞溶解活性取决于抗体，称为抗体依赖性细胞介导的细胞毒性（ADCC）。 ADCC是由未直接识别靶抗原的FCRIIIA（CD16）接收器诱导的细胞，但与特异性结合到靶表面的抗原的IgG抗体的FC片段相互作用细胞。可用的证据，包括我们的证据，强烈表明配体介导的激活聚类细胞毒性淋巴细胞上的受体调节细胞内信号的动力学，形成高度有序的突触界面，颗粒递送的动力学以及靶细胞裂解的效率（1-6）。接收器聚类可以通过与靶细胞上的其他膜配体共聚类的抗原共聚类进一步调节，靶细胞相互作用 NK细胞表面上抑制受体或粘合分子。我们假设差异在FCRIIIA（CD16）中，聚类/共簇可能会对受体介导的显着影响信号传导影响ADCC的效率。这是该项目的目标是研究同型和异型配体聚类调节配体在CD16参与度抑制的能力受体和粘合剂分子调节ADCC的效率。我们将使用良好的CD16.NK92 我们已经开发出来为NK细胞（7-12）和新鲜激活的人NK细胞的功能建模的细胞研究CD16聚类/共簇与其他接收器的作用。为了实现这一目标，我们将利用荧光纳米颗粒（NINLP），可以加载用于CD16，粘合分子和的配体以各种比率和密度为抑制性受体，并将检查这些模型的结合动力学膜聚集到NK细胞以及诱导细胞内Ca2+信号的动力学。我们也会利用呈现相同配体的平面脂质双层，要么分散在双层中或共定位与个体化系统交联，并将分析配体的交联如何影响结构 NK细胞脱粒的突触界面和动力学。预期的结果将提供显着提高了对控制原发性和激活的细胞溶解活性的机制的理解人类NK细胞设计新的基于NK细胞的免疫治疗策略，以提高ADCC的效率治疗病毒感染，自身免疫性疾病和癌症。