Costimulatory ligand mobility effects on T cell activation

共刺激配体迁移率对 T 细胞活化的影响

• 批准号: 8431504
• 负责人: Janis K. Burkhardt
• 金额: $ 34.96万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2017-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8431504
• 关键词: Actin-Binding Protein; Actinin; Actins; Adoptive Transfer; Affect; Antibodies; Antigen-Presenting Cells; Antigens; Autoimmune Diseases; Automobile Driving; Binding; Biochemical; Biological Assay; CD80 gene; Cell membrane; Cells; Clinical; Collaborations; Complex; Cytoplasmic Tail; Cytoskeleton; Dendritic Cells; Development; Diffusion; Engineering; Equilibrium; Event; Exhibits; Fluorescence Recovery After Photobleaching; Hypersensitivity; Immune response; Immunity; In Vitro; Intercellular adhesion molecule 1; Interleukin-2; Knowledge; Label; Lateral; Ligands; Lipid Bilayers; Mass Spectrum Analysis; Measures; Mediating; Membrane; Modeling; Molecular; Molecular Conformation; Monitor; Movement; Mutate; Natural Killer Cells; Nature; Patients; Pattern; Peptide/MHC Complex; Peptides; Play; Printing; Process; Production; Protein Binding; Role; Shapes; Side; Signal Transduction; Signaling Molecule; Structure; Surface; Synapses; T cell response; T-Cell Activation; T-Cell Proliferation; T-Lymphocyte; TCR Activation; Tail; Testing; Transplant Recipients; Tyrosine Phosphorylation; Vaccines; adaptive immunity; base; copolymer; immunological synapse; in vivo; inhibitor/antagonist; insight; intercellular cell adhesion molecule; intravital imaging; moesin; mutant; nanolithography; nanoscale; novel; public health relevance; receptor; research study; response; surface coating; therapeutic target; transplantation medicine; vaccine development

DESCRIPTION (provided by applicant): Costimulatory signals lower the threshold for T cell activation, and tune the immune response, driving T cells towards distinct effector lineages and establishing the balance between immunity and tolerance. Because of their central role in shaping the immune response, and because of the conserved nature of costimulatory receptor-ligand interactions, costimulatory molecules are powerful therapeutic targets. Interaction of T cells with pMHC and costimulatory ligands such CD80/86 and ICAM-1 takes place at the immunological synapse. Several pieces of evidence suggest that the DC cytoskeleton plays an important role in modulating signaling events at the immunological synapse, but the molecular basis for this is not understood. We have discovered that while pMHC moves relatively freely on the DC membrane, the DC actin cytoskeleton constrains the mobility of ICAM-1 and CD80, and we have identified two actin-binding proteins, moesin and ¿-actinin, that play a key role in this process. We hypothesize that cytoskeletal constraints to mobility of ICAM-1 and CD80 on the DC surface promote costimulatory signaling, by creating tension on receptors and modulating dynamics of signaling microclusters on the T cell side of the synapse. This hypothesis will be tested by carrying out three specific aims. First, we will characterize the interactions of moesin and ¿- actinin with basic sequences in the cytoplasmic tails of ICAM-1 and CD80, and test the effects of perturbing these interactions on lateral diffusion of ICAM-1 and CD80. Second, in collaboration with membrane biophysicist Tobias Baumgart, we will use novel mixed mobility surfaces to test the effects of varying ICAM-1 mobility and patterning while maintaining pMHC in a mobile state. Several aspects of the T cell response to these surfaces will be assessed, including specific signaling events, LFA-1 conformational change, and dynamics of the T cell cytoskeleton and associated signaling molecules. Finally, we will engineer DCs in which ICAM-1 mobility is altered, either by perturbing actin-binding proteins or by mutating interacting residue in the ICAM-1 tail, and test the effects on T cell activation and lineage development in vitro. Adoptive transfer experiments will also be performed to test the effects of ICAM-1 mobility on T cell-DC interactions in vivo using intravital imaging. Taken together, these studies will test an unexplored aspect of costimulatory signaling, and will provide important new insights into how the DC actin cytoskeleton modulates the immune response. This information will guide clinical efforts to manipulate DC function in vaccine development, transplantation medicine and treatment of allergy and autoimmune disease.

描述（通过应用程序提供）：共刺激信号降低了T细胞激活的阈值，并调整免疫响应，将T细胞驱动到明显的效应谱系，并在免疫和公差之间建立平衡。由于它们在塑造免疫响应中的核心作用，并且由于共刺激受体 - 配体相互作用的保守性质，因此刺激性分子是强大的治疗靶标。 T细胞与PMHC的相互作用和类CD80/86和ICAM-1的共刺激配体的相互作用发生在免疫突触。几个证据表明，直流细胞骨架在调节免疫突触的信号事件中起着重要作用，但尚不清楚这一点的分子基础。我们发现，尽管PMHC在DC膜上相对自由移动，但DC肌动蛋白细胞骨架限制了ICAM-1和CD80的迁移率，并且我们已经确定了两种肌动蛋白结合蛋白Moesin和Moesin and-Actinin，在此过程中起着关键作用。我们假设通过对受体产生张力并调节突触T细胞侧的信号传导微量群体的动态，ICAM-1和CD80对ICAM-1和CD80在DC表面上的迁移率的细胞骨架约束。该假设将通过执行三个具体目标来检验。首先，我们将表征Moesin和»肌动蛋白与ICAM-1和CD80的细胞质尾巴中的基本序列的相互作用，并测试这些相互作用对ICAM-1和CD80侧向扩散的影响。其次，与膜生物物理学家Tobias Baumgart合作，我们将使用新型的混合迁移率表面来测试不同的ICAM-1迁移率和模式的影响，同时将PMHC保持在移动状态。将评估T细胞对这些表面的响应的几个方面，包括特定的信号事件，LFA-1会议变化以及T细胞细胞骨架和相关信号分子的动力学。最后，我们将通过扰动肌动蛋白结合蛋白或通过突变ICAM-1尾巴中的相互作用居住地来设计ICAM-1迁移率的DC，并测试体外T细胞激活和谱系发展的影响。还将使用插入式成像测试ICAM-1迁移率对体内T细胞-DC相互作用的影响。综上所述，这些研究将测试共刺激信号传导的意外方面，并将提供有关直流肌动蛋白细胞骨架如何调节免疫响应的重要新见解。该信息将指导临床工作，以操纵直流功能在疫苗开发，移植医学以及过敏和自身免疫性疾病的治疗中。