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Mechanisms of impaired T-cell mechanosensing of melanoma antigens

黑色素瘤抗原 T 细胞机械感应受损的机制

基本信息

批准号：
9899742
负责人：
MICHELLE KROGSGAARD
金额：
$ 94.63万
依托单位：
GEORGIA INSTITUTE OF TECHNOLOGY
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-04-01 至 2022-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9899742
关键词：
Address Affinity Animal Model Animals Antigens Autoantigens Avidity Binding Biological Assay Blood Blood Circulation CD8-Positive T-Lymphocytes CD8B1 gene Cell membrane Cell physiology Cell surface Cells Cessation of life Chickens Clinical DNA Data Development Equilibrium Functional disorder Grant Human Image Immune Immunity Immunology Immunosuppression Immunotherapeutic agent Immunotherapy Impairment In Situ Kinetics Ligand Binding Ligands Link Major Histocompatibility Complex Measurement Mechanics Melanoma Cell Methods Microfluidics Molecular Molecular Analysis Mus Myeloid-derived suppressor cells Nature Outcome Ovalbumin Patient-Focused Outcomes Patients Peptide Receptor Peptides Receptor Cell Receptor Signaling Regulatory T-Lymphocyte Reporting Role Sampling Signal Transduction Skin Cancer Spleen System T cell therapy T-Cell Activation T-Cell Receptor T-Lymphocyte TCR Activation Techniques Testing Time Tissues Transforming Growth Factor beta Transgenic Mice Tumor Immunity Tumor-Infiltrating Lymphocytes United States United States National Center for Health Statistics Work advanced disease anti-melanoma immunity base checkpoint receptors design digital drug efficacy effector T cell exhaustion gp100 Antigen high throughput analysis immune checkpoint immunogenic improved improved outcome in vivo in vivo Model innovation mechanotransduction melanoma mouse model neoantigens novel strategies patient response physical science pre-clinical programmed cell death ligand 1 programmed cell death protein 1 protective effect response single molecule success tool tumor tumor microenvironment two-dimensional

项目摘要

Project Summary This project investigates how the tumor microenvironment (TME) impairs in situ interactions of T-cell surface molecules with counter-molecules on the melanoma cells to suppress anti-tumor immunity. Detailed mechanistic understanding will be obtained by an integrated approach that combines physical science (PS) based tools with two complementary pre-clinical mouse models of melanoma T cell immunity, which will be further tested using biospecimens from melanoma patients. The molecular focus is the T-cell receptor (TCR) that initiates the T-cell antigen recognition upon binding to peptide-major histocompatibility complex (pMHC), and the coreceptor CD8 that co-ligates with the pMHC. The first PS tool is quantifying TCR mechanosensing by single-molecule force probes through in situ kinetic analyses of molecular interactions with concurrent imaging of intracellular signals on a single cell. The second PS tool is DNA-based digital tension probes that report cell generated pulling forces on the TCR and CD8 via engaged pMHC. One animal model is a recognized standard that uses melanoma conjugated with a chicken ovalbumin antigen recognized by the OT-I TCR. The other animal model is a melanoma self-antigen gp100 in conjunction with JR209 humanized transgenic mice. By analyzing the mechanically regulated two-dimensional (2D) ligand binding of TCR and/or CD8 at the T-cell membrane, we observed that the TCR avidities for the pMHC of CD8 T cells infiltrating primary murine melanomas grown in vivo are significantly reduced relative to T cells within non-tumor associated tissues (spleen and blood). Such differential avidities were not detected by the conventional assay using pMHC tetramer, attesting to the power of our mechanics-based methods for analyzing TCR–pMHC interactions. We also found melanomas to substantially alter the force-dependent TCR–pMHC bond durability: in tumor-free animals, the TCR and pMHC formed a catch-slip bond whose lifetime first increased and then decreased with increasing force, which we have previously demonstrated to govern T cell signaling and effector function, whereas in melanoma-bearing animals, the TCR–pMHC bond lifetime only decreased with increasing force, i.e., behaved as a slip bond and were associated with reduced T cell effector functions. We hypothesize that deficient CD8 T cell immunity in melanoma results, at least in part, from impaired antigen recognition within the TME, as manifested by the altered TCR mechanosensing of pMHC. Three specific aims are proposed to test our hypothesis: 1) Determine the molecular interactions crucial to T cell antigen recognition that are impaired by the TME; 2) Define the functional consequences of suppressed T cell antigen recognition; and 3) Elucidate the mechanisms underlying the TME suppression of T cell antigen recognition. Completing these aims has the potential to identify new immunotherapeutic targets for the treatment of melanoma to improve the outcomes of patients with advanced disease.

项目总结