Defining the role of T cell help in germinal centers by intercellular enzymatic labeling

通过细胞间酶标记定义 T 细胞在生发中心的作用

• 批准号: 10566601
• 负责人: Gabriel D Victora
• 金额: $ 78.5万
• 依托单位: ROCKEFELLER UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-21 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10566601
• 关键词: 2019-nCoV; Address; Affinity; Antibodies; Antibody Affinity; Antibody-Producing Cells; Antigenic Specificity; Antigens; Autoimmune Diseases; B-Lymphocytes; Biological Assay; Biology; Biotin; Cell Communication; Cell model; Cells; Clonal Expansion; Cloning; Development; Disease; Epitopes; Equilibrium; Fine needle aspiration biopsy; Gene Expression Profile; Generations; HIV; Haptens; Helper-Inducer T-Lymphocyte; Hemagglutinin; Human; Hypersensitivity; Immunoglobulin Genes; Immunoglobulins; Infection; Infection Control; Influenza; Injections; Investigation; Label; Link; Measures; Memory B-Lymphocyte; Methods; Modality; Modeling; Mus; Mutation; Outcome; Output; Peptides; Physiological; Population; Process; Proteins; RNA vaccination; Reagent; Role; Specificity; Structure of germinal center of lymph node; Surface; System; T-Lymphocyte; TNFRSF5 gene; TNFSF5 gene; Testing; Vaccination; Vaccine Design; Vaccines; Variant; Viral Antigens; Viral Proteins; Virion; Virus; Virus Diseases; Work; antigen binding; base; clinically relevant; combat; experimental study; follow-up; gain of function; in vivo; lymph nodes; novel; pathogen; peptide A; response; single-cell RNA sequencing; theories; transcriptomics

PROJECT SUMMARY Generation of high affinity antibodies in germinal centers (GCs) is a critical step in a wide variety of clinically relevant processes, from protection against pathogens by prior infection or vaccination to the development of allergies and autoimmune diseases. Antibody affinity maturation follows a prototypical Darwinian framework, in which GC B cells introduce random mutations into the antigen-binding portions of their immunoglobulin (Ig) genes, generating variations in affinity within their progeny. Rare B cells that acquire affinity-increasing mutation are then selectively expanded within the GC population, thus increasing the average affinity of GC B cells as a whole, in a process we refer to as positive selection. Despite decades of work, the precise cellular mechanisms of positive selection—in other words, how GCs “pick out” B cells with the highest affinity—remains a topic of debate. More than 10 years ago, we provided the first in vivo evidence in mice for a role for T follicular helper (Tfh) cells as arbiters of this selective process. In our model, Tfh cells would sense how much peptide a B cell could present on its surface (which in turn depended on the B cell’s affinity), providing help selectively to the highest-affinity B cells. However, despite accumulating functional evidence for this model, selective delivery of T cell help to B cells based on their affinity has never been directly demonstrated in physiological settings. To achieve this, we developed LIPSTIC, a method that allows us to directly record T cell help to B cells with great precision in vivo. In Aim 1 of this project, we propose to use LIPSTIC as a means to directly test the T cell help model in classic hapten-carrier induced GC selection models. In Aim 2, we will follow up on this by testing our findings from mouse LIPSTIC in human vaccine-induced GCs. In Aim 3, we use the original LIPSTIC in conjunction with two novel versions on this strategy to investigate the dynamics of multi-antigen driven selection in influenza-induced GCs.

项目总结