R01AI153442

An Experimentally-Refined, Dynamic Gene Regulatory Network Model of T-Cell Memory

Summary
T cell memory induced by prior exposure to a pathogen or vaccination provides enhanced protection against a subsequent infection with the same pathogen. Enhanced protection is partially driven by clonal expansion, which leads to an increased number of T cells capable of recognizing the antigen. Additionally, memory T cells possess a "rapid recall ability" that allows them to fight pathogens by producing cytokines and other effector molecules within minutes of re-exposure (as opposed to days, upon initial exposure). We recently showed that rapid recall correlates with the epigenetic poising of enhancers and promoters of the "rapid-recall genes" in memory T cells. Importantly, the sites of epigenetic change significantly overlap with the risk loci for autoimmune and atopic disease, suggesting that this mechanism is important for human health. However, it is still unclear if and how the epigenetic poising causes enhanced expression of rapid recall genes. Furthermore, memory T cells persist for a lifetime; yet the mechanisms that maintain the memory epigenome – for decades – are not known. Our preliminary data suggest that rapid recall is coordinated by several families of transcription factors (TFs) and thousands of putative DNA regulatory elements. This complexity requires a systems-level, engineering approach. Thus, this proposal is a collaboration between the groups of Artem Barski, a T cell biologist, and Emily Miraldi, a mathematical modeler, to create experimentally validated, genome-scale models of memory immune responses across heterogeneous T cell populations.

Aim 1. Using single-cell genomics, we will characterize the gene expression and chromatin dynamics of T cell activation in naïve and memory cells and build mathematical models that integrate these data (along with relevant existing genomics resources) into a dynamic gene regulatory network (GRN). Our GRN model will predict the molecular drivers (TFs) and regulatory elements that orchestrate rapid recall.

Aim 2. Although T-cell activation in naïve and memory cells similarly promotes nuclear translocation of inducible TFs, our data lead us to hypothesize that chromatin remodeling upon initial pathogen exposure alters the occupancy of inducible TFs in memory T cells and that this is the basis of rapid recall. We will combine dynamic TF perturbation and occupancy experiments to establish the molecular interactions driving rapid recall.

Aim 3. We will identify the mechanisms by which memory T cells maintain the epigenome conducive for rapid recall – over the human lifespan. We hypothesize that constitutive TFs maintain the epigenome poised for rapid recall. We propose dynamic TF perturbation experiments to uncover the identities of these regulators.

This study will help uncover basic mechanisms of T cell memory and identify potential targets for manipulating immunologic memory responses. Because rapid recall is the basis for vaccination and central to allergy, asthma, and cancer immunity, this study will have a broad impact on human health.

Childrens Hospital Medical Center

TO ASSIST PUBLIC AND PRIVATE NONPROFIT INSTITUTIONS AND INDIVIDUALS TO ESTABLISH, EXPAND AND IMPROVE BIOMEDICAL RESEARCH AND RESEARCH TRAINING IN INFECTIOUS DISEASES AND RELATED AREAS, TO CONDUCT DEVELOPMENTAL RESEARCH, TO PRODUCE AND TEST RESEARCH MATERIALS. TO ASSIST PUBLIC, PRIVATE AND COMMERCIAL INSTITUTIONS TO CONDUCT DEVELOPMENTAL RESEARCH, TO PRODUCE AND TEST RESEARCH MATERIALS, TO PROVIDE RESEARCH SERVICES AS REQUIRED BY THE AGENCY FOR PROGRAMS IN INFECTIOUS DISEASES, AND CONTROLLING DISEASE CAUSED BY INFECTIOUS OR PARASITIC AGENTS, ALLERGIC AND IMMUNOLOGIC DISEASES AND RELATED AREAS. PROJECTS RANGE FROM STUDIES OF MICROBIAL PHYSIOLOGY AND ANTIGENIC STRUCTURE TO COLLABORATIVE TRIALS OF EXPERIMENTAL DRUGS AND VACCINES, MECHANISMS OF RESISTANCE TO ANTIBIOTICS AS WELL AS RESEARCH DEALING WITH EPIDEMIOLOGICAL OBSERVATIONS IN HOSPITALIZED PATIENTS OR COMMUNITY POPULATIONS AND PROGRESS IN ALLERGIC AND IMMUNOLOGIC DISEASES. BECAUSE OF THIS DUAL FOCUS, THE PROGRAM ENCOMPASSES BOTH BASIC RESEARCH AND CLINICAL RESEARCH. SMALL BUSINESS INNOVATION RESEARCH (SBIR) PROGRAM EXPANDS AND IMPROVES PRIVATE SECTOR PARTICIPATION IN BIOMEDICAL RESEARCH. THE SBIR PROGRAM INTENDS TO INCREASE AND FACILITATE PRIVATE SECTOR COMMERCIALIZATION OF INNOVATIONS DERIVED FROM FEDERAL RESEARCH AND DEVELOPMENT, TO INCREASE SMALL BUSINESS PARTICIPATION IN FEDERAL RESEARCH AND DEVELOPMENT, AND TO FOSTER AND ENCOURAGE PARTICIPATION OF SOCIALLY AND ECONOMICALLY DISADVANTAGED SMALL BUSINESS CONCERNS AND WOMEN-OWNED SMALL BUSINESS CONCERNS IN TECHNOLOGICAL INNOVATION. THE SMALL BUSINESS TECHNOLOGY TRANSFER (STTR) PROGRAM STIMULATES AND FOSTERS SCIENTIFIC AND TECHNOLOGICAL INNOVATION THROUGH COOPERATIVE RESEARCH AND DEVELOPMENT CARRIED OUT BETWEEN SMALL BUSINESS CONCERNS AND RESEARCH INSTITUTIONS, TO FOSTER TECHNOLOGY TRANSFER BETWEEN SMALL BUSINESS CONCERNS AND RESEARCH INSTITUTIONS, TO INCREASE PRIVATE SECTOR COMMERCIALIZATION OF INNOVATIONS DERIVED FROM FEDERAL RESEARCH AND DEVELOPMENT, AND TO FOSTER AND ENCOURAGE PARTICIPATION OF SOCIALLY AND ECONOMICALLY DISADVANTAGED SMALL BUSINESS CONCERNS AND WOMEN-OWNED SMALL BUSINESS CONCERNS IN TECHNOLOGICAL INNOVATION. RESEARCH CAREER DEVELOPMENT AWARDS SUPPORT THE DEVELOPMENT OF SCIENTISTS DURING THE FORMATIVE STAGES OF THEIR CAREERS. INDIVIDUAL NATIONAL RESEARCH SERVICE AWARDS (NRSAS) ARE MADE DIRECTLY TO APPROVE APPLICANTS FOR RESEARCH TRAINING IN SPECIFIED BIOMEDICAL SHORTAGE AREAS. IN ADDITION, INSTITUTIONAL NATIONAL RESEARCH SERVICE AWARDS ARE MADE TO ENABLE INSTITUTIONS TO SELECT AND MAKE AWARDS TO INDIVIDUALS TO RECEIVE TRAINING UNDER THE AEGIS OF THEIR INSTITUTIONAL PROGRAM.

93.855 - Allergy and Infectious Diseases Research

National Institute of Allergy and Infectious Diseases (NIAID) [HHS - NIH]

Cincinnati, Ohio 45229 United States

Single Zip Code

NIH Research Project Grant (Parent R01 Clinical Trial Not Allowed) (PA-20-185)

Amendment Since initial award the total obligations have increased 540% from $537,532 to $3,442,537.