The SARS-CoV-2 pandemic highlighted the urgent need for better understanding of the mechanisms controlling broadly protective immune responses to rapidly evolving viral pathogens and generating vaccine candidates able to elicit such responses. The Washington University Cooperative Center on Human Immunology (WashU-CCHI) application (Mechanisms of Immune Protection Against Respiratory Viruses) proposes a comprehensive research plan towards two main goals: (a) defining the mechanisms of germinal center persistence after vaccination in humans and how germinal center dynamics impact engagement of de novo B cells and generation of robust CD4+ T cell, long-lived memory B cell, and bone marrow plasma cell responses (Project 1); (b) determining the functional caliber of systemic and mucosal immune responses to vaccines and infection and how these impact durability, breadth, and protection (Project 2). Three Cores will synergize with the two research projects to support the successful completion of the research aims. The Administrative Core (Core A) will manage the consortium, coordinate cross-project activities, and create the structure and environment needed to accomplish WashU-CCHI’s goals. The Clinical Core (Core B) will provide the clinical and statistical expertise to support the design and conduct of the human subjects’ research studies conducted under Projects 1 and 2. The Proteomics Core (Core C) will capitalize on an array of unique technologies for the interrogation of the circulating antibody protein and B cell repertoires in samples collected under Projects 1 and 2. The integrated and synergistic activities across these Projects and Cores will drive the successful completion of the WashU-CCHI’s ambitious research agenda, enabling achievement of our long-term goals of providing key insights on human immune responses and informing evaluation of new mucosal vaccines targeting the human respiratory tract against existing and emerging respiratory viral pathogens.
The Washington University Cooperative Center on Human Immunology (WashU-CCHI) will define the cellular and molecular mechanisms governing generation of broad and durable T cell, memory B cell and bone marrow plasma cell responses to rapidly evolving respiratory viral pathogens. It will also determine the functional caliber of systemic and mucosal immune responses to influenza and SARS-CoV-2 vaccination and infection in humans. The assembled multi-disciplinary team of investigators has extensive expertise in immunology, virology, pathogenesis, universal vaccine development, proteomics, metabolic labeling, and structural biology as well as a well-established track record of successful collaborations.
View our website at https://vaccinecenter.wustl.edu/
Our U19 Center consists of three Cores and two Projects:
Core A – ADMINISTRATIVE CORE
ELLEBEDY, ALI HASSAN, Core Lead
The Administrative Core (Core A) will serve as a central entity to manage, coordinate, and supervise WashU-CCHI center’s mission. The goal of the Core is to provide administrative support and oversight of the research activities performed by the Projects and Scientific Cores, and to ensure successful execution of the center’s missions. The following key activities will be performed by Core A: (1) Grant management for the WashU-CCHI through facilitating and ensuring regular and frequent communication between Projects and Cores to ensure a vibrant collaborative environment, as well as assistance in the preparation and submission of budgetary and scientific documents to the NIH. (2) Fiscal oversight and budgetary support for the overall program, including the management of subcontracts. (3) Development and deployment of a data management plan for the integration of information from different Projects and Cores and to ensure timely and comprehensive data deposition into NIH-recommended/approved public repositories. (4) Development and implementation of a conflict resolution plan, should it be necessary. A group of senior faculty members who are not directly linked to the Projects or Scientific Cores has been recruited to serve as mediators. (5) Support of communication with other CCHI entities and outside collaborators. (6) Regular communication with the NIAID program officer and other NIAID staff, coordination of reports to the NIH, and oversight to ensure compliance with NIH and local institutional requirements. To achieve these objectives and support a highly collaborative environment, the Administrative Core will coordinate formal monthly meetings between Program participants (Program Directors, Project and Core Leaders and Key Personnel) under the guidance of the Program Directors. Participants in these meetings will be responsible for sharing data, evaluating progress, and planning further steps as they relate to the specific goals of the program and aims of individual projects. Each meeting will include a general discussion of results, goals, and progress, as well as a forum for discussion of key decisions and initiatives. Additionally, the Administrative Core will plan annual site meetings, which will provide an opportunity for all research project PIs and key trainees to present progress and receive guidance from our External Advisory Committee.
CORE B – CLINICAL CORE
PRESTI, RACHEL MARGERET, Core Lead
The WashU-CCHI Clinical Core (Core B) combines the resources of two highly successful clinical research units at Washington University, the Infectious Disease Clinical Research Unit (IDCRU) led by Rachel Presti, MD, PhD, and the Emergency Care Research Core (ECRC) led by Philip Mudd, MD, PhD, as well as a Statistical Unit led by Charles Goss, PhD. The combined units provide highly experienced faculty, clinical coordinators, statisticians, laboratory technicians, data and quality personnel, and pharmacy support with the expertise to conduct the proposed clinical studies of the WashU-CCHI. The leads of the three units have a history of successful collaboration with both each other and the investigators leading the proposed WU-CCHI scientific projects. We have designed our research approach in close collaboration with the scientific leads of Projects 1 and 2 to design cutting edge clinical and translational research projects that are able to obtain and curate samples and clinical information to address many key questions in the immunology of both infection and vaccination against influenza and SARS-CoV-2. We have established functional and collaborative relationships with other Departments and Divisions at Washington University, including Emergency Medicine, Radiology, Hematology/Oncology, and Pulmonology, which have allowed us to collect unique samples, including lymph node fine needle aspirates (FNA) and core biopsies (CB), bone marrow aspirates (BMA), bronchoalveolar lavage (BAL) and endobronchial biopsies (EBBx), in addition to blood, saliva, and nasal swabs collected in the research units. The IDCRU is well positioned to enroll participants in vaccine studies that include metabolic labeling with deuterium labeled water to determine the temporal origin and turnover rate of immune cells as well as biospecimen collection including FNA, CB, BMA, BAL and EBBx. ECRC is well positioned to enroll participants with acute infection and collect BAL, EBBx as well as blood, saliva, and nasal swabs. Our processing laboratories have developed seamless protocols to perform initial processing and collaborate closely with research labs for more specialized processing of samples. Design and analysis of the clinical protocol and research projects will be enabled by expert statisticians in the Statistical Unit.
CORE C – PROTEOMICS CORE
GEORGIOU, GEORGE GEORGIOU, Core Lead
Core C will be responsible for the in-depth determination of the molecular composition, temporal dynamics and functional properties of the antibodies that comprise the polyclonal response to influenza HA or to SARS-CoV2 S in peripheral blood and in the respiratory track, following infection or vaccination. Core C will also perform the comprehensive sequencing and functional analyses of the natively paired VH:VL BCR repertoire encoded by B cell subsets of interest from peripheral blood, lymph node FNA, bone marrow aspirates and from respiratory track specimens. Both the IgG and the IgA serological and BCR repertoires will be determined and compared. Furthermore, we will analyze the immunoglobulin subclass repertoires. The studies by Core C will be enabled by a set of technologies developed by the UT Austin team, namely Ig-Seq: bottom-up high resolution LC-MS/MS based identification and quantification of antigen-specific circulating antibodies: BCR-Seq:very high throughput sequencing of natively paired VH and VL cDNA from single B cells and HuRep: extensive functional analysis of the B cell encoded repertoire displayed on yeast. Core C, together with Projects 1 and 2, will seek to address a plethora of key questions on the humoral responses to infection by respiratory pathogens and also following vaccination, including: (i) How does the sequence and functional diversity of the peripheral blood antibody repertoire compares to those of respiratory track antibodies? (ii) What fraction of the mucosal antibodies develop locally and are produced by tissue resident plasma cells versus being produced at other anatomical locations and then exported to the respiratory track following transcytosis from peripheral blood? (iii) What is the temporal persistence of individual IgG/IgA antibody clones in the respiratory track? (iv) To what extent does the concentration of individual IgG antibodies in peripheral blood correlates with their level in the mucosa following transcytosis via FcRn? Also, a related question is whether there exist abundant centrally produced antibodies that are not found in the respiratory track, either because of poor transepithelial export or enhanced mucosal elimination (e.g. due to proteolysis). (v) How do B cell clonal expansions in peripheral blood, lymph node aspirates and in the bone marrow correlate with the concentration of the respective antibody in circulation and in BALF? Finally, (iv) very importantly, together with Project 1 we will delineate the binding and neutralization breadth of the dominant anti-HA or anti-SARS-CoV2 antibodies in circulation and in the respiratory track.
PROJECT 1
ELLEBEDY, ALI HASSAN, Project Lead
The induction of immune memory is the basis of vaccination, which arguably is the single most impactful medical intervention in human history. Nonetheless, vaccines generally have been less effective against respiratory viral infections. Indeed, the protection offered by currently licensed vaccines against the rapidly evolving respiratory viral pathogens influenza and SARS-CoV-2 is limited in breadth and short-lived in duration. These shortcomings have necessitated annual (or more frequent) booster immunizations against these viruses. There is an urgent need to understand the unique immunological challenges faced by these vaccines to be able to enhance their protective capacity and durability. Specifically, key knowledge gaps remain with respect to the clonal and functional dynamics of the germinal center (GC) response over time, and how these dynamics impact the durability, breadth, and ultimately the protective capacity of vaccine induced immune responses. In this Project, we will utilize cohorts of vaccinated adults with unique matched samples from blood, draining lymph nodes, and bone marrow and employ stable isotope labeling of proliferating cells to study at the cellular, molecular, and genetic levels how GC response dynamics impact qualitative and quantitative antibody, B cell, and T cell responses after influenza virus or SARS-CoV-2 vaccination. These innovative studies will provide new information on human immune responses and inform design of new vaccines targeting mutable respiratory pathogens.
PROJECT 2
DIAMOND, MICHAEL S., Project Lead
SARS-CoV-2 and influenza A viruses are human pathogens with broad geographic range that cause pandemics and jeopardize human health. While the rapid deployment of vaccines against COVID-19 and annual campaigns with seasonally-matched inactivated, intramuscularly-delivered influenza vaccines have saved millions of human lives, it has become increasingly apparent that intramuscularly-delivered vaccines do not effectively induce mucosal immunity in the respiratory tract, which in theory, could better limit virus infection or transmission at the portal of entry or egress. Although vaccination of antigen-naïve populations provides benefit against SARS-CoV- 2 infection, the impacts of intramuscular boosting on protection from infection by recent circulating strains has been less impressive, in part due to the effects of immune imprinting. In Project 2 of the WU-CCHI, we hypothesize that viral infection in the context of prior recent vaccination induces mucosal immune responses that functionally differ from those after infection or vaccination alone in the levels and types of cross-neutralizing and Fc effector functions of antibodies (Abs), and cross-reactive T cell responses. Project 2 will address key knowledge gaps as to the functional quality of infection- and vaccine-induced systemic and mucosal immunity. To achieve these goals, we will utilize ongoing human natural history cohorts of infected and vaccinated adults with unique clinical samples to study how vaccination impacts qualitative and quantitative systemic and mucosal antibody, B and T cell responses, and Fc effector functions seen after SARS-CoV-2 or IAV infection. We also will utilize samples from a unique influenza A virus human challenge cohort to assess how recent immunization with a quadrivalent influenza vaccine (Flucelvax®) modulates induction of mucosal immunity and control of infection. Our innovative studies on SARS-CoV-2 and influenza infection and vaccination will provide new information on human immune responses and inform evaluation of new mucosal vaccines targeting the human respiratory tract.
