Biology subjects

Randall, T. D.

Publications and source records attributed to Randall, T. D..

10 recordsLinked to original sources

bioRxiv2026

Intranasal immunization with live-attenuated RSV-vectored SARS-CoV-2 vaccines elicits antigen-specific systemic and mucosal immunity and protects against viral challenge and natural infection

The emergence of new SARS-CoV-2 variants and breakthrough infections underscores the need for next-generation vaccines capable of protecting from natural infection and/or preventing virus transmission to others. Intranasal vaccination offers a promising approach by eliciting local immune responses in the nasal mucosa, the primary site of infection and reservoir for transmissible virus. We evaluated two live-attenuated, respiratory syncytial virus vectored vaccines in which the RSV F and G surface glycoproteins were replaced with a chimeric SARS-CoV-2 Spike protein from either the ancestral USA/WA-1/2020 strain (MV-014-212) or the Delta variant (MV-014-212-delta). A single intranasal dose of either vaccine elicited systemic and mucosal immunity in K18-hACE2 mice, including serum neutralizing antibodies, Spike-specific memory B cells and plasmablasts, and Spike-specific CD8 lung-resident memory T cells. Although MV-014-212-delta vaccination provided the best protection against Delta variant virus challenge, both vaccines decreased viral loads in nasal discharge, lung and brain, and reduced weight loss and mortality. In naturally acquired infection studies, vaccinated hamsters exposed to infected cagemates exhibited minimal weight loss, limited viral replication within the nasal mucosa, and attenuated lung pathology. Therefore, intranasal RSV-vectored vaccines can elicit broad protective respiratory immunity, suggesting that this platform could be leveraged for other respiratory pathogens.

immunology↗

bioRxiv2026

IFN gamma-induced IRF1 synergizes with TLR7 signals to tune the IRF4-IRF8 axis and drive pathogenic effector B cell fate

Interferon regulatory factor 1 (IRF1), a transcription factor encoded within the 5q31 locus harboring systemic lupus erythematosus (SLE) associated variants, promotes inflammatory responses by T and myeloid cells. Although IFN{gamma}-activated B cells also express IRF1, its role in B cell biology and SLE is unclear. Here, we use a mouse SLE model, single-cell multiomics, and human B cells to show that IRF1 intrinsically regulates Irf4 gene chromatin accessibility and expression in B cells to control the balance between the antibody secreting cell (ASC) lineage commitment factor, IRF4, and the B cell identity factor, IRF8. We demonstrate that IRF1, through its integration of IFN{gamma} and TLR7 induced transcriptional programs, tips B cells toward a terminal effector inflammatory AC fate at the expense of preserving more stem-like, resting and regulatory B cells that do not elicit autoantibody-associated pathology in SLE. Thus, IRF1 serves as a central node controlling B cell-driven autoimmune disease.

immunology↗

bioRxiv2026

Terminally Differentiated Influenza-Specific Effector Memory B Cells Circulate after Live Attenuated Influenza Vaccination

Live attenuated influenza vaccination (LAIV) is the only FDA approved mucosal vaccine. Easily assayed, circulating correlates of protection after LAIV are lacking. Using fluorochrome labeled hemagglutinin (HA) antigen, we previously identified a subset of HA-specific (HA+) IgDneg memory B cells that circulate after inactivated intramuscular vaccination (IIV), express the master transcriptional regulator, T-bet, as well as effector memory genes and predict durable antibody (Ab) responses to IIV. Here we profile the circulating HA+ IgDneg memory B cell response in a cohort of immunized patients who seroconvert after LAIV to identify which, if any, circulating HA+ B cells predict antibody responses after LAIV. Although we report LAIV elicits circulating T-bet+ HA+ IgDneg B cells that are phenotypically similar to those we described after IIV, we find no correlation between the magnitude of these cells and systemic HA-IgG responses after LAIV. Supervised and unsupervised analyses demonstrate that unlike IIV, LAIV preferentially elicits circulating HA+ IgDneg B cells that co-express TBX21 and the terminal effector cell gene, Zeb2. Consistent with their terminal differentiation status, LAIV-elicited T-bet+ cells cannot be recalled as short-lived antibody-secreting cells (ASCs) after systemic or mucosal antigen re-challenge. We conclude that the transcriptional profiles and functions of HA+ IgDneg B cells vary by influenza vaccine platform.

immunology↗

bioRxiv2025

Mucosal delivery of influenza antigens using a replication deficient adenovirus supports broadly reactive antibody responses and heterologous viral immunity in the respiratory tract of animals

Systemically administered influenza vaccines provide strain-limited protection, while influenza infection of the respiratory epithelium supports development of lung resident memory B and T cells and more broadly reactive antibody responses. To test whether local antigen delivery is critical for establishing broad immunity, we directly compared respiratory tract and systemic delivery of influenza antigens to mice and hamsters using a replication-deficient adenovirus serotype 5 vector (Ad5[E1-,E2b-,E3-]). Both immunization routes elicited antibody responses in the lower respiratory tract and antigen-specific B and T cells in the draining lymph node. However, only intranasal immunization established lung-resident memory B and T cells, induced IgA responses in the upper respiratory tract directly at the site of viral entry and supported generation of IgA and IgG antibodies that bound antigenically drifted and distantly related influenza strains, including those of avian origin. Intranasal immunization accelerated viral clearance following heterologous virus challenge and was associated with limited pulmonary inflammation and fibrosis. Thus, intranasal immunization with the immunologically stealthy Ad5[E1-,E2b-,E3-] platform supports respiratory and systemic immunity to divergent influenza strains in the absence of overt lung immunopathology, suggesting that local antigen delivery may be key to development of more broadly protective "universal" flu vaccines.

immunology↗

bioRxiv2023

Alloreactivity and autoreactivity converge to support B cell epitope targeting in transplant rejection

Donor-specific antibody (DSA) responses against human leukocyte antigen (HLA) proteins mismatched between kidney transplant donors and recipients cause allograft loss. The rules governing the immunogenicity of non-self donor HLA are poorly understood. Using single-cell, molecular, structural, and proteomic techniques, we profiled the HLA-specific B cell response in the kidney and blood of a transplant recipient with antibody-mediated rejection (AMR). We observed an immunodominant B cell antibody response focused on topographically exposed, solvent-accessible mismatched HLA residues along the peptide-binding groove - a subregion comprising only 20% of the HLA molecule. We further demonstrated that, even within a diverse cohort of transplant recipients, the B cell alloresponse consistently converges on this same immunodominant subregion on the crown of the HLA molecule. Based on these findings, we propose that B cell immunodominance in transplant rejection relies on antigenic topography, and we suggest that this link could be exploited for organ matching and therapeutics.

immunology↗

bioRxiv2023

A high-throughput multiplex array for antigen-specific serology with automated analysis.

High-throughput customizable CBA automated script-based analysisThe utility of high-throughput systems to evaluate antigen-specific antibody (Ab) has been highlighted by the SARS-CoV-2 pandemic. Pathogen-specific Ab levels are often used to assess protection following vaccination and, in the case of novel pathogens, an indication of prior exposure. Several platforms exist to visualize antigen-specific Ab, however most are not quantitative and are difficult to scale for population level studies. Additionally, the sensitivity across platforms differs making direct comparisons between studies difficult. Cytometric bead arrays (CBA) are an attractive platform for antigen-specific Ab measurements as they can be used to assess Ab reactivity against several antigens and of several isotypes to be performed simultaneously. Additionally, CBAs exhibit high sensitivity and can be designed to provide quantitative measurements. Using commercially available particles, a biotin-Streptavidin bead loading strategy, and the inclusion of indirect standards, we describe a flexible system that can be modified to include a variety of antigens. Here we describe two arrays, focused on antigens derived from either {beta}-coronaviruses or influenza virus. To support the high-throughput capacity of this system, we developed a suit of automated software tools, the CBA Toolbox, to process raw data into antigen-reactive IgM, IgA, and IgG concentrations. We describe quality control requirements, assay performance, and normalizations to accurately quantitate antigen-specific Ig.

immunology↗

bioRxiv2022

Chitinase-3-like 1 regulates TH2 cells, TFH cells and IgE following helminth infection

Data from patient cohorts and mouse models of atopic dermatitis, food allergy and asthma strongly support a role for the chitinase-like protein ChI3L1 in allergic disease. To address whether CHI3L1 also contributes to TH2 responses following nematode infection, we infected Chi3l1-/- mice with Heligmosomoides polygyrus (Hp) and analyzed T cell responses. Not surprisingly, we observed impaired TH2 responses in Hp-infected Chi3l1-/- mice. However, we also found that T cell intrinsic expression of Chi3l1 was required for ICOS upregulation following activation of naive CD4 T cells and was necessary for the development of the IL-4+ TFH subset, which supports germinal center (GC) B cell reactions and IgE responses. The requirement for Chi3l1 in TFH and IgE responses was also seen following alum-adjuvanted vaccination. While Chi3l1 was critical for IgE humoral responses it was not required for vaccine or infection induced IgG1 responses. These results suggest that Chi3l1 specifically modulates IgE responses that are highly dependent on help from IL-4-producing TFH cells.

immunology↗

bioRxiv2021

Critical roles of ICOS in controlling Foxp3-expressing T follicular cell subsets during early-stage germinal center reactions

ICOS is a T cell costimulatory receptor critical for Tfh cell generation and function. However, the role of ICOS in Tfr cell differentiation remains unclear. Using Foxp3-Cre-mediated ICOS knockout (ICOS FC) mice, we show that ICOS deficiency in Treg-lineage cells drastically reduces the number of Tfr cells during GC reactions but has a minimal impact on conventional Treg cells. Single-cell transcriptome analysis of Foxp3+ cells at an early stage of the GC reaction suggests that ICOS normally inhibits Klf2 expression to promote follicular features including Bcl6 upregulation. Further, ICOS costimulation promotes nuclear localization of NFAT2, a known driver of CXCR5 expression. Notably, ICOS FC mice had an unaltered overall GC B cell output but showed signs of expanded autoreactive B cells along with elevated autoantibody titers. Thus, our study demonstrates that ICOS costimulation is critical for Tfr cell differentiation and highlights the importance of Tfr cells in maintaining humoral immune tolerance during GC reactions.

immunology↗

bioRxiv2020

Single-dose intranasal administration of AdCOVID elicits systemic and mucosal immunity against SARS-CoV-2 in mice

The coronavirus disease 2019 (COVID-19) pandemic has highlighted the urgent need for effective preventive vaccination to reduce burden and spread of severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2) in humans. Intranasal vaccination is an attractive strategy to prevent COVID-19 as the nasal mucosa represents the first-line barrier to SARS-CoV-2 entry before viral spread to the lung. Although SARS-CoV-2 vaccine development is rapidly progressing, the current intramuscular vaccines are designed to elicit systemic immunity without conferring mucosal immunity. Here, we show that AdCOVID, an intranasal adenovirus type 5 (Ad5)-vectored vaccine encoding the receptor binding domain (RBD) of the SARS-CoV-2 spike protein, elicits a strong and focused immune response against RBD through the induction of mucosal IgA, serum neutralizing antibodies and CD4+ and CD8+ T cells with a Th1-like cytokine expression profile. Therefore, AdCOVID, which promotes concomitant systemic and local mucosal immunity, represents a promising COVID-19 vaccine candidate.

immunology↗

bioRxiv2019

Fcrl5 and T-bet define influenza-specific memory B cells that predict long-lived antibody responses

Seasonal influenza vaccination elicits hemagglutinin (HA)-specific CD27+ memory B cells (Bmem) that differ in expression of T-bet, BACH2 and TCF7. T-bethiBACH2loTCF7lo Bmem are transcriptionally similar to effector-like memory cells while T-betloBACH2+TCF7+ Bmem exhibit stem-like central memory properties. T-bethi Bmem do not express plasma cell-specific transcription factors but do exhibit transcriptional, epigenetic, metabolic and functional changes that poise the cells for antibody production. Consistent with these changes, D7 HA+ T-bethi Bmem express intracellular immunoglobulin and T-bethi Bmem differentiate more rapidly into ASCs in vitro. The T-bethi Bmem response positively correlates with long-lived humoral immunity and clonotypes from T-bethi Bmem are represented in the early secondary ASC response to repeat vaccination, suggesting that this effector-like population can be used to predict vaccine durability and recall potential.

immunology↗