Biology subjects

Hardy, M. Y.

Publications and source records attributed to Hardy, M. Y..

2 recordsLinked to original sources

bioRxiv2025

Functional immune profiling reveals CD4+ T cell dysregulation associated with celiac disease

T cells integrate signals from antigen and co-stimulatory receptors to calibrate the strength and quality of their responses. This signal integration is influenced by genetic background, which can modulate thresholds for immune tolerance and strength of responses to threat. Celiac disease (CeD) is an autoimmune disorder driven by well-defined genetic risk and characterised by immune dysregulation in response to dietary gluten. However, whether sensitivity or response differences in naive T cell programming contributes to disease susceptibility is not known. To investigate such variation, we developed a sensitive quantitative platform, the momentum assay, which combines standardised, T cell activation with subsequent stimulus withdrawal, enabling measurement of T cell proliferation and survival over time. This assay is integrated with the Cyton2 mathematical model to infer underlying cellular timer programs from population-level dynamics. We applied this method to assess whether naive T cells from individuals with celiac disease (CeD) exhibited altered responses compared to healthy donors (HDs). We found that CD4+ but not CD8+ T cells from CeD patients showed a hypo-proliferative response following stimulation, associated with impaired secretion of the proliferative and pro-survival cytokine IL-2. Moreover, surface expression of early activation marker, CD69 remained elevated for longer on CD4+ T cells from CeD donors after stimulus withdrawal, suggesting prolonged activation and subtle alterations in regulatory feedback mechanisms. These findings reveal previously unrecognised quantitative alterations in naive T cell programming in CeD and underscore the utility of model-based analytical frameworks for detecting subtle functional perturbations in complex immune-mediated diseases.

immunology↗

bioRxiv2025

BASTA, a simple whole blood assay for measuring beta-cell antigen specific CD4+ T-cell responses in type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease where T-cells mediate the destruction of the insulin-producing {beta}-cells found within the Islets of Langerhans in the pancreas. Currently, autoantibodies to {beta}-cell antigens are the only tests available to detect {beta}-cell autoimmunity. T-cell responses to {beta}-cell antigens, which are known to cause T1D, can only be measured in research settings due to the complexity of assays and the large blood volumes required. Here we describe the {beta}-cell antigen specific T-cell assay - BASTA. BASTA is a simple whole blood assay that can detect human CD4+ T-cell responses to {beta}-cell antigens by measuring antigen-stimulated IL-2 production. BASTA is both more sensitive and specific than the CFSE-based Proliferation Assay. We used BASTA to identify the regions of preproinsulin which stimulated T-cell responses specifically in blood from people with T1D. BASTA can be done with as little as 2-3 mL of blood. We found that effector memory CD4+ T cells are the primary producers of IL-2 in response to preproinsulin peptides. We then evaluated responses to individual and pooled preproinsulin peptides in a cross-sectional study of pediatric subjects: without T1D, without T1D but with a first-degree relative with T1D, or diagnosed with T1D. In contrast to other preproinsulin peptides, full-length C-peptide (PI33-63) showed excellent specificity for T1D (AUC = 0.86). We suggest that BASTA will be a useful tool for monitoring changes in {beta}-cell specific CD4+ T-cell responses both in research and clinical settings. One Sentence Summary{beta}-cell antigen specific CD4+ T-cell responses in children with T1D can be measured using a simple whole blood assay.

immunology↗