Oral Presentation International Celiac Disease Symposium 2026

Functional screening of candidate antigens that may be driving the expansion of CD8+ T-cell clones with lymphoma driver mutations in type I refractory celiac disease  (147050)

Jennifer M Chen 1 2 , Claire Milthorpe 1 , Thiruni Adikari 2 , Megan Faulks 1 , Raymond Louie 2 , Jerome Samir 2 , Melinda Hardy 3 , Jason Tye-Din 3 , Fabio Luciani 2 , Chris Goodnow 1 2 , Manu Singh 4 5
  1. Garvan Institute of Medical Research, Darlinghurst , NSW, Australia
  2. University of New South Wales, Kensington, NSW, Australia
  3. WEHI, University of Melbourne, Parkville, VIC, Australia
  4. Centre for Immunology and Allergy Research, Westmead Institute for Medical Research, Westmead , NSW, Australia
  5. Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia

Decoding the antigen specificities of autoreactive T-cells remains a major bottleneck in understanding the drivers of autoimmune disease. Celiac disease is treated by removing its known trigger antigen, gluten, from the diet. Approximately 1% of individuals non-responsive to a gluten-free diet are diagnosed with type I refractory celiac disease (RCD-I). We recently identified expanded T-cell clones carrying somatic mutations in RCD-I duodenal biopsies such as expanded CD8+ T-cell clones with STAT3 gain-of-function mutations. While these findings implicate these mutated T-cell clones in disease pathogenesis, their functional relevance is unclear since the antigen specificity of their T-cell receptors (TCRs) is unknown.

We developed a modular antigen discovery platform informed by neoantigen screening strategies to identify T-cell reactivity to candidate antigens. First, we engineered Jurkat T-cell lines to express RCD-I patient derived TCRs by transducing full-length TCRαβ chains into CD8+ TCRαβ‑ Jurkat-76 cells. These cells were then co-cultured with HLA-matched antigen-presenting cells engineered to express minigene antigen libraries to systematically screen candidate T-cell antigens. Proof-of-concept experiments established the platform’s ability to investigate antigens presented by HLA class I and II molecules. Overnight co-culture with gliadin minigene-expressing EBV-immortalised human B-cell lines activated Jurkat-76 cells expressing a gluten-reactive DQ2.5-restricted TCR. Compatibility with HLA class I restricted TCRs was demonstrated by the activation of CD8+ Jurkat-76 cells expressing the 1G4 TCR after co-culture with NY-ESO-1 minigene expressing EBV immortalised human B-cell lines. NY-ESO-1 is the cancer-testis antigen recognised by the 1G4 TCR. Ongoing work will extend the platform to primary human T-cells, providing a sensitive, high-throughput assay for interrogating TCR specificity, including the testing of TCRs identified in expanded RCD-I T-cell clones.

Establishing sensitive methods for investigating TCR specificity could reveal previously undescribed antigens recognised by T cells that may contribute to RCD-I pathogenesis and inform new therapeutic strategies to improve clinical outcomes.