Tu106 - Phenotype-based Isolation of Antigen-specific CD4+ T Cells in Autoimmunity: A Study of Celiac Disease

Tuesday, June 21, 2022

6:15 PM – 7:45 PM PT

Presenting Author(s)

MC

Marketa Chlubnova, n/a

Phd candidate
Institute of Clinical Medicine, University of Oslo, 0450 Oslo, Norway.
Oslo, Oslo, Norway

Co-Author(s)

AC

Asbjørn Christophersen, n/a

PostDoc, MD
Institute of Clinical Medicine, University of Oslo, 0450 Oslo, Norway.
Oslo, Oslo, Norway
SD

Shiva Dahal-Koirala, n/a

PostDoc
Institute of Clinical Medicine, University of Oslo, 0450 Oslo, Norway.
Oslo, Oslo, Norway
JJ

Jørgen Jansen, n/a

Professor, MD
Department of Gastroenterology, Akershus University Hospital, 1478 Lørenskog, Norway.
Oslo, Oslo, Norway
KL

Knut Lundin, n/a

Professor, MD
Department of Gastroenterology, Oslo University Hospital Rikshospitalet, 0372 Oslo, Norway.
Oslo, Oslo, Norway
LS

Ludvig Sollid, n/a

Professor, MD
Institute of Clinical Medicine, University of Oslo, 0450 Oslo, Norway.
Stanford, California, United States

The pathogenic immune response in celiac disease (CeD) is orchestrated by phenotypically distinct CD4+ T cells that recognize gluten epitopes in the context of disease-associated HLA-DQ allotypes. Cells with the same distinct phenotype, but with elusive specificities, are increased across multiple autoimmune conditions. Here we test whether in CeD sorting of T cells based on their distinct phenotype (Tphe cells) yields gluten-reactive cells. The method`s efficiency is benchmarked by parallel isolation of gluten-reactive T cells (Ttet cells), using HLA-DQ:gluten peptide tetramers. From gut biopsies of 12 untreated HLA-DQ2.5+ CeD patients, Ttet+/Tphe+, Ttet-/Tphe+ and Ttet-/Tphe- cells are sorted for single cell T-cell receptor (TCR)-sequencing (n=8) and T-cell clone (TCC)-generation (n=5). The generated TCCs are TCR sequenced and tested for their reactivity against deamidated gluten. Gluten-reactivity is observed in 91.2% of Ttet+/Tphe+ TCCs, 65.3% of Ttet-/Tphe+ TCCs and 0% of Ttet-/Tphe- TCCs. Interestingly, only 55% of gluten reactive Ttet-/Tphe cells were reactive to known gluten epitopes, suggesting an existence of yet undiscovered ones. TCR sequencing reveals clonal expansion and sequence sharing across patients, features reflecting antigen-driven responses. The feasibility to isolate antigen-specific CD4+ T cells by sole use of phenotypic markers in CeD outlines a potential avenue for characterizing disease-driving CD4+ T cells in autoimmune conditions. It also allows for effective and simple strategy for isolation of cells for the purpose of antigen/epitope discovery.