Louise F. Risnes (Norway)
University of Oslo - Rikshospitalet Department of ImmunologyAuthor of 1 Presentation
GLUTEN-SPECIFIC CD4+ T CELLS EXPRESS A DISTINCT SET OF MARKERS AFTER GLUTEN CHALLENGE THAT CORRELATE WELL ON THE TRANSCRIPTOMIC AND PHENOTYPIC LEVEL
Abstract
Background and Aims
It is well-established that oral gluten challenge of treated CeD patients induces a flux of gluten-specific T cells into peripheral blood. However, the activation profile of these cells remains uncertain. We investigated the transcriptome and phenotype of such cells following gluten challenge to identify a read-out for antigen-specific responses.
Methods
Treated CeD patients underwent a 3-day gluten challenge. Blood was sampled on day 6 after challenge. PBMCs were stained with HLA-DQ:gluten-tetramers (tet). Tet+ and tet- gut-homing (integrin β7+) effector-memory T (TEM) cells were sorted on day 6 for bulk RNA-sequencing. Tet+ cells were analysed by a mass cytometry staining panel designed based on differentially expressed (DE) genes coding for cell surface markers.
Results
We observed a clear increase in gut-homing gluten-specific effector-memory T cells in blood 6 days after initiation of gluten challenge in all participants (4 vs. 53 tet+ integrin β7+ TEM / 106 CD4+ cells) and detected over 3000 DE protein coding genes, among them 94 DE genes coding for cell surface markers after gluten challenge. The markers selected for mass spectrometry correlated well with RNA levels except for CD47, CD52, CD103 and CD314 (NKG2D).
Conclusions
Transcriptome analysis from gut-homing, gluten-specific CD4+ T cells in blood after gluten re-exposure revealed 94 DE genes coding for cell surface markers. Based on the phenotypical similarity with gluten-specific T cells from the intestine and formation of a distinct cell cluster, gluten-specific T cells from blood after gluten challenge may serve as an alternative outcome measure in clinical drug trials.