RT Journal Article SR Electronic T1 The TRPA1 ion channel is expressed in CD4+ T cells and restrains T-cell-mediated colitis through inhibition of TRPV1 JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 1584 OP 1596 DO 10.1136/gutjnl-2015-310710 VO 66 IS 9 A1 Samuel Bertin A1 Yukari Aoki-Nonaka A1 Jihyung Lee A1 Petrus R de Jong A1 Peter Kim A1 Tiffany Han A1 Timothy Yu A1 Keith To A1 Naoki Takahashi A1 Brigid S Boland A1 John T Chang A1 Samuel B Ho A1 Scott Herdman A1 Maripat Corr A1 Alessandra Franco A1 Sonia Sharma A1 Hui Dong A1 Armen N Akopian A1 Eyal Raz YR 2017 UL http://gut.bmj.com/content/66/9/1584.abstract AB Objective Transient receptor potential ankyrin-1 (TRPA1) and transient receptor potential vanilloid-1 (TRPV1) are calcium (Ca2+)-permeable ion channels mostly known as pain receptors in sensory neurons. However, growing evidence suggests their crucial involvement in the pathogenesis of IBD. We explored the possible contribution of TRPA1 and TRPV1 to T-cell-mediated colitis.Design We evaluated the role of Trpa1 gene deletion in two models of experimental colitis (ie, interleukin-10 knockout and T-cell-adoptive transfer models). We performed electrophysiological and Ca2+ imaging studies to analyse TRPA1 and TRPV1 functions in CD4+ T cells. We used genetic and pharmacological approaches to evaluate TRPV1 contribution to the phenotype of Trpa1−/− CD4+ T cells. We also analysed TRPA1 and TRPV1 gene expression and TRPA1+TRPV1+ T cell infiltration in colonic biopsies from patients with IBD.Results We identified a protective role for TRPA1 in T-cell-mediated colitis. We demonstrated the functional expression of TRPA1 on the plasma membrane of CD4+ T cells and identified that Trpa1−/− CD4+ T cells have increased T-cell receptor-induced Ca2+ influx, activation profile and differentiation into Th1-effector cells. This phenotype was abrogated upon genetic deletion or pharmacological inhibition of the TRPV1 channel in mouse and human CD4+ T cells. Finally, we found differential regulation of TRPA1 and TRPV1 gene expression as well as increased infiltration of TRPA1+TRPV1+ T cells in the colon of patients with IBD.Conclusions Our study indicates that TRPA1 inhibits TRPV1 channel activity in CD4+ T cells, and consequently restrains CD4+ T-cell activation and colitogenic responses. These findings may therefore have therapeutic implications for human IBD.