Circulating and Tissue-Resident CD4+ T Cells With Reactivity to Intestinal Microbiota Are Abundant in Healthy Individuals and Function Is Altered During Inflammation by Hegazy, AN, West, NR, Stubbington, MJT, Wendt, E, Suijker, KIM, Datsi, A, This, S, Danne, C, Campion, S, Duncan, SH, Owens, BMJ, Uhlig, HH, McMichael, A, Bergthaler, A, Teichmann, SA, Keshav, S, Powrie, F