Expression profiling of MDR1+ and MDR1- human memory T cells from the blood and clinically-inflamed gut tissue

The aim of this study was to characterize the transcriptional signature of MDR1+ human memory T cells isolated from clinically inflamed gut tissue, and compare it to local MDR1- memory T cells Human mononuclear cells were isolated from the peripheral blood of a healthy adult donor (Ficol density centrifugation) or from resected lesioned gut tissue of a patient with active Crohn's disease. For cell isolation from gut tissue, tissue was rinsed with PBS, treated with 0.15% DTT to remove mucous, then with 1 mM EDTA to remove epithelial cells and intra-epithelial lymphocytes. Remaining tissue was digested using Liberase-TL (Roche) plus 10 U/mL DNase I. Mononuclear cells were then filtered through 70 mM nylon filters and isolated via a 30%/ 70% Percol gradient. Mononuclear cells from blood or gut tissue were FACS-sorted into CD3+ CD4+ CD45RO+ MDR1+ or MDR1- memory T cells, using Rhodamine 123 (Rh123) efflux as a surrogate for MDR1 expression/ activity. Sorted cells were harvested directly ex vivo (without further in vitro culture or manipulation) prior to RNA extraction. MDR1- memory CD4+ T cells vs. MDR1+ memory CD4+ T cells from healthy donor peripheral blood or from active Crohn's disease lesioned tissue; MDR1- or MDR1+ memory CD4+ T cells from blood vs. inflamed gut tissue