Tissue samples were maintained in cold saline or University of Wisconsin (UW) solution and brought to the laboratory within 2-4hrs of organ procurement. Intestinal sections were opened along their mesenteric borders, washed in cold PBS (Mediatech, Manassas, VA). Jejunum was defined from the proximal two-fifths of the small intestine between the duodenojejunal flexure and ileocecal valve, and the proximal two-thirds of ileum is the proximal ileum and the distal one-thirds as distal ileum, and colon samples were from the sigmoid colon. Proximal PPs were taken from proximal ileum, distal PPs were from distal ileum, and mLNs were separated from each regional mesentery. Samples were processed using enzymatic and mechanical digestion resulting in high yields of live lymphocytes, as described 21 (link).