383 Defining the tuft cell/acetylcholine/muscarinic receptor axis in inflammatory bowel disease and colon cancer

Objectives/Goals: We aim to clarify the role of the intestinal tuft cell-acetylcholine (ACh)-muscarinic receptor axis in inflammatory bowel disease (IBD) and colitis-associated colorectal cancer (CAC) and to investigate whether altering tuft cell activity impacts colitis severity and CAC. Methods/Study Population: (1) To characterize tuft cell distribution in intestinal tissues of humans with and without IBD and CAC, we will use immunohistochemistry, RNAscope, and in situ hybridization. (2) In mice treated with dextran sodium sulfate (DSS) to induce colitis, we will use indolepropionic acid and succinate to manipulate intestinal tuft cell numbers. We will derive enteroids from these and control mice and compare tuft cell numbers, ACh synthetic markers, and anti- and pro-inflammatory cytokines. (3) We will compare the effects of altered tuft cell populations on colitis severity and tumor number and size in mice treated with or without DSS/azoxymethane to induce colitis and CAC. Results/Anticipated Results: Intestinal tuft cells are key participants in anti-inflammatory signaling. Hence: (1)compared to tissue from healthy controls, we anticipate finding altered tuft cell distribution and fewer tuft cells in intestinal tissues from humans with IBD and CAC; (2) compared to controls, intestinal enteroids from mice treated with indolepropionic acid or succinate prior to DSS treatment will retain more tuft cells and an augmented anti-inflammatory cytokine signature; (3) mice with augmented tuft cell numbers will exhibit attenuated colitis and CAC. Discussion/Significance of Impact: Interplay between gut immune and epithelial cells, neurons, and the microbiome underlies colitis. Current therapies target only immune cells, with limited efficacy. Studying other players in IBD pathogenesis, like tuft cells, is likely to reveal novel therapeutic targets.