Interrogating the Small Intestine Tuft Cell–ILC2 Circuit Using In Vivo Manipulations

Recent findings position tuft cells as key mediators of intestinal immunity through their production of the cytokine interleukin (IL)-25 and activation of group 2 innate lymphoid cells (ILC2s). Though tuft cells are found in numerous epithelial tissues, their phenotype and function have been best characterized in the small intestine, where robust in vivo techniques have enabled the dissection of their cellular function, ontogeny, and key signaling pathways. We describe methods for the identification, quantification, and manipulation of tuft cells, focusing on analysis of ILC2s as a readout of tuft cell function. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Ex vivo analysis of small intestinal tuft cells and ILC2 by flow cytometry Alternate Protocol: Ex vivo analysis of small intestinal tuft cells and ILC2 by flow cytometry in the context of type 2 inflammation Basic Protocol 2: Ex vivo analysis of small intestinal tuft cells by imaging of intestinal Swiss roll Basic Protocol 3: Tuft-ILC2 circuit activation by oral gavage of adult Nippostrongylus brasiliensis worms Basic Protocol 4: Circuit activation by colonization with Tritrichomonas spp. Basic Protocol 5: Circuit activation by treatment with succinate in drinking water Basic Protocol 6: Circuit activation by treatment with recombinant IL-25.