Table 1: Functions of intestinal innate immune cells, role in IBD, and response to IL-33 stimulation.

Cell Function Role in IBD IL-33 effect Goblet cell Secretion of mucin, TFF3 and RELM-β. Aberrant accumulation of mucin. Low TFF3 secretion. Mucosecretagogue activity. Macrophage Phagocytosis. Antigen presentation. Intestinal antigenic tolerance. Loss of tolerance. Increased CD14 and NF-κB expression. Secretion of TNF, IL-1β, CXCL1, and CCL3. Basophil mast cell Defense against parasites. Allergic response. Controversial. Increased expression of surface ST2. Th2 cytokine secretion. Synergistically increases the IgE-mediated degranulation. Eosinophil Defense against parasites. Allergic response. Higher eosinophilic protein content in feces and intestinal fluid. Production of superoxide, IL-3, IL-5, IL-8, and GM-CSF. Dendritic cell Antigen presentation. Phagocytosis. Macropinocytosis. Accumulation in inflamed area. Increased expression of TLR2, TLR4, and CD40. Increases expression of MCH-II, CD86, and IL-6. Th2 differentiation.