Innate Immunity Modulation by the IL-33/ST2 System in Intestinal Mucosa

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.