Table 1.

Immunomodulatory cellular functions attributed to colonic host defense peptides.

Host defense peptide	Immune function	References
Cathelicidin	• Alter chemokine responses • Inhibit TLR4 activation (leukocytes) • Enhance TLR4 signaling (enterocytes) • Chemoattractant • Increase MUC2 expression • Induce NET formation	(9–23)
β-defensin	• Chemoattractant • Activate dendritic cells and monocytes • Stimulate cytokine release • Increase epithelial barrier function • Induce epithelial cell migration • Induce MUC2 expression	(24–32)
REGIII	• Promote epithelial cell proliferation • Prevent apoptosis	(33, 34)
RELM-β	• Increase epithelial cell proliferation • Chemoattract T-cells • Regulate REGIII expression • Regulate epithelial cell barrier function • Increase mucus secretion • Promote fibrosis	(35–41)