Chicken cathelicidin-B1, an antimicrobial guardian at the mucosal M cell gateway

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 104; no. 38; pp. 15063 - 15068
• Main Authors: Goitsuka, Ryo, Chen, Chen-lo H, Benyon, Lesley, Asano, Yusuke, Kitamura, Daisuke, Cooper, Max D
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 18.09.2007; National Acad Sciences
• Subjects: Amino Acid Sequence; Amino acids; Animals; antibacterial properties; Antimicrobial Cationic Peptides - genetics; Antimicrobial Cationic Peptides - pharmacology; Antimicrobial Cationic Peptides - physiology; antimicrobial peptides; Antimicrobials; Avian Proteins - genetics; Avian Proteins - pharmacology; Avian Proteins - physiology; B lymphocytes; bacterial infections; Base Sequence; Biological Sciences; bursa of Fabricius; Bursa of Fabricius - cytology; Bursa of Fabricius - immunology; cathelicidin-B1; Cells; Cellular immunity; Chickens; Chickens - immunology; Complementary DNA; disease resistance; DNA, Complementary - metabolism; Epithelial cells; Epithelial Cells - immunology; epithelium; exons; gene expression; Genes; Gram-negative bacteria; Gram-Negative Bacteria - drug effects; Gram-positive bacteria; Gram-Positive Bacteria - drug effects; Immune system; Immunity, Mucosal; Immunohistochemistry; messenger RNA; Molecular Sequence Data; mucosa; nucleotide sequences; Peptides; Phylogeny; Poultry; Proteins; Skin; T lymphocytes
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0707037104

Mucosal epithelial M cells provide an efficient portal of entry for microorganisms. Initially defined by their irregular microvilli and abundant transcytotic channels in the avian bursa of Fabricius, M cells also are found in the lymphoid follicle-associated epithelium of the mammalian appendix, Peyer's patches, and other mucosal surface-lymphoid interfaces. We describe here a previously unrecognized cathelicidin gene in chickens, chCATH-B1, that is expressed exclusively in the epithelium of the bursa of Fabricius. Like the mature peptides of previously identified cathelicidins, the carboxyl-terminal peptide of chCATH-B1 has broad antimicrobial activity against Gram-positive and Gram-negative bacteria. chCATH-B1 expression is restricted to the secretory epithelial cell neighbors of the M cells, whereas its mature peptide is transported to become concentrated on the fibrillar network surrounding basolateral surfaces of the M cells that overlie the bursal lymphoid follicles. We conclude that chCATH-B1 is well placed to serve a protective antimicrobial role at the M cell gateway.