title: Soluble CD14 in human breast milk and its role in innate immune responses.
abstract: Immune factors secreted in milk are important for health in the neonatal gut. We have detected the bacterial pattern recognition receptor, soluble CD14 (sCD14) in human breast milk at different times during lactation. The molecule occurs in a single form in milk, in contrast to human serum, in which there are two isoforms. Produced by mammary epithelial cells, milk sCD14 mediates secretion of innate immune response molecules such as interleukin-8, tumor necrosis factor-alpha, and epithelial neutrophil activator-78 by CD14-negative intestinal epithelial cells exposed to lipopolysaccharide (LPS) or bacteria. Although present at low concentrations in milk, LPS-binding protein may be implicated in the biological effects observed. Our findings support the premise that milk sCD14 acts as a 'sentinel' molecule and immune modulator in homeostasis and in the defense of the neonatal intestine. In so doing, it may prevent the immune and inflammatory conditions of the gut to which non-breastfed infants are predisposed.
authors.affiliation: Nestlé Research Center, Vers-Chez-Les-Blanc, Lausanne, Switzerland.
authors.forename: K
authors.initials: K
authors.lastname: Vidal
authors.forename: M O
authors.initials: MO
authors.lastname: Labéta
authors.forename: E J
authors.initials: EJ
authors.lastname: Schiffrin
authors.forename: A
authors.initials: A
authors.lastname: Donnet-Hughes
mesh_terms: D000209:Acute-Phase Proteins; D002352:Carrier Proteins; D004847:Epithelial Cells / Q000276:immunology / Q000378:metabolism; D005260:Female; D019073:HT29 Cells; D006801:Humans; D018928:Immunity, Mucosal; D007231:Infant, Newborn / Q000276:immunology*; D016209:Interleukin-8 / Q000096:biosynthesis; D007413:Intestinal Mucosa / Q000276:immunology; D018950:Lipopolysaccharide Receptors / Q000276:immunology* / Q000302:isolation & purification; D008070:Lipopolysaccharides / Q000276:immunology; D008562:Membrane Glycoproteins; D008895:Milk, Human / Q000276:immunology*; D014407:Tumor Cells, Cultured; D000099231:Lipopolysaccharide-Binding Protein
chemical_list: D000209:Acute-Phase Proteins; D002352:Carrier Proteins; D016209:Interleukin-8; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D000099231:Lipopolysaccharide-Binding Protein