title: Glycosylation of human milk lactoferrin exhibits dynamic changes during early lactation enhancing its role in pathogenic bacteria-host interactions.
abstract: Human milk lactoferrin (hmLF) is the most abundant glycoprotein present in human milk and displays a broad range of protective functions in the gut of newborn infants. hmLF is N-glycosylated, but little is known about the lactation stage-related development of the glycosylation phenotype. hmLF glycosylation from milk samples from five donors during the first 10 weeks of lactation was assessed and observed to be more diverse than previously reported. During this period dynamic changes in glycosylation were observed corresponding to a decrease in glycosylation in the second week followed by an increase in total glycosylation as well as higher order fucosylation thereafter. Gene expression analysis was performed in milk somatic cells from a sixth subject. It was found that fucosyltransferase expression increased during entire period, whereas expression of genes for the oligosaccharyl transferase complex decreased in the second week. The effect of hmLF glycosylation was examined for the protein's ability to affect bacterial binding to epithelial cells. hmLF significantly inhibited pathogen adhesion and purified hmLF glycans significantly reduced Salmonella invasion of colonic epithelial cells to levels associated with non-invasive deletion mutants. This study indicates that hmLF glycosylation is tightly regulated by gene expression and that glyco-variation is involved in modulating pathogen association.
authors.affiliation: Department of Chemistry, Functional Glycobiology Program, University of California Davis. One Shields Ave, Davis, California 95616, USA.
authors.forename: Mariana
authors.initials: M
authors.lastname: Barboza
authors.forename: Janneth
authors.initials: J
authors.lastname: Pinzon
authors.forename: Saumya
authors.initials: S
authors.lastname: Wickramasinghe
authors.forename: John W
authors.initials: JW
authors.lastname: Froehlich
authors.forename: Isabelle
authors.initials: I
authors.lastname: Moeller
authors.forename: Jennifer T
authors.initials: JT
authors.lastname: Smilowitz
authors.forename: L Renee
authors.initials: LR
authors.lastname: Ruhaak
authors.forename: Jincui
authors.initials: J
authors.lastname: Huang
authors.forename: Bo
authors.initials: B
authors.lastname: Lönnerdal
authors.forename: J Bruce
authors.initials: JB
authors.lastname: German
authors.forename: Juan F
authors.initials: JF
authors.lastname: Medrano
authors.forename: Bart C
authors.initials: BC
authors.lastname: Weimer
authors.forename: Carlito B
authors.initials: CB
authors.lastname: Lebrilla
mesh_terms: D001422:Bacterial Adhesion; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002460:Cell Line; D019453:Escherichia coli O157 / Q000502:physiology; D005260:Female; D005583:Fourier Analysis; D005647:Fucosyltransferases / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006031:Glycosylation; D006602:Hexosyltransferases / Q000235:genetics / Q000378:metabolism; D054884:Host-Pathogen Interactions; D006801:Humans; D007774:Lactation; D007781:Lactoferrin / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008895:Milk, Human / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry; D011499:Protein Processing, Post-Translational; D012475:Salmonella / Q000502:physiology; D017423:Sequence Analysis, RNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: C490098:LTF protein, human; D008565:Membrane Proteins; D011134:Polysaccharides; D005647:Fucosyltransferases; D006602:Hexosyltransferases; C025620:dolichyl-diphosphooligosaccharide - protein glycotransferase; D007781:Lactoferrin