title: Development of gut-homing receptors on circulating B cells during infancy.
abstract: B cell gut-homing is mainly mediated by α4β7, CCR9 and CCR10. We here studied the expression of these receptors on B cells from cord blood and from peripheral blood at 1, 4, 18 and 36 months of age in a prospective cohort of Swedish infants. The proportion of all B cells expressing α4β7 as well as the fraction of CCR10+ B cells expressing α4β7 was highest in early infancy. Nearly all naïve B cells in all age groups expressed α4β7, whereas the expression on class-switched B cells decreased with age. Moreover, the proportion of both IgA+ and IgG+ B cells expressing α4β7, CCR9 and CCR10 were higher during the first months when compared to adults. In conclusion, the high fraction of circulating IgA+ and IgG+ B cells expressing CCR9 and CCR10 in the first months of life indicates activation of naïve B cells in the gut, coinciding with bacterial colonization.
authors.affiliation: Department of Rheumatology and Inflammation Research, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden. anna-carin.lundell@rheuma.gu.se
authors.forename: Anna-Carin
authors.initials: AC
authors.lastname: Lundell
authors.forename: Hardis
authors.initials: H
authors.lastname: Rabe
authors.forename: Marianne
authors.initials: M
authors.lastname: Quiding-Järbrink
authors.forename: Kerstin
authors.initials: K
authors.lastname: Andersson
authors.forename: Inger
authors.initials: I
authors.lastname: Nordström
authors.forename: Ingegerd
authors.initials: I
authors.lastname: Adlerberth
authors.forename: Agnes E
authors.initials: AE
authors.lastname: Wold
authors.forename: Anna
authors.initials: A
authors.lastname: Rudin
mesh_terms: D000328:Adult; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D002675:Child, Preschool; D006801:Humans; D007107:Immune System / Q000166:cytology* / Q000254:growth & development*; D007070:Immunoglobulin A / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism; D007223:Infant; D007231:Infant, Newborn; D016023:Integrins / Q000378:metabolism; D007422:Intestines / Q000166:cytology / Q000276:immunology*; D018655:Lymphocyte Count; D008875:Middle Aged; D054388:Receptors, CCR / Q000378:metabolism; D054447:Receptors, CCR10 / Q000378:metabolism; D016201:Receptors, Lymphocyte Homing / Q000378:metabolism*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000378:metabolism
chemical_list: C119309:CC chemokine receptor 9; C515706:CCR10 protein, human; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D016023:Integrins; D054388:Receptors, CCR; D054447:Receptors, CCR10; D016201:Receptors, Lymphocyte Homing; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; C071777:integrin alpha4beta7