title: Infant B cell memory differentiation and early gut bacterial colonization.
abstract: Germ-free animal models have demonstrated that commensal bacterial colonization of the intestine induces B cell differentiation and activation. Whether colonization with particular bacterial species or groups is associated with B cell development during early childhood is not known. In a prospective newborn/infant cohort including 65 Swedish children, we examined the numbers and proportions of CD20(+), CD5(+), and CD27(+) B cells in blood samples obtained at several time points during the first 3 y of life using flow cytometry. Fecal samples were collected and cultured quantitatively for major facultative and anaerobic bacteria at 1, 2, 4, and 8 wk of life. We found that the numbers of CD20(+) B cells and CD5(+)CD20(+) B cells reached their highest levels at 4 mo, whereas CD20(+) B cells expressing the memory marker CD27 were most numerous at 18 and 36 mo of age. Using multivariate analysis, we show that early colonization with Escherichia coli and bifidobacteria were associated with higher numbers of CD20(+) B cells that expressed the memory marker CD27 at 4 and 18 mo of age. In contrast, we were unable to demonstrate any relation between bacterial colonization pattern and numbers of CD20(+) or CD5(+)CD20(+) B cells. These results suggest that the intestinal bacterial colonization pattern may affect the B cell maturation also in humans, and that an early gut microbiota including E. coli and bifidobacteria might promote this maturation.
authors.affiliation: Department of Rheumatology and Inflammation Research, The Sahlgrenska Academy at University of Gothenburg, 405 30 Göteborg, Sweden. carin.lundell@rheuma.gu.se
authors.forename: Anna-Carin
authors.initials: AC
authors.lastname: Lundell
authors.forename: Viktor
authors.initials: V
authors.lastname: Björnsson
authors.forename: Annika
authors.initials: A
authors.lastname: Ljung
authors.forename: Margareta
authors.initials: M
authors.lastname: Ceder
authors.forename: Susanne
authors.initials: S
authors.lastname: Johansen
authors.forename: Gunhild
authors.initials: G
authors.lastname: Lindhagen
authors.forename: Carl-Johan
authors.initials: CJ
authors.lastname: Törnhage
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; D000375:Aging / Q000276:immunology*; D015703:Antigens, CD / Q000276:immunology; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D001421:Bacteria, Anaerobic / Q000276:immunology*; D001688:Biological Products / Q000276:immunology*; D002454:Cell Differentiation / Q000502:physiology*; D002657:Child Development / Q000502:physiology*; D002675:Child, Preschool; D015331:Cohort Studies; D004926:Escherichia coli / Q000276:immunology*; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D007156:Immunologic Memory / Q000502:physiology*; D007223:Infant; D007231:Infant, Newborn; D007422:Intestines / Q000276:immunology* / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D013548:Sweden
chemical_list: D015703:Antigens, CD; D001688:Biological Products; C010546:bifidobacterin