title: Neonatal colonisation expands a specific intestinal antigen-presenting cell subset prior to CD4 T-cell expansion, without altering T-cell repertoire.
abstract: Interactions between the early-life colonising intestinal microbiota and the developing immune system are critical in determining the nature of immune responses in later life. Studies in neonatal animals in which this interaction can be examined are central to understanding the mechanisms by which the microbiota impacts on immune development and to developing therapies based on manipulation of the microbiome. The inbred piglet model represents a system that is comparable to human neonates and allows for control of the impact of maternal factors. Here we show that colonisation with a defined microbiota produces expansion of mucosal plasma cells and of T-lymphocytes without altering the repertoire of alpha beta T-cells in the intestine. Importantly, this is preceded by microbially-induced expansion of a signal regulatory protein α-positive (SIRPα(+)) antigen-presenting cell subset, whilst SIRPα(-)CD11R1(+) antigen-presenting cells (APCs) are unaffected by colonisation. The central role of intestinal APCs in the induction and maintenance of mucosal immunity implicates SIRPα(+) antigen-presenting cells as orchestrators of early-life mucosal immune development.
authors.affiliation: School of Clinical Veterinary Science, University of Bristol, Langford, Bristol, United Kingdom. C.F.Inman@bham.ac.uk
authors.forename: Charlotte F
authors.initials: CF
authors.lastname: Inman
authors.forename: Georgina M
authors.initials: GM
authors.lastname: Laycock
authors.forename: Louisa
authors.initials: L
authors.lastname: Mitchard
authors.forename: Ross
authors.initials: R
authors.lastname: Harley
authors.forename: James
authors.initials: J
authors.lastname: Warwick
authors.forename: Rachel
authors.initials: R
authors.lastname: Burt
authors.forename: Pauline M
authors.initials: PM
authors.lastname: van Diemen
authors.forename: Mark
authors.initials: M
authors.lastname: Stevens
authors.forename: Mick
authors.initials: M
authors.lastname: Bailey
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000938:Antigen-Presenting Cells / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D018928:Immunity, Mucosal; D007413:Intestinal Mucosa / Q000254:growth & development / Q000276:immunology* / Q000382:microbiology*; D013552:Swine