title: Gastric LTi cells promote lymphoid follicle formation but are limited by IRAK-M and do not alter microbial growth.
abstract: Lymphoid tissue inducer (LTi) cells are activated by accessory cell IL-23, and promote lymphoid tissue genesis and antibacterial peptide production by the mucosal epithelium. We investigated the role of LTi cells in the gastric mucosa in the context of microbial infection. Mice deficient in IRAK-M, a negative regulator of TLR signaling, were investigated for increased LTi cell activity, and antibody mediated LTi cell depletion was used to analyze LTi cell dependent antimicrobial activity. H. pylori infected IRAK-M deficient mice developed increased gastric IL-17 and lymphoid follicles compared to wild type mice. LTi cells were present in naive and infected mice, with increased numbers in IRAK-M deficient mice by two weeks. Helicobacter and Candida infection of LTi cell depleted rag1(-/-) mice demonstrated LTi-dependent increases in calprotectin but not RegIII proteins. However, pathogen and commensal microbiota populations remained unchanged in the presence or absence of LTi cell function. These data demonstrate LTi cells are present in the stomach and promote lymphoid follicle formation in response to infection, but are limited by IRAK-M expression. Additionally, LTi cell mediated antimicrobial peptide production at the gastric epithelium is less efficacious at protecting against microbial pathogens than has been reported for other tissues.
authors.affiliation: Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA.
authors.forename: J
authors.initials: J
authors.lastname: Shiu
authors.affiliation: Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
authors.forename: M B
authors.initials: MB
authors.lastname: Piazuelo
authors.affiliation: Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA.
authors.forename: H
authors.initials: H
authors.lastname: Ding
authors.affiliation: Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Czinn
authors.affiliation: Cardinal Bernardin Cancer Center, Loyola University Chicago, Maywood, Illinois, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Drakes
authors.affiliation: Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA.
authors.forename: A
authors.initials: A
authors.lastname: Banerjee
authors.affiliation: Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA.
authors.forename: N
authors.initials: N
authors.lastname: Basappa
authors.affiliation: Department of Microbial and Molecular Pathogenesis, Texas A & M Health Science Center, Texas, USA.
authors.forename: K S
authors.initials: KS
authors.lastname: Kobayashi
authors.affiliation: Institute for Genomic Sciences, University of Maryland, Baltimore, Maryland, USA.
authors.forename: W F
authors.initials: WF
authors.lastname: Fricke
authors.affiliation: Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA.
authors.forename: T G
authors.initials: TG
authors.lastname: Blanchard
mesh_terms: D000818:Animals; D002175:Candida / Q000276:immunology*; D002177:Candidiasis / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D005753:Gastric Mucosa / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D016998:Helicobacter / Q000276:immunology*; D016481:Helicobacter Infections / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D018398:Homeodomain Proteins / Q000235:genetics / Q000276:immunology; D053592:Interleukin-1 Receptor-Associated Kinases / Q000235:genetics / Q000276:immunology*; D053759:Interleukin-23 / Q000235:genetics / Q000276:immunology; D008221:Lymphoid Tissue / Q000276:immunology* / Q000473:pathology; D051379:Mice; D018345:Mice, Knockout
chemical_list: D018398:Homeodomain Proteins; D053759:Interleukin-23; C064658:RAG-1 protein; D053592:Interleukin-1 Receptor-Associated Kinases; C507772:Irak3 protein, mouse