title: DC-LAMP+ dendritic cells are recruited to gastric lymphoid follicles in Helicobacter pylori-infected individuals.
abstract: Infection with Helicobacter pylori is associated with development of ulcer disease and gastrointestinal adenocarcinoma. The infection leads to a large infiltration of immune cells and the formation of organized lymphoid follicles in the human gastric mucosa. Still, the immune system fails to eradicate the bacteria, and the substantial regulatory T cell (Treg) response elicited is probably a major factor permitting bacterial persistence. Dendritic cells (DCs) are professional antigen-presenting cells that can activate naive T cells, and maturation of DCs is crucial for the initiation of primary immune responses. The aim of this study was to investigate the presence and localization of mature human DCs in H. pylori-infected gastric mucosa. Gastric antral biopsy specimens were collected from patients with H. pylori-associated gastritis and healthy volunteers, and antrum tissue was collected from patients undergoing gastric resection. Immunohistochemistry and flow cytometry showed that DCs expressing the maturation marker dendritic cell lysosome-associated membrane glycoprotein (DC-LAMP; CD208) are enriched in the H. pylori-infected gastric mucosa and that these DCs are specifically localized within or close to lymphoid follicles. Gastric DC-LAMP-positive (DC-LAMP(+)) DCs express CD11c and high levels of HLA-DR but little CD80, CD83, and CD86. Furthermore, immunofluorescence analyses demonstrated that DC-LAMP(+) DCs are in the same location as FoxP3-positive putative Tregs in the follicles. In conclusion, we show that DC-LAMP(+) DCs with low costimulatory capacity accumulate in the lymphoid follicles in human H. pylori-infected gastric tissue, and our results suggest that Treg-DC interactions may promote chronic infection by rendering gastric DCs tolerogenic.
authors.affiliation: Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, and Göteborg University Vaccine Research Institute (GUVAX) and the Mucosal Immunobiology and Vaccine Center (MIVAC), Göteborg, Sweden.
authors.forename: Malin
authors.initials: M
authors.lastname: Hansson
authors.forename: Malin
authors.initials: M
authors.lastname: Sundquist
authors.forename: Susanne
authors.initials: S
authors.lastname: Hering
authors.forename: B Samuel
authors.initials: BS
authors.lastname: Lundin
authors.forename: Michael
authors.initials: M
authors.lastname: Hermansson
authors.forename: Marianne
authors.initials: M
authors.lastname: Quiding-Järbrink
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D003713:Dendritic Cells / Q000378:metabolism* / Q000502:physiology; D005260:Female; D005756:Gastritis / Q000382:microbiology / Q000473:pathology; D005786:Gene Expression Regulation / Q000276:immunology*; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000382:microbiology; D059666:Lysosomal-Associated Membrane Protein 3 / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D013270:Stomach; D055815:Young Adult
chemical_list: D059666:Lysosomal-Associated Membrane Protein 3