title: The probiotic Escherichia coli strain Nissle 1917 induces gammadelta T cell apoptosis via caspase- and FasL-dependent pathways.
abstract: Human gammadelta T cells play a vital role in the innate and adaptive immune response to microbial antigens by acting as antigen-presenting cells while at the same time being capable of directly activating CD4(+) T cells. Pathogenic microbes or loss of tolerance toward the host's own microflora trigger many diseases including inflammatory bowel diseases. We previously demonstrated that Escherichia coli Nissle 1917 directly interacts with the adaptive immune system by regulating central T cell functions. Here we aimed to investigate whether E. coli Nissle regulates gammadelta T cell function, thereby linking the innate and adaptive immune system. In our study, we demonstrate that, in contrast to the other probiotic strains tested, E. coli Nissle increased activation, cell cycling and expansion of gammadelta, but not alphabeta T cells. In gammadelta T cells, E. coli Nissle reduced tumor necrosis factor-alpha secretion but increased IL-6 and CXCL8 release. However, after activation, only E. coli Nissle induced gammadelta T cell apoptosis, mediated via Toll-like receptor-2 by caspase- and FasLigand-dependent pathways. gammadelta T cells play an important role in the recognition of microbial antigens and the perpetuation of inflammatory processes. The demonstration that E. coli Nissle, but not the other bacteria tested, profoundly regulate gammadelta T cell function contributes to explaining the biological function of this probiotic strain in inflammatory diseases and provides us with a better understanding of the role of gammadelta T cells.
authors.affiliation: Department of Medicine, Division of Gastroenterology and Hepatology, Charité-Universitätsmedizin Berlin, Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Guzy
authors.forename: Daniela
authors.initials: D
authors.lastname: Paclik
authors.forename: Anja
authors.initials: A
authors.lastname: Schirbel
authors.forename: Ulrich
authors.initials: U
authors.lastname: Sonnenborn
authors.forename: Bertram
authors.initials: B
authors.lastname: Wiedenmann
authors.forename: Andreas
authors.initials: A
authors.lastname: Sturm
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000276:immunology*; D020169:Caspases / Q000276:immunology; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D016207:Cytokines / Q000187:drug effects / Q000378:metabolism; D004926:Escherichia coli; D053222:Fas Ligand Protein / Q000276:immunology; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000178:diet therapy / Q000382:microbiology; D008213:Lymphocyte Activation / Q000187:drug effects; D019936:Probiotics / Q000494:pharmacology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000276:immunology* / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D051195:Toll-Like Receptor 2 / Q000276:immunology / Q000378:metabolism
chemical_list: D016207:Cytokines; D053222:Fas Ligand Protein; D016692:Receptors, Antigen, T-Cell, gamma-delta; D051195:Toll-Like Receptor 2; D020169:Caspases