title: Accumulation of a potent gammadelta T-cell stimulator after deletion of the lytB gene in Escherichia coli.
abstract: Activation of human Vgamma9/Vdelta2 T cells by many pathogens depends on the presence of small phosphorylated non-peptide compounds derived from the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway of isoprenoid biosynthesis. We here demonstrate that in Escherichia coli mutants deficient in lytB, an essential gene of the MEP pathway, a potent Vgamma9/Vdelta2 T-cell activator accumulates by a factor of approximately 150 compared to wild-type E. coli. The compound responsible for the strong immunogenicity of this E. coli mutant was subsequently characterized and identified as a small pyrophosphorylated metabolite, with a molecular mass of 262 Da, derived from the MEP pathway. Stimulation of human peripheral blood mononuclear cells (PBMC) with extracts prepared from the lytB-deficient E. coli mutant led to upregulation of T-cell activation markers on the surface of Vgamma9/Vdelta2 T cells as well as proliferation and expansion of Vgamma9/Vdelta2 T cells. This response was dependent on costimulatory growth factors, such as interleukin (IL)-2, IL-15 and IL-21. Significant levels of interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) were secreted in the presence of IL-2 and IL-15, but not in the presence of IL-21, demonstrating that proliferating phosphoantigen-reactive Vgamma9/Vdelta2 T cells do not necessarily produce proinflammatory cytokines.
authors.affiliation: Biochemisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany. matthias.eberl@biochemie.med.uni-giessen.de
authors.forename: Matthias
authors.initials: M
authors.lastname: Eberl
authors.forename: Boran
authors.initials: B
authors.lastname: Altincicek
authors.forename: Ann-Kristin
authors.initials: AK
authors.lastname: Kollas
authors.forename: Silke
authors.initials: S
authors.lastname: Sanderbrand
authors.forename: Ute
authors.initials: U
authors.lastname: Bahr
authors.forename: Armin
authors.initials: A
authors.lastname: Reichenberg
authors.forename: Ewald
authors.initials: E
authors.lastname: Beck
authors.forename: Donald
authors.initials: D
authors.lastname: Foster
authors.forename: Jochen
authors.initials: J
authors.lastname: Wiesner
authors.forename: Martin
authors.initials: M
authors.lastname: Hintz
authors.forename: Hassan
authors.initials: H
authors.lastname: Jomaa
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D001685:Biological Factors / Q000276:immunology / Q000302:isolation & purification; D002455:Cell Division / Q000276:immunology; D002478:Cells, Cultured; D002852:Chromatography, Ion Exchange; D016207:Cytokines / Q000096:biosynthesis; D004896:Erythritol / Q000031:analogs & derivatives* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D029968:Escherichia coli Proteins; D006801:Humans; D007378:Interleukins / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology*; D008970:Molecular Weight; D010088:Oxidoreductases; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000032:analysis*; D013403:Sugar Phosphates / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D015854:Up-Regulation / Q000276:immunology; D000098546:Interleukin-21
chemical_list: C114232:2-C-methylerythritol 4-phosphate; D001426:Bacterial Proteins; D001685:Biological Factors; D016207:Cytokines; D029968:Escherichia coli Proteins; D007378:Interleukins; D016692:Receptors, Antigen, T-Cell, gamma-delta; D013403:Sugar Phosphates; D010088:Oxidoreductases; C109866:ispH protein, E coli; D000098546:Interleukin-21; D004896:Erythritol