Accumulation of a potent gammadelta T-cell stimulator after deletion of the lytB gene in Escherichia coli.
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.
Eberl
Matthias
M
Biochemisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany. matthias.eberl@biochemie.med.uni-giessen.de
Altincicek
Boran
B
Kollas
Ann-Kristin
AK
Sanderbrand
Silke
S
Bahr
Ute
U
Reichenberg
Armin
A
Beck
Ewald
E
Foster
Donald
D
Wiesner
Jochen
J
Hintz
Martin
M
Jomaa
Hassan
H
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
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