A Secreted Low--Molecular-Weight Protein From Helicobacter pylori Induces Cell-Cycle Arrest of T Cells

Regulation of Murine Dendritic Cell Immune Responses byHelicobacter felisAntigen

“…T-cell division in response to treatment of Helicobacter proteins has been previously studied, but not in the context of concomitant DC stimulation, as we have done here. In other studies, specific proteins from Helicobacter including vacuolating cytotoxin A have been reported to inhibit T-cell proliferation to subsequent antigen challenge (28,29,65). Our studies are of prime importance, because these investigations have shed light on the ability of T cells to elicit an immune response to DC stimulation, under the regulation of Helicobacter Ag, a system of great relevance to the events occurring in the gastric lamina propria in infection.…”

“…Results are representative of two independent experiments. Ag may be inducing cell cycle arrest or the suppression of nuclear factor of activated T cells (29,65). In a series of novel investigations, we have characterized the phenotypes of DC from the gastric lamina propria of H. felisinfected mice.…”

Helicobacterpylori-induced modification of the histone H3 phosphorylation status in gastric epithelial cells reflects its impact on cell cycle regulation

“…The latter virulence factor was shown to be responsible for inducing a G 1 /S delay in T cells. 18,29 Others demonstrated that VacA alone was able to inhibit the G 1 to S progression in gastric epithelial cells. 30 Thus, we conclude that a G 1 /S delay contributed little, or not at all, to the decrease of pH3Ser10.…”

“…The VRK1 kinase assay was performed as described previously. 29 Briefly, immunoprecipitated VRK1 was incubated in a kinase buffer with 1 µg of recombinant histone 3 and 5 µCi of 32 P γ-dATP for 30 min at 30°C. The samples were loaded and separated on a denaturing 15% SDS-polyacrylamide gel at 200 V for 4 h and transferred to a PVDF membrane.…”

Helicobacter pyloriPersistence: an Overview of Interactions betweenH. pyloriand Host Immune Defenses

“…In vitro experiments indicate that live H. pylori or H. pylori products can interfere with multiple functions of T lymphocytes (37,77,78,219,256) (Fig. 4).…”