VacA's Induction of VacA-Containing Vacuoles (VCVs) and Their Immunomodulatory Activities on Human T Cells.
Vacuolating cytotoxin A (VacA) is a secreted pore-forming toxin and one of the major virulence factors of Helicobacter pylori (H. pylori), which actively supports the persistence and survival of the bacteria in the special ecological niche of the human stomach. H. pylori genomes harbor different allelic forms of the vacA gene, which translate into functionally distinct VacA toxin types. VacA internalizes into various cell types via membrane or specific receptor interactions finally forming acidic endocytic VacA-containing vacuoles (VCVs). In this review, we focus on different characteristics of VacA, its interaction with host cells, the formation and protein content of VCVs and their intracellular transport into human T cells, which finally leads to the immunosuppressive phenotype of VacA. Immunomodulatory activities of VacA on human T cells are discussed with a focus on T-cell proliferation and calcium signaling.
Max von Pettenkofer-Institut f&#252;r Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universit&#228;t, Pettenkoferstraße 9a, M&#252;nchen D-80336, Germany.
Ciara
C
Utsch
Max von Pettenkofer-Institut f&#252;r Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universit&#228;t, Pettenkoferstraße 9a, M&#252;nchen D-80336, Germany. haas@mvp.uni-muenchen.de.
Rainer
R
Haas
D000818:Animals; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000276:immunology* / Q000633:toxicity; D006801:Humans; D056747:Immunomodulation; D013601:T-Lymphocytes / Q000276:immunology*; D014617:Vacuoles / Q000276:immunology
D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori
IL-2 secretion; VacA channel; apoptosis; cell vacuolation; proliferation inhibition; protein-protein interaction; vesicle transport