Helicobacter pylori gamma-glutamyl transpeptidase and its pathogenic role

Table 1 Reported Helicobacter pylori gamma-glutamyl transpeptidase effects

Effects	Ref.
Involved in H. pylori colonization and persistence in the gastric mucosa	[5,6]
Hydrolysis of extracellular glutamine and glutathione to generate glutamate that is transported into the H. pylori cell	[8]
Highly active periplasmic deamidase involved in ammonia production	[8,20]
Significantly higher GGT activity in strains obtained from patients with peptic ulcer disease	[21]
Gastric epithelial cell death - Mitochondria-mediated apoptosis in gastric epithelial cells	[7,16,24]
Cell-cycle arrest of gastric epithelial cells	[24]
Glutathione degradation-dependent gastric epithelial cell death	[8,27]
H2O2 generation, nuclear factor-κB activation and interleukin-8 production in gastric epithelial cells	[21,27]
Induction of EGF-related growth factors and COX-2 in gastric epithelial cells	[15]
Induction of apoptosis and inflammation in human biliary cells	[25]
Degradation of the apoptosis-inhibiting protein survivin in gastric epithelial cells	[30]
Inhibition of T cell proliferation and induction of G1 cell cycle arrest	[9-11]
Induction of microRNA-155 in human T cells	[38]
Gastric persistence and immune tolerance	[12]

H. pylori: Helicobacter pylori; GGT: Gamma glutamyl transpeptidase; EGF: Epidermal growth factor; COX-2: Cyclooxygenase 2.