The characteristics of IL-22 in Helicobacter pylori infection
Objective To investigate the characteristics of IL-22 in Helicobacter pylori (H.pylori)infection.Methods Thirty H.pyloripositive and fifteen H.pylori negative gastric biopsy specimens were enrolled,IL-22 mRNA expression was detected by real-time PCR and the protein level of IL-22 was determined by ELISA in gastric tissue.The H.pyloriand cell coculture system was established and IL-22 expression was measured by real-time PCR to investigate the main source of IL-22 in gastric tissue.The IL-22-producing T cell was examined by FCM in the gastric mucosa tissue.Results Gastric mucosal IL-22 mRNA and protein levels were significantly higher in H.pylori-positive patients than uninfected patients (P＜0.05).A H.pyloriand cell coculture system was established successfully and gastric epithelial cell and T cell were the main source of IL-22 in gastric tissue.IL-22 was produced by CD4+ and CD8+ T cells and these T cells were increased in H.pylori-infected gastric mucosa (P＜0.05).Conclusion IL-22 took part in H.pyloriinfection induced immune response and increased IL-22-producing T cells was the important feature of H.pyloriinfection. 
 
Key words: 
Helicobacter pylori infection;  IL-22 ;  T lymph cell