RESUMO
CD4(+) T cell responses are critical for the pathogenesis of Helicobacter pylori infection. The present study evaluated the role of the Th17 subset in H. pylori infection. H. pylori infection induced significant expression of IL-17 and IFN-gamma in mouse gastric tissue. IL-23 and IL-12 were increased in the gastric tissue and in H. pylori-stimulated macrophages. Cell responses were examined by intracellular staining for IFN-gamma, IL-4, and IL-17. Mice infected with H. pylori developed a mixed Th17/Th1 response; Th17 responses preceded Th1 responses. Treatment of mice with an anti-IL-17 Ab but not a control Ab significantly reduced the H. pylori burden and inflammation in the stomach. H. pylori colonization and gastric inflammation were also lower in IL-17(-/-) mice. Furthermore, administration of recombinant adenovirus encoding mouse IL-17 increased both H. pylori load and inflammation. Further analysis showed that the Th1 cell responses to H. pylori were downregulated when IL-17 is deficient. These results together suggest that H. pylori infection induces a mixed Th17/Th1 cell response and the Th17/IL-17 pathway modulates Th1 cell responses and contributes to pathology.
Assuntos
Infecções por Helicobacter/imunologia , Infecções por Helicobacter/patologia , Helicobacter pylori/imunologia , Interleucina-17/fisiologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/microbiologia , Células Th1/imunologia , Células Th1/microbiologia , Animais , Modelos Animais de Doenças , Regulação para Baixo/genética , Regulação para Baixo/imunologia , Feminino , Infecções por Helicobacter/microbiologia , Helicobacter pylori/crescimento & desenvolvimento , Interferon gama/biossíntese , Interleucina-12/biossíntese , Interleucina-17/biossíntese , Interleucina-17/deficiência , Interleucina-17/genética , Interleucina-23/biossíntese , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Subpopulações de Linfócitos T/patologia , Células Th1/patologia , Regulação para Cima/genética , Regulação para Cima/imunologiaRESUMO
BACKGROUND: Recombinant adenoviruses (rAd) are well-characterized viral vectors and have been studied in many human diseases. However, there are no detailed methods for transferring genes to the stomach using rAd. METHODS: Gastric epithelial cells were infected with rAd encoding green fluorescence protein (AdGFP) for different times, or with AdGFP that had been incubated in artificial gastric juice at different pH values for 1 h. Gene expression was detected by fluorescence microscope and flow cytometry. Mice were infected via oral administration with rAd encoding red fluorescence protein and beta-galactosidase (AdRFP-lacZ) or rAd encoding mouse interleukin-17 (AdmIL-17), and tissues were collected at the indicated times after infection. LacZ expression in different tissues was detected by X-gal staining and IL-17 expression in the stomach was assessed by the real-time polymerase chain reaction and an enzyme-linked immunosorbent assay. Inflammation in the stomach was also assessed. RESULTS: rAd could infect the gastric epithelial cells and tolerate pH 5 for 1 h in vitro. Adenovirus-mediated genes were specifically expressed in the gastrointestinal tract and transgene expression persisted in gastric tissue for up to 7 days after oral administration of AdRFP-lacZ. Oral administration of AdmIL-17 induced mIL-17 expression in gastric tissue at the mRNA and protein levels and protein level peaked on day 5 post-infection. IL-6, a target protein of IL-17, and gastric inflammation also increased in AdmIL-17-infected mice. CONCLUSIONS: The present study has established a detailed method for transferring adenovirus-mediated gene to the stomach, which may provide a valuable approach for gene therapy or the study of the basic biology of gastric diseases.
Assuntos
Adenoviridae/genética , Técnicas de Transferência de Genes , Terapia Genética , Neoplasias Gástricas/genética , Administração Oral , Animais , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Feminino , Trato Gastrointestinal , Interleucina-17/genética , Interleucina-6/genética , Interleucina-6/metabolismo , Rim/citologia , Rim/metabolismo , Óperon Lac/genética , Proteínas Luminescentes/genética , Camundongos , Camundongos Endogâmicos BALB C , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias Gástricas/virologia , Transgenes/fisiologia , beta-Galactosidase/genética , Proteína Vermelha FluorescenteRESUMO
Helicobacter pylori infection is a risk factor for development of peptic ulcers, and psychological stress (PS) may have a role in the pathogenesis of this condition. However, no interaction between PS and H. pylori infection (HI) has been established in the development of peptic ulcer, because colonization by H. pylori is the first step in the infection of the gastric mucosa, we examined H. pylori colonization of the stomach in BALB/c mice after PS. The mice were subjected to PS in a communication box test, in which they observed other mice experiencing a physical stressor (electrical) before they were inoculated with H. pylori. We found that the H. pylori colonization in the stomach of psychologically stressed mice was significantly greater than in the control mice (P < 0.05), and histological examination showed that the gastric mucosal injury in the stressed mice was more extensive than in the control mice (P < 0.05). To explore the underlying mechanisms, we administered RU486 (a type II glucocorticoid (GC) receptor antagonist) to antagonize the effect of endogenous corticosterone: this treatment decreased colonization by H. pylori in the psychologically stressed mice. We conclude that HI of the stomach of BALB/c mice is enhanced by PS, and the effect may be mediated by GCs.