ABSTRACT
The initial step in bacterial infection is adherence of the bacterium to the target cell surface. Helicobacter pylori exploits the interaction of bacterial adhesin protein HopQ with human epithelial CEACAMs (CEACAM1, 5, and 6) to stably adhere to gastric epithelial cells, which is necessary for delivery of the H. pylori CagA oncoprotein into the epithelial cells via a type IV secretion system. In contrast to human CEACAMs, however, HopQ does not interact with Ceacam1 (mouse CEACAM1) in vitro or in CHO cells ectopically expressing Ceacam1. Since the mouse genome lacks Ceacam5 and Ceacam6, no significant HopQ-Ceacam interaction may occur in mouse gastric epithelial cells. Here, we found that the mouse stomach has a much lower expression level of Ceacam1 than the expression level of CEACAM1 in the human stomach. Consistently, mouse gastric epithelial cells resist CagA delivery by cagA-positive H. pylori, and the delivery is restored by ectopic expression of human CEACAM1 or CEACAM5 in mouse gastric epithelial cells. Thus, despite the fact that mice are routinely used for H. pylori infection studies, a low expression level of Ceacam1 in the mouse stomach together with the loss or greatly reduced interaction of HopQ with Ceacams make the mouse an inappropriate model for studying the role of H. pylori-delivered CagA in gastric pathogenesis, including the development of gastric cancer.
Subject(s)
Helicobacter Infections , Helicobacter pylori , Adhesins, Bacterial/genetics , Adhesins, Bacterial/metabolism , Animals , Antigens, Bacterial/genetics , Antigens, Bacterial/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Cricetinae , Cricetulus , Epithelial Cells/metabolism , Helicobacter pylori/metabolism , Mice , Protein Transport , Stomach , Type IV Secretion Systems/genetics , Type IV Secretion Systems/metabolismABSTRACT
BACKGROUND: It has been more than two decades since a link was found between maternal oral health and adverse pregnancy outcome. Obstetricians and gynecologists play a core role in the screening, prevention and referral of the pregnant women for periodontal diseases. Thus, a study was conducted to assess the knowledge of the association between periodontal status and pregnancy outcomes. METHODS: An online survey was done by distributing self-administered questionnaire to the obstetricians and gynecologists. The survey consisted of three parts: demographic variables, consent and questionnaire. The qualitative data was recorded and analyzed. RESULTS: Out of 237 participants, 95.8% of the participants agreed that there is a relation between periodontal disease and pregnancy; 73.8% with preterm birth, 60.3% with low birth weight infants and 38.4% with pre-eclampsia. CONCLUSIONS: The knowledge of the association between periodontal status and pregnancy outcomes was found to be insufficient. The gynecologists must be provided with periodic orientation to enhance and update their knowledge on maternal periodontal health.