Cloning, Expression, Purification and Toxicity Evaluation of Helicobacter pylori Outer Inflammatory Protein A
Omid Teymournejad1, Ashraf Mohabati Mobarez1, Zuhair Mohammad Hassan2
1Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
Abstract:
The Helicobacter pylori outer membrane proteins play an important role in pathogenesis; the outer inflammatory protein A (OipA) is one of these proteins which play the main role in the development of inflammation. In this study, purification of recombinant H. pylori OipA was performed by Ni-NTA affinity chromatography. Gastric carcinoma epithelial cells (AGS cell) were treated by different concentrations of recombinant OipA for various lengths of time and cell viability was evaluated by the viability assay. Statistical analysis showed that OipA had toxic effects on AGS cells in a concentration of 500 ng/ml after 24 and 48 h, and this toxic dose was 256 ng/ml after 72 h. OipA had direct toxic effects on gastric epithelial cells and the toxicity was observed to depend on time and dose of H. pylori exposure. Attachment of H. pylori to gastric epithelial cells is a key part in the pathogenesis and enables H. pylori to damage the epithelial cells with OipA.
Insights
Helicobacter pylori outer inflammatory protein A (OipA) directly harms gastric epithelial cells. This OipA toxicity depends on the dose and duration of exposure, contributing to H. pylori pathogenesis.
Area of Science:
- Microbiology
- Cell Biology
- Pathogenesis Research
Background:
- Helicobacter pylori outer membrane proteins are crucial in disease development.
- Outer inflammatory protein A (OipA) is a key virulence factor implicated in inflammation.
- Understanding OipA's direct effects on gastric cells is vital for comprehending H. pylori pathogenesis.
Purpose of the Study:
- To investigate the direct cytotoxic effects of purified recombinant H. pylori OipA on gastric carcinoma epithelial cells (AGS cells).
- To determine the dose- and time-dependent toxicity of OipA.
- To elucidate the role of OipA in H. pylori-induced gastric epithelial cell damage.
Main Methods:
- Purification of recombinant H. pylori OipA using Ni-NTA affinity chromatography.
- Treatment of AGS cells with varying concentrations of OipA for different time periods (24, 48, and 72 hours).
- Evaluation of cell viability using a standard viability assay.
Main Results:
- OipA demonstrated significant toxic effects on AGS cells.
- A concentration of 500 ng/ml OipA was toxic after 24 and 48 hours.
- A lower concentration of 256 ng/ml OipA was toxic after 72 hours, indicating time- and dose-dependent toxicity.
- OipA directly damages gastric epithelial cells, contributing to H. pylori pathogenesis.
Conclusions:
- Recombinant H. pylori OipA exhibits direct dose- and time-dependent toxicity towards gastric epithelial cells.
- OipA's cytotoxic effects are a significant factor in H. pylori-mediated gastric pathogenesis.
- These findings highlight OipA as a critical target for understanding and potentially mitigating H. pylori-induced gastric diseases.
