2013 Fiscal Year Final Research Report
Group A Streptococcus translocates across an epithelial barrier
| Project/Area Number |
24791961
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Morphological basic dentistry
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| Research Institution | Osaka University |
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Principal Investigator |
SUMITOMO Tomoko 大阪大学, 歯学研究科(研究院), 助教 (50423421)
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| Project Period (FY) |
2012-04-01 – 2014-03-31
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| Keywords | レンサ球菌 / 上皮バリア / 細胞間隙 |
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| Research Abstract |
Group A Streptococcus pyogenes (GAS) is a human pathogen that causes local suppurative infections and severe invasive diseases. Systemic dissemination of GAS is initiated by bacterial penetration of the epithelial barrier of the pharynx or damaged skin. In this study, culture supernatants of tested GAS strains showed proteolytic activity against human occludin and E-cadherin. We identified streptococcal pyrogenic exotoxin B (SpeB) as the proteolytic factor that cleaves E-cadherin in the region neighboring the calcium-binding sites within the extracellular domain. Of note, the wild type strain efficiently translocated across the epithelial monolayer along with cleavage of occludin and E-cadherin, whereas deletion of the speB gene compromised those activities. Taken together, our findings indicate that the proteolytic efficacy of SpeB in junctional degradation allows GAS to invade deeper into tissues.
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