Structural analysis and virulence assessment of novel factor in Helicobacter cinaedi

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K15465
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 49050:Bacteriology-related
• Research Institution: National Institute of Infectious Diseases
• Principal Investigator: Aoki Sae 国立感染症研究所, 細菌第二部, 研究員 (10908453)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: Helicobacter cinaedi / autotransporter protein

Outline of Final Research Achievements

The cytotoxicity of H. cinaedi infection in Caco-2 and HT29 cells
was assessed using a lactate dehydrogenase assay, and it was found that cytotoxicity significantly decreased upon HcaA knockout. Adhesion assays further revealed that the HcaA-knockout strain showed significantly reduced attachment to Caco-2 cell compared to that of the wild-type strain. Furthermore, when C57BL/6 mice were infected with wild-type and HcaA-knockout strains, bacterial colonization was evaluated on days 7, 14, and 28 post-infection. The results indicated that the number of colonized bacteria significantly decreased in mice infected with the HcaA-knockout strain.

Free Research Field

細菌学

Academic Significance and Societal Importance of the Research Achievements

本研究成果は、H. cinaedi が産生するタンパク質であるHcaAが病原性を有しており、感染病態に寄与している可能性を示した。特に、HcaAによる接着能は生体内においても認められたことから、H. cinaediの感染成立に寄与していることが明らかとなった。したがって、多様な感染病態を示す H. cinaedi 感染症における HcaAの役割を明らかにし、Helicobacter 属菌の新規病原因子の解明や、H. cinaedi 感染メカニズムに対する理解につながることが期待されるものである。