Serological immune response against major secretory proteins expressed by Pseudomonas aeruginosa upon intratracheal infection

2022 Fiscal Year Final Research Report

• Project/Area Number: 18K16521
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 55060:Emergency medicine-related
• Research Institution: Kyoto Prefectural University of Medicine
• Principal Investigator: Kinoshita Mao 京都府立医科大学, 医学(系)研究科(研究院), 助教 (20816384)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Keywords: 抗体価 / V抗原 / 自然免疫 / 緑膿菌

Outline of Final Research Achievements

We focused on quantifying antibodies specific to the V antigen (PcrV) and type III secretory protein (ExoU) expressed by P. aeruginosa to evaluate the serological immune response. We intratracheally infected male ICR mice with several P. aeruginosa strains and quantified antigen-specific antibody titers across 8 weeks. Intratracheal infection of P. aeruginosa PA103 at a sublethal dose decreased the body temperature of mice. The IgG and IgA serum titers against PcrV and ExoU did not increase over 8 weeks, and the IgM titer initially increased for 4 weeks and then decreased. Specific antibodies against PcrV and ExoU may be difficult to produce naturally. Therefore, the IgM expression against major secretory proteins of P. aeruginosa is critical.

Free Research Field

感染症

Academic Significance and Societal Importance of the Research Achievements

今後、緑膿菌肺感染に対する免疫反応をin vivoで調べることで、抗体療法のメカニズム解明、ワクチン開発、最適な投与経路の決定などに役立てることができる。今回の結果から、亜致死量の緑膿菌感染症に対しては、IgGやIgAよりもIgMの発現が重要であることが明らかになった。