Mechanism of escape of Salmonella from humoral immune system by secreting a virulence factor

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K15272
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Bacteriology (including mycology)
• Research Institution: Chiba University
• Principal Investigator: Takaya Akiko 千葉大学, 大学院薬学研究院, 准教授 (80334217)
• Research Collaborator: TOKOYODA Koji ドイツリウマチ研究センター, PI
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: サルモネラ / 骨髄IgG分泌プラズマ細胞 / SiiE / ワクチン

Outline of Final Research Achievements

Salmonella can escape from the host immune system by producing virulence factors, leading to establishment of systemic infection. To understand the mechanism by which Salmonella escapes the adaptive immune response, we focused on the influence of Salmonella infection on the production of immunoglobulin (Ig)-secreting plasma cells. We show that SiiE secreted from S. Typhimurium is required and sufficient to prevent an efficient humoral immune response, selectively reducing the numbers of IgG-secreting plasma cells in the bone marrow. Furthermore, attenuated SiiE-deficient Salmonella induces high and lasting titers of specific IgG, mice vaccinated with SiiE-deficient Salmonella strongly suppressed the expansion of virulent Salmonella in the spleen compared to mice vaccinated with SiiE+-Salmonella. These findings suggest that SiiE is a virulent factor involving in the escape of Salmonella from humoral immune response.

Free Research Field

細菌学