A KAKENHI (Grant-in-Aid for Scientific Research) project on the interactions between Streptococcus pneumoniaeand viruses has been awarded.

Mechanisms by Which Pneumococcal Proteases Promote Viral Pathogenesis and Infection

Funding Program: KAKENHI – Grant-in-Aid for Scientific Research (C)
Principal Investigator: Yukiko Akahori
Project Period: April 1, 2026 – March 31, 2029

Streptococcus pneumoniae is a common colonizer of the human nasopharynx and a leading cause of community-acquired pneumonia, particularly in young children and older adults. The bacterium expresses multiple serine proteases on its surface that have been implicated in disrupting the mucosal barrier and modulating host immune responses; however, their contribution to disease pathogenesis remains incompletely understood.

Influenza A virus (IAV) requires proteolytic cleavage of its hemagglutinin (HA) protein for productive infection. This project tests the hypothesis that pneumococcal serine proteases promote IAV infection through HA cleavage. Furthermore, by investigating how nasopharyngeal colonization with S. pneumoniae alters the host immune environment, this study aims to elucidate the molecular mechanisms by which pneumococci enhance viral infection and pathogenicity.

https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-26K10015/