@article{oai:rakuno.repo.nii.ac.jp:00005650,
 author = {Hwang, Insu and Mori, Kenichiro and Ohtani, Katsuki and 大谷, 克城 and Matsuda, Yasuyuki and Roy, Nitai and Kim, YounUck and Suzuki, Yasuhiko and Wakamiya, Nobutaka},
 issue = {2},
 journal = {Journal of innate immunity},
 month = {Mar},
 note = {Article, Collectins are C-type lectins that are involved in innate immunity as pattern recognition molecules. Recently, collectin kidney 1 (CL-K1) has been discovered, and in vitro studies have shown that CL-K1 binds to microbes and activates the lectin complement pathway. However, in vivo functions of CL-K1 against microbes have not been elucidated. To investigate the biological functions of CL-K1, we generated CL-K1 knockout (CL-K1-/-) mice and then performed a Streptococcus pneumoniae infection analysis. First, we found that recombinant human CL-K1 bound to S. pneumoniae in a calcium-dependent manner, and induced complement activation. CL-K1-/- mice sera formed less C3 deposition on S. pneumoniae. Furthermore, immunofluorescence analysis in the wild-type (WT) mice demonstrated that CL-K1 and C3 were localized on S. pneumoniae in infected lungs. CL-K1-/- mice revealed decreased phagocytosis of S. pneumoniae. Consequently, less S. pneumoniae clearance was observed in their lungs. CL-K1-/- mice showed severe pulmonary inflammation and weight loss in comparison with WT mice. Finally, the decreased clearance and severe pulmonary inflammation caused by S. pneumoniae infection might cause higher CL-K1-/- mice lethality. Our results suggest that CL-K1 might play an important role in host protection against S. pneumoniae infection through the activation of the lectin complement pathway.},
 pages = {217--228},
 title = {Collectin Kidney 1 Plays an Important Role in Innate Immunity against Streptococcus pneumoniae Infection},
 volume = {9},
 year = {2017}
}