Abstract: [Abstract] Objective The aim of this study is to clarify the role of syk kinase in inflammasomes activation during Listeria monocytogenes (LM) infection. Methods Murine peritoneal exudates macrophages pretreated with inhibitor of syk, P38MAPK, or PI3K kinase were infected with LM for 24h, the protein level of IL-18 in the supernatant was detected by ELISA kit, the activation condition of key molecule ASC in the infected-macrophages cytoplasm was observed under fluorescence microscope. Furthermore, the syk protein kinase phosphorylation level at different time point during LM infection were detected by western blot. Results IL-18 protein level produced by macrophages in the presence of syk inhibitor was significantly reduced compared with that in macrophages without pretreatment. Meanwhile, the percentage of ASC-speck formation in the cytoplasm of syk inhibitor pretreated-- macrophages infected with LM diminished apparently. Furthermore, we found that the phosphorylation level of syk could be detectable at 5min postinfection, which confirmed the critical role of syk in the inflammasomes activation upon LM infection. Conclusion Syk kinase signaling is required for the inflammasomes activation upon Listeria monocytogenes infection in murine macrophages.

Key words: syk, listeria monocytogenes, inflammasome