Inflammasome responses in macrophages induced by C-terminal peptides of Escherichia coli EscI protein

Abstract:

Abstract:［Objective］To analyze NLRC4 inflammasome responses in macrophages induced by C-terminal of Escherichia coli EscI protein． ［Methods］ NLRC4 inflammasome responses in mouse peritoneal macrophages were analyzed after delivery of the peptides containing C-terminal amino acid sequences of E.coli EscI protein in vitro.［Results］ The peptides containing C-terminal 15 amino acids of EscI protein could significantly activate NLRC4 inflammasome responses in macrophages pre-stimulated with lipopolysaccharide． Intracellular caspase-1 was activated and pyroptotic dead cells were found after peptides delivery． The contents of cytokines，IL-1β and IL-18，in supernatants were elevated significantly compared with that of the control (P＜0.05)．Besides，through comparison of IL-1β contents under different stimulation conditions，4 h incubation after peptides delivery (peptides: lipofectamine 2000=70 μg/μL) could obviously promote the secretion of IL-1β． ［Conclusion］ Peptides containing C-terminal 15 amino acids of E.coli EscI protein can significantly induce NLRC4 inflammasome activation in macrophages.

Key words:Keywords: macrophage，NLRC4 inflammasome，EscI protein，caspase-1，IL-1β