Lipopolysaccharide induced hyper—and hypo—responsiveness in macrophage cell lines

Objective: To build a cell model of LPS-induced hyper- and hypo-responsiveness in macrophage cells .Methods: Macrophage cell line RAW264.7 was pre-cultured with or without 10 ng/ml LPS for 18 h, then challenged with lipopolysaccharide(LPS), or MDP, Zymosan, PAF, FMLP, PMA for 24 h.The levels of TNF-α , IL-1, IL-6, IL-10 , NO and O-2 were measured.Results: LPS pretreatment markedly inhibited TNF-α NO and IL-6 production, but increased IL-1, IL-10 and O-2 release to LPS challenge.LPS pretreatment also altered macrophage responsiveness to the other stimuli.Conclusion: LPS can induce hyper- and hypo-responsiveness simultaneously in the macrophage cell lines.Changes in macrophage responsiveness depend on stimuli and effectors which are measured.