Figure 7
From: Detoxifying Escherichia coli for endotoxin-free production of recombinant proteins
Biological activity of LPS from KPM mutants in human macrophages. Macrophages were differentiated from human blood monocytes of healthy donors. On day seven of differentiation, macrophages were seeded at 1 × 105 cells/well and stimulated with LPS at the indicated amounts (LPS from S. Abortusequi, BW30270 and BL21 (DE3) at 0.01 μg/ml; LPS from strains KPM318, KPM335 and KPM404 at 0.1 μg/ml and 1 μg/ml, respectively) for 4 h at 37°C (A). To determine the antagonistic activity of LPS from KPM strains, macrophages were incubated with LPS samples from KPM318, KPM335 or KPM404 at 0.1 μg/ml or 1 μg/ml for 30 min at 37°C, followed by stimulation of the cells with 0.01 μg/ml of LPS from S. Abortusequi for 4 h (B). Cell-free supernatants were analyzed for TNF-α content by ELISA. The values represent the means and standard deviations from three independent experiments using cells from different donors.