FIG. 4.

Proinflammatory cytokine (TNF) production by THP-1 cells in response to LOS from Neisseria. Cells were challenged with 200 ng of LOS isolated from N. meningitidis, N. gonorrhoeae, E. coli, or S. enterica serovar Minnesota Re595 for 6 h, after which TNF concentrations in the supernatants were determined by ELISA. The neisserial LOS are ranked in order of decreasing oligosaccharide chain length (where known). Each bar represents the mean of quadruplicate data points ± the standard deviation.