Figure 6.

Monocytes are required for TLR4 survival effects. (a) The indicated cell subsets were depleted from N90 neutrophil preparations prior to culture with 100 ng/ml lipid A, after which neutrophil viability was analyzed by Annexin V-APC/7-AAD staining and flow cytometry. (b) N99 PMNs viability after culture with supernatants from purified monocytes exposed to 0 or 100 ng/ml lipid A for 20 h. Bars show mean percentage of viability ± SEM from (a) n = 3–5 (***P ≤ 0.001, **P ≤ 0.01, and ns P > 0.05 when compared with N90 neutrophils subjected to mock depletion and cultured in the absence of lipid A (A) or (b) n = 3 blood donors (****P ≤ 0.0001, ***P ≤ 0.001 when compared with N99 neutrophils cultured in the absence of lipid A). Each donor (n) represents an independent experiment.