Monocyte-derived macrophages secrete increased amounts of cytokine in response to E coli and P aeruginosa in the presence of SAA. (A-B) Monocyte-derived macrophages were incubated with SAA alone (○) or γ-irradiated bacteria (at 107 cfu's/mL) in the absence or presence of SAA (1, 10, 50 μg/mL) for 16 hours and supernatants were assayed for (A) TNF-α and (B) IL-10. The bacteria used were E coli (▪), S pneumoniae (▾), and B cepacia (▴). Data represent mean ± SEM of 4 donors. Statistical significance between bacteria + SAA and bacteria alone was calculated by Student paired t test (*P < .05; **P < .01). (C-D) Monocyte-derived macrophages from donors with low cytokine responses to P aeruginosa alone were incubated with γ-irradiated P aeruginosa strains at 107 cfu's/mL in the absence (□) or presence (▪) of SAA (10 μg/mL) for 16 hours. Supernatants were assayed for (C) TNF-α and (D) IL-10. Data represent mean ± SEM of 5 donors. Statistical significance between bacteria + SAA and bacteria alone was calculated by Student paired t test (*P < .05; **P < .01).
