Table 2.

Effects of neutralizing MAbs against proinflammatory cytokines on IP-10 and Mig production during whole-blood stimulation with heat-killed B. pseudomallei or E. coli LPSa

MAb% Inhibition
IP-10Mig
B. pseudomalleiLPSB. pseudomalleiLPS
Control2.8 ± 7.21.1 ± 10.32.5 ± 8.95.4 ± 14.7
Anti-IFN-γ19.0 ± 6.2 50.2 ± 5.5 35.1 ± 6.3 67.7 ± 6.0
Anti-IL-124.3 ± 5.959.1 ± 3.9 3.8 ± 6.761.5 ± 7.8
Anti-IL-180.6 ± 7.226.1 ± 6.2 8.4 ± 4.732.9 ± 6.8
Anti-TNF22.1 ± 1.1 36.7 ± 3.6 27.6 ± 8.6 58.6 ± 3.1
Anti-IL-12 +  anti-IL-1828.4 ± 5.4 65.0 ± 2.5 29.1 ± 10.5 71.9 ± 6.4
Anti-IFN-γ +  anti-IL-1233.8 ± 5.9# ND46.1 ± 6.2# ND
Anti-IFN-γ +  anti-IL-1821.3 ± 7.5 ND31.8 ± 9.1 ND
  • a Data are means ± SE for six healthy donors and expressed as percent inhibition relative to incubation with heat-killed B. pseudomallei only. Whole blood, diluted 1:1 in RPMI, was stimulated for 24 h at 37°C with 107 CFU of heat-killed B. pseudomallei per ml or LPS (10 ng/ml) in the presence or absence of neutralizing antibodies against TNF, IFN-γ, IL-12, or IL-18 (final concentration of all, 10 μg/ml). Incubation without stimulus resulted in low levels of IP-10 (653 ± 110 pg/ml) and Mig (253 ± 96 pg/ml). IP-10 levels after stimulation with heat-killed B. pseudomallei were 4,448 ± 955 pg/ml, and Mig levels were 3,851 ± 650 pg/ml. Stimulation with LPS increased IP-10 concentrations to 12,594 ± 1,686 pg/ml and Mig levels to 2,858 ± 807 pg/ml. *, P < 0.05 versus control antibody; #, P < 0.05 versus anti-IFN-γ. ND, not determined.