A Novel Murine Anti-Lactoferrin Monoclonal Antibody Activates Human Polymorphonuclear Leukocytes through Membrane-Bound Lactoferrin and TLR4

Figure 5

Phagocytosis-independent activation of huPMNs by M-860. (a) No effect of MDC on M-860-induced IL-8 production by PMNs. Cells were preincubated at 37°C with or without phagocytosis inhibitor MDC (25 μM) for 30 mins before the addition of PMA, M-860, or mIgG1. Three hours later, levels of IL-8 were measured by ELISA. (b and c) MDC significantly inhibits the uptake of FITC-labeled M-860 by huPMNs. After the pretreatment with/without MDC (25 μM) for 30 mins, FITC-coupled M-860 was added and cells were cultured for 1 hr further. Cells were fixed, stained with APC-coupled anti-CD11b (shown in red color, to visualized the cell membrane) before analysis by confocal microscopy. The percent of cells with intracellular FITC signal was quantified. Results were expressed as mean ± SEM of triplicates and represented at least two independent experiments.

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