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

Figure 4

M-860 induces the activation of huPMNs. Purified huPMNs were incubated with PMA, M-860, L3262, or corresponding mIgG1/RbIgG control Abs in the presence (a and b)/absence (c) of DHR123 for 1 hr at 37°C before FACS analysis. (a) Representative histograms showing the increased production of ROS induced by LTF-specific Abs. ROS production was measured by the conversion of DHR123 to fluorescent R123. (b) Bar graph showing the mean fluorescence intensity (MFI) of R123 in cells. (c) M-860 upregulates CD11b expression (an activated epitope) on huPMNs. (d) M-860 enhances the phagocytosis activity of huPMNs. Cells were cultured in medium (M), LPS, M-860, or mIgG1 at 37°C for 30 mins before the addition of FITC-labeled zymosan particles. After 1 hr, cells were collected and the percent of PMNs phagocytosed zymosan particles was analyzed by FACS. Results were expressed as mean ± SEM of 9 (b) or 6 (c) different individuals. versus M/mIgG; versus M/RbIgG; versus M; versus M/mIgG; versus M/RbIgG; versus M.

(a)

(b)

(c)

(d)