Human Anti-FLT3 Recombinant Antibody (clone D4-3) (CAT#: HPAB-0182CQ)

Figure 1 EB10, D4-3, and A2IN bind to recombinant FLT3-Fc protein and FLT3 expressed on leukemia cells.

All the three anti-FLT3 IgG also bound to surface-expressed wild-type receptor in EOL-1 and EM3 cells, as well as receptor with ITD mutations in BaF3/FLT3-ITD and MV4-11 cells, as analyzed by FACS.

Williams, B., Atkins, A., Zhang, H., Lu, D., Jimenez, X., Li, H.,... & Li, Y. (2005). Cell-based selection of internalizing fully human antagonistic antibodies directed against FLT3 for suppression of leukemia cell growth. Leukemia, 19(8), 1432.

Figure 2 The ability of purified Fab fragments and full-length IgG to competitively block FLT3/FL interaction was tested in an ELISA.

EB10, D4-3, and A2IN block FLT3/FL interaction. Serial dilutions of EB10, A2IN, or D4-3 Fab fragments (a) or IgG (b) were mixed with a fixed amount of FLT3-Fc and incubated at RT for 1 h. The mixtures were transferred to an FL-coated plate and incubated for 1 h.

Williams, B., Atkins, A., Zhang, H., Lu, D., Jimenez, X., Li, H.,... & Li, Y. (2005). Cell-based selection of internalizing fully human antagonistic antibodies directed against FLT3 for suppression of leukemia cell growth. Leukemia, 19(8), 1432.

Figure 3 Anti-FLT3 antibodies inhibit FL-induced phosphorylation of FLT3 in leukemia cells.

Treatment with FL results in strong FLT3 receptor phosphorylation in EOL-1 cells, which was significantly (85–90%) inhibited by D4-3 and EB10.

Williams, B., Atkins, A., Zhang, H., Lu, D., Jimenez, X., Li, H.,... & Li, Y. (2005). Cell-based selection of internalizing fully human antagonistic antibodies directed against FLT3 for suppression of leukemia cell growth. Leukemia, 19(8), 1432.

Figure 4 Inhibition of FL-stimulated proliferation of EOL-1 cells by the anti-FLT3 antibodies.

Cells were cultured in AIM-V medium for 68 h, with varying concentrations of antibodies (from 0 to 400 nM) in the presence of exogenous FL (30 ng/ml). In a background control, EOL-1cells were incubated with medium alone in the absence of exogenous FL. Cells were pulsed for 4 h with 3H-thymidine, harvested, and cpm measured by a beta scintillation counter. The percent of FL-induced EOL-1 cell growth inhibition was calculated using the following formula: [1-(cpm of antibody-treated sample−cpm of background sample)/(cpm of FL-only treated sample−cpm of background sample)]100%. Data shown are the mean±s.d. of triplicate determinations.

Williams, B., Atkins, A., Zhang, H., Lu, D., Jimenez, X., Li, H.,... & Li, Y. (2005). Cell-based selection of internalizing fully human antagonistic antibodies directed against FLT3 for suppression of leukemia cell growth. Leukemia, 19(8), 1432.