Figure 4

αCD22 Ab-MXD3 ASO conjugate shows in vivo anti-leukemic effects against engrafted leukemia cells in mice. (A) The αCD22 Ab-MXD3 ASO conjugate treatment showed MXD3 knockdown in the engrafted Reh cells at 8 h after treatment. MXD3 protein expression was measured in the cells harvested from BM. Images were acquired at 40× magnification/1.4 numerical aperture at room temperature using a Nikon Ti-U inverted microscope and NIS-Elements BR software. Scale bar indicates 50 µm. (B) The αCD22 Ab-MXD3 ASO conjugate treatment induced cell apoptosis in the engrafted Reh cells at 8 and 24 h after treatment. Cells were stained for human CD22 and annexin V. Red dots (lower quadrants): murine cells (CD22 negative), purple dots (upper left quadrant): live Reh cells (CD22 positive annexin V negative), and blue dots (upper right quadrant): apoptotic Reh cells (CD22 and annexin V positive) in BM.