Table II.

Effects of fixation on anti-CXCR4 mAb binding to BCD-treated cells

mAbControlBCDc
NonfixedFixedbNonfixedFixedb
MFI (% pos)aMFI (% pos)MFI (% pos)% ChangedMFI (% pos)% Change
Mouse IgG15.05 (1.91)5.14 (1.96)20.0 (1.87)26.1 (1.88)
12G5458.7 (99.9)433.0 (99.3)206.3 (96.9)−55.0624.7 (99.1)36.2
44708e407.0 (99.9)370.8 (99.9)197.9 (98.4)−51.4627.5 (98.5)54.2
44716e516.3 (99.9)430.3 (99.7)273.7 (99.1)−47.0617.8 (98.7)19.7
44717e650.0 (99.9)620.4 (99.9)399.5 (99.4)−38.5556.4 (97.5)−14.4
  • a Percent positive for each column was determined as percentage of cells >98% of the mIgG1 control.

  • b Immediately following BCD treatment and washes, cells were fixed with 1% paraformaldehyde in PBS. mAb binding was subsequently detected as described in Materials and Methods.

  • c Cells were treated with 20 mM BCD as described in Materials and Methods.

  • d Calculated as the percent change in MFI between the BCD-treated cells (fixed or nonfixed) and the control, nonfixed cells.

  • e Specific target epitopes have not been defined for these anti-CXCR4 mAbs. They do inhibit SDF-1-mediated chemotaxis at 50% neutralization dose between 5 and 20 μg/ml (provided by manufacturer).