Distinct Epitopes on CD13 Mediate Opposite Consequences for Cell Adhesion

Figure 8

Effect of anti-CD13 monoclonal antibodies on heterotypic aggregation of human monocytes to HMEC-1 endothelial cells. (a) CFSE-labeled U-937 cells were incubated with anti-CD13 monoclonal antibodies 452, C, or E for 3 hrs at 37°C. After washing, stimulated monocytes were transferred to monolayers of HMEC-1 cells in 48-well plates and incubated for 15 min at 37°C. Cells were gently washed with warm media and adhered monocytes were quantified with the plate fluorimeter Modulus II. (b) CFSE-labeled monocytes were incubated with different concentrations of anti-CD13 C or E, or with no antibody, for 1 hr at 37°C, and, after washing, mAb 452 (at 3 µg/ml) was added and incubation continued for 3 hours. After washing, stimulated monocytes were transferred to monolayers of HMEC-1 cells in 48-well plates and incubated for 15 min at 37°C. Plates were gently washed with warm media and adhered monocytes were quantified with the plate fluorimeter Modulus II. Data is presented as percentage of antibodies-treated cells attached to HMEC-1 monolayers, compared to the attachment of cells not treated with mAbs. Mean ± SD of three independent experiments. , , and .

(a)

(b)