Cross-inhibition of U937 homotypic aggregation between CD98 and CD29 antibodies.

Aggregation was measured under standard conditions in the presence of CD98-AHN-18 (1.5 μg/mL, left panels), MEM 101A (CD29, 0.3 μg/mL, middle panels), or 161-46 (CD43, 0.3 μg/mL, right panels). Blocking antibodies were added to U937 cultures 1 hour prior to the aggregating antibodies. The blocking antibodies used were to CD98 (A-C) or to CD29 (D-F). Results are expressed as the percentage of aggregation relative to the aggregation in the absence of blocking antibody (column labeled 0 in each panel). Means that differ significantly from control (absence of inhibitory antibody, P < .05) are shown with an asterisk. Antibodies were tested at a series of dilutions, starting with the most dilute and increasing in 2-fold steps along the x-axis. To obtain the actual concentration of antibody at each point (in μg/mL), the x-axis value should be multiplied by 0.6 for BU89 (CD98, □), 0.3 for MEM 108 (CD98, ■), 1.25 for P5D2 (CD29, □), and 0.5 for MAR4 (CD29, ■).