Effect of anti-CD9 in TC-EC intercellular interactions.

(A) BCECF-labeled A375 cells were allowed to adhere to EC-coated plates for 5 minutes in the presence of the indicated purified mAb (10 μg/mL). Adhesion data represent the mean ± SD of triplicate samples from 1 of 4 independent experiments. *Statistically significant at P < .05 compared with control mAb X63 and with anti-CD81. (B) BCECF-labeled A375 cells (green) and SNARF-labeled ECs (red) were mixed in the presence of anti-CD9 VJ1/10 or anti-HLA class I W6/32 mAb and allowed to aggregate for 30 minutes, under rotation, as described in “Materials and methods.” Cell aggregation was quantified by flow cytometry and fluorescence microscopy. (C) One representative aggregate is shown. ECs are marked with asterisks (originally labeled in red fluorescence).