Fig. 5.

ICAM-1 mediates adhesion of U937 cells to SSc dermal fibroblasts. Adhesion assays were performed using U937 cells and SSc dermal fibroblasts in the presence of neutralizing antibodies against ICAM-1 (A), CD99 (B), JAM-B (C) and JAM-C (D). The percent of maximal binding was defined as the number of cells adhering to the fibroblasts in the presence of the test antibody divided by the number of adherent cells on the control-treated fibroblasts. U937 cell adhesion to SSc dermal fibroblasts was significantly inhibited by a neutralizing antibody against ICAM-1 (92% of maximal binding). Means ± SEM are shown. n = the number of SSc patient-derived fibroblast lines. P< 0.05 was considered significant.