rhMIF up-regulates VCAM-1 and ICAM-1 expression on human PB MNs by cell-surface ELISA. (A) MNs (1 × 106 cells/well) were incubated in 96-well plates in RPMI with 5% FBS for 2 hours at 37°C. Medium was switched to serum free for 6 to 8 hours to achieve quiescence. MNs were stimulated with rhMIF (50 nM), and cell-surface ELISAs were performed. rhMIF induced a time-dependent increase in MN VCAM-1 expression. rhMIF-induced VCAM-1 expression became significantly higher at 4 hours, and it decreased to the basal level after 24 hours (*P < .05). TNF-α served as a positive control. Fold change in VCAM-1 expression compared with PBS is shown. (B) rhMIF induced expression of ICAM-1 in a time-dependent manner. rhMIF increased ICAM-1 expression at 4 hours, and the maximum response was between 8 and 12 hours. ICAM-1 expression in MNs remained significantly higher even after 24 hours compared with PBS (*P < .05). Panel B shows fold increase in ICAM-1 up-regulation compared with PBS. Data represent the mean of 4 individual experiments (n) ± SEM. *P < .05 was considered significant.
