IL-19 reduces ICAM-1 and VCAM-1 expression, and IL-19 reduces leukocyte–smooth muscle cell interaction. A: ICAM-1 and VCAM-1 expression is significantly increased in IL-19−/− VSMCs. WT or IL-19−/− VSMCs were serum starved, then stimulated with TNFα for the times indicated. Extracts were blotted with the indicated antibodies, and protein expression was quantitated by densitometry and normalized to GAPDH expression from three experiments. A representative of three Western blot analyses is shown. B: Monocyte adhesion is significantly increased in IL-19−/− VSMCs. VSMCs were grown on glass cover slides and stimulated with TNFα for 16 hours; labeled THP1 monocytes were incubated with the monolayers, and adherent cells were quantitated by counting per HPF. C: Enhanced leukocyte-VSMC adhesion in IL-19−/− VSMCs is reduced by anti-CAM antibody. Anti-ICAM1, VCAM1, or IgG1 antibody (10 mg/mL) was added to VSMC monolayers 1 hour before addition of THP1 cells. D: IL-19 significantly reduces ICAM-1 and VCAM-1 protein abundance in primary human VSMCs. VSMCs were pretreated with IL-19, then stimulated with TNF-α for 24 hours. Western blot analysis was quantitated by densitometry from at least three experiments, ∗P < 0.05 for times indicated, and is representative of at least three experiments. Original magnification, ×200 (B).