Fig. 2.

IL-19 reduces leukocyte-endothelial interactions in vivo. Wild-type C57BL/6 mice were injected a single time with 10.0 ng/g ip IL-19 for 16 h before a single injection with 20.0 ng/g ip TNF-α. A and B: after 4 h, leukocyte rolling (A) and adhesion (B) were quantitated by intravital microscopy. IL-19 treatment significantly reduces leukocyte rolling and adhesion. *P < 0.05; n = 5 mice/group. C and D: IL-19 reduces expression of E-selectin mRNA (C) and protein (D) in cultured ECs. Blot shown is representative of at least 3 experiments. *P < 0.05. E: antibody neutralization of the IL-20 receptor negates the inhibitory effect of IL-19 on THP-1 monocyte adhesion. Anti-IL-20Rα or negative control antibody was added to ECs 2 h before addition of IL-19. F: results represent means ± SE. *P < 0.05 for five high-power fields from triplicate experiments. All samples were pretreated with IL-19 for different times. S, ECs treated with IL-19 at the same time as TNF-α.