Figure 1. Integrin α₃β₁ mediates the U937 macrophage response to Pam₃CSK₄.

A) U937 macrophages stably transduced with integrin α₃-specific shRNA (Itgα3 shRNA) or non-targeting shRNA (Ctrl. shRNA) were stimulated with 100 ng/ml Pam₃CSK₄ for 6 hours under serum-free conditions. Values represent mean secretion of IL-6 relative to control shRNA and S.E.M.of three independent experiments. Cells transduced with control shRNA secreted a mean of 350 pg/ml, and cells transduced with integrin α₃-targeting shRNA secreted a mean of 61 pg/ml. * p = 0.014 B) U937 macrophages were treated with an integrin α₃β₁ blocking antibody (P1B5) or a control mouse ascites fluid (CMA) and stimulated with 100 ng/ml Pam₃CSK₄ for 6 hours under serum-free conditions. Values represent mean secretion of IL-6 relative to CMA-treated cells and S.E.M.of three independent experiments. CMA-treated cells secreted a mean of 1,068 pg/ml, and P1B5-treated cells secreted a mean of 607 pg/ml. * p = 0.014.