Clemastine

The following histamine receptor ligands and stimuli were used in this study: histamine (ALK‐Abello, Madrid, Spain) as agonist for all histamine receptors; 2‐pyridylethylamine (Tocris Bioscience, Bristol, UK) as selective H1 receptor agonist; amthamine (Tocris Bioscience, Bristol, UK) as selective H2 receptor agonist; 4‐methylhistamine as a H2 /H4 receptor agonist; ST‐1006 (Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University, Duesseldorf, Germany) as H4 receptor agonist (Sander et al., 2009); clemastine (Tocris) as selective H1 receptor antagonist; ranitidine (Tocris) as selective H2 receptor antagonist; and JNJ7777120 (Sigma Aldrich, Deisenhofen, Germany) as selective H4 receptor antagonist. All histamine receptor ligands were used at a concentration of 10 μM. In concentration–response experiments, the histamine receptor ligands were used in the range of 0.1 ‐ 100 μM. In extensive previous studies, we have shown that 10 μM is the optimal concentration to demonstrate and reproduce robust H4 receptor agonist mediated effects (Gschwandtner, Koether, Werfel, Stark, & Gutzmer, 2013). C5a (10 ng·ml−1; Sigma, Deisenhofen, Germany); recombinant human rh OSM (1 ng·ml−1) ImmunoTools, Friesoythe, Germany); GM‐CSF (10 ng·ml−1), IFN‐γ (200 ng·ml−1) (R&D, San Diego, CA, USA); LPS (50 ng·ml−1) Sigma Aldrich.