Figure 2.

PF‐06650833 inhibits rheumatoid arthritis (RA) pathophysiology. A, Human macrophages were exposed to anti–citrullinated protein antibody (ACPA) immune complexes (ICs) formed with cyclic citrullinated peptide–positive RA sera in the presence or absence of 100 nM interleukin‐1–associated kinase 4 inhibitor (IRAK4i) (PF‐06650833) or 100 nM Bruton’s tyrosine kinase inhibitor (BTKi) (PF‐303). Supernatants were analyzed by enzyme‐linked immunosorbent assay for induction of tumor necrosis factor (TNF). Values are the percent in relation to DMSO treatment (set at 100). Symbols represent individual subjects (n = 11 per group); bars show the mean. B, Human RA fibroblast‐like synoviocytes were stimulated with 10 μg/ml Pam₃Cys (Toll‐like receptor 1/2 [TLR‐1/2]), 10 ng/ml lipopolysaccharide (LPS) (TLR‐4), 100 ng/ml flagellin (TLR‐5), or 0.1 ng/ml interleukin‐1β (IL‐1β) in the presence or absence of 100 nM PF‐06650833. Cytokine and matrix metalloproteinase (MMP) content in supernatants was assessed by Meso Scale Discovery assay. Values are the percent of those observed with vehicle control. C, Compounds at the noted concentrations were profiled with DiscoverRx on the BioMAP platform. Data represent the log ratio of values in compound‐treated samples to controls, with negative values indicating inhibition and points outside of the gray shading demonstrating a statistically significant difference based on assay variability. Each point on the x‐axis represents the result of a different end point in each assay system: venular endothelial cells (4H), peripheral blood mononuclear cells (PBMCs) plus venular endothelial cells stimulated with LPS (LPS), PBMCs plus venular endothelial cells stimulated with superantigen (SAg), B cells plus PBMCs (BT), lung fibroblasts (MyoF), and macrophages plus venular endothelial cells (/Mphg). Unstim = unstimulated; MCP‐1 = monocyte chemotactic factor 1; VCAM‐1 = vascular cell adhesin molecule 1; uPAR = urokinase‐type plasminogen activator receptor; SRB = sulforhodamine B staining; VEGFR‐2 = vascular endothelial growth factor receptor 2; M‐CSF = macrophage colony‐stimulating factor; sPGE₂ = soluble prostaglandin E₂; MIG = monokine induced by interferon‐γ; bFGF = basic fibroblast growth factor; PAI‐1 = plasminogen activator inhibitor 1; TIMP‐1 = tissue inhibitor of metalloproteinases 1.