Binding of 1-11E/vIL-10 to arthritic cartilage. (A) Sections of cartilage from mouse model of antigen-induced arthritis (AIA), collagen-induced arthritis (CIA), and surgical destabilization of the medial meniscus (DMM) were incubated with Cy5.5 tagged 1-11E/vIL-10 (left panels) or C7/vIL10 (right panels). Binding to cartilage was diffused in all zones, although AIA staining was mostly in the superficial zone. No staining with C7/vIL10 was seen. Pericellular matrix of the chondrocytes is shown in green (AlexaFluor-488-labeled secondary) and the fusion protein (Cy5.5) in red. (B) Staining of human OA cartilage with 1-11E/vIL-10. Binding of the fusion protein was detected with mouse anti-vIL10, followed by anti-mouse-HRP. Binding was strong in the damaged area and as a territorial “halo” around the chondrocyte. Low background staining with C7/vIL-10 was seen.