Fig. 6

Detailed examination of therapeutic impact of optimal F3 dosing on collagen-induced arthritis in mice. Arthritis was induced as described above (n = 10 per group), and 20 mg/kg F3 was injected intraperitoneally once arthritis scores reached ~ 4. Treatments were administered 2×/week (arrows) for a total of 4 doses. a Paw thickness and b arthritis scores were determined every other day. c CT images of paws were obtained, and a representative cross section of the thumb metacarpal bone is shown for each group. d Morphometric bone analyses including bone density, e structure model index, f connectivity density, g trabecular spacing, and h trabecular thickness of medial metacarpals were quantitated as described in the Materials and methods section. i Mice were injected on day 18 with a ^99mTc-folate receptor-targeted imaging agent (EC20; 75 nmol/kg) and imaged 4 h later. Representative images are shown, and quantitation of radioactive intensity in the paws is plotted. j At the end of the study (day 18), sections of joint tissue were H&E stained. Representative images are shown for each treatment group. Black arrows denote immune cell infiltration. k Similar joint tissue sections were stained with desired markers for nuclei (DAPI, blue channel), macrophages (F4/80, red channel), FR-β (F3, green channel), and imaged by fluorescent microscopy. Additional images of different immune cell types can be viewed in SI Figs. BN - BS. l Staining intensity for each immune cell type was quantitated for healthy (black), untreated RA (blue), and F3-treated RA (red) mice. Error bars represent SEM and *, **, and *** denote p values < 0.05, < 0.005, and 0.0005, respectively for all panels