Figure 4
Imaging protease activity in vivo . PLP139-151-immunized mice were injected intravenously with various protease-activatable NIR fluorescence imaging agents [CB680 for cathepsin B activity; PS750 for pan-cathepsin activity (Cat B, L, S, K, V); MMP750 for pan-matrix metalloprotease activity (MMPs 2, 7, 9, 12, 13 and others); and RS680 for renin activity] upon achieving a clinical score of 2 or 3 and imaged by FMT 4000 using tomographic scanning capabilities. CFA control mice were injected 14 days following immunization. (A) Quantification of in vivo tomographic fluorescence data sets. (B) Quantification of epifluorescence signal from excised brains and spinal cords. Symbols indicate statistical significance (#p < 0.05, **p < 0.005). Fold change compared to CFA controls is indicated in parentheses for the in vivo imaged mice. (C) Low and high power magnifications of cathepsin B expressing macrophages/microglia in a frozen section of an inflammatory lesion in the dorsal sacral spinal cord of a perfused EAE mouse injected with CB680 24 h previously. Green (anti-F4/80); red (CB680); blue (DAPI).