Figure 3

BM-derived GFP⁺ single cells and vessel-associated cells express CD11b. Fluorescence microscopy for GFP combined with immunofluorescence detection of (A) CD11b, (B) vWF and (C) CD31, 24 hours after pMCAO. (A) Fluorescence detection of GFP and CD11b showed that most GFP⁺ cells co-expressed CD11b (yellow cells, indicated by arrows), and intermingled with CD11b⁺ host cells. Note also that a few GFP⁺ cells did not co-express CD11b (arrow head). Insert shows high magnification of GFP⁺ cells, some of which co-express CD11b, aggregated around a vessel. (B, C) Fluorescence detection of GFP and the endothelial cell markers vWF (B) and CD31 (C). Inserts show higher magnification of sections of the same vessels. Although there are indications that single vWF⁺ cells co-express GFP (arrows in B), this could not be reproduced using staining for CD31, and the majority of vWF⁺ and CD31⁺ cells showed no co-expression of GFP. Instead, GFP remained confined to round and elongated cells located in the juxtavascular space (insert in C). CD11b⁺ cells were visualized using Alexa Fluor^® 568-conjugated goat anti-rat IgG, vWF⁺ and CD31⁺ cells using Alexa Fluor^® 546-conjugated goat anti-rabbit IgG and Alexa Fluor^® 594-conjugated goat anti-rat IgG, respectively. Scale bars: 20 μm (A-C).