Figure 7

IL-1β and TNF-α are expressed by macrophages and microglia. (A) Infiltrating GFP⁺ cells consist of Gr1⁺ granulocytes and Gr1^- macrophages. (B) Double immunofluorescence for Gr1⁺ granulocytes and either IL-1β or TNF-α showed no detectable co-expression 24 hours after pMCAO. Immunofluorescence detection of GFP and IL-1β (C) or TNF-α (D) showed that these cytokines are expressed by resident GFP^- microglia and infiltrating GFP⁺ macrophages (E) Immunofluorescence double staining confirmed the flow cytometry results by showing that IL-1β and TNF-α are expressed by largely segregated subpopulations of cells. Very few IL-1β⁺TNF-α⁺ co-expressing cells were identified during microscopic analysis (E). Gr1⁺ granulocytes were visualized using Alexa Fluor^® 594-conjugated goat anti-rat IgG, and IL-1β⁺ and TNF-α⁺ cells using both Alexa Fluor^® 488-conjugated goat anti-rabbit and chicken anti-rabbit IgG. Scale bars: 50 μm (A) 20 μm (insert, A), 20 μm (B-E).