Figure 4: Effects of MWCNTs treatment on cultured macrophages. Cells extracted from MG after 1 week from injection and treated for 24 h with increasing concentration of MWCNTs (2.5, 5, 10, 25, 50 and 100 μg/ml) are CD45+ (red in A-F), Hm AIF-1+ (red in G-L) and show an increasing positivity for Thioflavin-S staining (yellow in M-R). Combined fluorescence/transmission (S, T) and TEM images clearly show the amyloid fibril deposition (yellow in S, T) and organized fibrillar material (arrowhead in U) by CD45+/Hm AIF-1+ macrophages (V-W) strictly associated with MWCNTs aggregates. Nuclei in blue are stained with DAPI. No signal is detected in negative control experiments (X). Bars in A-T, V-X: 10 μm; bar in U: 500 nm