Fig. 1

Astrocytes contain MHCII + LDs and interact with CD4 + T cells in the human brain. IHC demonstrate that astrocytes are in close contact with CD4 + T cells in the human brain (a). A proportion of the GFAP + astrocytes have a very high PLIN3 + LD load, both in cortex (b) and hippocampus (c). Quantification of PLIN3 + LDs in astrocytes revealed a significant decrease in AD brains, compared to control brains (d). T cells are in direct contact with astrocytes containing PLIN3 + LDs (stars) (e). The total number of PLIN3 + LDs is also significantly lower in AD brains, compared to control brains (f). For the statistical analysis of (d) and (f) the N number is 10 ctrl and 10 AD patients and was shown as violin plots with median and interquartile ranges. The level of significance for all the graphs is: * = P < 0.05, ** = P < 0.01, and *** = P < 0.001. MHCII + astrocytes are in direct contact with CD4 + T cells (g). PLIN3 + LDs are present in MHCII + astrocytes in cortex (h) and in hippocampus (i). Higher magnification confirmed co-localization of PLIN3 + LDs and MHCII (white arrows, i’-i”). PLA of PLIN3 and MHCII showed positive puncta, verifying direct contact between the proteins in the human brain (j). Scale bar (a,c,e, g,i): 5 μm; (b):10 μm; (h, j): 20 μm; (i’,i”): 1 μm