Figure 6

Microglial expression of HLA-DP, DQ, DR is reduced by macrophage colony-stimulating factor (M-CSF). (A) Representative image of basal HLA expression (green) in cultured adult human microglia. HLA expression is highly variable between cases and is expressed by some, but not necessarily all, microglia (PU.1-positive nuclei, red). (B) Following 96 hours exposure to M-CSF, the level of microglial HLA expression was found to be decreased compared to basal levels. (C) Quantification of the effect of M-CSF on HLA expression shows a significant reduction in the number of microglia expressing HLA. P < 0.0001, n = 18. Scale bar = 100 μm.