MAFB controls the acquisition of the anti-inflammatory transcriptional profile of M-MØ.. Homo sapiens

Macrophage phenotypic and functional heterogeneity derives from tissue-specific transcriptional signatures shaped by the local microenvironment. Most studies addressing the molecular basis for macrophage heterogeneity have focused on murine cells, while the factors controlling the functional specialization of human macrophages are less known. M-CSF drives the generation of human monocyte-derived macrophages with a potent anti-inflammatory activity upon stimulation. We now report that knock-down of MAFB impairs the acquisition of the anti-inflammatory profile of human macrophages, identify the MAFB-dependent gene signature in human macrophages and illustrate the co-expression of MAFB and MAFB-target genes in CD163+ tissue-resident and tumor associated macrophages. The contribution of MAFB to the homeostatic/anti-inflammatory macrophage profile is further supported by the skewed polarization of monocyte-derived macrophages from Multicentric Carpo Tarsal Osteolysis (OMIM#166300), a pathology caused by mutations in the MAFB gene. Our results demonstrate that MAFB critically determines the acquisition of the anti-inflammatory transcriptional and functional profiles of human macrophages. Overall design: Macrophages were differentiated from peripheral blood monocytes from 3 healthy donors with M-CSF (M-MØ) to generate anti-inflammatory M-MØ. Macrophages were transfected with either Control or MAFB-specific siRNA for 24h and global gene expression was analysed.