Development of alternatively activated (M2) macrophage phenotypes is a complex process that is coordinately regulated by a plethora of pathways and factors. Here, we report that RBP-J, a DNA-binding protein that integrates signals from multiple pathways including the Notch pathway, is critically involved in polarization of M2 macrophages. Mice deficient in RBP-J in the myeloid compartment exhibited impaired M2 phenotypes in vivo in a chitin-induced model of M2 polarization. Consistent with the in vivo findings, M2 polarization was partially compromised in vitro in Rbpj-deficient macrophages as demonstrated by reduced expression of a subset of M2 effector molecules including arginase 1. Functionally, myeloid Rbpj deficiency impaired M2 effector functions including recruitment of eosinophils and suppression of T cell proliferation. Collectively, we have identified RBP-J as an essential regulator of differentiation and function of alternatively activated macrophages.
Animals ; Cell Polarity ; drug effects ; genetics ; immunology ; Cell Proliferation ; drug effects ; genetics ; Chitin ; immunology ; pharmacology ; Eosinophils ; cytology ; immunology ; Gene Expression Regulation ; drug effects ; immunology ; Immunoglobulin J Recombination Signal Sequence-Binding Protein ; genetics ; immunology ; Macrophage Activation ; drug effects ; genetics ; Macrophages ; cytology ; immunology ; Mice ; Mice, Transgenic ; T-Lymphocytes ; cytology ; immunology