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

T-helper (Th)17 cell responses are important for the development of neutrophilic inflammatory disease. Recently, we found that acetyl salicylic acid (ASA) inhibited Th17 airway inflammation in an asthma mouse model induced by sensitization with lipopolysaccharide (LPS)-containing allergens. To investigate the mechanism(s) of the inhibitory effect of ASA on the development of Th17 airway inflammation, a neutrophilic asthma mouse model was generated by intranasal sensitization with LPS plus ovalbumin (OVA) and then challenged with OVA alone. Immunologic parameters and airway inflammation were evaluated 6 and 48 h after the last OVA challenge. ASA inhibited the production of interleukin (IL)-17 from lung T cells as well as in vitro Th17 polarization induced by IL-6. Additionally, ASA, but not salicylic acid, suppressed Th17 airway inflammation, which was associated with decreased expression of acetyl-STAT3 (downstream signaling of IL-6) in the lung. Moreover, the production of IL-6 from inflammatory cells, induced by IL-17, was abolished by treatment with ASA, whereas that induced by LPS was not. Altogether, ASA, likely via its acetyl moiety, inhibits Th17 airway inflammation by blockade of IL-6 and IL-17 positive feedback.
Animals ; Aspirin/pharmacology/*therapeutic use ; Cell Polarity/drug effects/immunology ; Feedback, Physiological/*drug effects ; Interferon-gamma/deficiency/metabolism ; Interleukin-17/*metabolism/pharmacology ; Interleukin-6/biosynthesis/*metabolism ; Lipopolysaccharides/pharmacology ; Lung/drug effects/metabolism/pathology ; Mice ; Mice, Inbred C57BL ; Pneumonia/*drug therapy/*immunology/pathology ; Th17 Cells/drug effects/*immunology/pathology ; Transforming Growth Factor beta1/pharmacology

OBJECTIVETo explore the effect of Astragalus membranaceus (AM) on T-helper cell type 1 (Thl) specific transcription factor T-box expressed in T cells (T-bet) expression and Thl/Th2 equilibrium.

METHODSThe levels of T-bet mRNA in peripheral blood mononuclear cells (PBMCs) from 15 patients with asthma and 15 healthy subjects were determined by reverse transcription-polymerase chain reaction (RT-PCR). PBMCs in asthma patients were incubated with AM and then the concentration of interferon gamma (IFN-gamma) and interleukin-4 (IL-4) in the supernate before and after AM intervention were determined by ELISA. The numbers of CD4 + CCR3 + and CD4 + CCR5 + cells were counted by flow cytometry.

RESULTSThe expression of T-bet mRNA and the level of IFN-gamma were lower, but level of serum IL-4 was higher in asthma patients when compared with those in healthy subjects respectively. After AM (60 microg/ml) intervention, the former two parameters raised and showed a positive correlation between them, while the level of IL-4 was decreased. The mean percentage of CD4 + CCR3 + cells in asthma patients was significantly higher but that of CD4 + CCR5 + cells was lower when compared with those in healthy subjects respectively. After AM intervention, the abnormal change in the two indexes was improved to certain extent, showing a reversing status of Th2 polarization.

CONCLUSIONAM could increase the expression of T-bet mRNA and Thl cytokines such as IFN-Y, and might reverse the Th2 predominant status in asthma patients.

Adult ; Asthma ; drug therapy ; immunology ; Astragalus membranaceus ; Cell Polarity ; Cross-Sectional Studies ; Female ; Humans ; Interferon-gamma ; biosynthesis ; blood ; Interleukin-4 ; blood ; Male ; Middle Aged ; Phytotherapy ; RNA, Messenger ; analysis ; Receptors, CCR3 ; Receptors, CCR5 ; blood ; Receptors, Chemokine ; blood ; T-Box Domain Proteins ; genetics ; Th1 Cells ; drug effects ; immunology ; Up-Regulation