Gratchev Alexei, Kzhyshkowska Julia, Kannookadan Sheila, Ochsenreiter Miriam, Popova Anna, Yu Xiaolei, Mamidi Srinivas, Stonehouse-Usselmann Eugenia, Muller-Molinet Isabelle, Gooi Liming, Goerdt Sergij
Department of Dermatology, Medical Faculty Mannheim, Ruprecht-Karls University of Heidelberg, Mannheim, Germany.
J Immunol. 2008 May 15;180(10):6553-65. doi: 10.4049/jimmunol.180.10.6553.
Alternatively activated (M2) macrophages regulate steady state-, cancer-, and inflammation-related tissue remodeling. They are induced by Th2-cytokines and glucocorticoids (GC). The responsiveness of mature macrophages to TGF-beta, a cytokine involved in inflammation, cancer, and atherosclerosis, is currently controversial. Recently, we demonstrated that IL-17 receptor B is up-regulated in human monocyte-derived macrophages differentiated in the presence of Th2 cytokines IL-4 and TGF-beta1. In this study, we show that mature human macrophages differentiated in the presence of IL-4, and dexamethasone (M2(IL-4/GC)) but not M2(IL-4) responds to TGF-beta1 which induced a gene expression program comprising 111 genes including transcriptional/signaling regulators (ID3 and RGS1), immune modulators (ALOX5AP and IL-17 receptor B) and atherosclerosis-related genes (ALOX5AP, ORL1, APOC1, APOC2, and APOE). Analysis of molecular mechanism underlying GC/TGF-beta cooperation revealed that surface expression of TGF-betaRII was high in M2(GC) and M2(IL-4/GC), but absent from M2(IL-4), whereas the expression of TGF-betaRI/II mRNA, TGF-betaRII total protein, and surface expression of TGF-betaRIII were unchanged. GC dexamethasone was essential for increased surface expression of functional TGF-betaRII because its effect was observed also in combination with IL-13, M-CSF, and GM-CSF. Prolonged Smad2-mediated signaling observed in TGF-beta1-treated M2(IL-4/GC) was due to insufficient activity of negative feedback mechanism what can be explained by up-regulation of SIRT1, a negative regulator of Smad7, and the retention of TGF-betaRII complex on the cell surface. In summary, mature human M2 macrophages made permissive to TGF-beta by GC-induced surface expression of TGF-betaRII activate in response to TGF-beta1, a multistep gene expression program featuring traits of macrophages found within an atherosclerotic lesion.
替代性活化（M2）巨噬细胞调节与稳态、癌症和炎症相关的组织重塑。它们由Th2细胞因子和糖皮质激素（GC）诱导产生。成熟巨噬细胞对转化生长因子-β（TGF-β）的反应性目前存在争议，TGF-β是一种参与炎症、癌症和动脉粥样硬化的细胞因子。最近，我们证明白细胞介素-17受体B在存在Th2细胞因子白细胞介素-4和TGF-β1的情况下分化的人单核细胞衍生巨噬细胞中上调。在本研究中，我们表明在白细胞介素-4和地塞米松（M2(IL-4/GC)）存在下分化的成熟人巨噬细胞对TGF-β1有反应，但M2(IL-4)则无反应，TGF-β1诱导了一个包含111个基因的基因表达程序，这些基因包括转录/信号调节因子（ID3和RGS1）、免疫调节因子（ALOX5AP和白细胞介素-17受体B）以及动脉粥样硬化相关基因（ALOX5AP、ORL1、APOC1、APOC2和APOE）。对GC/TGF-β协同作用潜在分子机制的分析表明，TGF-βRII的表面表达在M2(GC)和M2(IL-4/GC)中较高，但在M2(IL-4)中不存在，而TGF-βRI/II mRNA、TGF-βRII总蛋白以及TGF-βRIII的表面表达没有变化。GC地塞米松对于功能性TGF-βRII表面表达的增加至关重要，因为在与白细胞介素-13、巨噬细胞集落刺激因子（M-CSF）和粒细胞-巨噬细胞集落刺激因子（GM-CSF）联合使用时也观察到了其作用。在TGF-β1处理的M2(IL-4/GC)中观察到的Smad2介导的信号延长是由于负反馈机制活性不足，这可以通过Smad7的负调节因子沉默信息调节因子1（SIRT1）的上调以及TGF-βRII复合物在细胞表面的保留来解释。总之，成熟的人M2巨噬细胞通过GC诱导的TGF-βRII表面表达而对TGF-β产生反应，从而激活响应TGF-β1的多步骤基因表达程序，该程序具有动脉粥样硬化病变中发现的巨噬细胞特征。
