Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
Eur J Immunol. 2011 Jun;41(6):1531-4. doi: 10.1002/eji.201141670. Epub 2011 May 24.
Macrophages are ubiquitous phagocytes that can constitute up to 15% of the cellular content of tissues. These heterogeneous cells of the innate immune system perform important functions during health and disease. Equipped with receptors for the T helper cell cytokines INF-γ and IL-4, macrophages undergo specific activation programs during Th1 or Th2 immune responses. These activation profiles, termed classical (M1) or alternative (M2) activation respectively, are further tuned by the presence and recognition of microbial-associated molecular patterns, other cytokines, lipids, and even adhesion to the substratum. The activation of macrophages also relies on the maturation background of the cells, elicitation of complicated intracellular signalling cascades, and the crosstalk between the different signalling elements. Of interest, not all genes participating in the activation-related signalling cascades are equally important for the elicitation of functional profiles and a regulator gene hierarchy is emerging for the different types of activation. In this issue of the European Journal of Immunology, two papers add to our understanding of how cellular kinases and phosphatases, related to the PI3K pathway, regulate M1 or M2 activation programmes in macrophages.
巨噬细胞是无处不在的吞噬细胞，可占组织细胞含量的 15%。作为先天免疫系统的异质性细胞，巨噬细胞在健康和疾病中发挥着重要作用。巨噬细胞上表达的 T 辅助细胞细胞因子 INF-γ和 IL-4 的受体，使其在 Th1 或 Th2 免疫反应中经历特定的激活程序。这些激活状态分别被称为经典（M1）或替代（M2）激活，其进一步受到微生物相关分子模式、其他细胞因子、脂质，甚至与基底的黏附的存在和识别的影响。巨噬细胞的激活还依赖于细胞的成熟背景、复杂的细胞内信号级联的诱导以及不同信号元件之间的串扰。值得注意的是，并非所有参与激活相关信号级联的基因对于功能谱的诱导都同样重要，并且正在出现不同类型激活的调节基因层次结构。在本期《欧洲免疫学杂志》中，两篇论文增加了我们对细胞激酶和磷酸酶（与 PI3K 途径相关）如何调节巨噬细胞的 M1 或 M2 激活程序的理解。
