中文摘要：

巨噬细胞广泛分布于机体组织,在防御应答和维持组织平衡中发挥重要作用。因受不同环境因子作用,巨噬细胞可分化成为表型和功能不同的类型。广义上,巨噬细胞可分为经典活化型（M1细胞）和替代活化型（M2细胞）。前者主要发挥抗感染作用,促进Th1型细胞应答;后者在组织修复和促肿瘤发生中有重要作用。巨噬细胞的极化是细胞针对不同环境因子产生的一种应答机制,是胞内众多分子事件和信号通路参与调控的结果。了解其机制对于认识相关生理和病理现象具有重要意义。

英文摘要：

Macrophages are widely distributed immune ceils that play an indispensable role in homeostasis and defense. They can be phenotypically polarized by the microenvironment to mount specific functional programs. Polarized macrophages can be broadly classified in two main groups： classically activated macrophages （or M1 ）, and alternatively activated macmphages （or M2 ）. M1 exhibits anti-infection properties and promotes Thl responses,whilst M2 is essential in tissue repair and tumorigenesis. Polarization of macrophage appears to be cellular activity in response to the diverse environmental stimuli, regulated by an array of intracellular molecular events and signaling pathways. Defining the underlying mechanisms is believed to shed more light on the related physiological and pathophysiological phenomenon.