CD4+ Th cells are responsible for orchestrating diverse, pathogen-specific immune responses through their differentiation into a number of subsets, including TH1, TH2, TH9, T follicular helper, T follicular regulatory, and regulatory T cells. The differentiation of each subset is guided by distinct regulatory requirements, including those derived from extracellular cytokine signals. IL-2 has emerged as a critical immunomodulatory cytokine that both positively and negatively affects the differentiation of individual Th cell subsets. IL-2 signals are propagated, in part, via activation of STAT5, which functions as a key regulator of CD4+ T cell gene programs. In this review, we discuss current understanding of the mechanisms that allow IL-2–STAT5 signaling to exert divergent effects across CD4+ T cell subsets and highlight specific roles for this pathway in the regulation of individual Th cell differentiation programs.

中文翻译：

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IL-2-STAT5 信号在效应和调节性 CD4+ T 细胞群中的动态作用

CD4+ Th 细胞通过分化为多个亚群，包括 TH1、TH2、TH9、T 滤泡辅助细胞、T 滤泡调节性 T 细胞和调节性 T 细胞，负责协调多种病原体特异性免疫反应。每个亚群的分化由不同的监管要求指导，包括那些来自细胞外细胞因子信号的要求。IL-2 已成为一种关键的免疫调节细胞因子，它对单个 Th 细胞亚群的分化产生积极和消极的影响。IL-2 信号部分地通过激活 STAT5 来传播，STAT5 是 CD4+ T 细胞基因程序的关键调节因子。在这次审查中，