目前发现“肺胱硫醚-γ-裂解酶(CSE)/内源性H2S系统”在哮喘中起到保护作用。哮喘的发生呈年龄相关性，生命早期发病率高，随着年龄增长减退或消失，这与纠正失衡的Th2免疫相关，而IL-4在Th2分化中起重要作用。“CSE/内源性H2S系统”是否参与生命早期哮喘的发生发展，却不为人知。我们预实验发现肺CSE及内源性H2S呈年龄依赖性增加；成年期WT小鼠其哮喘程度和IL-4水平低于生命早期，提示存在“年龄增长的哮喘保护作用”。由此，我们推测“CSE/内源性H2S系统通过影响Th2分化，进而参与哮喘的发生发展”。为证实此假设，本研究利用不同年龄阶段WT和CSE-KO小鼠，外源性给予H2S及一系列体内外实验，观察“CSE/内源性H2S系统”与不同年龄段Th2细胞分化的关系及对哮喘的影响。旨在探讨“内源性H2S与哮喘发生发展之间的关系”，为哮喘早期干预提供新靶点。

Current studies have shown that “cystathionine gamma-lyase(CSE)/endogenous H2S pathway” plays a protective role in the pathogenesis of asthma. Asthma displays an age-dependent feature with a high prevelence in the early life stage, while it becomes weak or disappeared with growth. In addition, the IL-4 cytokine plays a critical role in the development and differentiation of Th2 cells. However, whether and how the CSE/endogenous H2S pathway involves in the development of asthma remain unknown. Our preliminary experiments have shown the expressions of CSE and endogenous H2S production rate displayed an age-dependent increase. The degree of asthma and the IL-4 level in BALF challenged at 16 week in WT mice was sevious than that challenged at 8 week. According to these results, we hypothesized that “the CSE/endogenous H2S pathway may involve in the development of asthma via influencing the differentiation of Th2”. To confirm the hypothesis, we will observe the effects of “the CSE/endogenous H2S pathway” on the differentiation of Th2 cells and the development of asthma by using wild type (WT) and CSE knock out (CSE-KO) mice with different age, and exogenous H2S application or performing a series of in vivo and in vitro experiments. The objective of this study is to clarify the relationship of CSE/endogenous H2S pathway and the development of asthma and provide a new therapeutic target for early asthma.