瘦素对细胞免疫的影响

目的探讨高瘦素水平在不同免疫状态下对免疫系统的影响。方法选用8周龄的清洁级BALB／c雄性小鼠40只，采用抽签法随机分为5组，分别注射外源性鼠瘦素和阻断瘦素抗体人为造成小鼠的不同瘦素水平状态，分别注射环孢素A（CsA）将小鼠分为正常免疫状态和免疫抑制状态两类，并设立相应的对照组。利用TUNEL技术，经流式细胞仪检测胸腺细胞中CD4^＋、CD8^＋细胞的凋亡情况。结果胸腺CD4^＋、CD8^＋细胞的凋亡结果一致。正常免疫状态下，注射瘦素组细胞凋亡率与其对照组的差异无显著性，注射瘦素抗体组细胞凋亡率较其对照组增高；免疫抑制状态下，注射瘦素组细胞凋亡率低于其对照组。结论瘦素可起正向免疫调节作用，减少胸腺细胞的凋亡，缺乏瘦素可增加胸腺CD4^＋、CD8^＋细胞凋亡。正常免疫状态下，瘦素水平升高不能显示其对免疫系统的调节作用；免疫抑制状态下，这种调节作用得以体现。该现象的存在为长期存活肾移植患者免疫状态的评估提供了一个新视角。

Impacts of Leptin on cellular immunity

Objective To appraise the impacts of leptin on immune system in different immunologic status. Methods Forty 8-week old male BALB/C mice were housed under controlled enviroment. The mice were comprised of 5 groups and injected murine leptin (leptin group) or antileptin (antileptin group) to provide different leptin status. By given CsA, the mice were classified into two categories, normal status and immunosuppression status, with corresponding control. At the sametime, thymocytes suspension was prepared, using TUNNEL flow cytometry to detect the apoptosis of CD4~+, CD8~+ cells within the thymocytes. Results The apoptosis of CD4~+and CD8~+ cells was similar. Under normal immune status, the apoptotic rate of the leptin group was of no significant difference with that of the control group, but it was higher in the antileptin group. Under immunnosuppression status, the apoptotic rate in the leptin group was lower than that in the control group. Conclusions Leptin can upregulate the immunity, decrease apoptosis of thymocytes. Leptin deficiency can increase apoptisis of thymic CD4~+ and CD8~+ cells. The impact of leptin on the immune system can only be observed in mice with immunosuppressive status and not in normal status.