瘦素(Leptin)与免疫系统的关系研究

为弄清高Leptin水平在不同免疫状态下对免疫系统的影响 ,选用 8周龄的清洁级BALB/c雄性小鼠共 4 0只 ,分成五组 ,分别用外源性鼠Leptin和Leptin抗体人为形成小鼠的不同Leptin水平状态 ,并利用CsA将小鼠分为正常免疫和免疫抑制状态两类 ,两种状态各设对照组 ,测定细胞增殖情况 ;用ELISA方法检测外周血和细胞培养液中IL 2、IL 4、IFN γ和Leptin的浓度。正常免疫状态下 ,Leptin组的脾细胞增殖与对照组无差异 ,细胞因子除IFN γ升高外 ,IL 2、IL 4均无差异 ;Leptin抗体组显示脾细胞增殖能力下降 ,各细胞因子测定示显示差异 ;免疫抑制状态下 ,Leptin组的细胞增殖活力较强 ,IL 2、IFN γ水平上升 ,IL 4分泌降低 ,这种结果也在几乎所有体外加入Leptin的各组中出现。表明Leptin可以起免疫调节作用 ,增加IFN γ、IL 2的合成 ,降低IL 4的产生 ,使免疫应答向Th1细胞方向偏离。在正常免疫状态下Leptin的调节作用不明显 ,而在免疫抑制情况下 ,这种调节作用可以得到体现。

Research on the Relationship between Leptin and Immunity

To make clear the impacts of leptin on immune system in different immune status, forty 8-week-old male BALB/c mice were housed under controlled surroundings. The mice comprised 5 groups. Mice were in different level of leptin by injection of exogenous murine leptin (leptin group) or anti-leptin(anti-leptin group). Mice were classified into two categories, normal state and immunosuppressive state by use of CsA, with corresponding controls. The splenocytes suspension was also prepared. IL-2, IL-4, IFN-γ and leptin in circulating blood and supernatants were measured by ELISA. In the mice with normal immune status, there was no statistical difference in the proliferation of splenocytes between the control and the leptin group. And the same results appeared in the level of IL-2 and IL-4 between these two groups with the exception of a higher level of IFN-γ in the leptin group. The proliferation of splenocytes decreased in the anti-leptin group, but there were no significant changes in the production of the cytokines. Under immunosuppression, the proliferation of splenocytes was obviously accompanied by a higher level of IL-2 and IFN-γ and a lower lever of IL-4 in the leptin group. The results demonstrated that leptin was a modulator(enhancer) of immune system. It could stimulate the synthesis of IL-2 and IFN-γ, and suppress the production of IL-4, thus making the T lymphocytes activation toward Th1 phenotype. Under immunosuppression, leptin played a functional role as a modulator on the immune system, but the situation was different in the normal immune status.