中文摘要：

目的探讨不同的Toll样受体（TLR）激动剂对小鼠脾细胞、树突状细胞（DC）和免疫后白细胞介素12p40（IL-12p40）和IL-5分泌的差异，进一步探讨其对辅助性T（Th）细胞功能的影响尤其是对Th1细胞分化的影响。方法不同剂量的TLR激动剂刺激小鼠脾细胞和DC24h或免疫小鼠后收集不同时间点血清，用ELISA检测培养上清液或血清中IL-12p40和IL-6的水平。自CD4^＋T细胞受体转基因（D011．10 OVA-TCR）小鼠脾脏的CD4^＋T细胞和与其具有相同背景基因BALB／c小鼠脾脏来源的抗原提呈细胞（APC），将两者按1：3混合培养，用不同浓度的TLR激动剂联合卵清蛋白（OVA）抗原肽刺激培养，收集不同时间点的上清液，ELISA检测γ干扰素（IFN-γ）的水平。结果Pam3CSK4、R848和CpG寡核苷酸（ODN）均能明显促进脾细胞和DC产生IL-12p40和IL-6，以时间和剂量依赖的方式促进抗原特异性的CD4^＋T细胞表达IFN-γ；来自明尼苏达沙门菌R595脂多糖的单磷酰脂A（MPLA-SM）诱导脾细胞产生细胞因子水平低、不能促进抗原特异性CD4^＋T细胞产生IFN-γ，但可促进DC大量表达IL-12p40和IL-6。四种TLR激动剂免疫小鼠后均能明显促进IL-12p40和IL-6产生。结论不同TLR激动剂作用于脾细胞、DC和免疫小鼠后诱导免疫应答产生细胞因子的能力不同，进一步影响Th1细胞的分化。

英文摘要：

Objective To investigate the secretion of IL-12p40 and IL-6 by splenocytes, dendritic cells stimulated by different Toll-like receptor （TLR） agonists or in the sera of mice immunized with different TLR agonists, and evaluate the effects of different TLR agonists on the function of T helper （Th） ceils, especially the differentiation of Th1 cells. Methods Supernatants of splenocytes and dendritic cells stimulated with different TLR agonists for 24 hours or sera of mice immunized with different TLR agonists at different time points were used to determine the levels of IL-12p40 and IL-6 by ELISA. CD4 ^＋T cells isolated from the spleens of ovalbumin-T cell receptor （OVA-TCR） transgenic BALB/c （DO11. 10） mice were co-cultured with antigen presenting cells （APCs） from congenic BALB/c mice at 1 ： 3 ratio of T： APCs. Cultures were stimulated with OVA peptide or OVA peptide plus different doses of TLR agonists and the supernatants collected at different time points were assayed by ELISA for detecting IFN-γ. Results Pam3CSK4, R848 and CpG oligodeoxynucleotide （ODN） promoted the production of IL-12p40 and IL-6 by splenocytes and dendritic cells obviously, and induced the expression of IFN-γ in antigen specific CD4 ^＋ T cells in a time- and dose-dependent manner. Monophosphoryl lipid A from Salmonella minnesota R595 lipopolysaccharide （MPLA-SM） induced low levels of cytokines by splenocytes and couldn＇t promote the production of IFN-γ by antigen specific CD4^＋T cells, but increased the expressions of IL-12p40 and IL-6 by DCs. All the sera of mice immunized with the four TLR agonists expressed high levels of IL-12p40 and IL-6. Conclusion Splenocytes, DCs stimulated or sera of mice immunized with different TLR agonists produced different levels of cytokines, which could further affect the differentiation of Thl cells.