人参皂苷衍生物AD-1对CD4^(+)T细胞亚群的调控及对DSS诱导的实验性结肠炎小鼠的影响北大核心CSCD

目的:探讨新型人参皂苷衍生物AD-1对体外分化CD4^(+)T细胞亚群的影响及对DSS诱导的实验性结肠炎小鼠CD4^(+)T细胞亚群的调控作用。方法:采用磁珠阴性选择法获得正常小鼠幼稚CD4^(+)T细胞,定向分化为Th1、Th2、Th17细胞、Treg,流式细胞术检测AD-1对其分化的影响。3%DSS三次循环法建立小鼠实验性结肠炎模型,AD-1药物干预后,流式细胞术、HE染色检测结肠、脾脏、肠系膜淋巴结中Th1、Th2、Th17细胞、Treg所分泌的细胞因子和特异性转录因子。结果:细胞活化后,早期标志物CD69无显著变化;AD-1下调Th1和Th17细胞分泌的细胞因子IFN-γ和IL-17A表达,上调Th2细胞分泌的细胞因子IL-4和Treg转录因子Foxp3及表面标志物CD25表达。AD-1可通过下调脾脏和肠系膜淋巴结中Th1和Th17细胞表达及上调Th2和Treg表达改善DSS诱导的小鼠实验性结肠炎。结论:AD-1对CD4^(+)T细胞活化无影响,但可抑制Th1和Th17细胞分化,促进Th2细胞和Treg分化,同时通过调节CD4^(+)T细胞亚群改善DSS诱导的小鼠实验性结肠炎。     

小檗碱对TNBS诱导的小鼠结肠炎的治疗作用研究

本研究探讨小檗碱(BBR)对2,4,6-三硝基苯磺酸(TNBS)诱导的小鼠克罗恩病(CD)模型的免疫调节作用。通过TNBS诱导小鼠造成CD模型,观察BBR对CD小鼠的疗效,并进一步探讨BBR治疗CD的作用及其机制。实验小鼠随机分为4组,分别为对照组、TNBS组(CD模型组)、CD模型BBR高剂量治疗组和CD模型BBR低剂量治疗组。于造模后疾病恢复期取各组脾脏和结肠,观察肠道大体损伤及病理情况,检测了结肠局部的炎症因子水平和脾脏中T细胞亚群数量变化、相关的细胞因子和转录因子的表达。BBR组与TNBS组相比,体重恢复时间提前、速度加快;结肠大体损伤及病理评分下降,结肠匀浆上清炎症因子的水平亦下降;脾脏中Th1、Th17及Treg细胞亚群的比例均有下降,相应的转录因子也有不同水平的降低。结果表明BBR治疗对TNBS诱导的小鼠结肠炎有效,其可通过免疫调节和抗炎症作用而治疗CD。     

辐射损伤后T细胞亚群的免疫重建特点及中药山茱萸的调节作用

目的:探讨小鼠辐射损伤后T细胞亚群免疫重建特点及山茱萸的调节作用。方法:采用X射线2.6 Gy单次全身照射建立小鼠辐射损伤模型及山茱萸实验模型,分别在辐射前后,检测小鼠血常规变化;应用流式细胞术检测CD3+、CD4+和CD8+T细胞及其Th1、Tc1、Th2、Th17和Treg亚群的比例。结果:辐射后第3天,外周血和脾脏中淋巴细胞总数及T细胞(包括CD4+、CD8+)比例显著降低(P0.05);T细胞在辐射后第5天开始重建,其中以CD8+T细胞为主,CD4+T细胞在第8天恢复重建。但T细胞分泌IFN-γ能力(Th1/Tc1)低于正常对照组(P0.05)。相反,Th2、Th17、Treg亚群比例显著增高(P0.05)。与照射组相比,山茱萸处理小鼠Th1亚群比例明显上调(P0.05),Th2、Th17、Treg亚群的比例或数量显著下降(P0.05)。结论:X射线单次照射后,CD8+T细胞免疫重建早于CD4+T细胞,但IFN-γ分泌能力较弱。山茱萸可显著上调Th1比例,抑制Th2、Th17、Treg增殖,改善辐射诱导T细胞亚群失衡,增强辐射损伤后Th1类细胞亚群的免疫重建优势。     

血小板生成素对免疫性血小板减少小鼠脾脏T淋巴细胞亚群的影响

目的探讨血小板生成素(TPO)对免疫性血小板减少(immune thrombocytopenia,ITP)小鼠脾脏T淋巴细胞极化的影响。方法将野生型ICR小鼠随机分为正常组、模型组、TPO组。模型组与TPO组小鼠腹腔注射(ip)抗小鼠CD41抗体(MWReg30),连续造模7 d。造模第1天起,TPO组连续9 d皮下注射(sc)3 600 U/kg重组人TPO注射液,正常组与模型组皮下注射等体积PBS。给药结束24 h后麻醉动物,取血,测血常规;取脾脏,计算脾脏指数;取脾脏细胞,流式细胞术检测辅助性T淋巴细胞(Th)、细胞毒性T淋巴细胞(CTL)、1型辅助性T淋巴细胞(Th1)、2型辅助性T淋巴细胞(Th2)、17型辅助性T淋巴细胞(Th17)、调节性T淋巴细胞(Treg)、滤泡辅助性T淋巴细胞(Tfh)比例。结果与正常组相比,模型组小鼠脾脏指数、Th1、Th17、Tfh、CTL/Th及Th1/Th2比值均显著升高,而外周血小板数量、Th2、Treg、Treg/Th17比例均显著降低;与模型组相比,TPO组小鼠脾脏指数、Th1、Tfh、CTL/Th、Th1/Th2比值均显著降低,外周血小板数量、Th2、Treg、Treg/Th17比值均显著升高,Th17比例变化不显著。结论 TPO治疗ITP还与其调节脾脏T淋巴细胞亚群比例相关。     

美沙拉嗪对DSS诱导小鼠溃疡性结肠炎模型Th1、Th17及Treg细胞亚群的影响

 目的:观察葡聚糖硫酸钠（DSS）诱导小鼠溃疡性结肠炎（UC）模型中辅助性T细胞（Th1、Th17亚群）及调节性T细胞（Treg）细胞亚群的变化,探讨美沙拉嗪（MSLZ）治疗UC的免疫学机制。方法: 采用流式细胞分析术检测DSS诱导的小鼠UC模型结肠组织及外周血单个核细胞中白细胞介素17（IL-17）、γ-干扰素（IFN-γ）及核转录因子Foxp3的表达,并检测MSLZ预治疗对小鼠UC 模型Th1、Th17和Treg亚群的影响。结果: 在DSS诱导的小鼠UC模型中,其外周血单个核细胞（PBMC）中CD3+T细胞高表达IL-17、IFN-γ及Foxp3,肠黏膜单个核细胞（LPMC）中CD3+T细胞高表达IFN-γ和Foxp3,但IL-17的表达与对照组无差异。进一步发现UC模型小鼠LPMC中Th17、Th1和Treg均显著高于对照组,但PBMC中只有Treg高于对照组。MSLZ预治疗能显著下调UC 模型小鼠PBMC和LPMC中Th17、Th1和Treg细胞亚群。结论: DSS诱导的小鼠 UC模型中CD4+T细胞亚群Th1、Th17及Treg细胞显著升高,提示CD4+T细胞亚群在UC发病中起重要作用,美沙拉嗪可能通过调节Th1、Th17及Treg细胞亚群发挥抗炎及治疗UC作用。     

间充质干细胞联合胰岛移植对受体鼠T淋巴细胞亚群的影响

目的研究骨髓间充质干细胞(MSCs)与胰岛共移植时,探讨MSCs如何通过T淋巴细胞亚群发挥免疫抑制作用。方法 Balb/c小鼠骨髓MSCs,与C57LB/6小鼠脾脏分离的T淋巴细胞和Balb/c小鼠脾淋巴细胞共培养,监测对T淋巴细胞增殖能力和细胞周期影响。与C57LB/6小鼠来源的T淋巴细胞共培养,流式细胞术分析T淋巴细胞亚群的变化。用Balb/c小鼠的骨髓MSCs和胰岛联合移植到C57BL/6糖尿病模型鼠,流式细胞术分析受体鼠T淋巴细胞亚群的变化。结果 MSCs可明显抑制T淋巴细胞增殖能力,使T细胞滞留在G0/G1期。使Th1/Th2和Tc1/Tc2比值向Th2和Tc2倾斜,对初始和记忆T细胞具有明显的抑制作用。MSCs联合胰岛移植可使免疫排斥反应减轻。结论 MSCs可抑制T淋巴细胞的增殖,Th1/Th2和Tc1/Tc2比值向Th2和Tc2倾斜,下调初始和记忆T细胞,以发挥免疫抑制作用。     

阿胶、黄明胶对被动吸烟小鼠肺脏Th17/Treg细胞亚群分化及相关细胞因子表达的影响差异

目的:探讨阿胶、黄明胶对被动吸烟小鼠肺脏Th17/Treg细胞亚群分化的影响及对肺脏的保护作用。方法:利用香烟烟雾暴露法建立小鼠被动吸烟模型,阿胶组和黄明胶组小鼠在烟熏同时分别给予阿胶和黄明胶干预。造模24周后,制作小鼠肺脏HE染色切片观察病理变化,利用流式细胞术检测肺脏Th17、Treg细胞亚群比例,利用ELISA试剂盒检测血清IL-6、IL-17A因子表达,利用RT-PCR法检测肺组织中RORγt、Foxp3因子转录水平。结果:模型组小鼠肺间质有大量炎性细胞浸润伴有肺实质损伤,肺脏Th17细胞亚群比例及RORγt因子转录水平显著升高(P均0. 05),Treg细胞亚群比例及Foxp3因子转录水平显著升高(P均0. 05),IL-17A、IL-6及TGF-β因子表达均显著升高(P均0. 05);阿胶组和黄明胶组炎性细胞浸润程度降低,肺实质损伤明显改善,阿胶组Th17亚群比例显著降低(P0. 05),Treg亚群比例及Foxp3因子转录水平均显著降低(P均0. 05),IL-17A、IL-6、TGF-β及RORγt因子转录水平均显著降低(P均0. 05);黄明胶组Th17亚群比例及RORγt、IL-17A及IL-6因子表达均无显著变化(P0. 05),Treg亚群细胞比例及Foxp3因子转录水平升高但差异无显著性(P0. 05)。结论:长期低剂量的香烟暴露会导致肺脏Th17细胞介导的炎症反应,阿胶通过下调Th17应答减轻肺脏局部炎症,且对肺脏的保护作用较黄明胶更为显著,黄明胶未表现出对Th17、Treg细胞亚群分化及相关细胞因子表达的显著影响,其抗炎机制有待进一步研究。     

CVB3诱导的病毒性心肌炎小鼠模型中CD4~+T细胞亚群格局及其作用

本研究主要关注BALB/c小鼠感染柯萨奇病毒B3型(CVB3)后CD4+T细胞亚群格局的变化及其对病毒性心肌炎发病的贡献度。CVB3腹腔感染小鼠后第7d,通过小鼠体重下降率、心肌损伤血清学指标肌酸激酶(CK)活性以及心肌组织病理学改变等多项指标证实小鼠心肌炎模型的成功建立。经Real-time PCR检测感染第7d脾脏CD4+T细胞亚群主要细胞因子IFN-γ、IL-4、IL-17A、IL-17F及转录因子Foxp3表达情况;以流式细胞术检测了CD4+T细胞各亚群比例,并通过多元线性回归分析法评估了各T细胞亚群对病毒性心肌炎发病的影响。结果显示,与对照组相比,CVB3感染小鼠脾脏IL-17A、IL-17F、IFN-γ表达均显著上升(分别约为12、8.5、5倍),而IL-4和Foxp3表达无明显变化。CVB3感染小鼠脾脏中CD4+IL-17+Th17细胞的上调幅度最为明显,约2.75倍,其次为IFN-γ+Th1细胞,上调约2.27倍,而Th2和Treg细胞无明显变化。进一步统计学分析显示,Th17对病毒性心肌炎发病的贡献度最高(1.808),Th1次之,贡献度为1.581,而Th2和Treg对病毒性心肌炎发病无显著影响,提示CD4+T细胞亚群格局变化与病毒性心肌炎发病密切相关,其中以Th17对心肌炎发病的贡献度尤为显著。     

骨髓间质干细胞降低大鼠移植物抗宿主反应的实验研究

目的 探讨MSCs对GVHD的作用及其机制.方法 建立大鼠同种异体骨髓移植模型,同时输入供者的T淋巴细胞诱导出移植物抗宿主反应,联合或不联合移植供体来源的MSCs,观察受鼠的生存时间,同时利用RT-PCR法研究Th1/Th2淋巴细胞亚群的比例,用ELISA法检测移植后体内IL-4细胞因子的浓度.结果 GVHD组的平均生存时间为(17.30±2.33)天,实验组的平均生存时间为(24.10±2.36)天 , 与单独移植HSCs相比,MSCs与HSCs共移植明显延长的受鼠的生存时间.同时,GVHD组Th1/Th 2 细胞比值为1.29±0.06,IL-4因子的浓度平均为(14.84±2.59) pg/mL,实验组Th1/Th 2细胞比值为(0.77±0.14),IL-4因子的浓度平均为(40.09±13.99) pg/mL.MSCs与 HSCs 共移植降低了体内Th1/Th2淋巴细胞亚群的比例,提高了体内IL-4细胞因子的浓度.结论 MSCs与HSCs共移植能有效抑制HSCs移植后致死性GVHD的发生,延长生存时间,同时MSCs 可能通过作用于体内Th1/Th2淋巴细胞亚群的比例,促进体内IL-4细胞因子的分泌从而间接发挥了抑制GVHD的作用.     

金黄色葡萄球菌诱导的乳腺炎小鼠脾脏Th 细胞变化研究

目的:在小鼠金黄色葡萄球菌性乳腺炎过程中,探讨脾脏内多种Th 细胞亚群数量和相关细胞因子、转录因子的动态变化及其意义。方法:本研究首先建立S.aureus 感染小鼠的乳腺炎模型,再利用流式细胞术和荧光定量PCR 技术,分别检测脾脏中多种Th 细胞亚群数量及相关因子mRNA 水平。结果:在S.aureus 感染小鼠乳房后的不同时间,脾脏内Th2细胞和Th17 细胞占CD4+淋巴细胞的比例分别显著增加(P<0.05),而Treg 细胞比例则明显降低(P<0.05)。并且,与Th 细胞分化、活化和效应相关的多种细胞因子及转录因子,均在转录水平有明显升高(P<0.05)。结论:乳腺炎不只是发生于乳腺局部的一种炎症反应,机体还能够调动脾脏的多种Th 淋巴细胞亚群,以分泌细胞因子的方式,组织有效的乳腺抗S.aureus 感染免疫应答。     

TLR3 preconditioning enhances the therapeutic efficacy of umbilical cord mesenchymal stem cells in TNBS-induced colitis via the TLR3-Jagged-1-Notch-1 pathway

Toll-like receptor-3 (TLR3) priming may enhance mesenchymal stem cell (MSC) immunosuppressive activity, but this mechanism has not been investigated in the context of inflammatory bowel disease. Thus, we assessed the immunosuppressive properties of TLR3-primed MSCs using a trinitrobenzene sulfonate (TNBS)-induced mouse model of colitis. Intraperitoneally injected polyribocytidylic acid (poly (I:C)- (a ligand of TLR3) primed human umbilical cord-derived MSCs (hUC-MSCs) migrated to the inflamed colon and effectively improved clinical and pathological manifestations in colitic mice compared with mice treated with unstimulated hUC-MSCs (UCMs). Poly (I:C)-MSCs decreased a wide range of inflammatory cytokines and increased systemic interleukin-10 (IL-10) levels in colonic tissues. Poly (I:C)-MSCs also impaired T-helper type 1/17 (Th1/17) cell expansion and enhanced the suppressive effects of regulatory T cells (Treg) in vitro and in vivo. Poly (I:C)-MSCs suppressed the proliferation of activated mesenteric lymph node (MLN) cells via the overproduction of prostaglandin E₂ (PGE₂) and upregulation of Jagged-1. PGE₂ produced by hUC-MSCs in response to poly (I:C) increased the production of IL-10 and promoted the differentiation of Treg, which could be reversed by inhibition of Notch-1. Collectively, preconditioning MSCs with poly (I:C) enhanced the therapeutic effects of hUC-MSCs in TNBS-induced colitis, and TLR3-activated Notch-1 signaling regulated the immune suppression of hUC-MSCs through the production of PGE₂.     

Hapten-induced colitis associated with maintained Th1 and inflammatory responses in IFN-gamma receptor-deficient mice

IFN-gamma is a potent pro-inflammatory cytokine thought to be involved in the pathogenesis of Crohn's disease. To further define the role of IFN-gamma in intestinal inflammation, we studied the effects of intra-colonic 2,4,6-trinitrobenzene sulfonic acid (TNBS) instillation in mice with a functionally inactivated IFN-gamma receptor 1 (IFN-gammaR1(- / -)). Our results indicate that IFN-gamma is not necessary for the induction of hapten-induced colitis: after TNBS administration both wild-type and IFN-gammaR1(- / -) mice lost body weight, and the histological features of TNBS-induced colitis were comparable. Colons of IFN-gammaR1(- / -) mice contained a greater number of cells, represented by macrophages and CD4(+) T cells; caudal lymph node cells produced more IFN-gamma and TNF-alpha upon stimulation in vitro. Moreover, IL-18 and IL-12 p40 RNA levels were comparably up-regulated after TNBS treatment in IFN-gammaR1(- / -) wild-type mice. These findings demonstrate that IFN-gamma is dispensable for the development of TNBS-induced colitis. Importantly, the production of Th1 cytokines (e. g. IFN-gamma and TNF-alpha) by caudal lymph node T lymphocytes was enhanced rather than decreased in IFNgammaR1(- / -) mice with no evidence for default Th2 development.     

Lactobacillus plantarum C29 alleviates NF-κB activation and Th17/Treg imbalance in mice with TNBS-induced colitis

In this study, we examined whether Lactobacillus plantarum C29 could restore 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced T helper 17 (Th17)/regulatory T cells (Tregs) imbalance in mice. Treatment with C29 inhibited the differentiation of splenic T cells into Th17 cells and the expression of retinoic acid receptor-related orphan receptor gamma t (RORγt) and IL-17 in vitro, whereas promoting the differentiation into Tregs. Oral administration of Lactobacillus plantarum C29 in mice attenuated TNBS-induced colon shortening, myeloperoxidase (MPO) activity, inducible Nitric oxide (NO) synthase, and cyclooxygenase-2 expression, and activation of NF-κB in the colon of mice. C29 treatment downregulated TNF-α, IL-17, and IL-1β expression, while increasing IL-10 expression. C29 treatment suppressed TNBS-induced Th17 cell differentiation and reduced IL-17 and RORγt expression, while promoting the TNBS-suppressed Tregs differentiation and IL-10 and forkhead box P3 expression. These findings suggest that C29 can alleviate colitis by modulating NF-κB activation as well as Th17/Treg balance.     

旋毛虫对三硝基苯磺酸和噁唑酮诱导肠炎小鼠结肠中Th1/Th2类细胞因子表达的影响

目的 研究旋毛虫(T. spiralis)对三硝基苯磺酸(TNBS)和噁唑酮(OXZ)诱导的实验性肠炎小鼠结肠中Th1/Th2类细胞因子表达的影响.方法 雌性BALB/c小鼠,随机分为50%乙醇对照组、T. spiralis应用组、TNBS(OXZ)诱导肠炎模型组、预先感染T. spiralis后诱导TNBS(OXZ)模型组(每组小鼠取材时保证6只以上).对各组小鼠肠黏膜固有层单个核细胞(LPMC)进行分离培养,采用ELISA方法观察感染T.spiralis和未感染T.spiralis小鼠于TNBS或OXZ诱导肠炎后3 d和7 d结肠中Th1/Th2类细胞因子蛋白的表达变化,包括IFN-γ、IL-12、IL-4、IL-10的表达量分析.结果 预先感染T. spiralis后诱导TNBS模型组小鼠在造模后3 d及7 d肠黏膜LPMC产生IFN-γ的水平均低于模型组(P＜0.05),而IL-4、IL-10的表达高于模型组(P＜0.05).预先感染T. spiralis后诱导TNBS模型组小鼠在造模后3 d肠黏膜LPMC产生IL-12的水平低于模型组(P＜0.05),第7天与模型组相比未见明显差异(P＞0.05).预先感染T. spiralis后诱导OXZ模型组小鼠在造模后3 d及7 d肠黏膜LPMC产生IFN-γ、IL-4及IL-10的水平均高于单纯造模组(P＜0.05).结论 T. spiralis对TNBS诱导的肠炎模型小鼠肠道局部免疫作用机制可能是通过诱导Th2型免疫反应及Tr1型细胞因子而抑制结肠炎小鼠Th1型过度免疫应答而实现的.在T.spiralis对OXZ模型小鼠的干预性研究中,没有按理论所设想的感染T.spiralis所产生的Th2型免疫反应会对OXZ诱导的Th2型炎症反应起叠加作用而加重病情.这提示我们,需要进一步探讨T.spiralis对拥有Th2型免疫应答的OXZ模型的具体作用机制.     

The signaling axis of microRNA-31/interleukin-25 regulates Th1/Th17-mediated inflammation response in colitis

Interleukin-25 (IL-25) is an important regulatory cytokine that has a key role on mucosal immune tolerance during inflammation response. However, the molecular mechanism that regulates the colonic IL-25 expression in Crohn's disease (CD) remains unclear. In this study, IL-25 level was proved to decrease in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis mice and IL-10 knockout (KO) spontaneous colitis mice. An inverse correlation between IL-25 and miR-31 was discovered in the colons from model mice and CD patients. Furthermore, target validation analysis demonstrated that miR-31 directly regulated IL-25 expression by binding to its messenger RNA 3′-untranslated region. Changing colonic miR-31 level in the colitis mice could affect the mucosal IL-12/23-mediated Th1/Th17 pathway and lead to either amelioration or aggravation of colonic inflammation. In addition, the therapeutic effects of anti-miR-31 in TNBS-induced colitis were abolished by colonic treatment with IL-25 antibody or colonic down-expression of IL-25. Our findings demonstrated that IL-25 could be a crucial anti-inflammatory cytokine in TNBS-induced colitis and the signaling of miR-31 targeting IL-25 might be a possible mechanism that regulates IL-12/23-mediated Th1/Th17 inflammatory responses during colonic inflammation process. Restoring colonic IL-25 expression and blocking Th1/Th17 responses via intracolonic administration of miR-31 inhibitor may represent a promising approach for CD treatment.     

Effect of Trichinella spiralis intervention on TNBS-induced experimental colitis in mice

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn’s disease (CD), are chronic autoimmune diseases with a high recurrence rate. Epidemiological data have shown that the incidence of IBD increases annually because of improved sanitary conditions and reduced parasitic infection rates. In this experiment, experimental colitis was induced in mice by administering 2,4,6-trinitrobenzene sulfonic acid (TNBS) 28?days after they were infected with Trichinella spiralis to confirm that T. spiralis infection could alleviate the severity of TNBS-induced colitis.Thirty-six male BALB/c mice aged 6–8 weeks were randomly divided into four groups: control group (with 50% ethanol, Control), T. spiralis-infected group (TS-Control), TNBS-induced colitis model group (Colitis), and T. spiralis-pre-infected and TNBS-induced colitis group (TS-Colitis). The mice were sacrificed 3, 7, and 14?days after the model was established. Changes in various colitis indicators to investigate the effect of T. spiralis infection on TNBS-induced murine CD model.Results showed that the weight, DAI score, and macroscopic and microscopic colon damage in the TS-Colitis significantly decreased compared with those in the Colitis. ELISA revealed that the IFN-γ expression decreased and the IL-4 expression increased in the TS-Colitis compared with those in the Colitis. Western Blotting results revealed that the NF-κB expression increased in the Colitis and higher than those in the TS-Colitis. And Flow cytometry results revealed that the percentage of CD4+CD25+Foxp3+ Treg cells significantly increased in the TS-Colitis.T. spiralis-infected mice induced Th2 immune responses and balanced Th1 immune responses stimulated by TNBS to ameliorate intestinal inflammation.     

Glycyrrhizin ameliorates experimental colitis through attenuating interleukin-17-producing T cell responses via regulating antigen-presenting cells

Glycyrrhizin, a component of Chinese medicine licorice root, has the ability to inhibit the functions of high-mobility group box 1 (HMGB1). While glycyrrhizin is known to have anti-inflammatory activities, the underlying mechanisms by which glycyrrhizin inhibits inflammation during the development of trinitrobenzenesulfonic acid (TNBS)-induced experimental colitis are not well understood. This study systemically examined the regulatory effects of glycyrrhizin on inflammatory response in TNBS-induced murine colitis and explored the potential mechanisms involved in this process. We reported that glycyrrhizin treatment ameliorated colitis and decreased the production of inflammatory mediators HMGB1, IFN-γ, IL-6, TNF-α, and IL-17. In addition, glycyrrhizin regulated responses of dendritic cells (DCs) and macrophages during the development of colitis. Furthermore, administration of glycyrrhizin suppressed the proliferation of Th17 cells in colitis. Moreover, the ability of DCs and macrophages to induce the differentiation of Th17 cells was enhanced in presence of HMGB1, which was inhibited by glycyrrhizin. These results demonstrated that glycyrrhizin alleviated colitis by inhibiting the promotive effect of HMGB1 on DC/macrophage-mediated Th17 proliferation. In conclusion, HMGB1 plays an important role in the development of colitis. As an inhibitor of HMGB1, glycyrrhizin might be a novel therapy for colitis.     

全反式维甲酸对Th2极化的调节作用

为了研究全反式维甲酸(all-trans retinoic acid,ATRA)对Th细胞分化的影响和可能的机制,无菌分离BALB/c小鼠脾细胞后,用2.5μg/ml的ConA刺激脾细胞,在不同时间加入不同剂量的ATRA,72 h后收集细胞,用3H-TdR掺入法测淋巴细胞增殖活性,用RT-PCR方法检测在Th细胞分化中起作用的细胞因子的mRNA表达水平。结果ATRA呈剂量依赖抑制ConA诱导的淋巴细胞的活化,10~(-5)mol/L的ATRA对ConA诱导的淋巴细胞活化的抑制作用最强;此抑制作用与作用时间呈相关性,ConA活化淋巴细胞24 h后加入ATRA对淋巴细胞活化的抑制作用最显著,并且淋巴细胞的活化程度越低,ATRA对其的抑制作用越强。ATRA可增强经ConA活化的淋巴细胞Th2型细胞因子(IL-4、IL-6)mRNA的表达水平,而Th1型细胞因子(IFN-γ、TNF-α)mRNA的表达水平显著性降低(P<0.05)。上述结果表明ATRA总体上可抑制ConA刺激的淋巴细胞增殖活性,但却可增强,Th2细胞的分化。这一研究为Th细胞免疫偏离的基础与临床研究提供了依据。