TREM-1促进巨噬细胞的迁移并参与脂多糖诱导的小鼠心肌功能障碍

目的探讨髓系细胞触发受体-l(triggering receptor expressed oil myeloid cells-1,TREM-1)对脂多糖(lipopolysaccharide,LPS)诱导的小鼠心肌功能障碍的作用以及对巨噬细胞RAW264.7迁移的影响。方法将健康C57BL/6J雄性小鼠随机分为对照组、LPS组、LPS+LP17组、LPS+TAK-242组并进行相应处理,6 h后超声心电图检测小鼠心功能指标,12 h取心肌组织HE染色观察病理改变,免疫组化染色观察巨噬细胞表面分子F4/80阳性表达,ELISA检测血清中炎症因子TNF-α、IL-6、IL-1β及IFN-γ的表达情况,实时荧光定量PCR检测TREM-1、BNP以及炎症因子TNF-α、IL-6、IL-1β、IFN-γ的mRNA水平;培养巨噬细胞RAW264.7,将细胞随机分为正常组、LPS组、LP17+LPS组、TAK-242+LPS组并进行对应处理,实时荧光定量PCR检测TREM-1与TLR4的mRNA水平,ELISA检测细胞培养液中炎症因子TNF-α、IL-6、IL-1β及IFN-γ的表达情况,Transwell小室观测RAW264.7细胞迁移情况,蛋白免疫印迹检测RAW264.7中TLR4/NF-κB信号通路相关蛋白水平。结果与对照组相比,超声心电图检测结果显示LPS组小鼠的EF与FS下降,LVD增大,IVS减小,LVPW变薄,变化均显著(P0.05),实时荧光定量PCR结果显示TREM-1 mRNA与BNP mRNA表达水平上升(P0.05),免疫组化染色法显示F4/80有大量阳性表达(P0.01),ELISA检测显示炎症因子TNF-α、IL-6、IL-1β、IFN-γ的含量增加(P0.05),实时荧光定量PCR检测也表明这些炎性因子mRNA水平升高(P0.05);与LPS组小鼠相比,注射TREM-1抑制剂LP17使EF、FS上升,有效抑制了LVD增大、IVS减小以及LVPW变薄的现象(P0.05),TREM-1 mRNA与BNP mRNA表达水平均降低(P0.05),心肌损伤减轻,F4/80阳性表达减少(P0.01),炎症因子水平也明显下降(P0.05),与注射TLR4抑制剂TAK-242的效果一致。与对照组相比,LPS诱导RAW264.7细胞后,细胞中TREM-1 mRNA与TLR4 mRNA水平升高(P0.05),炎症因子TNF-α、IL-6、IL-1β、IFN-γ的含量增加(P0.05),细胞大量迁移(P0.01),细胞中TLR4、MyD88、NF-κBp65、p-IκBα蛋白水平升高(P0.05);与LPS组相比,TREM-1抑制剂LP17预处理后再给予LPS诱导,细胞中TREM-1 mRNA与TLR4 mRNA水平降低(P0.05),炎症因子的含量下降(P0.05),RAW264.7细胞迁移被抑制(P0.01),TLR4、MyD88、NF-κBp65、p-IκBα蛋白水平也明显降低(P0.05)。结论给小鼠注射TREM-1抑制剂可有效减轻LPS诱导的心肌功能障碍,抑制RAW264.7细胞TREM-1表达可抑制细胞的迁移,TLR4/NF-κB途径可能参与了这一过程。     

三百棒通过调控TLR4/NF-κB信号通路对脂多糖诱导的RAW264.7细胞极化的影响

目的：探讨三百棒醇提物(TAAE)对脂多糖(LPS)诱导的小鼠单核-巨噬细胞RAW264.7极化趋向以及其对炎症反应的影响。方法：用LPS诱导RAW264.7细胞建立炎症模型。CCK-8法检测细胞活力;ELISA检测细胞因子(TNF-α、IL-1β、IL-6和IL-10)的水平;Griess法检测细胞培养上清液中一氧化氮(NO)的分泌情况;荧光染色双标法观察巨噬细胞的极化状态;免疫荧光染色检测NF-κB定位及表达;Transwell检测TAAE对RAW264.7细胞迁移和趋化性的影响;RT-qPCR检测TNF-α、IL-1β、IL-6、IL-10、Arg-1、NF-κB和TLR4的mRNA水平;Western blot检测iNOS、COX-2、TLR4、NF-κB、p-NF-κB、IκBα和p-IκBα蛋白水平。使用TLR4通路抑制剂TAK-242进一步验证TAAE对TLR4/NF-κB信号通路的影响。结果：与模型组相比较,TAAE降低LPS诱导的炎症模型RAW264.7细胞中M1型促炎因子(TNF-α、IL-1β和IL-6)及NO水平,促使M2型抑炎因子(IL-10和Arg-1)分泌...     

TGF-β1下调炎性巨噬细胞RAW264.7 TLR4受体的表达

目的探讨TGF-β1对小鼠巨噬细胞RAW264.7 TLR4受体表达的调节作用。方法 Teal-Time PCR法检测RAW264.7细胞TGF-β1和TLR4受体mRNA表达,ELISA法检测RAW264.7细胞TGF-β1的分泌,流式细胞术检测RAW264.7细胞TLR4受体的表达。结果一定剂量的LPS促进RAW264.7分泌TGF-β1,且呈剂量依赖关系,一定剂量的TGF-β1单独刺激下调RAW264.7的TLR4受体的表达,TGF-β1能够下调LPS活化的RAW264.7细胞TLR4受体表达。结论 TGF-β1可以通过下调巨噬细胞TLR4受体表达来控制机体炎性反应,这可能是TGF-β1作为免疫抑制剂抑制炎症反应的重要途径之一。     

N-乙酰半胱氨酸酰胺对脂多糖诱导的RAW264.7巨噬细胞炎症的保护作用及机制研究北大核心CSCD

目的研究N-乙酰半胱氨酸酰胺(NACA)对脂多糖(LPS)诱导的RAW264.7巨噬细胞炎症的保护作用及作用机制,为NACA治疗脓毒症提供理论依据。方法CCΚ-8法检测NACA和N-乙酰半胱氨酸(NAC)对RAW264.7细胞活力的影响;采用ELISA检测NACA和NAC对LPS诱导的RAW264.7细胞上清中TNF-α和IL-6水平;qRT-PCR检测NACA对LPS诱导的RAW264.7细胞中TNF-α、IL-6、IL-1β、ATF4、CHOP的mRNA表达的影响;Western blot检测NACA对LPS诱导的RAW264.7细胞中TLR4/NF-κB及PERΚ/ATF4/CHOP信号通路中关键蛋白表达的影响。结果0.1~5 mmol/L的NACA和NAC对RAW264.7细胞活力无明显的影响(P>0.05)。1 mmol/L和5 mmol/L的NACA和NAC可显著降低LPS诱导的RAW264.7细胞上清中TNF-α和IL-6的水平(P<0.01),且NACA的降低效果优于统计量的NAC。1 mmol/L和5 mmol/L的NACA也可显著降低LPS诱导的RAW264.7细胞中TNF-α、IL-6、IL-1β、ATF4、CHOP mRNA的表达(P<0.05、P<0.01)。Western blot结果表明,1 mmol/L和5 mmol/L的NACA可显著降低TLR4、p-IκB、p-65、p-PERK、p-eIF2α、ATF4、Bip和CHOP蛋白的表达(P<0.05、P<0.01)。结论NACA可能通过TLR4/NF-κB及PERΚ/ATF4/CHOP信号通路抑制LPS诱导的RAW264.7巨噬细胞的炎症反应,为NACA治疗脓毒症的抗炎性药物筛选提供了实验依据。     

青蒿琥酯对小鼠巨噬细胞RAW264.7中TLR4介导的炎症通路的抑制作用

目的观察青蒿琥酯(artesunate,AS)对脂多糖(lipopolysaccharide,LPS)刺激小鼠RAW264.7细胞Toll样受体4(Toll-like receptor 4,TLR4)介导炎症通路活化的影响,以探讨AS的抗炎作用机制。方法采用免疫荧光观察胞内TLR4表达和分布;免疫印迹检测TLR4及下游炎症通路关键分子的表达和活化;酶联免疫吸附法检测细胞培养上清中TNF-α、IL-6浓度。结果 AS对LPS诱导的TLR4表达及其在细胞中的聚集均有抑制作用;AS同时抑制TLR4衔接蛋白髓分化因子88和含TIR结构域干扰素诱导衔接蛋白表达,也抑制依赖于二者活化的肿瘤坏死因子受体相关因子6表达;对下游MAPK通路,AS抑制p38表达和磷酸化、JNK磷酸化,但对ERK1/2无显著影响;对下游NF-κB通路,AS下调抑制性-κBα(inhibitory-κBα,IκBα)的磷酸化,进而减少NF-κB亚基p50和p65活化入核的数量;最后,AS能够抑制LPS诱导的TNF-α和IL-6释放。结论 AS通过抑制LPS诱导的TLR4通路活化,减少致炎细胞因子的释放,从而发挥其抗炎作用。     

绿茶多酚通过抑制TLR4通路减轻蛛网膜下腔出血大鼠早期脑损伤

目的探讨绿茶多酚通过抑制TLR4通路对蛛网膜下腔出血大鼠早期脑损伤的影响。方法建立大鼠蛛网膜下腔出血模型,随机分为模型组、绿茶多酚组、TAK-242(TLR4抑制剂)组、绿茶多酚+TAK-242组,每组12只;另取12只大鼠设为假手术组。药物处理后,对所有大鼠进行神经功能缺损评分,检测各组大鼠脑组织含水量,采用Evans蓝外渗实验评定血脑屏障通透性,采用苏木精-伊红(HE)染色检测各组大鼠脑皮层神经元受损情况,采用酶联免疫吸附法(ELISA)检测血清中白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)水平,采用蛋白免疫印迹法检测脑组织中TLR4通路蛋白TLR4、MyD88、NF-κB p65表达情况。结果与假手术组相比,模型组大鼠皮层结构紊乱疏松,神经元出现变性、坏死,数目减少,细胞核固缩、深染等病理改变,脑组织及神经元受损,神经功能缺损评分、脑组织含水量、Evans蓝渗出量、血清中IL-6及TNF-α水平、脑组织TLR4、MyD88及NF-κB p65蛋白表达均明显升高(P<0.05);与模型组相比,绿茶多酚组、TAK-242组、绿茶多酚+TAK-242组大鼠脑皮层神经元损伤减轻,神经功能缺损评分、脑组织含水量、Evans蓝渗出量、血清中IL-6及TNF-α水平、脑组织TLR4、MyD88及NF-κB p65蛋白表达均降低(P<0.05);与绿茶多酚组及TAK-242组分别相比,绿茶多酚+TAK-242组大鼠脑组织及神经元病理损伤进一步减轻,神经功能缺损评分、脑组织含水量、Evans蓝渗出量、血清中IL-6及TNF-α水平、脑组织TLR4、MyD88及NF-κB p65蛋白表达均降低(P<0.05)。结论绿茶多酚可通过抑制TLR4通路减轻蛛网膜下腔出血大鼠早期脑损伤。     

小鼠侵袭性肺曲霉病发病过程中TLRs/NF-κB信号通路的激活

目的:研究小鼠侵袭性肺曲霉病(IPA)发生过程中TLRs/NF-κB信号通路的激活,探讨IPA的发病机理。方法:小鼠随机分为正常组(N)、正常接菌组(N+Af)和IPA模型组(IPA),经鼻吸入烟曲霉(Af)孢子后在不同时相点处死小鼠,无菌取肺组织行病理切片、Af菌落计数,RT-PCR法检测TLR2和TLR4 mRNA、蛋白印迹法检测NF-κBp65、IL-1β的表达。结果:(1)鼻吸入Af后72小时时,IPA组肺组织出现严重炎症反应,并有大量的菌丝生成,同时各时相点的菌负荷均高于N+Af组;(2)与N+Af组比较,IPA组TLR2 mRNA后期异常高表达,TLR4 mRNA持续低表达,NF-κBp65早期骤然升高后又持续下降,IL-1β一直呈低表达状态。结论:TLRs的异常激活导致宿主下游信号的低反应性,宿主不能清除Af促使了IPA的发生发展。     

贞芪扶正胶囊介导TLR4/MyD88/NF-κB信号通路抑制慢性湿疹小鼠炎症反应

目的 探讨贞芪扶正胶囊对慢性湿疹小鼠炎症反应的抑制作用.方法 SPF级C57BL/6小鼠30只,按随机数字表法随机分为对照组(control组)、模型组(CAD组)与贞芪扶正胶囊组(ZQFZ组).观察各组小鼠双耳肿胀程度、双耳变应评分;HE染色观察病灶处皮肤病理学变化;ELISA法检测血清炎性因子TNF-α、IL-6及IL-1β水平;RT-PCR检测皮肤中TNF-α、IL-6及IL-1β mRNA表达;Western blot检测TLR4、MyD88及NF-κB蛋白表达;RT-PCR检测皮肤中TLR4、MyD88及NF-κB mRNA表达.结果 ZQFZ可以显著改善小鼠双耳肿胀程度,降低小鼠双耳变应评分(P＜0.05);减轻小鼠皮肤炎症浸润并降低血浆及皮肤中TNF-α、IL-6及IL-1β蛋白与mRNA表达(P＜0.05);同时ZQFZ还可显著下调小鼠皮肤组织中TLR4、MyD88、NF-κB蛋白与mRNA表达(P＜0.05).结论 贞芪扶正胶囊可以通过抑制炎性反应达到治疗慢性湿疹作用,其作用机制可能与其调控TLR4/MyD88/NF-κB信号通路有关.     

Aβ1-42通过TLR4影响小鼠巨噬细胞RAW264.7炎症因子IL-1β和IL-6释放

目的探讨Aβ1-42对小鼠巨噬细胞RAW264.7向炎症性细胞转变的影响及机制。方法 RAW264.7细胞分别经过LPS与Aβ1-42刺激,RT-PCR和Western blot检测GM-CSF受体CSF2RA和CSF2RB的表达水平,ELISA检测在Aβ1-42刺激下的炎症因子IL-1β、IL-6和TNF-α水平;采用TLR4抑制剂分别干预LPS和Aβ1-42处理后的RAW264.7,检测CSF2RA与CSF2RB受体的表达变化,炎症因子IL-1β、IL-6的释放。结果 RAW264.7细胞表面GM-CSF受体CSF2RB在LPS与Aβ1-42处理后表达水平均比对照组升高(P0.05),而CSF2RA表达没有显著性改变;炎症因子IL-6与IL-1β在Aβ1-42刺激后分泌增加,同时TLR4抑制剂抑制LPS和Aβ1-42对细胞的刺激。结论 Aβ1-42通过TLR4促进小鼠RAW264.7细胞炎症因子IL-6、IL-1β的分泌。     

肺泡巨噬细胞TLR4/MyD88信号通路参与并介导了机械通气所致的肺损伤

目的探讨肺泡巨噬细胞Toll样受体4/髓样分化因子88(TLR-4/My D88)信号通路在呼吸机相关性肺损伤中的作用。方法 30只成年SD大鼠行经口气管插管,给予40 m L/kg潮气量通气240 min,建立呼吸机相关性肺损伤模型,机械通气结束后,使用4℃PBS经气管导管缓慢注入并回收支气管肺泡灌洗液(BALF),提纯肺泡巨噬细胞。收集并培养肺泡巨噬细胞,随机分为3组:PBS刺激组(CON组);TNF-α刺激联合PBS组(STI组);TNF-α刺激联合抗TLR4单克隆抗体(m Ab)干预组(ANT组);每组8个样本。CON组细胞用PBS结合2 h后,继续用PBS培养16 h;STI组细胞用PBS结合2 h后,采用20 ng/m L TNF-α培养16 h;ANT组细胞用PBS液及TLR4 m Ab结合2 h后,用20 ng/m L TNF-α培养16 h。ELISA检测各组上清液TNF-α、IL-1β、IL-6的表达;反转录PCR检测各组肺泡巨噬细胞TLR4、TLR9、髓样分化因子88(My D88)、核因子κB(NF-κB)的mRNA表达,Western blot法检测各组肺泡巨噬细胞TLR4、TLR9、My D88、NF-κB的蛋白表达。结果与CON组比较,STI组及ANT组细胞培养上清液TNF-α、IL-1β、IL-6的浓度明显增高;STI组肺泡巨噬细胞TLR4 mRNA、My D88 mRNA、NF-κB mRNA表达水平与蛋白表达水平明显增高;ANT组肺泡巨噬细胞TLR4 mRNA、My D88 mRNA、NF-κB mRNA表达水平与蛋白表达水平无明显变化。与STI组比较,ANT组细胞培养上清液TNF-α、IL-1β、IL-6的浓度明显降低;肺泡巨噬细胞TLR4 mRNA、My D88 mRNA、NF-κB mRNA表达水平与蛋白表达水平明显下调。3组TLR9 mRNA与蛋白表达水平相近。结论炎症因子刺激可调节TLR4、My D88、NF-κB分泌增加,肺泡巨噬细胞TLR4-My D88信号通路参与并介导了机械通气所致的肺损伤。     

Higher Monocyte Expression of TLR2 and TLR4, and Enhanced Pro-inflammatory Synergy of TLR2 with NOD2 Stimulation in Sarcoidosis

Introduction  Sarcoidosis is an inflammatory disease of unknown etiology. However, an infectious cause has been proposed suggesting a role for pattern-recognition receptors, such as Toll-like receptors (TLRs) and nucleotide-binding domain, leucin-rich repeat containing family proteins (NLRs), in the pathogenesis. Objective  Our aim was to investigate whether differences in TLR2 and TLR4 expression, and the response to TLR2, TLR4, and NOD2 stimulation, are associated with sarcoidosis. Materials and Methods  Blood mononuclear cells from sarcoidosis patients (n = 24) and healthy subjects (n = 19) were incubated with the TLR2 ligands PGN and Pam3CSK4, the TLR4 ligand LPS, the NOD2 ligand MDP, or medium alone. After 16 h, monocyte TLR2 and TLR4 expression and cytokine secretion, including TNFα, IL-1β, IL-6, IL-8, IL-10, and IL-12p70, were measured using flow cytometry and cytometric bead array. Results  TLR2 and TLR4 expression at baseline was significantly higher in patients. Combined TLR2 and NOD2 stimulation induced a four-fold higher secretion of TNFα and a 13-fold higher secretion of IL-1β in patients. Additionally, there was a synergistic effect of TLR2 with NOD2 stimulation on induction of IL-1β in patients, whereas IL-10 was synergistically induced in healthy subjects. Conclusion  Increased TLR expression and enhanced secretion of pro-inflammatory cytokines after combined TLR2 and NOD2 stimulation may be related to the pathogenesis of sarcoidosis. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. This study was supported by the Swedish Heart–Lung Foundation, King Oscar II Jubilee Foundation, the Swedish Research Council, the U.S. National Institutes of Health (Grant No. 1 R21 HL077579-01), the Stockholm County Council and Karolinska Institutet.     

人TLR4胞外区cDNA克隆及其酵母表达载体的构建

研究表明：TLR4是哺乳动物LPS作用的受体，介导LPS的生理和病理效应[1～3］。有关研究取得明显的进展，但对于其识别的配体目前还未阐明。新近发现并广为应用的酵母双杂交技术给上述研究提供了新的机遇。因此，本研究克隆TLR4胞外区cDNA，并构建酵母双杂交系统的靶基因，为进一     

Analysis of the Association of Polymorphisms rs5743708 in TLR2 and rs4986790 in TLR4 with Atopic Dermatitis Risk

Background: We carried out a meta-analysis to assess whether Toll-like receptor 2 (TLR2) rs5743708 and Toll-like receptor 4 (TLR4) rs4986790 polymorphisms are associated with the risk of atopic dermatitis.

Methods: A systematic search of PubMed, Embase, and Web of Science was performed to identify eligible case–control studies on the association of rs5743708 and rs4986790 with the risk of atopic dermatitis. Statistical analyses of the odds ratio (OR), 95% confidence interval (CI), and p value were performed using STATA software.

Results: Our meta-analysis included a total of nine case–control studies, all involving Caucasian populations. With respect to the TLR2 rs5743708 G/A polymorphism, there was a statistically significant difference in the overall risk of atopic dermatitis between the case and control groups [OR = 2.07, p value of association test, p_{(association)} = 0.001 in allele (A vs. G) model; OR = 1.93, p_{(association)} = 0.004 in carrier (A vs. G) model; OR = 2.07, p_{(association)} = 0.001 in heterozygote (GA vs. GG) model; OR = 1.99, p_{(association)} = 0.001 in dominant (GA+ AA vs. GG) model]. Similar positive results were observed in the subgroup analysis of “population-based control.” For the TLR4 rs4986790 A/G polymorphism, an increased atopic dermatitis risk was detected in the case group under the allele [OR = 1.78, p_{(association)} = 0.013], carrier [OR = 1.69, p_{(association)} = 0.027] and heterozygote [OR = 1.74, p_{(association)} = 0.020] models, but not the dominant [OR = 1.44, p_{(association)} = 0.070] model, in comparison to the population-based control group.

Conclusion: Our meta-analysis revealed a novel finding that the heterogeneous “GA” genotype of the TLR2 rs5743708 and “AG” genotype of the TLR4 rs4986790 may be associated with increased susceptibility to atopic dermatitis in Caucasians.     

硝普钠对内毒素诱导的U937细胞TLR4表达的影响

目的:研究一氧化氮(NO)供体硝普钠(SNP)对内毒素(LPS)诱导的人单核巨噬细胞株U937表达TLR4的影响,明确其抗炎机制.方法:佛波脂(PMA)诱导U937成熟后分为四组,即对照组(空白对照)、LPS组(10 ng/ml LPS+100 ng/ml rhLBP)、低剂量SNP组(LPS+rhLBP+50 μmol/L SNP)和高剂量SNP组(LPS+rhLBP+500 μmol/L SNP).用RT-PCR和Western blot测定TLR4 mRNA和蛋白表达.ELISA法测定细胞上清中的肿瘤坏死因子α(TNF-α)的含量.结果:低、高剂量SNP组TLR4 mRNA的OD值较LPS组(0.308±0.050、0.138±0.004 4 vs 0.342±0.098,P<0.05、P<0.01)低,较对照组高(0.030±0.012,均P<0.01).低、高剂量SNP组TLR4 蛋白的OD值较LPS组(4.42±1.01、3.06±0.07 vs 6.02±1.19,均P<0.01)低,较对照组(2.01±0.09,均P<0.01)高.低、高剂量SNP组TNF-α较LPS组显著降低(105.5±2.56、71.5±7.75 vs 128.67±39.67,均P<0.05),较正常组(60±17.2,P<0.05、P>0.05)高.结论:SNP可能通过抑制TLR4介导的LPS信号跨膜转导,降低其引起的炎症反应,提示SNP对急性肺损伤或脓毒血症可能具有预防和早期治疗的作用.     

Toll样受体2和Toll样受体4在HBV感染后的免疫作用

Toll样受体（TLR）是启动固有免疫和调节适应性免疫的重要分子,参与肝脏对病毒及细菌的免疫TLR2、TLR4过程。在HBV的慢性化进程中,TLR2、TLR4与Thl和Th2的免疫平衡及调节性T细胞（Treg）的免疫抑制相关,HBV感染后,HBcAg刺激巨噬细胞产生TNF—α的作用需要TLR2参与,HBeAg的表达与否与TLR2的表达状态有关,而TLR4通过诱导iNOS的表达和激发HBV特异性免疫在体内抗HBV过程中起重要作用：     

TLR2和TLR4单克隆抗体对DSS诱导的小鼠结肠炎肠黏膜细胞因子及肠道菌群的影响

目的 研究Toll样受体2单克隆抗体(Toll-like receptor 2 monoclonal antibody,TLR2McAb)、Toll样受体4单克隆抗体(TLR4McAb)对葡聚糖硫酸钠(dextran sulfate sodium,DSS)诱导的小鼠急性期溃疡性结肠炎组织学改变及肠道菌群结构的影响.方法 雄性BALB/c小鼠分为正常对照组(A)、急性期溃疡性结肠炎模型组(B)、TLR2McAb干预组(C)、TLR4McAb干预组(D)、TLR2McAb+TLR4McAb共同干预组(E),每组10只.A组饮用蒸馏水,B～E组饮用5%DSS水溶液以产生急性期溃疡性结肠炎,造模开始同时,每隔48 h予A、B两组小鼠腹腔内注射生理盐水,C～E组小鼠分别予以10μg的TLR2McAb、TLR4McAb、TLR2McAb+TLR4McAb,期间观察小鼠的疾病活动指数(disease activity index,DAI).干预7 d后处死小鼠,HE染色观察结肠炎症,并进行结肠组织病理学评分(histopathological score,HS);使用real-time PCR法检测各组结肠黏膜中IFN-γ、IL-4、IL-17表达;留取盲肠内粪便对大肠杆菌、双歧杆菌及乳酸杆菌进行培养并比较各菌群菌落计数(colony forming units,CFU)的变化.应用SPSS13.0软件进行统计学分析,以P<0.05为差异有统计学意义.结果 (1)与A组比较,B组的DAI及HS显著增高(DAI:9.700±2.406 vs 0.500±0.707,P<0.01;HS:16.500±2.991 vs 6.400±3.273,P<0.01);C、D组与B组比较DAI及HS差异均无统计学意义(P>0.05);E组的DAI及HS明显低于B组(DAI:5.700±3.498 vs 9.700±2.406,P<0.05;HS:9.500±3.308 vs 16.500±2.991,P<0.01).(2)与A组比较,B组小鼠结肠黏膜IFN-γ、IL-4及IL-17的mRNA表达明显增高;而C～E组结肠黏膜三种细胞因子的表达均有不同程度的降低.(3)A组大肠杆菌数量较少,B～E四组大肠杆菌均明显生长(与A组比较P<0.05),C～E组大肠杆菌数值与B组比较有所下降,但差异无统计学意义(P>0.05);B组双歧杆菌及乳酸杆菌数量均明显少于A组及C～E组(P<0.05),使用TLR2McAb、TLR4McAb干预后,C～E组双歧杆菌及乳酸杆菌数量上升,与A组比较差异无统计学意义(P>0.05).结论 TLR2McAb、TLR4McAb同时干预对DSS诱导的小鼠急性期溃疡性结肠炎有显著改善作用;两种McAb均能明显提高小鼠肠道内双歧杆菌及乳酸杆菌的菌群数量,从而改善肠道菌群结构,但对大肠杆菌数量无明显影响,且两抗体同时干预对肠道菌群结构的改善未见显著协同作用.     

Subcutaneous immunization with Streptococcus pneumoniae GAPDH confers effective protection in mice via TLR2 and TLR4

The surface localized Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) of Streptococcus pneumoniae is best known as housekeeping protein. Currently, GAPDH has been recognized as moonlighting protein and virulent factor. Therefore, we investigate whether GAPDH can act as a suitable vaccine candidate protein to prevent pneumococcal infection. In this study, mice received subcutaneous vaccination with recombinant GAPDH followed by challenge with D39 and 19F showing higher survival rate and lower bacterial loads in nasal washes and lung homogenates than control. Meanwhile, high titers of rGAPDH specific antibody and elevated titers of IgG subtype indicated that rGAPDH could elicit immune response in mice. Then, we investigated the mechanism that immunization with rGAPDH conferred protection against Streptococcus pneumoniae in host. In vitro experiments, rGAPDH induced phenotypic and functional maturation of BMDCs, because the high expression of CD40, CD86 and MHC II and the production of IL-12p70, IL-6 and TNF-α were observed after treatment with rGAPDH. However, the costimulatory molecules and cytokines declined significantly in TLR2^−/− and TLR4^−/− mice, indicating rGAPDH can be a potential ligand for both TLR2 and TLR4. Subsequent investigations suggested that rGAPDH could also activate the phosphorylation of MAPKs, PI3K-Akt and NF-κB. Meantime, upregulation of mir-146a and downregulation of mir-27a in BMDCs were observed. Taken together, our findings confirm that rGAPDH, a housekeeping protein, is also qualified as a vaccine candidate protein and rGAPDH activates BMDCs in a TLR2 and TLR4 dependent manner.     

TLR2和TLR4单克隆抗体对DSS诱导的小鼠结肠炎肠黏膜细胞因子及肠道菌群的影响

Objective To evaluate the effect of TLR2McAb and TLR4McAb on intestinal flora of DSS-induced colitis in mice. Methods Fifty healthy male BALB/c mice (SPF level), were randomly assigned into five groups: the control group( group A), the UC model group( group B), TLR2McAb intervention group( group C), TLR4McAb intervention group( group D) and TLR2McAb + TLR4McAb intervention group(group E). Clinical symptoms were evaluated by the disease activity index(DAI), while tissue sam ples were evaluated by histological scoring(HS). The quantities of mRNA for IFN-γ, IL-4 and IL-17 were determined by real-time PCR. Meanwhile, fecal samples were obtained directly from the cecum for microbiological studies. Results After the treatment with TLR2McAb and TLR4McAb, DAI and HS were decreased significantly. Compared with group A, inflammatory cytokines such as IFN-γ, IL-4 and IL-17 in group B were higher. Compared with group B, expression of these three cytokines in group C to E was all markedly decreased. Group A showed a considerable predominance of Lactobacillus spp and Bifidobacterium spp,while the UC model group showed a conspicuous increase of Escherichia coli and decreases of Lactobacillus spp and Bifidobacterium spp. After treatment with TLR2McAb or/and TLR4McAb, Lactobacillus spp and Bifidobacterium spp increased to the normal level. But counts of E. Coli in the three intervention groups were not changed. Conclusion TLR2McAb and TLR4McAb suppressed the development of DSS-induced colitis and increase cecum counts of Lactobacilli and Bifidobacteria.     

TLR2和TLR4单克隆抗体对DSS诱导的小鼠结肠炎肠黏膜细胞因子及肠道菌群的影响

Objective To evaluate the effect of TLR2McAb and TLR4McAb on intestinal flora of DSS-induced colitis in mice. Methods Fifty healthy male BALB/c mice (SPF level), were randomly assigned into five groups: the control group( group A), the UC model group( group B), TLR2McAb intervention group( group C), TLR4McAb intervention group( group D) and TLR2McAb + TLR4McAb intervention group(group E). Clinical symptoms were evaluated by the disease activity index(DAI), while tissue sam ples were evaluated by histological scoring(HS). The quantities of mRNA for IFN-γ, IL-4 and IL-17 were determined by real-time PCR. Meanwhile, fecal samples were obtained directly from the cecum for microbiological studies. Results After the treatment with TLR2McAb and TLR4McAb, DAI and HS were decreased significantly. Compared with group A, inflammatory cytokines such as IFN-γ, IL-4 and IL-17 in group B were higher. Compared with group B, expression of these three cytokines in group C to E was all markedly decreased. Group A showed a considerable predominance of Lactobacillus spp and Bifidobacterium spp,while the UC model group showed a conspicuous increase of Escherichia coli and decreases of Lactobacillus spp and Bifidobacterium spp. After treatment with TLR2McAb or/and TLR4McAb, Lactobacillus spp and Bifidobacterium spp increased to the normal level. But counts of E. Coli in the three intervention groups were not changed. Conclusion TLR2McAb and TLR4McAb suppressed the development of DSS-induced colitis and increase cecum counts of Lactobacilli and Bifidobacteria.