双歧杆菌的脂磷壁酸对小鼠腹腔MΦ的激活作用

目的 探讨青春型双歧杆菌的脂磷壁酸（LTA）对MΦ功能的影响。方法 将LTA注射于小鼠腹腔，分别采用中性红吞噬试验，MTT法，小鼠胸腺细胞增殖法和ELISA法，检测MΦ的吞噬能力，能量代谢水平，IL－1的活性及IL－6含量。结果 LTA注射组小鼠腹腔MΦ的吞噬能力，能量代谢水平，IL－1活性及IL－6含量均显著高于对照组（P＜0．01）。结论 双歧杆菌的LTA能激活MΦ，提高其吞噬能力和能量代谢水平，同时可分泌多种的具有杀瘤作用的活性因子。     

青春型双歧杆菌脂磷壁酸对巨噬细胞的免疫活性影响

双歧杆菌的脂磷壁酸 (ｌｉｐｏｔｅｉｃｈｏｉｃａｃｉｄ ,ＬＴＡ)有较强的免疫活性作用 ,能激活巨噬细胞以及增强单核细胞的呼吸暴发。作者观察了青春型双歧杆菌的ＬＴＡ刺激小鼠腹腔巨噬细胞后分泌的ＴＮＦ α活性以及ＩＬ 12、ＮＯ的含量 ,同时检测巨噬细胞的体外杀瘤活性 ,旨在探讨它对巨噬细胞的免疫调节作用。材料与方法ＬＴＡ :按照文献从青春型双歧杆菌中提取ＬＴＡ。提取的ＬＴＡ分别经紫外扫描和化学组分分析证实无明显蛋白质以及核酸污染。被动血球凝集试验显示ＬＴＡ能自主粘附鸡红细胞。实验动物 :ＢＡＬＢ/ｃ小鼠 ,雌雄各半 ,…     

双歧杆菌脂磷壁酸对HL-60细胞端粒酶活性的影响

目的 探讨双歧杆菌表面分子脂磷壁酸（ＬＴＡ）对体外培养的ＨＬ－６０白血病细胞端粒酶活性的影响。方法 采用ＰＣＲ－ＥＬＩＤＡ法检测经ＬＴＡ处理前后的ＨＬ－６０白血病细胞株端粒酶活性的改变。结果 经ＬＴＡ处理后,ＨＬ－６０白血病细胞的生长受到抑制,端粒酶活性明显降低。结论 双歧杆菌ＬＴＡ对ＨＬ－６０白血病细胞具有生长抑制作用,其抗肿瘤作用的机理可能与抑制肿瘤细胞的端粒酶活性有关。     

双歧杆菌干预对大鼠肠上皮细胞Toll样受体表达的影响

目的 通过观察双歧杆菌对大鼠肠上皮细胞Toll样受体(toll-like receptors,TLR)表达的影响,为双歧杆菌新生儿坏死性小肠结肠炎(necrotizing enterocolitis of newborn,NEC)的治疗提供理论依据.方法 选取50只健康SD大鼠,每组25只,适应性喂养1周后采取TNBS法造模,将造型大鼠随机均分为对照组与观察组,对照组给予常规饲养,观察组在常规饲养的基础上给予双歧杆菌经口2 mL/d灌服,连续饲养3周后比较两组大鼠一般状况、肠黏膜大体评分、组织学评分与RT-PCR检测结果.结果 造模后观察组大鼠不良反应比对照组大鼠少(χ2=3.920,P<0.05);观察组大鼠肠黏膜大体评分与组织学评分优于对照组大鼠(t=2.966、2.786,P<0.05);观察组大鼠肠组织中TLR2与TLR4表达低于对照组大鼠(t=19.403、20.331,P均<0.05).结论 双歧杆菌能够抑制TLR的表达,减轻肠黏膜损伤程度,促进肠道正常生理功能的恢复,为双歧杆菌治疗NEC提供了实验支持.     

双歧杆菌脂磷壁酸延缓脾脏衰老的研究

目的　研究双歧杆菌表面分子脂磷壁酸 (LTA)在D 半乳糖诱导的衰老小鼠体内 ,对脾脏指数和脾细胞DNA损伤的影响。方法　在建立D 半乳糖诱导的衰老小鼠模型的同时 ,注射双歧杆菌LTA ;然后测定模型对照组、正常对照组、试验组小鼠的脾脏指数 ,并以单细胞凝胶电泳试验检测脾脏淋巴细胞DNA氧化损伤的情况。结果　与正常对照组相比 ,模型对照小鼠的脾脏指数显著升高 (P <0 .0 5 ) ,脾淋巴细胞DNA受到了较严重的损伤 (P <0 .0 5 ) ;用双歧杆菌LTA处理后 ,试验小鼠的脾脏指数明显下降 (P <0 .0 5 ) ,脾淋巴细胞DNA的损伤程度显著降低 (P <0 .0 5 )。结论　双歧杆菌LTA能显著抑制衰老小鼠脾脏淋巴细胞DNA的氧化损伤 ,这可能与双歧杆菌抗衰老有关。     

双歧杆菌脂磷壁酸抗免疫衰老的实验研究

目的：探讨双歧杆菌抗衰老的分子机理。方法：在建立D-半乳糖诱导的衰老小鼠模型的同时，每日注射双歧杆菌LTA。检测各组小鼠体重增长曲线、胸腺形态、胸腺指数、用免疫组化方法检测胸腺c-fos、p16蛋白表达及用ELISA法检测外周血IL-2的含量。结果：与青年对照组小鼠相比，衰老模型组小鼠胸腺组织形态结构异常，体重、胸腺指数、胸腺c-fos蛋白表达与外周血IL-2含量显著下降，胸腺p16蛋白表达显著升高；而双歧杆菌LTA，能显著逆转上述这些变化。结论：双歧杆菌LTA具有抗衰老作用。     

双歧杆菌脂磷壁酸激活巨噬细胞活性机制的研究

目的：从信号分子PKC和细胞内游离Ca^2 ([Ca^2 ]i)这一途径探索青春型双歧杆菌的脂磷壁酸（lipoteichoic acid,LTA)激活小鼠腹腔巨噬细胞的机制，同时观察巨噬细胞之间缝隙连接通讯（GJIC）的变化。方法：γ-^32P ATP磷酸转移法测定巨噬细胞总PKC活性；激光共聚焦显微镜检测[Ca^2 ]i浓度的变化；激光漂白后荧光恢复技术（FRAP）观察GJIC的状态。结果：（1）LTA能明显提高巨噬细胞总PKC活性，呈剂量依赖性；（2）LTA可显著升高巨噬细胞[Ca^2 ]i的水平，并且EDTA和维拉帕米处理组、肝素和普鲁卡因处理组以及EDTA、维拉帕米、肝素和普鲁卡因处理组巨噬细胞内[Ca^2 ]i亦升高，但明显低于对照组（P＜0．01）。（3）巨噬细胞被LTA刺激后，其平均荧光恢复率明显高于对照组（P＜0．01）。结论：LTA可通过提高PKC活性，升高[Ca^2 ]i的水平以及增强GJIC的功能来激活巨噬细胞。     

纳米氧化铁双歧杆菌脂磷壁酸对人胃癌荷瘤鼠体内细胞因子水平的影响

目的 探讨纳米氧化铁(Fe3 O4)双歧杆菌脂磷壁酸(Bigidobacterium lipoteichoic acid,BLTA)对人胃癌荷瘤鼠体内细胞因子水平的影响,研究以纳米Fe3 O4为载体的BLTA(Fe3 O4-BLTA)对BGC-823胃癌移植瘤的抑制机制. 方法 用人低分化BGC-823胃癌细胞株移植到40只雄性BALB/c裸鼠建立胃癌荷瘤鼠模型.将随机分组的荷瘤鼠,进行不同浓度的纳米Fe3 O4-BLTA复合物灌胃12 d后处死.取移植瘤观察其肿瘤抑制率,应用免疫组化技术,检测瘤体内CD31微血管密度值(microvessel density,MVD)及血管内皮生长因子(VEGF)的阳性率.提取腹腔巨噬细胞,用ELISA法检测细胞因子含量. 结果 纳米Fe3O4-BLTA低剂量组(10μ/d)对肿瘤的抑制率达到49%;纳米Fe3 O4-BLTA低剂量组的CD31-MVD(57.000±6.790)与VEGF的表达(O.0224士0.0763)均比其他剂量组低(P相似文献   

双歧杆菌表面分子诱导大肠癌细胞分化的研究

目的 研究双歧杆菌表面分子完整肽聚糖（whole peptidoglycan,WPG)、脂磷壁酸（lipo-teichoic acid,LTA)和多糖（polysaccharides,PS)的直接抗肿瘤作用。方法 采用MTT、形态学、流式细胞能的机理。结果 LTA抑制LoVo细胞的生长,将细胞阻滞于G0／G1期。50μg/mlLTA使细胞核与细胞浆向成熟细胞分化,并且降低细胞膜的流动性。LoVo细胞特征性分化酶－肠型碱性磷酸酶的合成亦显著增加。LTA还诱导细胞内钙离子浓度增加,增加的钙离子来自于外钙内流而非内贮钙释放。结论 LTA作用于LoVo细胞后,直接抑制了该细胞的生长,并诱导LoVo细胞向成熟细胞分化,钙离子内流引起的信号传导在此过程中可能发挥了重要的作用。     

双歧杆菌LTA上调ICAM-1表达及其在LAK抗肿瘤中的作用

目的 探讨双歧杆菌脂磷（ｌｉｐｏｔｅｉｃｈｏｉｃ ａｃｉｄ,ＬＴＡ）作用于ＬｏＶｏ细胞后是否能增强ＬＡＫ对该细胞的识别和杀伤,以及ＩＣＡＭ－１在其中的作用。方法采用ＭＴＴ方法观察了ＬＡＫ对ＬｏＶｏ细胞的识别和杀伤作用,并用流式细胞仪和ＥＬＩＳＡ的方法检测了ＬｏＶｏ细胞表面ＩＣＡＭ－１的表达。结果５０μｇ／ｍｌ ＬＴＡ作用３ｄ,ＬＡＫ对ＬｏＶｏ细胞的粘附率由９．６２％增加到２４．４２％,ＬｏＶｏ细胞     

紫癜性肾炎患者外周血单个核细胞Toll样受体3和4的信号转导途径

背景：目前关于Toll样受体3和Toll样受体4介导的信号转导通路在紫癜性肾炎的发病机制中的作用尚不清楚。目的：分析Toll样受体3和Toll样受体4在过敏性紫癜和紫癜性肾炎发病机制中的作用。方法：选取过敏性紫癜患儿64例,分为过敏性紫癜无肾损害组36例及过敏性紫癜性肾炎组28例,另选健康儿童30例作为正常对照组。实时荧光定量PCR检测外周血单核细胞Toll样受体3、Toll样受体4、髓样分化蛋白2、髓样细胞分化因子88、白细胞介素1β、白细胞介素6、白细胞介素12 mRNA的基因相对表达量;应用流式细胞术检测外周血单核细胞Toll样受体3、Toll样受体4蛋白表达率。结果与结论：①过敏性紫癜患儿Toll样受体4 mRNA及蛋白表达显著高于正常对照组(P < 0.05)。紫癜性肾炎组Toll样受体4 mRNA及蛋白表达均显著高于紫癜无肾损害组(P < 0.05)。②过敏性紫癜组髓样分化蛋白2、髓样细胞分化因子88、白细胞介素1β、白细胞介素6 mRNA的表达均显著高于正常对照组(P < 0.05),白细胞介素12 mRNA的表达显著低于正常对照组(P < 0.05);紫癜性肾炎组髓样分化蛋白2、髓样细胞分化因子88、白细胞介素1β、白细胞介素6 mRNA的表达显著高于紫癜无肾损害组(P < 0.05),紫癜性肾炎组白细胞介素12 mRNA的表达显著低于紫癜无肾损害组(P < 0.05)。③过敏性紫癜组患儿外周血单核细胞Toll样受体4 mRNA与蛋白表达呈正相关(r=0.60,P < 0.01);过敏性紫癜患儿Toll样受体4 mRNA与髓样分化蛋白2、髓样细胞分化因子88、白细胞介素1β、白细胞介素6表达均呈正相关(P < 0.01),与白细胞介素12 mRNA表达呈负相关(r=-0.66,P < 0.01)。提示Toll样受体4可能通过髓样细胞分化因子88依赖信号转导途径介导过敏性紫癜的免疫发病机制,Toll样受体4的过度活化可能与过敏性紫癜的肾损伤有关。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程全文链接：     

Toll-like receptor (TLR) expression of immune system cells from metastatic breast cancer patients with circulating tumor cells

The risk posed by breast cancer represents a complex interaction among factors affecting tumor immunity of the host. Toll-like receptors (TLRs) are members of the innate immune system and generally function to attract host immune cells upon activation. However, the good intentions of TLRs are sometimes not transferred to positive long-term effects, due to their involvement in exacerbating inflammatory effects and even contributing to continued inflammation. Chronic inflammatory states are considered to favor an increased predisposition to cancer, with continuous activation of inflammatory cytokines and other hallmarks of inflammation exerting a deleterious effect. Circulating tumor cells (CTCs) are neoplastic cells present in the peripheral blood circulation that have been found to be an indicator of disease progression and long-term survival. In the present study, we examined the expression of TLRs on dendritic cells, which play a major role in eliciting anti-tumor immunity, in metastatic breast cancer patients with CTCs. Flow cytometric data showed significant differences between circulating tumor cell (CTC) positive patients and CTC negative patients in their expression of TLR2 by CD8 positive cytotoxic T cells and TLR2, TLR4, TLR3, and TLR8 by CD11c positive dendritic cells (p < 0.05). Expression of TLR2, TLR4, and TLR8 was increased in CTC positive patients, whereas TLR3 expression was decreased in the dendritic cell population.     

不同Toll样受体介导的树突状细胞因子表达

目的研究树突状细胞在不同Toll样受体(TLR)配体刺激下的早期反应。方法将鼠骨髓细胞诱导分化得到DC,利用TLR配体刺激,采用芯片分析方法研究其免疫相关基因在9h的表达;采用细胞因子分析系统,检测了12、48h细胞培养上清中细胞因子、趋化因子的产生。结果在给予LPS、PolyI:C、R848、CpG和anti-CD40刺激9h后,IL-1、IL-2rg、IL-13、CCL2、CCL4和CCL7的基因表达明显升高,CCL3、CCL5和CXCL9、CXCL10、CXCL11的表达增加最为显著(P<0.01);而IL-10(PolyI:C除外),CCL-6的表达降低(P<0.05)。培养12h后,IL-1、IL-6、IL-10、IL-12(p40)、IL-12(p70)、TNFa、G-CSF、GM-CSF、KC和MIP-1a(CCL3)产生在5种TLR配体刺激下均显著增加(P<0.01);培养48h后,IL-1、IL-10、IL-12(p40)、IL-12(p70)、TNFa、IFN-γ、G-CSF和MIP-1a(CCL3)产生也同样显著增加(P<0.01)。相对于其它TLR配体,CpG刺激时MIP-1a(CCL...     

Human salivary proteins with affinity to lipoteichoic acid of Enterococcus faecalis

Enterococcus faecalis is associated with refractory apical periodontitis and its lipoteichoic acid (Ef.LTA) is considered as a major virulence factor. Although the binding proteins of Ef.LTA may play an important role for mediating infection and immunity in the oral cavity, little is known about Ef.LTA-binding proteins (Ef.LTA-BPs) in saliva. In this study, we identified salivary Ef.LTA-BPs with biotinylated Ef.LTA (Ef.LTA-biotin) through mass spectrometry. The biotinylation of Ef.LTA was confirmed by binding capacity with streptavidin-FITC on CHO/CD14/TLR2 cells. The biological activity of Ef.LTA-biotin was determined based on the induction of nitric oxide and macrophage inflammatory protein-1α in a macrophage cell-line, RAW 264.7. To identify salivary Ef.LTA-BPs, the Ef.LTA-biotin was mixed with a pool of human saliva obtained from nine healthy subjects followed by precipitation with a streptavidin-coated bead. Ef.LTA-BPs were then separated with 12% SDS-PAGE and subjected to the mass spectrometry. Six human salivary Ef.LTA-BPs including short palate lung and nasal epithelium carcinoma-associated protein 2, zymogen granule protein 16 homolog B, hemoglobin subunit α and β, apolipoprotein A-I, and lipocalin-1 were identified with statistical significance (P < 0.05). Ef.LTA-BPs were validated with lipocalin-1 using pull-down assay. Hemoglobin inhibited the biofilm formation of E. faecalis whereas lipocalin-1 did not show such effect. Collectively, the identified Ef.LTA-BPs could provide clues for our understanding of the pathogenesis of E. faecalis and host immunity in oral cavity.     

Presentation of lipoteichoic acid potentiates its inflammatory activity

Lipoteichoic acid (LTA) is a major immunostimulatory molecule in the cell wall of Gram-positive bacteria. Adhesion of LTA to a polystyrene surface drastically increased its immunostimulatory potency in human whole blood in comparison to soluble LTA, although only 1% of the LTA had bound, as determined using rhodamine-labelled LTA. The release of the proinflammatory cytokines IL-1beta, TNF and IL-6 and the chemokines IL-8 and G-CSF was increased 2- to 10-fold, but IL-10 release was unaltered. This presentation effect was not shared by lipopolysaccharide (LPS) or other toll-like receptor 2 agonists and was less pronounced in polypropylene vessels. LTA did not induce cytokine release in silicone-coated borosilicate vessels, but covalent coupling of LTA to polystyrene beads restored cytokine induction in these vessels, indicating that presentation of LTA on a surface is in fact essential for its immunostimulatory potency. This novel aspect of presentation as a factor in the recognition of LTA may reflect the physiological situation in the bacterial cell wall, where LTA is anchored in the bacterial membrane and projects through the peptidoglycan. In practical terms, contamination of medical devices with components of Gram-positive bacteria may pose an underestimated inflammatory risk.