树突状细胞激活介导副干酪乳杆菌L9对CD4~+T细胞的分化作用研究

为研究副干酪乳杆菌L9(L9)诱导CD4+T细胞分化的作用机制,以骨髓源树突状细胞(BMDCs)为模型,通过酶联免疫和流式细胞术分析L9对BMDCs调节性细胞因子分泌以及CD103表达的影响;利用L9诱导后的BMDCs与小鼠脾CD4+T细胞联合培养,分析调节性T(Foxp3+Treg)细胞的比例。结果表明,与空白组相比,L9的干预能够显著促进BMDCs中白介素(IL-10)和转化生长因子β(TGF-β)的分泌以及CD103的表达(P0.05),并呈现浓度依赖效应;同时,经L9诱导后的BMDCs,显著提高了CD4+T细胞中Foxp3+Treg细胞的比例(P0.05)。L9通过调节BMDCs中调节性细胞因子的分泌以及CD103的表达,促进CD4+T细胞向Foxp3+Treg细胞分化。     

外周血中CD4+、CD8+T、CD4+CD25+Treg在绵羊接种布鲁氏菌M5-90弱毒疫苗后的动态变化

为研究绵羊接种布鲁氏菌弱毒M5-90株后外周血中CD4+、CD8+T、CD4+CD25+Treg细胞的动态变化规律,本研究选择11只健康绵羊,每10 d免疫一次,共免疫3次,分别在免疫前、免疫后10d、20 d、30 d利用流式细胞术检测外周血中CD4+、CD8+T、CD4+CD25+Treg淋巴细胞亚群.在免疫后的第20 d,CD4+T、CD8+T细胞百分含量达到最高水平(P＜0.05)后均缓慢下降;在第10d,CD4+CD25+Treg细胞缓慢升高,至20 d、30 d均显著升高(p＜0.05);在布鲁氏菌M5-90疫苗免疫应答过程中CD4+CD25+Treg细胞参与了机体的免疫反应调控,对CD4+T、CD8+T淋巴细胞的比例进行调节,并且维持CD4+/CD8+比值稳定,起到平衡Th1/Th2细胞间反应的作用.     

猪繁殖与呼吸综合征病毒诱导CD4(+)CD8(+)CD25(+)Foxp3(+)型T调节细胞(Tregs)

本研究旨在分析猪繁殖与呼吸综合征病毒诱导的T调节细胞(Tregs)。作者采集了感染后不同时间点(dpi)的血清、血液、扁桃体和纵隔淋巴细胞样品,检测了PBMC和淋巴细胞中的CD4(+)CD8(-)CD25(+)Foxp3(+)、CD4(+)CD8(+)CD25(+)Foxp3(+)或CD4(-)CD8(+)CD25(+)Foxp3(+)表型的频率,分析了产生IL-10或TGF-β的细胞。14dpi时PRRSV增加了CD4(+)CD8(+)CD25(+)Foxp3(+)型细胞的数量,并且CD4(+)CD8(+)CD25(+)Foxp3(+)型细胞的数量维持不变直到28dpi。病毒血症和诱导的调节细胞呈正相关。在淋巴组织中持续检测到CD4(+)CD8(+)CD25(+)Foxp3(+)诱导的Treg细胞。对产生IL-10和TGF-β的细胞分析显示针对猪繁殖与呼吸综合征病毒,CD4(+)CD8(-)Foxp3(较低的)和CD4(+)CD8(+)Foxp3(较高的)型细胞中等强度地增加IL-10细胞的比例。在PRRSV刺激后,只在CD4(+)CD8(+)Foxp3(较高的)样本中检测到TGF-β。总之PRRSV感染增加CD4(+)CD8(+)CD25(+)Foxp3(较高的)基因型的Tregs细胞的频率以及产生TGF-β。     

旋毛虫抗原基因T668重组蛋白对鼠结肠炎的保护效应

旋毛虫感染已被证实对Th1型免疫应答为主的炎症性肠病具有良好的干预作用。寄生虫特异性抗原基因表达的蛋白在发挥免疫调节过程中扮演重要角色。本研究目的是探讨旋毛虫表达T668重组蛋白对肠炎模型鼠的保护作用。BALB/c小鼠腹腔注射50μg T668蛋白1次/10d,共3次,直肠内灌注5mg三硝基甲苯磺酸(TNBS)以诱导肠炎发生,通过检测疾病活动指数、组织病理变化进行评估及Th1、Th2型免疫反应相关细胞因子变化情况。T668重组蛋白明显改善疾病活动指数(DAI)及宏观和微观上病理评分。肠道细胞ELISA检测显示,T668蛋白免疫造模后3、7dIL-10和TGF-βLPMC产生水平高差异显著(P<0.05),而3、7dIFN-γ、IL-17和3d后的IL-12LPMC产生水平低差异显著(P<0.05);免疫细胞检测7d的蛋白免疫组CD4+CD25+Foxp3+Treg表达比未免疫组显著降低(P<0.05)。T668表达的重组蛋白对IBD是一个潜在的保护剂。     

CD4~+CD25~+调节性T细胞与鸡REV持续性感染的相关性研究

为探讨CD4~+CD25~+调节性T细胞(Treg)在禽网状内皮组织增生症病毒(REV)垂直感染引起鸡持续性病毒血症中的作用,在鸡胚发育第7天经卵黄囊接种REV建立先天性感染动物模型,通过流式细胞术分析不同日龄REV感染鸡外周血和免疫器官中CD4~+CD25~+Treg细胞的比例及其动态变化,进一步运用绝对荧光定量技术对病毒载量进行连续监测。结果显示:与对照组相比,在7、15、30、45日龄时,感染组鸡胸腺、法氏囊、外周血以及脾脏中CD4~+CD25~+Treg细胞的比例均显著升高;血液和脾脏中的病毒载量随着日龄增长而逐渐升高,胸腺和法氏囊中的病毒载量随着日龄增长而逐渐降低;外周血和免疫器官中REV的m RNA表达水平与CD4~+CD25~+Treg细胞出现的频率呈正相关。研究提示:REV感染鸡体内高频出现的CD4~+CD25~+Treg细胞与REV的持续性感染存在显著的相关性。     

猪瘟免疫猪接种PRRSV Nsp2Δ1882-2241弱毒疫苗后免疫应答及T细胞表型变化特征

选择17头28日龄的CSFV和PRRSV抗体均为阴性的仔猪,于试验的第1天和第14天分别对其进行猪瘟耐热保护剂活疫苗（兔源）和高致病性猪繁殖与呼吸综合征Nsp2A1882—2241弱毒疫苗免疫。在免疫后的第28、42天采集外周血液,分析特异性抗体表达量和外周血T淋巴细胞表型的变化,评估猪瘟免疫对猪繁殖与呼吸综合征免疫的影响。结果显示,在CSF免疫后第28、42天,CSFV高抗组中的CD4^＋、CD4^＋／CD8^＋、CD4^＋CD8^＋和CD4-CD8数目均比CSFV低抗组高,CD3^＋和CD8^＋细胞数量比CSFV低抗组低;PRRS高抗组中,CD4CD8-细胞含量高于PRRS低抗组;在CSF免疫后第28天,CSFV抗体产生较高（阳性比率为73．33％）,PRRSV抗体产生较低（阳性比率仅为6．67％）。在CSF免疫后的第42天,CSF高抗组中PRRSV抗体阳性比率较CSF低抗组高8．33％。结果表明,CSFV特异性抗体产生高时能增加PRRSV特异性细胞免疫应答,增加CD4^＋细胞、CD4^＋CD8^＋细胞数量,提高机体免疫水平。CD3＋和CD4CD8-细胞应答作用值得重视。     

胸腺外CD4和CD8双阳性T细胞的研究概述

胸腺依赖性细胞即 T细胞具有多种重要的免疫功能 ,不同的免疫功能与其细胞膜上的分化抗原 (CD)的种类相关联。其中 CD4和 CD8是关键的分化抗原。 CD4分子是单链糖蛋白 ,是自身主要组织相容性复合体 (MHC) 类抗原的受体。研究表明 ,其功能性分子可能是低聚体 [1 ] 。CD8分子也是糖蛋白 ,包含α链和β链 ,是 MHC 类抗原的受体。 CD4和 CD8与相应 MHC抗原结合是 T细胞在胸腺外发挥免疫功能的生化基础 ,也与 T细胞在胸腺微环境中的分化有关。来自骨髓的前 T细胞表面无任何 CD标志 ,在胸腺微环境中先后表达CD2、CD7、CD3抗原和 T…     

四君子汤发酵液的抗肿瘤作用及其对荷瘤小鼠免疫功能的影响

本试验研究了四君子汤发酵液对S180肿瘤模型小鼠的抗肿瘤作用和对免疫功能的影响。采用血清溶血素法检测荷瘤小鼠体液免疫功能;MTT比色法检测淋巴细胞的增殖和流式细胞术检测T细胞亚群。结果表明,四君子汤发酵液具有明显的抑制肿瘤生长的作用,并且可以增强环磷酰胺（CTX）的抗肿瘤作用,降低CTX免疫抑制的副作用。四君子汤发酵液可以提高免疫器官指数;对肿瘤小鼠脾淋巴细胞转化、血清抗体产生都有促进作用;可以明显提高模型小鼠CD3^＋和CD8^＋T淋巴细胞水平,降低由于肿瘤引起的CD4^＋/CD8^＋T淋巴细胞比值的升高,与模型组比较差异显著（P〈0.05）。研究表明四君子汤发酵液的抗肿瘤作用和增强机体免疫调节功能有关。     

调节性T细胞及在结核分支杆菌感染中的作用研究进展

结核病是由结核分支杆菌引起的慢性消耗性传染病。结核分支杆菌属于胞内寄生菌,机体的抗结核免疫主要依赖特异性的细胞免疫。调节性 T 细胞（Treg）是一类具有免疫抑制功能的 T 细胞亚群,在结核病的发生发展过程中起重要作用,Treg 在抗结核免疫中的作用成为研究热点。论文就调节性 T 细胞在结核分支杆菌感染中作用的研究进展做一综述。     

紫锥菊、黄芪对感染IBDV雏鸡胸腺、小肠中CD4~＋、CD8~＋ T淋巴细胞动态分布的影响

将14日龄雏鸡随机分为3组,A组灌服1 mL的紫锥菊、黄芪合剂,B、C组灌服生理盐水,连续灌服7 d。21日龄时A、B组雏鸡接种传染性法氏囊病病毒（IBDV）,用免疫组化法观察雏鸡胸腺、小肠中CD4＋、CD8＋T淋巴细胞动态分布的变化。结果表明,用药组和攻毒对照组相比较,CD4＋T淋巴细胞差异显著（P〈0.05）,但是CD8＋T淋巴细胞差异不显著（P〉0.05）,与空白对照组相比CD4＋淋巴细胞显著增多。胸腺、小肠中24日龄时CD4＋、CD8＋T细胞数量较其他日龄差异显著（P〈0.05）。总试验期胸腺中CD4＋、CD8＋含量是所测总数的60%。表明紫锥菊、黄芪对机体免疫有显著增强作用,以胸腺中CD4＋、CD8＋含量多于小肠,能显著降低IBDV对机体造成的损伤。     

微小隐孢子虫抗原CTL细胞表位预测及多表位基因的原核表达

应用多个服务器对微小隐孢子虫（Cryptosporidium parvum）候选疫苗抗原的氨基酸序列进行分析,预测可能存在的CD8＋细胞毒性T细胞（CD8＋cytotoxic T lymphocyte,CD8＋CTL）表位。从6种常见的免疫效果较好的候选疫苗抗原基因中选出10个分值较高的表位基因串联在一起,形成一条多表位基因,进行人工合成,表位之间用柔性氨基酸GGGGS或GPGPG链接,命名为CpCTL10。将该多表位基因重组入高效融合表达载体pET-28a（＋）,获得重组质粒pET-28a（＋）-CpCTL10,转化大肠杆菌BL21（DE3）进行诱导表达,表达产物进行SDS—PAGE、Western blot分析。结果显示,CpCTL10基因在大肠杆菌中主要以包涵体形式高效表达,表达的重组蛋白占菌体蛋白总量的55．3％,纯化的重组蛋白纯度达75．1％。Western blot分析显示表达产物能与感染隐孢子虫的鼠阳性血清发生特异性反应,表明表达的重组蛋白具有较好的抗原性,为多抗原多表位疫苗的研制打下某础．     

Factors affecting disease manifestation of toxocarosis in humans: Genetics and environment

Toxocara canis is regarded as the main cause of human toxocarosis but the relative contribution of T. cati is probably underestimated; serological and other diagnostic methods used in most studies of this zoonotic disease do not distinguish between the two parasites. The definitive hosts for T. canis are caniidae. Pups generally have higher infection rates than adult animals and are a major source of eggs in the environment. Humans usually acquire T. canis infection by accidental ingestion of embryonated eggs or encapsulated larvae from the environment or contaminated food, such infections may lead to visceral larva migrans (VLM), ocular larva migrans (OLM) or covert toxocarosis (CT). Although a mixed Th1- and Th2-mediated immunological response, particularly with high levels of IgE and eosinophilia is observed, the underlying mechanisms of molecular and immunopathogenesis for the development of the symptomatic syndromes of VLM, OLM, or of asymptomatic CT are largely unclear. Studies have indicated that immunological defences against various infectious diseases may be highly influenced by complex interactions of environmental and host genetic factors e.g. MHC class I and II, also known as human leucocyte antigen (HLA). Toxocara spp. infections are associated with a polarized CD4⁺ Th2 response with high IgE levels and eosinophilia, mediated mainly by HLA class II molecules. Associations have been made between HLA class II and pathological severity and host genetic effects on exposure to infection. Recent research suggests Foxp3⁺ CD4⁺CD25⁺-expressing T regulatory (Treg) cells play a role in regulation of the immunopathology of granulomas in experimental toxocaral granulomatous hepatitis and in enhanced expression of TGF-β1, which is an important factor for the local survival and function of Treg observed during T. canis invasion in the mouse small intestine, liver, muscle, and brain. Since the potential susceptibility loci HLA class II molecules, are considered involved in the regulation of a Th2-dominant immunity which is highly controlled by Foxp3⁺ CD4⁺CD25⁺ Treg cells by stimulation through TGF-β1, which thus provides a beneficial environment to T. canis larvae but severe injuries to local organs. However, TGF-β1 variant Leu10Pro known to be involved in disease severity warrants further elucidation as this too may have a role in the severity of human toxocarosis. Exploration of TGF-β1 polymorphism, Foxp3⁺ CD4⁺CD25⁺ Treg cells, and MHC polymorphisms may allow insight into the contribution made by environmental and genetic factors in influencing disease syndrome type and severity in humans with toxocarosis.     

Association of tumour‐infiltrating regulatory T cells with adverse outcomes in dogs with malignant tumours

Regulatory T cells (Tregs) infiltrate into a variety of tumour tissues and associate with poor prognosis in humans. However, data on association of Treg infiltration with prognosis is limited in canine tumours. The purpose of this study was to examine the number of tumour‐infiltrating Tregs and its association with overall survival (OS) in dogs with malignant tumours. The following 168 canine tumours were included: 37 oral malignant melanomas (OMMs); 14 oral squamous cell carcinomas (OSCCs); 16 pulmonary adenocarcinomas (PAs); 37 mammary carcinomas (MCs); 36 mast cell tumours (MCTs) and 28 hepatocellular carcinomas (HCCs). Normal tissues were obtained from 8 healthy dogs as controls. The number of forkhead box P3 (Foxp3)‐positive Tregs in intratumoral and peritumoral areas was investigated by immunohistochemistry. OS was compared between high and low Treg groups. The number of intratumoral and peritumoral Foxp3‐positive Tregs was significantly higher in OMM, OSCC, PA and MC compared with each normal tissue. There were few Foxp3‐positive Tregs in MCT and HCC. With intratumoral Tregs, the OS in the high Treg group was significantly shorter than that in the low Treg group in OMM, OSCC and PA. With peritumoral Tregs, there was no significant difference for OS between the 2 groups in each tumour type. These results suggest that Tregs infiltrate into a variety of canine tumours and the abundance of Tregs are associated with poor prognosis in some solid tumour types.