米糠多糖对免疫抑制鸡外周血CD4~+和CD8~+ T淋巴细胞亚群的调节作用

为探讨米糠多糖对免疫抑制鸡免疫功能的调节作用,采用流式细胞技术检测了环磷酰胺和传染性法氏囊病毒诱导免疫抑制鸡在服用米糠多糖(剂量为150 mg/kg)和不服用米糠多糖情况下,外周血中CD4+和CD8+T淋巴细胞亚群数量的动态变化。结果显示,米糠多糖能够抑制环磷酰胺和传染性法氏囊病毒处理鸡外周血中CD4+和CD8+T淋巴细胞数量的降低;提高健康雏鸡外周血中CD4+T淋巴细胞比率,对CD8+T淋巴细胞作用不明显。     

猪圆环病毒2型感染小鼠脾脏内CD4~+CD25~+调节性T细胞的动态变化

为分析猪圆环病毒2型(PCV2)感染小鼠后脾细胞中CD4+CD25+调节性T细胞(Tregs)占CD4+T细胞比例的动态变化,探讨Tregs与PCV2感染的关系,本研究选择清洁级昆明小鼠60只,随机分成实验组和对照组,实验组腹腔接种PCV2,分别在接种后第0 d、5 d、10 d、20 d、30 d和60 d取脾脏制备单细胞悬液,用FITC-CD4和PE-CD25单克隆抗体标记Tregs,采用流式细胞仪检测Tregs占总CD4+T细胞百分比的动态变化。结果表明感染组小鼠脾细胞中Tregs百分比从第5 d开始逐步上升,第20 d达峰值后逐渐下降,感染组Tregs百分比第10 d、20 d、30 d时显著高于对照组(p0.05),但第60 d两组间差异不显著(p0.05)。试验结果证明PCV2感染昆明小鼠后,可在小鼠脾脏内诱导明显的Tregs增殖,这些增殖的细胞可能在PCV2感染中发挥免疫抑制作用。     

青蒿组方对球虫感染雏鸡血液中CD4^+和CD8^+T淋巴细胞的影响试验

为研究青蒿组方中药对鸡免疫力的影响,试验选取14日龄三黄鸡120只,平均分为4组:感染给药组(1组),感染不给药组(2组),不感染给药组(3组),不感染不给药组(4组).感染组人工接种柔嫩艾美耳球虫孢子化卵囊.接种后第4、7、10 d运用流式细胞仪测定各组鸡血液中CD4^+、CD8^+T淋巴细胞值及二者的比值.结果:1组CD4^+、CD8^+T淋巴细胞值及其比例在接种后第4、7、10 d均高于2组,差异显著(P<0.05);2组CD4^+、CD8^+T淋巴细胞平均比值低于其他3个组.结论:青蒿组方中药可促进鸡血液中CD4^+、CD8^+T淋巴细胞生成,进而增强机体的免疫功能.     

传染性支气管炎病毒结构蛋白免疫鸡对CD4+CD8+T淋巴细胞亚群的影响

为了比较传染性支气管炎病毒3种主要结构蛋白免疫鸡后对CD4+、CD8+T淋巴细胞亚群的不同影响.本试验以pVAX1载体为携带工具,制备分别含有IBV主要结构蛋白基因的质粒免疫健康雏鸡,采用流式细胞仪(FACS)对免疫鸡外周血中CD4+、CD8+T淋巴细胞数进行检测.结果显示:各试验组间,携带N蛋白基因的质粒在免疫后3周内CD4+T淋巴细胞数和CD8+T淋巴细胞数均高于其他组,且差异极显著(P＜0.01).由此可见,IBV的N蛋白可明显诱导CD8+T淋巴细胞的CTL免疫作用和CD4+T淋巴细胞的辅助性免疫作用,其细胞免疫原性高于S1蛋白和M蛋白.     

E.tenella初次感染雏鸡外周血T淋巴细胞亚群及增殖能力变化的动态研究

应用流式细胞术（ FCM）和MTS比色法检测雏鸡初次感染柔嫩艾美尔球虫（ E． tenella）后外周血中CD3＋CD4＋、CD3＋CD8＋T淋巴细胞及其增殖能力的动态变化。数据显示,E． tenella初次感染雏鸡后7～20 d CD3＋CD4＋、CD3＋CD8＋T 淋巴细胞比例明显高于对照组雏鸡（ P＜0．05和P＜0．01）,并且均于12 d时达到峰值。初次感染后7～20 d雏鸡外周血中CD4＋／CD8＋T淋巴细胞亚群的比值明显升高,于感染后16 d时达到1．78。 E． tenella初次感染雏鸡后12～20 d外周血淋巴细胞增殖能力明显高于对照组雏鸡（ P＜0．05）,并于16 d达到峰值。试验表明E． tenella初次感染雏鸡能激活淋巴细胞产生增殖反应,CD3＋CD4＋、CD3＋CD8＋T淋巴细胞在抵抗E． tenella初次感染过程中有重要作用。     

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。     

刺五加多糖对雏鸡脾脏中CD4+ 和CD8+T淋巴细胞定位分布的影响

为了研究刺五加多糖（ASPS）对雏鸡脾脏中CD4+和CD8+ T淋巴细胞定位分布的影响,从组织学角度评价ASPS对脾脏的免疫调节作用,试验将1日龄海兰褐公雏饲养至7日龄时选取150只,随机分为3组：空白对照组、ASPS低剂量组（ASPSL）和高剂量组（ASPSH）,每组50只,所有组每天注射1次,连续注射3天。免疫后的第7、14、21和28天分别取其脾脏制作冰冻切片,采用免疫组织化学方法检测CD4+和CD8+ T淋巴细胞的定位分布。结果显示,与空白对照组比较,免疫注射后21天和28天时ASPSL组和ASPSH组CD4+ T淋巴细胞的数量均显著增加（P<0.05）,而且ASPS能够促进红髓中CD4+ T淋巴细胞向动脉周围淋巴鞘迁移,从而使单个动脉周围淋巴鞘面积较对照组明显增加,而ASPS对脾脏中CD8+ T淋巴细胞的数量和分布无明显影响。由此可知,ASPS能够通过影响脾脏中CD4+ T淋巴细胞的定位分布发挥免疫调节作用,这对于进一步揭示ASPS的免疫调节机制具有重要意义。     

川楝素对妊娠小鼠子宫组织中CD4+/CD8+T细胞和F4/80+巨噬细胞的影响

为探讨CD4+、CD8+ T淋巴细胞和F4/80+巨噬细胞在流产发生机制中的意义,研究中药单体成分川楝素诱导小鼠流产的作用及机理,本试验给妊娠5 d小鼠连续3 d腹腔注射不同剂量的川楝素溶液,对照组以等量的蒸馏水代替,于妊娠9 d处死.在给药后发现随着注射川楝素剂量的增加,小鼠的流产率逐渐上升,CD4+、CD8+ T淋...     

营养限制及补偿对羔羊体重及外周血液CD4+和CD8+T淋巴细胞的影响

本试验旨在研究羔羊营养限制期(第1～60天)和营养补偿期(第61～150天)体重和外周血液中CD4+和CD8+T淋巴细胞的变化规律.选用80只体况中等、平均体重为(14.72±1.10)kg的3月龄乌珠穆沁羔羊,随机分为对照组(CG)、限制组Ⅰ(RG Ⅰ)、限制组Ⅱ(RGⅡ)和限制组Ⅲ(RG Ⅲ)4个组.营养限制期4组饲粮能氮水平分别为代谢能(ME):10.88、10.88、9.41和8.62 MJ/kg;粗蛋白质(CP):15%、10%、10%和5.7%.营养补偿期各组饲喂同一能氮水平饲粮(ME:9.75 MJ/kg;CP:12%).在试验期每周称重并在第1天、第30天、第60天、第90天和第150天饲喂前从各组羊颈静脉采血,采用流式细胞仪检测羔羊血液中的CD4+和CD8+T淋巴细胞比例.结果表明:1)营养限制结束,RG Ⅰ组、RG Ⅱ组和RG Ⅲ组平均体重均显著低于CG组(P＜0.05).补偿期RGⅢ组平均日增重显著高于CG组(P＜0.05).2)营养限制前期(第1～30天)各组CD4+和CD8+T淋巴细胞浓度均呈上升趋势.补偿期结束时CD4+T淋巴细胞浓度RG Ⅰ组最低RGⅡ组最高,CD8+T淋巴浓度RGⅡ组最低RG Ⅰ组最高,差异均不显著(P＞0.05).结果提示,乌珠穆沁羔羊受不同能氮营养水平限制后体重和免疫机能有补偿效应,而且低能高氮比高能低氮限饲后得到的补偿效果较好,表明限饲蛋白质比限饲能量对补偿生长的负影响更大.蛋白质和能量同时限饲补偿生长最差.     

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的紫锥萄、黄芪合荆,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.     

AA肉鸡血液CD3+、CD4+和CD8+T淋巴细胞的变化规律

采用流式细胞仪检测1、3、5、7、14、21、28、35、42、49日龄AA肉鸡血液中的CD3、CD4、CD8阳性T细胞比例。研究结果表明:1～5日龄T细胞逐渐进入血液参与细胞免疫,7、21日龄注射疫苗起免疫应答作用,28日龄后基本形成稳固的细胞免疫水平。     

The Localization Changes of CD4+ and CD8+ T Lymphocytes in Chicken Lung at Different Ages

The aim of this study was to investigate the immune state of chicken lung in different periods.With lung tissue of Hy-line White chicken at different ages,the distribution and quantity changes of CD4⁺ and CD8⁺T lymphocytes in lung were studied using immunohistochemistry staining.The results showed that CD8⁺T lymphocytes appeared firstly in embryonic at 18 d,while CD4⁺T lymphocytes appeared at 1-day-old chicken.At 4-day-old,there were aggregates of lymphocytes at the junction of the primary and secondary bronchi,which formed obvious broncho-associated lymphoid tissue (BALT).CD4⁺T lymphocytes of each age mainly occupied the central area of BALT,while CD8⁺T lymphocytes mainly surrounded the periphery.Since 56 days old,CD8⁺T lymphocytes are distributed in the inner wall of third-order bronchial airway,atrial septum,gas exchange area and interlobular connective tissue,and are distributed throughout the lung.In terms of quantity change,with the growth of daily age,the number of CD4⁺T lymphocytes and CD8⁺T lymphocytes gradually increased,and the number of CD4⁺ T lymphocytes was more than that of CD8⁺ T lymphocytes before 35 days of age,while the number of CD8⁺ T lymphocytes was significantly more than that of CD4⁺ T lymphocytes at the same age thereafter.The results showed that the distribution and number of CD4⁺ and CD8⁺T lymphocytes in the lungs of chickens were correlated with the age,and the changes could reflect that the lungs before the age of 35 days were dominated by humoral immunity,while the lungs after that tended to be cellular immunity.     

In vitro effects of meloxicam on the number,Foxp3 expression,production of selected cytokines,and apoptosis of bovine CD25+CD4+ and CD25-CD4+ cells

The purpose of this study was to evaluate the effect of meloxicam (MEL) on selected immune parameters of bovine CD25^highCD4+, CD25^lowCD4+, and CD25-CD4+ cells. Peripheral blood mononuclear cells (PBMCs) collected from 12-month-old heifers were treated with MEL at a concentration corresponding to the serum level of this medication following administration at the recommended dose (MEL 5 × 10^-6 M) and at a concentration 10 times lower (MEL 5 × 10^-7 M). After 12 and 24 h of incubation with the drug, the percentage of CD25^highCD4+ cells decreased; however, this disturbance was quickly reversed. Furthermore, the absolute number of CD25^highCD4+ cells in the PBMC populations treated with MEL 5 × 10^-6 M for 48 and 168 h was increased. Prolonged (168 h) exposure to the drug increased the percentage of Foxp3+ cells in the CD25^highCD4+ cell subpopulation. The higher dose of MEL was found to significantly increase the percentage of IFN-γ+ cells among the CD25-CD4+ cells. These results indicated that MEL does not exert an immunosuppressive effect by depleting CD4+ cells and suppression of IFN-γ+ production by these cells. Furthermore, IL-10 and TGF-β production was not changed following exposure to MEL.     

传染性法氏囊病病毒超强毒感染SPF鸡免疫器官中CD4+和CD8+T淋巴细胞动态分布

利用免疫组织化学染色对传染性法氏囊病病毒（IBDV）超强毒LX株感染SPF鸡免疫器官中CD4^ 和CD8^ T淋巴细胞的动态分布进行了研究。超强毒LX株接种2周龄SPF雏鸡，在其法氏囊、脾脏、胸腺、盲肠扁桃体、骨髓和哈氏腺中均可检出IBDV抗原的存在和CD4^ 与CD8^ T淋巴细胞的数量改变。在法氏囊中，CD4^ 淋巴细胞主要存在于淋巴滤泡间隙和滤泡皮质，而CD8^ T淋巴细胞则丰在于整个淋巴滤泡和滤泡间隙，并且CD8^ T淋巴细胞数量明显多于CD4^ T淋巴细胞，在接种后14d仍未见CD4^ 和CD8^ T淋巴细胞数量减少。脾脏中CD4^ T淋巴细胞主要存在于外周小动脉淋巴鞘或散在，而CD8^ T淋巴细胞则多存在于外周小动脉淋巴鞘和红髓。接种后胸腺中CD4^ 和CD8^ T淋巴细胞在皮质中减少，但在髓质增多，尤其是CD8^ T淋巴细胞数明显多于CD4^＋T淋巴细胞。盲肠扁桃体中CD4^ 和CD8^ T淋巴细胞主要存在于发生中心，尤其是CD8^ T淋巴细胞数比CD4^ T淋巴细胞明显多。骨髓和哈氏腺中也可见CD4^ 和CD8^ T淋巴细胞，而且CD8^ T淋巴细胞更多。在这些淋巴器官中，病毒损伤部位出现CD4^ 和CD8^ T淋巴细胞的迁入聚集，表明T淋巴细胞可能参与IBDV超强毒的免疫致病过程。     

高温下清凉冲剂对鸡免疫器官中CD4+、CD8+ T细胞数量的影响

采用免疫组化方法检测鸡免疫器官中CD4^＋、CD8^＋T细胞数量，探讨高温下清凉冲剂对机体细胞免疫机能的影响及其药理作用。108只农大3号35目龄公雏，随机分为3组，每纽36只鸡，即常温对照组、高温对照组和高温用药组。用药组饲喂中药煎荆（浓度为1g／ml），用药量与饲料量比为1：1000。在试验的第1、4、8、10天各组捕杀5只。分别采取胸腺、脾脏、法氏囊检测。结果高温下。用药组免疫器官中CD4^＋、CD8^＋T细胞数量均高于高温对照组。第8、10天差异极显著（P〈0．01）。表明高温下清凉冲剂可以增加鸡免疫器官中CD4^＋、CD8^＋T细胞数量，有效地提高鸡细胞免疫水平。     

CD34+, CD41+ acute megakaryoblastic leukemia in a dog

A clinically normal, 5-year-old intact female German Shepherd dog was presented to the local veterinarian to be spayed. Results of a preoperative CBC included mild nonregenerative anemia, severe thrombocytopenia, and 17% unclassified cells. On cytologic examination of aspirates from the dog's enlarged spleen and peripheral lymph nodes, a population of primitive round cells that occasionally resembled megakaryocytes was observed. A bone marrow aspirate specimen was markedly hypercellular with approximately 65% of marrow cells comprising a homogeneous population of immature hematopoietic cells similar to those found in the spleen, lymph nodes, and peripheral blood. Using immunocytochemical stains with canine-specific antibodies, all neoplastic cells strongly expressed cytoplasmic CD41 and 20-70% of the neoplastic cells expressed CD34 weakly to moderately. Rare (<0.5%) neoplastic cells weakly expressed vWF. The cells were negative for all other markers. Based on these results and the morphology of the neoplastic cells, a diagnosis of acute megakaryoblastic leukemia (AMegL) was made. In spite of treatment, results of a CBC performed 1 week later indicated progressive anemia and thrombocytopenia, and the dog was euthanized. To our knowledge, this report documents the first case of canine AMegL diagnosed with both anti-canine CD34 and CD41 antibodies.     

The role of CD4+CD25+ regulatory T cells in viral infections

Many virus infections result in the suppression of one or more functions of the immune system. Multiple mechanisms have been proposed to explain viral-induced immunosuppression, including an imbalance in the cellular Th1/Th2 or cytokine profile, induction of anergy, depletion of effector cells and most recently the activation of CD4+CD25+ regulatory T (T reg) cells. CD4+CD25+ T reg cells are a subset of circulating CD4+ T cells with suppressive properties. CD4+CD25+ T reg cells were first identified in mice as cells capable of maintaining self-tolerance by suppressing autoreactive T cells. This review focuses on interactions between CD4+CD25+ T reg cells and viral pathogens. Most cases in which CD4+CD25+ T reg cells participate in response to infection reported so far involve chronic or persistent viral infections. Examples have been growing recently and include members of different viral families including retroviridae, herpesviridae and picornaviridae. It is currently not known how microbes are recognized by CD4+CD25+ T reg cells and whether exoantigen-specific T reg cells are of the same lineage as self-reacting natural T reg cells or represent peripherally induced counterparts derived from CD4+CD25- T cells. The findings that T reg cells influence the functional immunity during viral infections, however, might indicate that, in some cases, virus-specific T reg cells not only influence immune pathology or prevent pathogen elimination but also can promote a generalized state of immunosuppression in vivo such that the host is more susceptible to secondary infections with other pathogens or has reduced resistance to tumors. Conceivably, the activities of T reg cells might be one of the contributing reasons why it has been difficult so far to produce effective vaccines against some persisting viral infections.