CD4和CD8分子在细胞免疫中的作用及其与PRRSV感染的关系

CD4和CD8是T细胞的两个重要的细胞表面标志，它们在T细胞免疫应答中发挥重要的作用本文将T细胞的免疫学基础及CD4和CD8与PRRSV感染的关系进行综述。     

益生菌对Balb/C小鼠外周血CD3、CD4和CD8分子表达水平的影响

为研究益生菌增强Balb/C小鼠免疫功能的作用机理,本试验将48只Balb/C小鼠分为对照组（生理盐水灌服组）和试验组（益生菌灌服高、中、低剂量组）,下文记为C、P-L、P-M和P-H组。分别在灌服7、14、21、28d后,每组随机选取3只小鼠处死,取其外周血离心后收集上清,采用ELISA方法分别检测CD3、CD4和CD8分子的表达量。结果显示,试验7d后,与对照组相比,P-L和P-H组小鼠血清CD3分子表达量分别显著上升54.78%(P <0.05)、98.52%(P <0.05);21d后,P-H组小鼠血清CD3分子表达量与对照组相比显著升高83.51%(P <0.05);7d后与对照组相比,P-L、P-M和P-H组小鼠血清CD8分子表达量分别显著上升44.94%(P <0.05)、46.73%(P <0.05)和43.78%(P <0.05);14d后,与对照组相比,P-L、P-M和P-H组小鼠血清CD8分子表达量分别显著上升39.27%(P <0.05)、40.05%(P <0.05)和36.02%(P <0.05);21d...     

鸡CD4和CD8分子研究进展

鸡CD4和CD8分子是T细胞表面重要的表面标志,绝大部分胸腺细胞表面都表达CD4和CD8分子,但大多数脾脏和外周血的T细胞表面只表达CD4或CD8分子,或两者都不表达。少数脾脏和外周血中存在的CD4 CD8 T 细胞具有重要的生物学功能。不同品种鸡的CD4 基因具有高度的保守性,而CD8αcDNA 在胞外区表现为多型性。鸡的CD4和CD8分子在组织分布、结构和功能等方面有着很大的相似性。针对鸡CD4 和CD8分子的单克隆抗体为研究这些免疫细胞的生理功能及细胞表面标志的生物学作用等创造了有利条件。     

CD163与猪繁殖与呼吸综合征病毒研究进展

猪繁殖与呼吸综合征,又称猪蓝耳病,是由猪繁殖与呼吸综合征病毒(PRRSV)感染、引发的猪的一种流行性传染病。PRRSV病毒通过感染机体的巨噬细胞或单核细胞,进一步引发怀孕母猪妊娠后期流产或胎儿死亡。同时,该病毒感染仔猪后,可引发机体较为严重的呼吸系统相关疾病。目前研究发现,PRRSV在感染过程中,需要与CD163蛋白分子结合,从而介导其自身的膜结构与宿主细胞膜进一步融合,从而感染宿主细胞。本文系统地介绍了PRRSV的基因组结构、感染途径以及与CD163蛋白的相关性,以期为进一步研发相关抗体及生产蓝耳病抗性的猪种奠定基础。     

流式分析外周血CD4和CD8淋巴细胞样本制备及其分离培养方法

CD是英文cluster of differentiation的缩写,中文意思是分化抗原,是表达在细胞表面的分子.这些分子将免疫细胞分成不同的细胞群.细胞表面的标记抗体(例如CD4,CD8)可以用来识别和定量不同细胞群,在免疫毒理研究中,利用流式细胞技术对动物脾脏或外周血中T细胞亚群CD4+T(辅助性T细胞)和CD...     

苷肽注射液对犬外周血CD 4、CD 8比值的影响

以20只健康犬为研究对象,随机分为四组,每组5只,分别注射苷肽注射液、苷肽注射液和犬五联疫苗、犬五联疫苗、生理盐水,各组犬于注射的第0、2、7、15天采血,检测不同组之间的CD 4＋和CD 8＋比值变化规律。结果表明：苷肽注射液单独应用和与疫苗同时应用,在注射的第2天就可以显著提高CD4＋、CD8＋比值,到第7天时达到最高值。并且发现,注射苷肽注射液同时注射犬五联疫苗组和单独注射苷肽注射液组CD4＋、CD8＋比值显著高于单独注射犬五联疫苗组（P〈0.05）,这说明苷肽注射液具有增强免疫的作用。     

免疫增强剂TMFN对犬外周血CD4/CD8比值的影响

采用检测犬外周血 CD4和 CD8比值变化的方法 ,观察犬注射免疫增强剂 TMFN和犬疫苗后 ,不同组之间的 CD4和 CD8比值 ,以证明该免疫增强剂对犬免疫系统的影响。结果表明 ,该免疫增强剂能够提高正常犬的细胞免疫水平 ,在犬注射疫苗的同时应用该免疫增强剂 ,可显著提高疫苗的免疫效力     

猪繁殖与呼吸综合征病毒感染与免疫过程中猪细胞因子的应答及意义

猪繁殖与呼吸综合征(porcine reproductive and respiratory syndrome,PRRS)是猪的一种严重的传染性疾病,其长年流行给养猪业造成重大经济损失。接种弱毒疫苗或灭活疫苗是控制PRRS的首选策略,但在现有技术水平下,由于疫苗毒株存在免疫抑制等因素,预防效果不理想。因而,深入研究PRRSV感染和/或接种疫苗后的免疫学应答机理是研究开发新型高效疫苗的必然基础。作者回顾性地综述感染PRRSV或接种PRRSV疫苗后宿主产生细胞因子的动态规律,探讨猪体防御PRRS的机制及开发新型高效疫苗的新思路。     

Marc-145细胞CD151蛋白主要抗原表位区的表达及其与猪繁殖与呼吸综合征病毒感染关系的研究

为研究CD151与猪繁殖与呼吸综合征病毒(PRRSV)感染的关系,根据GenBank中已发表的CD151蛋白的基因序列设计并合成一对特异性引物,从Marc-145细胞中扩增出294 bp的CD151基因片段并克隆入pGEX4T-3载体,转化人大肠杆菌用IPTG进行诱导表达,经SDS-PAGE和Western blot对表达产物进行鉴定.表达蛋白纯化后用于免疫小鼠制备抗CD151蛋白血清,用ELISA和IFA检测抗血清的效价及特异性.将抗CD151蛋白血清与Marc-145细胞孵育后再感染PRRSV,观察细胞CPE验证该血清对PRRSV的阻断效果.结果表明成功构建了pGEX4T-3-CD151,获得了相对分子质量为37 ku的重组CD151蛋白.制备的抗血清特异性结合Marc-145细胞并有效阻断PRRSV感染Marc-145细胞.这些研究结果为进一步阐明CD151与PRRSV感染的关系提供一定的理论基础.     

荧光定量RT-PCR检测鸡CD4、CD8基因表达水平

白细胞分化抗原CD4和CD8在机体免疫应答及其信号传递过程中发挥着重要作用。本试验建立了定量检测鸡CD4和CD8 mRNA表达水平的SYBR Green I实时荧光定量RT-PCR（RRT-PCR）方法,并采用该方法对26-50日龄商品鸡外周血淋巴细胞（PBL）中CD4和CD8 mRNA表达水平进行了检测。结果显示：所建立的RRT-PCR对CD4和CD8 mRNA的扩增效率分别为93%和91%;线性范围分别在10^-4-10^-9和10^-3-10^-9;相关系数分别为0.998 0和0.999 9;最低分别能检测105和120拷贝;熔解曲线分别在78.2和86.7℃附近出现1个单特异峰;组内变异系数分别在1.13%-2.15%和1.17%-3.68%,组间变异系数分别在1.16%-3.25%和1.66%-2.86%。26-50日龄鸡PBL CD4和CD8的mRNA表达水平有小幅波动,与采用流式细胞术检测结果的报道一致。本试验建立的RRT-PCR方法敏感性高、稳定性和再现性好,为检测鸡CD4、CD8基因表达水平提供了精确定量的新方法。     

Longitudinal evaluation of CD4+ and CD8+ peripheral blood and mammary gland lymphocytes in cows experimentally inoculated with Staphylococcus aureus.

Staphylococcus aureus is a major pathogen associated with mastitis, a disease affecting both women and dairy cows. The longitudinal profiles of bovine peripheral blood and mammary gland lymphocyte phenotypes in response to S. aureus-induced mastitis were investigated in dairy cows. Increased percentage of CD4 lymphocytes in the mammary gland between 1 and 8 days post-inoculation, increased milk CD4 protein density per cell between 1-8 days post-inoculation, and a statistically significant negative correlation between post-inoculation bacterial counts in milk and blood lymphocyte CD4 protein density were found. Together with blood and milk leukocyte counts, the milk lymphocyte CD4/CD8 ratio and the milk lymphocyte CD4 protein density were more informative indicators than milk somatic cell counts and bacteriology for identification of early vs. late inflammatory phases. These findings suggest that CD4+ lymphocytes play a protective role in the early stages of S. aureus-induced mastitis.     

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.     

Cytokine profiles of peripheral blood and airway CD4 and CD8 T lymphocytes in horses with recurrent airway obstruction

Equine recurrent airway obstruction (RAO) is thought to result from an aberrant immune response to inhaled antigens, modulated by T lymphocytes via the secretion of pro-inflammatory cytokines. However data relating to the phenotypes of the T lymphocytes present in peripheral blood and bronchoalveolar lavage fluid of RAO horses and their cytokine profiles are contradictory. The aim of this study was to further investigate the cytokine (IL-4, IL-5, IL-13 and INF-gamma) mRNA expression profile in peripheral blood lymphocytes and bronchoalveolar lavage lymphocytes from RAO and control horses, before and at 48 h after horses were exposed to hay/straw. In contrast to previous studies, cytokine expression was quantified in populations of CD4 and CD8 T lymphocytes which were purified using magnetic bead antibody cell separation. Hay/straw exposure induced clinical airway obstruction, airway neutrophilia and airway lymphocytosis in RAO horses, and, induced a mild, but significant, airway neutrophilia in controls. However, hay/straw exposure had no significant effect on peripheral blood lymphocyte or bronchoalveolar lavage lymphocyte cytokine expression in either group. In conclusion, RAO was not associated with alterations in lymphocyte cytokine expression that are consistent with Th1 or Th2 responses, but rather with a general down-regulation in expression of the measured cytokines in peripheral blood lymphocytes and bronchoalveolar lavage lymphocytes.     

Gene expression profiles of CD4/CD8 double‐positive T cells in porcine peripheral blood

A characteristic subset of T cells, known as double positive T cells (DPTC) and expressing both cluster of differentiation 4 (CD4) and CD8, is observed in porcine peripheral blood. Previous studies suggested that DPTC might be memory cells. However, detailed phenotypes and functions of DPTC are yet to be fully elucidated and thus, the relatedness of DPTC with memory phenotypes remains unclear. In this study, DPTC gene expression profiles in peripheral blood were analyzed by DNA microarray in Experiment 1 and compared with those of CD4 single positive T cells (4SPTC) and CD8 single positive T cells (8SPTC). Expressions of IFNG, CCL5, NCK2, CCR2 and ITGB1 were higher than that of 4SPTC and 8SPTC. In contrast, expressions of CCR7 and SELL were lower than that of 4SPTC and 8SPTC. These results suggested that DPTC were either effector T cells or effector memory T cells (T_EM). Next, to determine whether DPTC were effector T cells or T_EM, differences in the response of DPTC and 8SPTC against immunized/primed antigens were compared (Experiment 2). While DPTC showed quick elevation of IL2 and CD25 gene expressions against in vitro stimulation of primed/immunized antigens, 8SPTC did not. These results suggest that at least some DPTC likely belong to T_EM.     

Chicken peripheral blood CD3+CD4-CD8- cells are regulated by endocrine and nerve systems

The existence of CD3(+)CD4(-)CD8(-) T cells in thymus and spleen has already been known. However, because of the presence of large amounts of thrombocytes in peripheral blood (PB), the proportion of CD3(+)CD4(-)CD8(-) T cells in PB has yet to be investigated. Therefore, the proportion of peripheral T cell-subsets was investigated in 6-week-old chickens. The percentage of CD3(+) cells, CD4(+) cells, CD8 alpha(+) cells, CD8 beta(+), and CD3(+)CD4(-)CD8(-) cells was 76%, 41%, 14%, 5%, and 15%, respectively. The proportion of CD3(+)CD4(-)CD8(-) cells in PB increased during egg-laying periods and in chickens treated with an analog of estrogen, while it decreased with age and in response to restraint stress. All of the CD3(+)CD4(-)CD8(-) cells expressed TCR1, and did not have NK activity. CD3(+)CD4(-)CD8(-) cells represent about 60% of peripheral TCR1(+) cells. These findings indicate that the proportion of CD3(+)CD4(-)CD8(-) cells is regulated by the endocrine and nerve systems.     

Canine CD4(+)CD8(+) double positive T cells in peripheral blood have features of activated T cells

In dogs a CD4(+)CD8(+) double positive T cell subpopulation exists that has not been phenotypically defined yet. We demonstrate that canine CD4(+)CD8(+) T cells are mature CD1a(-) and TCRαβ(+) T cells. To analyse the activation potential of CD4(+)CD8(+) T cells, PBMC from dogs vaccinated against canine distemper virus (CDV) were re-stimulated with CDV. Upon antigen-specific stimulation, the CD4(+)CD8(+) T cell fraction increases and consists nearly exclusively of proliferated cells. Similarly, other features of activated effector/memory T cells such as up-regulation of CD25 and MHC-II as well as down-regulation of CD62L (L-selectin) were observed in CD4(+)CD8(+) T cells after stimulation. Canine CD4(+)CD8(+) T cells are less abundant, but more heterogeneous than porcine ones, comprising a small proportion expressing the β chain of CD8 in addition to the CD8α chain, like human CD4(+)CD8(+) T cells. In summary, this analysis provides the basis for functional characterisation of the in vivo relevance of CD4(+)CD8(+) T cells in T-cell mediated immunity.     

呕吐毒素对断奶仔猪外周血液中CD4~+、CD8~+淋巴细胞及抗氧化水平的影响

为了探讨低剂量呕吐毒素对断奶仔猪外周血液中CD4+和CD8+淋巴细胞及抗氧化水平的影响,将用10头平均体重为(7.70±1.00)Kg的三元杂交断奶仔猪,随机分成两组,对照组(基础饲粮)和脱氧雪腐镰刀菌烯醇(DON)组(基础饲粮+DON),试验开始前以及第8、16、24、36天采取仔猪前腔静脉静脉血液检测CD4+、CD8+淋巴细胞和CAT、GSH-Px、SOD、MDA的活性。结果对照组与DON组的CD4+、CD8+淋巴细胞差异都不显著,但是血清CAT、GSH-Px、SOD、MDA的活性都会发生明显变化。2 mg/Kg低剂量DON污染饲粮对断奶仔猪外周血液的CD4+、CD8+淋巴细胞不产生明显影响,对血清中抗氧化体系平衡会产生一定的损害。     

Evaluation of protective immunity in gilts inoculated with the NADC-8 isolate of porcine reproductive and respiratory syndrome virus (PRRSV) and challenge-exposed with an antigenically distinct PRRSV isolate.

OBJECTIVES: To determine whether intrauterine inoculation of porcine reproductive and respiratory syndrome virus (PRRSV) interferes with conception and whether exposure to one strain of PRRSV provides protection against challenge-exposure (CE) with homologous or heterologous strains of PRRSV. ANIMALS: 40 gilts. PROCEDURE: Gilts were inoculated by intrauterine administration of a PRRSV isolate (NADC-8) at breeding. Inoculated and noninoculated gilts were exposed oronasally to homologous (NADC-8) or heterologous (European isolate) PRRSV during late gestation. Specimens from gilts and fetuses were tested against CE virus. Lack of virus in gilts indicated protective immunity for the dam, in fetuses indicated protection of gilt from reproductive losses, and in both groups indicated complete protection. RESULTS: In the homologous CE group, interval from inoculation to CE ranged from 90 to 205 days, and protection was complete. In the heterologous CE group, interval from inoculation to CE ranged from 90 to 170 days, and protection was incomplete. The CE virus was detected in gilts necropsied 134 to 170 days after CE and in a litter necropsied 170 days after CE. CONCLUSIONS: Homologous protection can be induced in gilts by exposure to live PRRSV. Heterologous protection from reproductive losses can be induced in gilts by exposure to live PRRSV; however, this protection is incomplete and may have a shorter duration than homologous protection. CLINICAL RELEVANCE: Exposure of swine to enzootic PRRSV will provide protection against homologous PRRSV-induced reproductive losses. Extent and duration of protection against heterologous PRRSV may be variable and dependent on antigenic relatedness of the virus strains used for inoculation and CE.     

Evaluation of the influence of meloxicam and flunixin meglumine on the apoptosis of peripheral blood CD4+ and CD8+ T cells in calves

The aim of the study was to determine whether treatment with recommended doses of meloxicam or flunixin had an effect on the apoptosis of peripheral blood T lymphocytes in calves. The study was carried out on 4-5 months old calves (n = 24, 8 per group). Experimental animals were injected subcutaneously with a single dose of 0.5 mg x kg(-1) of meloxicam or intravenously with 3 doses of 2.2 mg x kg(-1) day(-1) of flunixin. The non-treatment animals served as control. Blood samples were taken at day 0 and at days 1, 2, 3, 5, 7 and 14 after the first NSAIDs injection. Apoptosis was determined by flow cytometry using Annexin V-PE/7-AAD staining. The kinetic analysis of apoptosis in the total lymphocyte population, as well as in the CD4+ and CD8+ subsets did not reveal significant differences in the frequency of early apoptotic cells between control and experimental groups throughout the period studied. Although, 24 h after administration of the first dose of NSAIDs, late-stage apoptosis/necrosis was significantly increased in the total lymphocyte population (the meloxicam group), as well as in the CD4+ (the meloxicam group and the flunixin group) and CD8+ (the flunixin group) subsets of T cells. However, this disturbance was transient, relatively poorly expressed and, thus, unlikely to be of clinical significance. Our results indicate that the use of meloxicam or flunixin in accordance with the recommended dosage regimen in cattle do not have a clinically significant influence on apoptosis of peripheral blood T cells.