细胞因子与抗感染免疫

在机体炎症和免疫应答过程中,由免疫细胞产生的一类具有免疫调节和效应功能的小分子多肽或糖蛋白,称细胞因子（ｃｙｔｏｋｉｎｅ）。在天然免疫中,细胞因子多由单核细胞产生,因此称为单核因子（Ｍｏｎｏｋｉｎｅ）,它们除介导单核吞噬细胞的效应功能外,也在活化淋巴细胞和调节特异性免疫方面有重要的作用［１］。在特异性免疫中,细胞因子多由活化的淋巴细胞产生,因此称为淋巴因子（Ｌｙｍｐｈｏｋｉｎｅ）。它们参与淋巴细胞的活化、生长与分化,参与天然免疫的调节和放大。淋巴因子不仅是特异性免疫的效应分子且是免疫系统与炎症系…     

原虫感染对宿主免疫应答的影响

原虫感染可引起严重的肠道黏膜免疫应答,其侵入机体时,会触发机体的固有免疫应答和适应性免疫系统反应,包括诱导特异性抗体的产生以及效应T淋巴细胞的形成。T淋巴细胞包括CD_4~+和CD_8~+两大类,CD_4~+为辅助性T淋巴细胞,通过膜表面分子及其所分泌的细胞因子辅助并调控B淋巴细胞和巨噬细胞的活化与功能;CD_8~+是杀伤细胞,也是肠道上皮细胞主要表达因子,功能与自然杀伤细胞相似,可以与被感染上皮细胞接触将其杀死。B淋巴细胞主要功能是制备抗原特异性抗体,发挥体液免疫作用。文章将从两方面论述原虫与机体免疫应答之间的相互调节作用。     

弓形虫感染引起小鼠体内CD_8~+T淋巴细胞免疫的研究

弓形虫感染可诱导宿主机体产生强烈的CD_8~+T淋巴细胞免疫应答,这对机体有效控制弓形虫感染具有重要作用。在感染过程中,CD_8~+T淋巴细胞可刺激机体产生IFNγ等细胞因子,并促进细胞溶解,能够有效阻止机体内潜伏性感染的活化过程。然而,部分易感小鼠体内CD_8~+T淋巴细胞会在感染期间发生功能障碍。文章就慢性感染中CD_8记忆应答的发展及其功能障碍机制展开论述。     

共轭亚油酸的免疫功能研究进展

共轭亚油酸(Conjugatedlinoleicacid,CLA)具有广泛的生物学功能,对增加动物体免疫球蛋白含量、免疫细胞的增殖、T细胞和自然杀伤细胞的活化,细胞因子的产生及免疫应答具有不同的调节作用。文中就共轭亚油酸的免疫调节作用,综述近年来国内外的研究进展。     

鸡球虫病的细胞免疫机理

宿主(鸡)感染球虫后,产生非特异性免疫应答和特异性免疫应答———体液免疫应答和细胞免疫应答。非特异性免疫因素主要是遗传因素或体内外理化因素对球虫的杀灭作用。体液免疫主要通过依赖腔上囊B淋巴细胞实现,细胞免疫主要通过依赖胸腺的T淋巴细胞实现。实验分别摘除胸腺和腔上囊,发现鸡球虫病的免疫力可由于摘除胸腺而受到抑制,而摘除腔上囊则无影响,结果表明抗体作用居于次要地位,而细胞免疫居于主要地位。1T淋巴细胞在鸡球虫保护性免疫中的作用用抑制细胞介导免疫力的药物环孢菌素A(CsA)处理鸡后,研究T淋巴细胞在鸡球虫中的保护作用…     

影响鸡免疫应答因素分析

鸡的免疫类型分非特异性免疫和特异性免疫.特异性免疫又分为细胞免疫和体液免疫.细胞免疫是指来自于骨髓中的淋巴细胞在胸腺依赖区中被诱导分化成熟为T细胞,在受到抗原或有丝分裂源的刺激后,分化增殖转化为致敏淋巴细胞所表现出来特异性免疫.这类免疫应答不能通过血清传递,只能通过致敏淋巴细胞所传递.体液免疫是指来自于骨髓的淋巴细胞在法氏囊依赖区诱导分化为成熟的B细胞.在抗原物质的刺激下产生抗体以及血液性抗体与相应抗原接触后引起一系列抗原抗体反应的免疫应答方式[1].分析和掌握影响鸡免疫应答因素,对于制定适合现地养禽场的免疫程序和选择合理疫苗,保证该养禽场生物安全生产具有重要意义.     

免疫佐剂 CpG—DNA的研究进展

特异性免疫即是含有PAMP的反应物与天然免疫细胞上的PRR相结合,激活天然免疫应答,从而活化抗感染途径,并最终发挥获得性免疫应答的一系列反应过程。CpG—DNA作为一种在进化中高度保守的PAMP,它可以模拟感染过程,克服新型疫苗PAMP不足的缺陷,从而诱导强烈的免疫应答。CpG—DNA可以直接激活B淋巴细胞、单核／巨噬细胞和树突状细胞,上调免疫刺激分子的表达,调节免疫反应,诱导IL-12、IL-1和TNF-等多种细胞因子的分泌,此外,它还能间接刺激NK细胞、T淋巴细胞。由于其独特的优点,CpG—DNA在畜牧兽医临床中显示其极强的使用价值和广阔的应用前景。     

不同剂量小鹅瘟病毒VP3基因疫苗肌肉注射诱导小鼠细胞免疫

将小鹅瘟(Gosling plagne,GP)VP3基因疫苗(pcDNA-GPV-VP3)分别按每只50、100、200 μg肌肉注射免疫BALB/c小鼠,以pcDNA3.1( )和生理盐水为对照,于免疫后7、14、21、28、35、63、105 d采血用淋巴细胞转化实验(MTT法)和流式细胞仪(FACS)分别检测小鼠外周血T淋巴细胞转化效果和CD4 、CD8 T淋巴细胞动态变化.结果表明,pcDNA-GPV-VP3免疫小鼠能够诱导机体产生良好的细胞免疫应答.50、100 μg pcDNA-GPV-VP3免疫后小鼠外周血T淋巴细胞对ConA刺激的反应显著或极显著高于200 μg组、空载体和生理盐水对照组,且以100 μg组最优,而200 μg组的转化效果比空载体组差;100 μg pcDNA-GPV-VP3免疫小鼠后所诱导的CD4 T淋巴细胞免疫功能最强,50 μg组次之;50 μg pcDNA-GPV-VP3免疫小鼠后所诱导的CD8 T淋巴细胞免疫功能最强,100 μg组次之.     

用E—玫瑰花环法检测117例健康牛羊猪外周血T淋巴细胞值

<正> 淋巴细胞是动物体内最主要的免疫细胞,按其免疫功能和细胞膜表面受体可分为T淋巴细胞和B淋巴细胞两大类。T淋巴细胞表面具有绵羊红细胞(Sheep red blood cell简稱SRBC)受体,在体外一定条件下,能与SRBC結合形成E—玫瑰花环(Brythroeyte—rosette)。T淋巴细胞具有多种生物学功能,不仅在产生抗体上起调节作用,而具对免疫性疾病、变態反应性疾病、器官移植術及腫瘤性疾病均有主要的影响。因此,检测家畜外周血液中T淋巴细胞正常值。对防治各种与免疫有关的疾病具有十分重要的临床意义。识别T淋巴细胞,有多种检测方法,多采     

枸杞多糖对动物免疫系统的影响

<正>动物的免疫系统是动物机体产生免疫应答的物质基础,主要由免疫器官和免疫细胞组成,前者有中枢免疫器官和外周免疫器官,后者包括免疫活性细胞(T淋巴细胞、B淋巴细胞)和免疫辅助细胞等。研究表明,枸杞子中含量较多的是水溶性多糖,占干枸杞子的5%~8%[1],它具有一定的生理活性和药物活性,枸杞多糖(LBP)可增加正常小鼠的皮重以达到提高中枢免疫器官的功能,能提高各种免疫活性细胞包     

猪外周血T淋巴细胞增殖反应MTT检测方法的建立

T细胞增殖反应是宿主T细胞识别病原的结果,也是宿主细胞免疫应答的重要指标之一。为了便于检测猪群在病原感染或者疫苗免疫过程中产生的细胞免疫应答,本研究应用MTT法建立了体外检测猪外周血T细胞增殖反应的研究方法。通过密度梯度离心法从外周血分离得到外周血单个核细胞（PBMC）,然后利用单核细胞和淋巴细胞不同的生长特性（贴壁与否）,弃掉贴壁的单核细胞,获得外周血淋巴细胞(PBL)。外周血淋巴细胞的流式分析结果显示,分离获得的PBL中T细胞所占比例达到了80%以上。应用MTT法分析了非特异性刺激物刀豆蛋白A（ConA）的浓度和细胞培养密度对T细胞增殖的影响。结果显示,ConA的工作浓度为5 μg/mL、细胞培养密度为2×106/mL时T细胞的增殖反应最强烈。本研究所建立的猪外周血T细胞增殖反应检测法可以为研究猪针对病原或疫苗的细胞免疫反应提供参考。     

Overview of the Immune Dynamics of the Digestive System

The digestive tract of the chicken is a major site of pathogen exposure. Although the bird has a multifaceted set of tools to prevent or resist infection, any activation of the immune system can divert nutrients away from production. Therefore, prevention of pathogenic exposure is preferred. However, it is unlikely that the bird can escape exposure to all pathogens during its life, thus the ability to respond to immunologic challenges is essential. The immune system of birds is similar to that of mammals in terms of structure and function, although some differences do exist, particularly in regulatory aspects. The innate immune system responds nonspecifically to foreign molecules and is essential for the induction of the specific (acquired) immune response. Cells of the innate immune system include macrophages, dendritic cells, heterophils, and natural killer cells. The acquired immune response involves recognition of a specific antigen and response by lymphocytes. Cytotoxic T lymphocytes are especially effective at inducing cells infected with intracellular pathogens to undergo apoptosis. Helper T lymphocytes increase the effectiveness of innate immune cells in combating extracellular pathogens and are also essential for activating B lymphocytes, which produce antibodies specific to the invading pathogen. All aspects of the immune system function together, although one aspect will often dominate, depending on the type and severity of the infection. This paper reviews the basics of avian immune function in general and discusses the immune system in the digestive tract in particular in birds. The consequences of activation of the immune system are presented.Currently, growth-promoting antibiotics are not used in poultry in many countries; the North American industry may be moving in that direction as well, either through legislation or consumer pressure. Several nonantibiotic means of manipulating the immune system to prevent the health- and performance-suppressing effects of immune system activation are presented here.     

Immunophenotypic and functional effects of bunker C fuel oil on the immune system of American mink (Mustela vison)

The relationship between exposure to environmental contaminants and immunotoxicity in vulnerable marine species is unknown. In this study, we used American mink (Mustela vision) as a surrogate species for the sea otter to examine the immunotoxic effects of chronic exposure to a low concentration of bunker C fuel oil (500 ppm admixed in the feed for 113-118 days). The mink immune system was monitored over time by flow cytometric analysis for alterations in the immunophenotype of blood lymphocytes and monocytes and by mitogen-stimulated proliferation assays for changes in peripheral blood mononuclear cell function. Fuel oil exposure caused a mild, yet significant (P < 0.05) increase in the absolute numbers of specific peripheral blood lymphocyte subsets (CD3+T cells) and monocytes, an increase in the level of expression of functionally significant cell surface proteins (MHC II, CD18), and an increase in mitogen-induced mononuclear cell proliferative responses. This heightened state of cellular activation along with the increase in specific cell surface protein expression on both the innate and adaptive immune cells is similar to the pro-inflammatory or "adjuvant-like" effect described in laboratory models of polycyclic aromatic hydrocarbon exposure in other species. These results show the benefits of using a controlled laboratory model for detecting and characterizing subtle petroleum oil-induced perturbations in immune responses. In addition this study establishes a framework for studying the effects of environmental petroleum oil exposure on the immune system of free-ranging marine mammals. Expansion of these studies to address biolgical significance is warranted.     

Changes in the peripheral leukocyte phenotype of calves in clinical cases of bronchopneumonia complicated with chlamydial co-infectious agent

This paper reports the alterations in peripheral blood leukocyte phenotype in respiratory diseased calves affected with chlamydial and non-chlamydial co-infectious agent. The etiological contribution of chlamydial infectious agent in examined clinical cases of enzootic bronchopneumoniae syndrome was confirmed in affected calves serologically both by complement fixation test (CF) and enzyme immunoassay (EIA). Changes in leukocyte subpopulations in the blood of the calves were detected both with routine haematological methods and by FCM using specific monoclonal antibodies directed against CD14, CD45, CD2, CD4, CD8 and WC4 (a specific surface marker for bovine B-lymphocytes). The results obtained by flow cytometry analysis indicate that polymorfonuclear neutrophils (PMNLs) and T lymphocytes, especially CD8-positive cells, may play a significant role in cellular immune response against Chlamydophila psittaci (Chl. psittaci) co-infection in calves suffering from enzootic bronchopneumonia syndrome. A repercussion of this was a significant increase of the cell numbers in peripheral blood of the infected animals. Effective recruitment from a reserve marginal pool of these cells into blood vessels and activation of bone marrow proliferation are probably the reason for their high circulating number.     

维生素D3的免疫功能及其对家禽免疫细胞和免疫因子的调节

维生素D3是一种新的神经内分泌-免疫调节剂,主要表现为对单核/巨噬细胞、T淋巴细胞、B淋巴细胞、胸腺细胞的增殖分化及细胞功能具有重要影响。维生素D3与T淋巴细胞、B淋巴细胞和巨噬细胞分泌抗体、淋巴因子、补体和单核因子等功能紧密相关。但关于维生素D3对家禽免疫细胞、免疫因子调节的研究甚少。本文就维生素D3的免疫功能及其对家禽T淋巴细胞、抗原呈递细胞(APC)和免疫因子调节的研究现状和展望作一综述。     

Effect of synthetic agonists of toll-like receptor 9 on canine lymphocyte proliferation and cytokine production in vitro

Synthetic agonists of TLR9 containing novel DNA structures and R'pG (wherein R=1-(2'-deoxy-beta-d-ribofuranosyl)-2-oxo-7-deaza-8-methyl-purine) motifs, referred to as immune modulatory oligonucleotides (IMOs), have been shown to stimulate T(H)-1-type-immune responses and potently reverse allergen-induced T(H)-2 responses to T(H)-1 responses in vitro and in vivo in mice. In order to investigate the immunomodulatory potential of IMOs in dogs, canine peripheral blood mononuclear cells (PBMC) from healthy dogs were stimulated with three different IMOs and a control IMO, alone or in combination with concanavalin A (ConA). Lipopolysaccharide (LPS) was used as a positive control for B lymphocyte activation. Carboxyfluorescein diacetate succinimidyl ester and phenotype staining was used to tag proliferating T and B lymphocytes (CD5(+) and CD21(+)) by flow cytometry. Real-time PCR and ELISA were processed to assay cytokine production of IFN-gamma, IL-10, TGF-beta, IL-6 and IL-10. Like LPS, IMOs alone induced neither proliferation of CD5(+) T cells nor CD21(+) B cells, but both LPS and IMO had the capacity to co-stimulate ConA and induced proliferation of B cells. In combination with ConA, one of the IMOs (IMO1) also induced proliferation of T cells. IMO1 also significantly enhanced the expression of IFN-gamma on the mRNA and protein level in canine PBMC, whereas expression of IL-10, TGF-beta and IL-4 mRNAs was not induced by any of the IMOs. These results indicate that in canine PBMC from healthy dogs, IMO1 was able to induce a T(H)-1 immune response including T- and B-cell proliferation.     

Kinetics of IL-2 receptor expression on lymphocyte subsets from goats infected with Mycobacterium avium subsp. paratuberculosis after specific in vitro stimulation

Quantification of surface IL-2R expression on activated lymphocytes by flow cytometry have recently been reported to be useful in measuring cellular immunity against Mycobacterium avium subsp. paratuberculosis in goats (Whist et al., 2000, Vet. Immunol. Immunopathol. 73, 207-218). To characterise the phenotype of the peripheral lymphocytes expressing IL-2R after in vitro stimulation with purified protein derivative (PPD) from M. a. paratuberculosis, cells were processed for dual or triple colour analysis by flow cytometry (CD4 and IL-2R or CD8, gammadelta-TcR and IL-2R). To distinguish the response of antigen-specific T cells from non-specific stimulation, we performed a time-course study of proliferating cells in a group of M. a. paratuberculosis-infected animals and a control group. Following in vitro stimulation with PPD of whole blood for three different periods of time, IL-2R expression was detected mainly not only in gammadelta-T cells, but also in CD4+ and CD8+ T cells. We found a specific response of gammadelta-T cells from infected animals after 24h of stimulation. Following 120h of stimulation, however, gammadelta-T cells from control animals up-regulated IL-2R to the same level as those from infected animals, indicating either a non-specific stimulation or activation due to a first line of defence against Mycobacterium antigens. The CD4+ cells showed a specific response to PPD stimulation at all three time points. A minor population of antigen reactive gammadelta+ cells also expressed CD8. The proliferative responses differed between alphabeta and gammadelta-T cells; the IL-2R+ alphabeta T cell population mainly comprised proliferating cells, while the gammadelta+ population showed less expansion.     

Expression and in vitro upregulation of MHCII in koala lymphocytes

Understanding and measuring immune activity of the koala (Phascolarctos cinereus), is important to studies of the epidemiology and impact of the widespread chlamydial and koala retroviral (KoRV) infections that occur in this iconic but increasingly threatened species. To explore the interaction of disease and immunity, and to assess the potential for use of class II major histocompatibility complex (MHCII) upregulation as an indicator of lymphocyte activation in in vitro immune assays, we have investigated the expression of MHCII in koala lymphocytes by flow cytometry. MHCII expression was upregulated in mitogen stimulated B lymphocytes in vitro but no such increase was detected in vivo in free-living koalas with active inflammation. In assessing phenotypic baseline data of captive koalas, we have identified that MHCII is expressed predominantly on circulating B lymphocytes (85.7 ± 2.4%) but on very few T lymphocytes (3.4 ± 1.9%), even following activation, and suggest that the latter finding might be compensated by the greater absolute numbers of peripheral blood B lymphocytes in this species relative to many eutherian species.     

玉屏风多糖对小鼠派氏结形态结构及其T细胞亚群的影响

通过研究玉屏风多糖（YPF-P）对小鼠派氏结（Peyer's patches,PPs）形态结构及其T细胞亚群的影响,探讨其对小鼠肠黏膜的免疫调节作用。选取96只SPF小鼠随机分为6组,分别为空白对照组（0.2 mL生理盐水）、YPF-P阳性对照组（YPF-P 200 mg/kg）、环磷酰胺（cyclophosvnamide,Cy）免疫抑制组（80 mg/kg Cy）及YPF-P低、中、高剂量组（100、200、400 mg/kg YPF-P）,饲喂1周,取小肠PPs,常规切片HE染色后应用图像分析技术检测PPs形态结构的变化;体外培养小鼠PPs淋巴细胞,采用流式细胞术研究PPs中T淋巴细胞亚群的变化。结果表明,YPF-P对小鼠小肠PPs的生长发育具有促进作用,Cy可极显著降低小鼠小肠PPs面积、小肠纵切面面积及PPs面积和小肠纵切面面积的比值（P < 0.01）,低、中、高剂量YPF-P可在一定程度上缓解Cy对小鼠小肠的损伤作用。同时,YPF-P可显著或极显著提高PPs中CD3⁺、CD4⁺ T淋巴细胞及CD4⁺/CD8⁺（P < 0.05; P < 0.01）。结果显示,YPF-P能提高Cy诱导的免疫抑制小鼠的肠黏膜免疫功能,并能促进PPs中相关T淋巴细胞增殖,对小鼠肠黏膜功能具有增强作用。     

An immunophenotypic study of canine leukemias and preliminary assessment of clonality by polymerase chain reaction.

There is a relative lack of information in the veterinary literature regarding the immunophenotypes present in canine leukemias. Utilizing a panel of thirty monoclonal antibodies, canine leukemias were assessed by flow cytometry alone or by flow cytometry in combination with immunocytochemical staining of smears. Canine chronic lymphocytic leukemia (CLL) occurred in older dogs (mean age 9.75 years; range 1.5-15 years; n = 73 cases). Blood lymphocyte counts ranged from 15,000 to 1,600,000/microl. Surprisingly, 73% of CLL cases involved proliferation of T lymphocytes (CD3+), and 54% of CLL cases had large granular lymphocyte (LGL) morphology. LGL CLL's were almost exclusively proliferation's of T cells that expressed CD8 and the leukointegrin alphaDbeta2 and more frequently expressed T cell receptor (TCR) alphabeta (69%) than TCRgammadelta (31%). The non-LGL T cell CLL cases (19% of CLL) involved proliferation of TCRalphabeta T cells in which no consistent pattern of CD4 or CD8 expression was found. B cell CLL, based on expression of CD2 or CD79a, comprised 26% of canine CLL cases. These results are in marked contrast to people where greater than 95% of CLL cases involve proliferation of B lymphocytes. Thirty eight (38) acute leukemias were also immunophenotyped. The majority (55%) of these leukemias had a phenotype most consistent with a myeloid origin. Acute LGL leukemias were also observed (7/38), although less commonly than the CLL counterpart. CD34 expression was common in acute, non-LGL leukemias of dogs, both myeloid and lymphoid. In some circumstances, it can be difficult to differentiate a reactive (polyclonal) lymphoid proliferation from a neoplastic (monoclonal) one. Therefore, as an adjunct to phenotypic studies, we have developed a polymerase chain reaction (PCR) based test for assessment of clonality in T cell proliferations. The test amplifies the junction of the variable gamma (Vgamma) and joining gamma (Jgamma) gene segments region of the TCR gamma genes. Preliminary data indicates that our test is effective and is capable of differentiating a neoplastic from a reactive lymphoproliferative process.