H-Y抗原候选基因的研究进展

雄性特异性组织相容性抗原(male specific minor histompatibility antigens,H-Y抗原)是由Y染色体上的基因编码,在雄性动物细胞中普遍表达(包括胚胎和滋养层细胞)。H-Y抗原不仅能引起基因型相同的雌性动物排斥雄性组织,也能导致人白细胞抗原匹配干细胞移植术后出现移植抗宿主性疾病(GVH)。细胞毒性T淋巴细胞检测到几个不同的H-Y抗原表位,这些肽是从胞内蛋白分离出来,由主要组织相容性复合分子结合呈递在细胞表面。H-Y抗原肽与人白细胞抗原Ⅰ类和Ⅱ类分子特异结合参与免疫反应,从而影响移植结果。近年来越来越多的文献报道了H-Y抗原的相关研究,作者主要综述编码H-Y抗原的相关候选基因,并对它在疾病等方面的前景作出了一些展望。     

应用酯酶染色法对初生仔猪哺乳前猪瘟免疫外周血T细胞的检测

T细胞和B细胞是参与动物机体特异性免疫应答的主要细胞。在抗原的作用下,T细胞参与细胞免疫过程,同时还协助B细胞完成体液免疫应答。在淋巴细胞再循环中,参与再循环的淋巴细胞绝大多数是T细胞。在外周血中,T细胞占淋巴细胞总数的正常值的60％～70％。再循环的意义是增加淋巴细胞与抗原物质接触的机会,并不断补充淋巴细胞以维持免疫功能。T细胞正常比值的改变     

如何重构猪群的非特异性免疫屏障

动物机体的免疫力包括非特异性免疫力与特异性免疫力。特异性免疫力（Specific immunity）是指动物机体对抗原特异性识别而产生的免疫力,即产生免疫应答和由此产生的免疫抗体。特异性免疫力具有高度的特异性和很强的针对性与专一性。动物机体的特异性免疫力主要体现在细胞免疫（T细胞）与体液免疫（B细胞）两个方面。     

免疫佐剂的研究进展

佐剂（A山uvants）是先于抗原或与抗原同时注射于动物体内，能非特异性地改变或增强机体对该抗原的特异性免疫应答的物质，亦称免疫增强剂。[1]佐剂可选择性的改变免疫应答类型，产生体液和／或细胞免疫。改变体液抗体种类，IgG亚类及抗体的亲和性。佐剂可改变抗原的构型，使疫苗诱导T－辅助细胞和细胞毒T淋巴细胞（CHL）反应。佐剂可改变兔疫反应为MHCⅠ型或MHCⅡ型、MHCⅠ型反应通常是在细胞内寄生的病原体如病毒感染时产生，诱导CTL，而蛋白质或多肽抗原则不能诱导。佐剂如免疫刺激复合物，QS21与蛋白质、多肽或灭活病毒结合可…     

兽用免疫佐剂的研究现状及发展趋势

免疫佐剂具有调节免疫系统功能,使机体对抗原特异性免疫应答达到非特异性增强或改变,对免疫反应类型改变或使抗原免疫原性增强,但自身没有抗原性物质.佐剂对抗原及参与免疫应答细胞产生作用,通过对巨噬细胞活性的增强,T、B细胞反应促进来发挥自身作用.抗原表位可由佐剂突出,对免疫应答具有较强的诱导;一些会缓慢释放颗粒化抗原,而实现免疫应答的持续诱导.随着研究的深入,很多物质都被发现具有佐剂功能,主要有以下几类.     

动物用免疫增强剂的研究进展

免疫增强剂也称免疫佐剂,是一类单独或与抗原同时使用,通过不同作用方式,如增强巨噬细胞活性、抗原物质的免疫原性和稳定性及促进抗体的合成与分泌等,进而增强动物机体非特异性和特异性免疫的物质。研究表明,免疫增强剂能提高动物自身免疫力,消除动物免疫抑制,增强动物对细菌和病毒性传染病的抵抗力。近年来,国内外学者都在寻找特异性     

介绍几种新型免疫增强剂

动物免疫增强剂是指通过不同的作用方式，如增强巨噬细胞蚕噬功能，提高免疫活性细胞功能、增强抗原物质免疫原性和稳定性等，从而非特异性地增强动物机体非特异性和特异性免疫力的药物。动物免疫增强剂在动物疫病防治中有广阔的应用前景，是新药物科学的最新成果。     

如何重构猪群的非特异性免疫屏障

动物机体的免疫力包括非特异性免疫力与特异性免疫力。特异性免疫力是指动物机体对抗原特异性识别而产生的免疫力,即产生免疫应答和由此产生的免疫抗体。特异性免疫力具有高度的特异性和很强的针对性与专一性。动物机体的特异性免疫力主要体现在细胞免疫(T细胞)与体液免疫(B细胞)两个方面。1998年,在畜牧兽医学术界,大连三仪集团董事长江国托博士针对我国动物疫病发生与流行中出现的新情况与存在的问     

肿瘤多肽疫苗研究进展

肿瘤的发生、发展和治疗与机体免疫系统功能密切相关,伴随着肿瘤抗原、抗原递呈、T细胞识别机制的突破性研究进展,研究者发现抗肿瘤多肽疫苗能够通过肿瘤抗原多肽识别抗原递呈细胞表面的主要组织相容性复合体(MHC)分子,形成肽-MHC-T细胞受体复合物,引起相应的细胞毒性T淋巴细胞免疫反应,从而杀伤肿瘤。因此,研制既能打破肿瘤患者存在的免疫耐受又能诱发针对肿瘤相关抗原特异性免疫应答的高效多肽疫苗已成为肿瘤免疫治疗研究的热点。论文综述了肿瘤多肽疫苗抗肿瘤相关机制及其在该领域所取得的最新临床研究进展。     

牛结核病体外免疫诊断技术

牛分支杆菌感染的主要特征是引起 细胞免疫反应。现在牛结核病的诊断试验是 以T细胞反应机制为基础的。低敏感性的结 核血清学试验是不值得提倡的,血清学试验 最好作为细胞学试验的补充而不是替代。最 近,发现了牛结核γ干扰素试验是一种快速 的(24h)惟一使用全血的体外试验,该方法 在澳大利亚应用,结果表明,比传统的结核菌 素法诊断牛结核更敏感。假阳性反应的难题 归因于所使用的抗原制品间的交叉反应特 性,设动物对牛PPD和禽PPD的γ干扰素反 应作对照可解决假阳性的问题。虽然牛结核 特异性蛋白已确认并被分类,这些特异性蛋 白可能在血清学或细胞学诊断试验中使用, 但是它们可能因牛对牛分支杆菌感染的免疫 反应的遗传多样性而受到限制。     

人兽共患寄生虫病候选疫苗分子筛选方法研究进展

人兽共患寄生虫种类多、宿主广泛且危害严重。血吸虫病、棘球蚴病、囊尾蚴病、旋毛虫病、弓形虫病等是常见的重要人兽共患寄生虫病。人类和家畜饱受寄生虫病的危害,这对公共卫生和畜牧业造成了很大的影响。控制传染源、切断传播途径和保护易感群是控制人兽共患寄生虫病流行的综合防控措施。在综合防控策略中,疫苗的使用是切断循环链、控制乃至消灭人兽共患寄生虫病的理想和有效途径之一。选用高效的抗原筛选方法挖掘潜在的疫苗候选分子是开发疫苗的前提和关键。抗原筛选技术的更新换代使得研究者发掘出了更多新抗原和保护性多肽。现有的抗原筛选方法主要包括传统的粗抗原筛选法、cDNA文库筛选法、蛋白质组学筛选法、生物信息学及多组学技术联合筛选法。很多抗原筛选的方法是伴随寄生虫疫苗研究的发展应运而生的,粗抗原筛选法是基于抗原抗体相互反应的免疫学原理而设计的,此方法筛选的天然抗原可引起机体较强的免疫反应;cDNA文库筛选抗原的优势在于筛选更有针对性,所以候选产物的成分更单一、明确;蛋白质组学筛选法是基于质谱而兴起的一种筛选技术,它既可对未知蛋白组分进行鉴定,还可对鉴定结果进行差异比较,在未知分子的发现和功能特殊的靶分子筛选中发挥着重要作用;随着后基因时代的到来,生物信息学及多组学联合筛选技术使得抗原筛选逐步进入了多维、立体的筛选模式,也使得候选抗原及其表位的功能研究更加深入,这为基因工程疫苗和多肽疫苗候选分子的筛选提供了技术手段。     

动物鹦鹉热衣原体疫苗研究现状

鹦鹉热衣原体为多种人畜共患病的病原体。衣原体免疫学机制研究表明其主要引发Th1细胞调节的细胞免疫和体液免疫。减毒活疫苗、灭活疫苗的使用在一定程度上控制了其发病率。基因工程疫苗,如重组亚单位苗、核酸疫苗、细茵载体苗等也都在深入研究中。同时,人们也在筛选特异性的抗原,构建各种疫苗载体及选择免疫佐剂和免疫途径等方面做了大量的工作。     

Marek's disease virus-transformed chicken T-cell lines respond to lymphokines.

Current assays for chicken interleukin-2 (IL-2) utilize mitogen-activated lymphocytes. However, very high inter-assay variability and sporadic high background proliferation limit their usefulness. In view of the above, several Marek's disease virus (MDV)-transformed T-cell lines (which grow well in a serum-supplemented medium) were tested for a response to chicken IL-2 when grown in serum-free media. Five of six lines examined showed a dose-dependent proliferative response to chicken T-cell conditioned media. One line, MDCC-CU14, was chosen for further studies. In addition to the tumor cells' dose-dependent responses to semi-purified chicken IL-2, they expressed T-cell activation antigens on the cell surface. Furthermore, the level of surface expression was enhanced on cells provided IL-2. Co-incubation of the tumor cells with monoclonal antibody INN-CH-16 (specific for an antigen on the surface of activated T-cells) and IL-2 resulted in a modulation of lymphokine-induced proliferation. Together, these data suggest that signalling mechanisms in MDV T-cell tumors are intact and that these lines can be used as an assay for chicken T-cell lymphokines. Furthermore, they provide an interesting model for the study of avian and mammalian T-cell transformation. Implications for the study of Marek's disease are also discussed.     

二氟沙星人工抗原的合成与鉴定

通过化学方法合成了二氟沙星人工免疫原和包被原；采用碳二亚胺法将半抗原二氟沙星与载体蛋白BSA连接制备人工免疫原；并采用氯甲酸异丁酯法将二氟沙星与载体蛋白OVA连接制备人工包被原，经FeCl3显色反应、紫外扫描分析和动物免疫试验证实人工抗原合成成功。这对抗二氟沙星单克隆抗体的制备具有重要意义。     

Iscoms

The common problem for defined purified antigens or antigen determinants has been to make them immunogenic regardless of whether they are produced conventionally, produced as cloned genetechnology products or chemically synthesized. The first problem is to get the protective antigen into a submicroscopic particle where the antigen is presented in several copies, i.e. as a multimer. For some antigens it seems also necessary to enhance the immunogenicity with an adjuvant. The immunostimulating complex (iscom) was created to fulfil these criteria by assembling antigens in a multimeric form on a matrix with built-in adjuvant to form a particle. The components are held together by hydrophobic interactions. The iscom has turned out to be highly immunogenic, inducing high antibody mediated and cell-mediated immunity including cytotoxic T cell response to influenza virus. In a mouse model iscoms containing influenza virus envelope proteins induced protective immunity by one intranasal administration. Protective immunity was also induced to a retrovirus--feline leukemia virus. In a monkey model system iscoms containing gp360 of Epstein-Barr virus induced protection to induction of tumours. Iscoms have also been used as carriers for small molecules such as oligopeptides, which combination appeared to be highly immunogenic.     

Complement-fixation and Hemagglutination Antigens from a Chlamydial (Ornithosis) Agent Grown in Cell Cultures

Methods are described for the preparation of complement-fixation (CF) and hemagglutination (HA) antigens from the Texas turkey ornithosis agent grown in McCoy cell culture monolayers. The particulate antigens prepared for this study were satisfactory for testing mammalian sera by direct CF tests and avian sera by indirect CF or modified direct CF tests. Comparison of titers were made on human, bovine and ovine sera using direct CF tests employing antigen prepared for this study, 6 BC yolk sac antigen, and a commercially available antigen.

The HA antigen agglutinated mouse erythrocytes, but it was not of value in hemagglutination inhibition tests because of “nonspecific” inhibitors in both mammalian and avian sera.

     

Antigen-independent priming: a transitional response of bovine gammadelta T-cells to infection

Analysis of global gene expression in immune cells has provided unique insights into immune system function and response to infection. Recently, we applied microarray and serial analysis of gene expression (SAGE) techniques to the study of gammadelta T-cell function in humans and cattle. The intent of this review is to summarize the knowledge gained since our original comprehensive studies of bovine gammadelta T-cell subsets. More recently, we have characterized the effects of mucosal infection or treatment with microbial products or mitogens on gene expression patterns in sorted gammadelta and alphabeta T-cells. These studies provided new insights into the function of bovine gammadelta T-cells and led to a model in which response to pathogen-associated molecular patterns (PAMPs) induces 'priming' of gammadelta T-cells, resulting in more robust responses to downstream cytokine and/or antigen signals. PAMP primed gammadelta T-cells are defined by up-regulation of a select number of cytokines, including MIP1alpha and MIP1beta, and by antigens such as surface IL2 receptor alpha (IL-2Ralpha) and CD69, in the absence of a prototypic marker for an activated gammadelta T-cell, IFN-gamma. Furthermore, PAMP primed gammadelta T-cells are more capable of proliferation in response to IL-2 or IL-15 in the absence of antigen. PAMPs such as endotoxin, peptidoglycan and beta-glucan are effective gammadelta T-cell priming agents, but the most potent antigen-independent priming agonists defined to date are condensed oligomeric tannins produced by some plants.     

Immunity to bovine virus diarrhoea virus in calves: the role of different T-cell subpopulations analysed by specific depletion in vivo with monoclonal antibodies.

Gnotobiotic calves were injected intravenously with murine monoclonal antibodies (mAb) directed against the BoCD4, BoCD8 or BoWC1 antigens that define the three major T-lymphocyte subpopulations in cattle. This produced a transient, specific depletion of each cell type in the circulation. Calves were then infected intranasally with a non-cytopathogenic biotype of bovine virus diarrhoea virus and the effect of the specific depletion with the mAb on viraemia and shedding of virus from the nasopharynx determined. Depletion of the cells expressing the BoCD4 antigen resulted in an extension of the duration of viraemia and an increase in the titre of virus in blood. No effect on nasopharyngeal shedding was noted. Depletion of either of the other two T-cell subsets that expressed the BoCD8 antigen or the BoWC1 antigen present on the gamma/delta T-cells had no demonstrable effect. These findings are interpreted as showing that the BoCD4+ cells play a pivotal role in controlling a primary infection with this virus but MHC class I restricted BoCD8+ T-cells are not a major effector mechanism. The BoCD4+ cells may be acting directly or be mediators of T-cell help.     

斑点免疫吸附试验诊断羊脑多头蚴病的研究

以原头节可溶性粗抗原经Sephadex G-200层析纯化抗原为包被抗原，兔抗羊IgG-HRP结合物为显色剂，建立检测羊脑多头蚴病血清抗体的Dot-ELISA，并以ELISA作平行对照。结果，粗抗原和层析纯化抗原检测86头份羊脑多头蚴病阳性血清，其敏感性分别为94．18％和93．02％，两种抗原的敏感性无显著差异；检测122头份绦虫蚴病阴性血清，18头份棘球蚴病阳性血清，35头份细颈囊尾蚴病阳性血清，其特异性分别为90．29％和95．43％。两种抗原的特异性差异显著。Dot-ELISA和ELISA两种方法的符合率为100％。层析纯化抗原比粗抗原的特异性有了明显提高，而敏感性没有降低。层析纯化抗原和操作术式都具有良好的重复性，Dot-ELISA和ELISA对比试验结果相近，且具简便、快速及不需要复杂设备等优点，是一种检测羊脑多头蚴病血清抗体的理想方法。