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1.
Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides biotype Small Colony (MmmSC), is still a major cattle disease in Africa. Development of long-term protective vaccines, the only relevant strategy to achieve CBPP eradication, requires the characterisation of the protective immune mechanism. To this aim, the present study investigated the cellular immune response persisting in the lymph nodes of cattle infected naturally and experimentally by contact, one year post exposure. The lymph node cell composition, MmmSC responsiveness and phenotype of the MmmSC-responding lymphocytes were compared between animals according to the different outcomes of the infection. To unravel the protective mechanism, the study focussed on the MmmSC-specific memory immune response generated in recovered cattle, known to develop long-term immunity and to be resistant to reinfection. An MmmSC-specific immune response, mediated by IFNgamma-secreting CD4 T-cells, was detected in the lymph nodes of all recovered cattle. Furthermore, the magnitude of this immune response was significantly higher in animals with complete recovery than in recovered animals presenting lung sequestra. The findings suggest that, in recovered cattle, a subset of MmmSC-primed IFNgamma-secreting CD4 T-cells homed to the regional lymph nodes as MmmSC-specific memory T-cells, likely responsible for the protective anamnestic response. Induction and expansion of this subset of MmmSC-specific CD4 memory T-cells might be a major goal to develop efficient long term protective vaccines against CBPP. 相似文献
2.
Dedieu L Balcer-Rodrigues V Yaya A Hamadou B Cisse O Diallo M Niang M 《Veterinary immunology and immunopathology》2005,107(3-4):217-233
Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides SC (MmmSC), is one of the most significant cattle disease in Africa. The control measures, which led to eradication from numerous countries are not feasible in Africa where the only prophylaxis relies on vaccination. However, the attenuated vaccines, used up to now in Africa, are of low efficiency. The development of an improved vaccine is, therefore, a necessity. The purpose of this study was to compare some immunological parameters in MmmSC-infected cattle (endobronchial versus natural in-contact infection) and assess the response in correlation with the clinical outcome (death versus recovery). Characterization of the immune parameters elicited in recovered animals, known to be refractory to new infection, will be an important step towards development of new vaccines against CBPP. A significant outcome of this study was the demonstration that all MmmSC-infected cattle developed a MmmSC-specific cell-mediated immune response. A kinetic analysis of the MmmSC responsiveness showed that the main difference between endobronchially- and in-contact infected animals was the delay before the onset of the MmmSC-specific immune response. The first MmmSC-responding PBMC sample was selected from each animal for cell phenotyping. The phenotypic analysis of this early MmmSC-induced response revealed the predominant contribution of the CD4 T-cells in all animals whereas IFNgamma was only constantly produced in recovered animals. Evolution of this early MmmSC-specific immune response was then followed by a kinetic analysis of the MmmSC-induced CD4 T-cell response and IFNgamma released. The results demonstrated that in recovered animals, the MmmSC-specific CD4 Th1-like T-cell response was maintained until slaughtering whereas in animals with acute disease, progression of CBPP was associated with a decreased ability of the PBMC to produce IFNgamma. The results led to the identification of immune parameters, which correlate with protection against CBPP and to a relevant strategy for the development of improved vaccines against this disease. 相似文献
3.
Parra A García N García A Lacombe A Moreno F Freire F Moran J Hermoso de Mendoza J 《Veterinary microbiology》2008,129(3-4):315-324
Biofilm formation where bacterial cells adhere to a surface and surround themselves in a polysaccharide matrix is thought to be an important factor in disease initiation and persistence for many bacterial species. We have examined biofilm formation by Mycoplasma mycoides subsp. mycoides small colony using a simple model without an air/liquid interface and have found that adherent Mmm SC was more resistant to many stresses, including heat, osmotic shock and oxidative stress. Biofilms of Mmm SC also exhibited remarkable persistence and were able to survive for up to 20 weeks in stationary phase. Significant variation was seen between Mmm SC strains in their ability to form a biofilm and the morphology of the biofilm produced with some strains unable to produce microcolonies. Proteomic analysis found that a number of proteins linked to adherence were over-expressed in biofilms compared with planktonic cells. 相似文献
4.
Totté P Rodrigues V Yaya A Hamadou B Cisse O Diallo M Niang M Thiaucourt F Dedieu L 《Veterinary research》2008,39(1):8
A better understanding of protective immune memory against contagious bovine pleuropneumonia (CBPP) is needed in order to facilitate the development of safer vaccines based on selected components of the pathogen. For this purpose, cells collected from lymph nodes draining the lungs of Mycoplasma mycoides subsp. mycoides small colony biotype (MmmSC)-infected cattle were stimulated with the pathogen in vitro and evaluated concurrently for proliferation (CFSE based method), expression of activation, memory markers and cytokine production. Direct evidence is presented for a major contribution of CD4+ T cells to the vigorous proliferative and T1 biased cytokine recall responses observed in cattle that have recovered from infection but not in animals developing the acute form of the disease. Two different phenotypes of MmmSC-specific memory CD4 were observed based on CD62L expression and proliferative capacities. Furthermore, recall proliferation of B cells also occurred but was strictly dependent on the presence of CD4. The information provided in this study will facilitate the search for MmmSC antigens that have potential for the development of subunit vaccines against CBPP. 相似文献
5.
Contagious bovine pleuropneumonia (CBPP) caused by Mycoplasma mycoides subsp. mycoides (Mmm) is an economically very important cattle disease in sub-Saharan Africa. CBPP impacts animal health and poverty of livestock-dependent people through decreased animal productivity, reduced food supply, and the cost of control measures. CBPP is a barrier to trade in many African countries and this reduces the value of livestock and the income of many value chain stakeholders. The presence of CBPP also poses a constant threat to CBPP-free countries and creates costs in terms of the measures necessary to ensure the exclusion of disease. This opinion focuses on the biomedical research needed to foster the development of better control measures for CBPP. We suggest that different vaccine development approaches are followed in parallel. Basic immunology studies and systematic OMICs studies will be necessary in order to identify the protective arms of immunity and to shed more light on the pathogenicity mechanisms in CBPP. Moreover a robust challenge model and a close collaboration with African research units will be crucial to foster and implement a new vaccine for the progressive control of this cattle plague. 相似文献
6.
Sacchini F Naessens J Awino E Heller M Hlinak A Haider W Sterner-Kock A Jores J 《Veterinary research》2011,42(1):77
ABSTRACT: Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides, is an important livestock disease in Africa. The current control measures rely on a vaccine with limited efficacy and occasional severe side effects. Knowledge of the protective arms of immunity involved in this disease will be beneficial for the development of an improved vaccine. In previous studies on cattle infected with M. mycoides subsp. mycoides, a correlation was detected between the levels of mycoplasma-specific IFN-γ-secreting CD4+ T lymphocytes and reduced clinical signs. However, no cause and effect has been established, and the role of such cells and of protective responses acquired during a primary infection is not known.We investigated the role of CD4+ T lymphocytes in CBPP by comparing disease patterns and post mortem findings between CD4+ T cell depleted and non-depleted cattle. The depletion was carried out using several injections of BoCD4 specific murine monoclonal antibody on day 6 after experimental endotracheal infection with the strain Afadé. All cattle were monitored clinically daily and sacrificed 28-30 days post-infection. Statistically significant but small differences were observed in the mortality rate between the depleted and non-depleted animals. However, no differences in clinical parameters (fever, signs of respiratory distress) and pathological lesions were observed, despite elimination of CD4+ T cells for more than a week. The slightly higher mortality in the depleted group suggests a minor role of CD4+ T cells in control of CBPP. 相似文献
7.
【目的】制备鸭多杀性巴氏杆菌灭活疫苗,有效控制贵州省鸭多杀性巴氏杆菌发生和流行。【方法】以实验室分离保存的A:L1型多杀性巴氏杆菌地方流行株为菌种,通过涂板法测定该菌株生长曲线,并采用改良寇氏法计算该菌株对鸭的半数致死量(median lethal dose, LD50),将该菌培养至终浓度为1×1010 CFU/mL后分别制备白油佐剂灭活疫苗和卡波姆佐剂灭活疫苗,经疫苗质量检验后进行免疫雏鸭试验;通过攻毒保护试验评价比较两种疫苗的保护率,并对攻毒试验鸭肝脏、肺脏、脾脏进行病理组织学观察。【结果】A:L1型多杀性巴氏杆菌疫苗株培养至18 h到达峰值,活菌数可达1.0×1010 CFU/mL;LD50为5 CFU;制备的两种疫苗安全性良好;攻毒保护试验结果显示,一免后卡波姆佐剂灭活疫苗免疫保护率可达62.5%,高于白油佐剂灭活疫苗(50.0%)及商品灭活疫苗(50.0%)。二免后卡波姆佐剂灭活疫苗优势更为明显,免疫保护率可达87.5%,高于白油佐剂灭活疫苗(75.0%)及商品灭活疫苗(62.5%)。病... 相似文献
8.
牛溶血性曼氏杆菌及牛荚膜A型多杀性巴氏杆菌是导致牛呼吸道疾病（bovine respiratory disease,BRD）的重要细菌性病原,每年给养牛业带来巨大的经济损失,目前对其疫苗研究仍显不足。本研究选用牛溶血性曼氏杆菌（Mannheimia haemolytica,Mh） Mh422株和牛荚膜A型多杀性巴氏杆菌（Pasteurella multocida,Pm） PmCQ2株作为疫苗菌株,分别制备了2种菌体浓度的Mh和Pm单价灭活菌苗及3种菌量配比（1∶1、2∶1和3∶1）的Mh-Pm二联灭活苗,以小鼠为模型,皮下多点免疫（0.2 mL）,加强免疫2次,免疫剂量均为首免的一半。首免后第7天及其后每隔5 d,小鼠尾静脉采血分离血清,ELISA方法检测抗体效价,三免后第20天,分别以Mh422或PmCQ2进行腹腔攻毒测定免疫保护效果。结果显示,所有小鼠接种疫苗均无不良反应,二免后第10天抗体达较高水平,三免后抗体水平持续升高,第15天到达高峰,其后25 d维持高水平,后缓慢下降。Mh单菌苗的2种免疫剂量对Mh422株攻毒的免疫保护率均为0,而Pm单菌苗的2种免疫剂量对PmCQ2株攻毒的免疫保护率全为100%;Mh和Pm间无交叉免疫保护作用;3种菌量配比的Mh-Pm二联疫苗对Mh422株和PmCQ2株攻毒的各自免疫保护率分别为53%～71%和100%。该研究结果表明,所制备的Mh422单菌苗对同型攻毒无免疫保护作用,在诱导机体抗体产生方面,Mh和Pm间无相互抑制作用,PmCQ2株具有促进Mh422株灭活疫苗对Mh422的免疫保护作用,这为牛溶血性曼氏杆菌和牛多杀性巴氏杆菌二联疫苗的进一步研究提供了理论基础。 相似文献
9.
寄生虫病带来了相当大的社会经济影响,人畜共患寄生虫给人们带来巨大的疾病负担,并给养殖业造成严重的经济损失。因此,寄生虫病的防治是人们迫切需要研究的课题。寄生虫存在很多形式的免疫逃避机制,灭活疫苗、减毒活疫苗、亚单位疫苗等未达到理想的预防寄生虫病的效果,很多研究表明DNA疫苗有望成为预防和治疗寄生虫病的有效方法。DNA疫苗是一种新型疫苗,可同时诱导机体产生持久的体液免疫和细胞免疫,通过在宿主内表达外源蛋白来提供保护性免疫。DNA疫苗与其他亚单位疫苗不同的是,免疫原由摄取抗原编码DNA的细胞在宿主内合成。体内蛋白质的合成也能进行抗原加工、修饰并递呈到宿主的免疫系统中,类似于自然感染的方式。笔者就DNA疫苗免疫机制、设计原则、免疫途径、优缺点及近几年寄生虫DNA疫苗的研究进展进行综述,以期为寄生虫DNA疫苗的开发提供理论参考。 相似文献
10.
旨在建立一种检测牛传染性胸膜肺炎（CBPP）血清抗体的间接ELISA方法,用于该病的监测。利用生物信息学软件对CBPP的病原丝状支原体丝状亚种国内分离株Ben-1株的全基因组进行分析,选取脂蛋白rP0308作为包被抗原,通过一系列反应条件的优化,建立了基于rP0308蛋白的间接ELISA抗体检测方法,并对其性能进行评价。结果显示该方法的敏感性为92%,特异性为96%,与牛支原体、牛鼻支原体、无乳支原体、口蹄疫、牛病毒性腹泻、牛传染性鼻气管炎和牛结核分枝杆菌等阳性血清均不发生交叉反应,批内变异系数在2.41%~6.03%,批间变异系数在2.94%~6.59%,重复性良好。利用本方法和商品化的cELISA试剂盒分别对实验室保存的1 648份临床样品进行检测,该方法与商品化试剂盒的阴性符合率为89.1%,阳性符合率为79.2%,总符合率为88.7%。以上研究结果表明,本研究建立的间接ELISA方法具有良好的敏感性、特异性和重复性,具有良好的临床应用前景。 相似文献
11.
本研究旨在探索猪流行性腹泻病毒(porcine epidemic diarrhea virus,PEDV)灭活疫苗不同抗原含量对仔猪感染的保护作用。测定不同浓缩倍数PEDV感染性病毒粒子数和病毒粒子总数,用不同浓缩倍数抗原分别制备灭活疫苗免疫小鼠,利用ELISA抗体检测方法、中和试验、ELISPOT方法测定体液免疫与细胞免疫产生情况,筛选合适抗原含量疫苗进行仔猪免疫并测定抗体,利用攻毒试验研究浓缩疫苗与保护之间的关系。结果显示,当抗原含量达8×106 pfu·mL-1以上时,灭活疫苗能有效刺激小鼠产生体液免疫及细胞免疫。以2 mL含8×106 pfu·mL-1抗原的灭活PEDV疫苗免疫仔猪可抵抗PEDV攻毒引起的腹泻及连续排毒,相较于总病毒粒子数,感染性病毒粒子数与抗体产生呈显著相关(r = 0.998 1),中和效价与仔猪保护呈显著相关性(r=0.974 7)。PEDV灭活疫苗可以提供良好的免疫保护,其中感染性病毒数量是提升抗体水平的关键因子,抗体滴度作为一项体液免疫的指标是判断免疫保护的重要参考。 相似文献
12.
三种猪繁殖与呼吸综合征疫苗免疫效果评价 总被引：2，自引：0，他引：2
为研究不同猪繁殖与呼吸综合征病毒(PRRSV)疫苗的的免疫特性,分别采用PRRSV变异株(JXA1-R)弱毒疫苗、经典PRRSV(VR 2332)弱毒疫苗、变异株(JXA1)灭活疫苗,免疫接种PRRSV抗原和抗体阴性的健康断奶仔猪,免疫接种后70d用PRRSV变异株强毒攻毒,ELISA检测血清中PRRSV特异的抗体水平及IFN-γ、IL 2、IL 4、IL 8、IL 10的水平,并进行临床症状和肺部病理组织学观察和评分。结果表明,VR 2332、JXA1-R弱毒疫苗对免疫猪攻毒保护效果差异不显著,均为63.6%(7/11),JXA1灭活疫苗免疫攻毒保护效果较差,为36.4%(4/11)。试验还发现病毒感染猪血清中细胞因子IFN-γ和IL-10的比值可以作为评价疫苗免疫效果的一个指标。 相似文献
13.
研究使用健康易感仔猪对3批猪支原体肺炎活疫苗(168株)分别进行了免疫效力试验、免疫期试验、临床效力试验、同类制品的免疫效力比较试验和免疫期比较试验,以及5批疫苗免疫商品猪的临床试验。结果表明：猪支原体肺炎活疫苗(168株)免疫仔猪60天后,免疫组有80%以上的保护率,免疫后7个月,试验组仍有50%以上的保护率;同类制品免疫效力和免疫期比较试验结果表明两种猪支原体活疫苗差异不明显。临床观察和病理剖检结果表明免疫保护率在85%以上。以上结果都说明猪支原体肺炎活疫苗（168株）具有很好的免疫效力。 相似文献
14.
Bovine schistosomosis, caused by Schistosoma bovis, constitutes a serious veterinary problem in many parts of the world. The vaccination approaches for the control of bovine schistosomosis include the use of irradiation-attenuated S. bovis cercarial or schistosomular vaccines, S. bovis adult worms or whole-egg antigens and defined antigen vaccine. Irradiated S. bovis cercarial or schistosomular vaccines provide partial protection against S. bovis infection. However, this type of vaccine requires live infectious cercariae or viable schistosomula for induction of protection. Unfortunately, experimental immunizations with dead schistosome antigens have been largely unsuccessful. The surge of new techniques in cellular immunology and molecular biology has made possible the development of potential candidate vaccine antigens from various species of schistosomes including S. bovis. The efficiency of these vaccines has been evaluated in experimentally infected calves. These vaccines will probably replace the irradiated S. bovis vaccines. A broad-spectrum antischistosome vaccine which can kill a variety of human and animal schistosome species is yet to be produced. 相似文献
15.
猪繁殖与呼吸综合征(porcine reproductive and respiratory syndrome,PRRS)是一种主要表现为母猪繁殖障碍与仔猪呼吸道症状的传染病。近年来,猪繁殖与呼吸综合征病毒(porcine reproductive and respiratory syndrome virus,PRRSV)变异株不断出现,免疫逃避及持续性感染使得猪群发病率或复发率均相继增高,给养猪业带来了巨大的损失。目前所采用的胃肠道途径接种活疫苗或灭活疫苗的方法无法诱导对猪群的全面保护作用。为减少养猪业的经济损失,亟需研制新防制方法和新疫苗接种途径。作者主要从黏膜免疫的免疫部位、呼吸道保护性黏膜免疫反应诱导、黏膜免疫途径、佐剂的选择及病毒的免疫抑制反应等方面简要论述了有效防制PRRSV的黏膜免疫方法的研究进展,为进一步了解黏膜免疫抵御PRRSV突变株感染及黏膜疫苗研制等方面提供有用的信息。 相似文献
16.
Vemulapalli R He Y Sriranganathan N Boyle SM Schurig GG 《Veterinary microbiology》2002,90(1-4):521-532
Brucella abortus vaccine strain RB51 is an attenuated, stable rough mutant that is being used in many countries to control bovine brucellosis. Our earlier study demonstrated that the protective efficacy of strain RB51 can be significantly enhanced by overexpressing Cu–Zn superoxide dismutase (SOD), a homologous protective antigen. We have also previously demonstrated that strain RB51 can be engineered to express heterologous proteins and mice vaccinated with such recombinant RB51 strains develop a strong Th1 type of immune response to the foreign proteins. The present study is aimed at combining these two characteristics to generate new recombinant RB51 vaccines with enhanced abilities to protect against brucellosis and simultaneously able to protect against infections by Mycobacterium spp. We constructed two recombinant RB51 strains, RB51SOD/85A which overexpresses SOD with simultaneous expression of the 85A, a protective protein of Mycobacterium spp., and RB51ESAT which expresses ESAT-6, another protective protein of M. bovis, as a fusion protein with the signal sequence and few additional amino terminal amino acids of SOD. Mice vaccinated with these recombinant strains developed specific immune responses to the mycobacterial proteins and significantly enhanced protection against Brucella challenge compared to the mice vaccinated with strain RB51 alone. 相似文献
17.
Singh Rajinder Verma Prem C. Singh Satparkash 《Tropical animal health and production》2010,42(3):465-471
Virosome based vaccines against Newcastle disease (ND) were prepared and evaluated for their immunogenicity and protective
efficacy in chickens. Envelop of Newcastle disease virus (NDV) was solubilised with Triton X-100 to yield virosomes which
were later on encapsulated in poly-lactide-co-glycolide (PLG) microspheres. The birds were immunized intranasally with virosomes
or PLG microspheres encapsulated virosomes, and efficacy of these preparations was compared with commercial LaSota vaccine.
The preparations protected the chickens against virulent virus challenge infection, however the microencapsulated virosome
vaccine gave slightly lesser degree of protection than non encapsulated counterpart. The humoral and cell mediated immune
response generated as well as the protection afforded by virosome preparations were found to be comparable with LaSota vaccine.
The results substantiate the potential of virosome based vaccines to provide high level of immunity and protection against
Newcastle disease. 相似文献
18.
Chalmers WS 《Veterinary microbiology》2006,117(1):25-31
Molecular technology has given us a greater insight into the aetiology of disease, the functioning of the immune system and the mode of action of veterinary pathogens. The knowledge gained has been used to develop new vaccines with specific, reactive antigens which elicit protective immune mediated responses (humoral and/or cell mediated) in the host. These vaccines should not burden the immune system by initiating responses against non-essential antigens. However, the efficacy of these vaccines is only as good as the delivery technology or route used to present them to the immune system. Some vaccines, traditionally given by the parenteral route, are now given by the natural route; either orally or intranasally. Two major advantages, often interrelated, are the rapid onset of immunity and stimulation of the local, mucosal immunity. These new technologies are now making an impact on current vaccine development. The balance has to be found between what is technologically feasible and what will provide at least as good a protective immunity as current, conventional vaccines. As new and emerging diseases appear globally, new opportunities arise for molecular and conventional technologies to be applied to both the development and delivery of novel vaccines, as well as the improvement of vaccines in current use. 相似文献
19.
Nkando I Ndinda J Kuria J Naessens J Mbithi F Schnier C Gicheru M McKeever D Wesonga H 《Research in veterinary science》2012,93(2):568-573
A live, attenuated vaccine is currently the only viable option to control of CBPP in Africa. It has been suggested that simple modifications to current vaccines and protocols might improve efficacy in the field. In this report we compared the current vaccine formulation with a buffered preparation that maintains Mycoplasma viability at ambient temperature for a longer time. Groups of animals were vaccinated with the two formulations and compared with non vaccinated groups. Half of the animals in each group were challenged 3 months post vaccination, the other half after 16 months. Protection levels were measured using the pathology index, calculated from post mortem scores of lesions from animals killed during the course of clinical disease. In the challenge at 3 months post vaccination, the protection levels were 52% and 77% for the modified and current vaccine preparations, respectively. At 16 months post vaccination, the protection levels were 56% and 62% for the modified and current vaccine preparations, respectively. These findings indicate that there are no differences in protection levels between the two vaccines. Because of its longer half life after reconstitution, the modified vaccine might be preferred in field situations where the reconstituted vaccine is likely not to be administered immediately. 相似文献
20.
Oligodeoxynucleotides containing unmethylated CpG motifs (CpG ODN) have been proven to be immunoprotective in mouse models. However, little work has been conducted on in vivo immune responses in chicken with CpG ODN. The objective of this study was to investigate the immunoadjuvant effects of CpG ODN to Newcastle disease (ND) vaccine and its protective effects against ND virus in SPF chicken. In this report, the titre of serum IgG to ND vaccine and the proliferation of lymphocytes were monitored in SPF chickens. The results demonstrated that the above-mentioned immune responses were significantly stronger in chickens that received CpG ODN than in the birds that received only ND vaccine. Furthermore, ND vaccine plus CpG ODN protected SPF chicken from challenge with an otherwise lethal dose of ND virus. These data suggest that CpG ODN holds considerable promise as an adjuvant for future vaccines against ND virus. 相似文献