共查询到19条相似文献，搜索用时 328 毫秒
1.
本研究通过对鸡败血支原体（MG）强毒株黏附素GapA的N端（98aa-322aa）高变区作为免疫原免疫小鼠．利用Bac-to-bac系统构建GapAN重组杆状病毒，感染Sf9昆虫细胞，以作为检测抗原，筛选获得5株抗GapAN端的单克隆抗体：3D4、5810、185、1D7和4B3。经部分免疫学特性鉴定，5株单抗具备良好的免疫反应性，并且在免疫荧光试验及Western-blot检测过程中发现这些单抗针对的抗原表位存在明显差异，这些单抗的成功制备为下一步深入研究MG的黏附特性奠定了基础。 相似文献
2.
《畜牧与兽医》2015,(6):1-6
临床分离获得1株猪流行性腹泻病毒(PEDV),对其纤突(S)基因5'端序列分析比较表明,该分离株(NB2011)与目前国内流行的猪流行性腹泻病毒毒株同源性为99%以上,与经典毒株(CV777)的同源性仅为82.6%。经氨基酸分析比较,PEDV纤突蛋白发生明显变异,在抗原位点35-55aa以及100-145aa区间存在很大差异。本试验对CV777株与临床分离的NB2011株的S基因N端差异较大的区段(CV777-S661,NB-S673)进行原核表达,分别获得经典株和流行株S基因N端表达蛋白。Western blotting结果表明,S661和S673重组蛋白均能与PEDV阳性血清产生特异性反应,且不与PEDV阴性血清反应。对两种蛋白进行交叉斑点试验,结果表明两者在反应原性上存在差异。研究结果为进一步阐明PEDV流行毒株抗原表位的变异及研究PEDV免疫保护机制打下基础。 相似文献
3.
金黄色葡萄球菌是引起奶牛乳腺炎的主要传染性病原菌.本实验采用分子克隆及蛋白表达技术,成功的表达了金黄色葡萄球菌纤维素结合蛋白A(FnBPA)D片段并对其免疫学活性进行了初步研究.表达产物免疫实验动物后,获得较高效价的抗体.用制备血清进行吞噬调理试验,抗金黄色葡萄球菌黏附等一系列试验,证明 抗体对金黄色葡萄球菌具有吞噬调理作用,也有抗金黄色葡萄球菌黏附的作用,这将为制备奶牛乳房炎金黄色葡萄球菌黏附素疫苗奠定基础. 相似文献
4.
《中国兽医杂志》2018,(10)
为了构建牛冠状病毒(BCoV)抗原表位基因原核表达载体,并制备多克隆抗体,利用基因合成技术获得BCoV S蛋白两段抗原表位(351 aa～403 aa、771 aa～784 aa)的基因串联体R,将其重组到pET-28a(+)质粒中,转化至大肠杆菌BL21(DE3)感受态细胞,诱导表达抗原表位融合蛋白,用纯化的蛋白免疫新西兰兔制备多克隆抗体。结果显示,成功构建了BCoV抗原表位基因重组表达质粒,获得了融合蛋白的抗血清,Western-Blot检测显示,该抗血清可与BCoV的融合蛋白特异性结合。表明成功构建了BCoV抗原表位基因原核表达载体并获得了BCo V抗血清,本研究为BCoV诊断试剂盒的开发和BCoV多表位疫苗的研究奠定了基础。 相似文献
5.
La Sota与V4疫苗F蛋白的B细胞表位活性检测与比较 总被引：1，自引：0，他引：1
根据La Sota 和V4疫苗株F蛋白B细胞表位预测的结果,进行了表位区的鉴定和比较.将两疫苗株F基因预测存在差异的表位,根据序列位置邻近合并分成6段表位区,分别对每个毒株的6段表位区进行了亚克隆,并对每个毒株的预测区进行了表达.应用建立的Tricine缓冲体系50 g/L～200 g/L线性梯度聚丙烯酰胺凝胶蛋白电泳对表达情况进行了分析,得到5段多肽的大小分别是P1为8.0 ku,P2为10.8 ku,P4为11.6 ku,P5为13.5 ku,P6为10.5 ku.应用La Sota特异性抗血清,利用Western blotting对表达的各肽段进行了抗原性鉴定.结果表明,P1、P4、P5、P6段呈阳性反应,说明其中含有线性B细胞表位.这4段分别位于F蛋白的1 aa～48 aa,201 aa～274 aa,377 aa～458 aa和469 aa～530 aa,以前发现的中和性表位均不在这4段区域内.而P2段在Western blotting中无抗体反应性,表明它不含线性表位.比较研究发现NDV La Sota与V4株的P4区的B细胞表位活性存在着重要的差异,这种差异可能造成两个毒株的免疫原性差异. 相似文献
6.
GP5是猪繁殖与呼吸综合征病毒(PRRSV)变异最大的结构蛋白,能够诱导机体产生中和抗体。2003~2008年从广西各县市采集PRRSV阳性病料,扩增得到的49株PRRSV ORF5基因序列,并对序列进行比较和分析。49个毒株的ORF5分别属于美洲型的Ⅰ、Ⅱ、Ⅳ亚群,推导氨基酸分析发现:在中和表位区域GXLZ-1、GXLZ-2由H38→N38、L39→I39,Ⅱ亚群所有毒株序列由L39→I39;在R13和R151毒力相关位点,GXGG-1变为Q13,GXLZ-1和GXLZ-2变为K151,其他毒株未发生突变,推测Ⅱ亚群广西毒株的毒力比Ⅰ、Ⅳ亚群的强;从2003~2005年和2006~2008年这2个时间段分析,在9 aa、16 aa、54 aa、59 aa、94 aa、104 aa、185 aa出现了时间性的基因变异;遗传进化树分析发现,随着时间的推移,获得的广西毒株与CH-1 a、MLV株亲缘关系逐渐发生偏离,2006年6月之后所获得毒株亲缘关系很近,相互之间同源性很高,且与国内PRRSV变异毒株JXA1高度同源,推断2006年后获得的毒株与变异株可能由同一毒株演化而来。 相似文献
7.
口蹄疫病毒非结构蛋白3AB单克隆抗体的制备及其对应表位区分析 总被引：1，自引：0，他引：1
为鉴定口蹄疫病毒(FMDV)的非结构蛋白3AB的抗原表位,本研究以原核表达并纯化的FMDV 3AB重组蛋白免疫BALB/c小鼠,采用淋巴细胞杂交瘤技术制备杂交瘤细胞,通过间接ELISA进行筛选,获得6株能够稳定分泌抗3AB蛋白特异性单克隆抗体(MAb)的杂交瘤细胞.这6株MAbs亚类鉴定均为IgG1型,轻链均为K链.间接免疫荧光试验结果表明,这6株MAbs均能够识别FMDV 3AB蛋白.采用制备的MAb对分段表达的3AB蛋白进行western blot分析,结合位点分别位于3AB的第aa 55～aa 70、aa 64～aa 79、aa130～aa145区段.该结果为进一步探索3AB蛋白的结构和功能以及建立诊断方法奠定了基础. 相似文献
8.
为了解广东省H9亚型禽流感病毒HA基因变异情况,对2017—2018年从广东省活禽市场获得的13株H9亚型禽流感病毒HA基因进行序列分析,发现13个毒株均属于h9.4.2.5分支;潜在的糖基化位点均为8个,主要变异表现在218～220 aa处1个位点缺失和313～315 aa处1个位点增加;受体结合位点主要表现为K149N、A150T、V198T、Q234L和Q235M突变,其中234～236 aa位点突变为LMG,与人源受体相同,具有可感染人的分子特征;抗原性相关位点除201 aa位点较为保守外,其余6个位点主要表现为G90E、S145D、D153G、N167G、A168N、T200R位点的突变,此外168 aa由天冬氨酸(D)突变为天冬酰胺(N),并成为主要氨基酸。以上基因突变提示,当前流行毒株的抗原性可能发生了较大变异,现有疫苗株可能对流行毒株不能提供有效的保护,需要研发新的疫苗毒株。 相似文献
9.
《黑龙江畜牧兽医》2010,(17)
为了研究猪传染性胃肠炎病毒(TGEV)M蛋白的B细胞表位的分布,试验采用Kyte-Doolit-tle、Emini和Jameson-Wolf方案对TGEVM蛋白的氨基酸序列进行预测。结果表明:TGEVM蛋白N端19～43 aa、103～109 aa、138～155 aa、198～205 aa、220～228 aa和237～257 aa区段内很可能是B细胞表位优势区域;由此构建pGEX-6P-M112、pGEX-6P-M119用于表达TGEV M蛋白N端的19～43 aa和C端的237～257 aa肽段的原核表达载体,从而为验证分析TGEV M蛋白的B细胞表位预测的有效性及其M蛋白的结构与功能提供参考。 相似文献
10.
从辽宁某鹅场无菌采集病死雏鹅肝脏、肾脏等病料，通过鹅胚接种、核酸检测、电镜观察等方法进行病原的分离鉴定，并对所分离的毒株进行遗传变异分析和抗原表位预测。经过接种病料鹅胚的病变特征观察、病毒PCR核酸扩增和序列分析以及透射电镜形态鉴定，确认成功分离到1株GAstV(goose astrovirus),暂命名GAstV/LN/202101(简称LN202101)。针对编码衣壳蛋白保守结构域N和P2 Capsid domain的核苷酸序列对该毒株进行遗传进化树和同源性分析，结果显示该毒株与江西株JX01(MZ576222.1)等近2年发现的毒株亲缘关系较近，在同一簇分支，且属于GAstV-Ⅱ型；但同源性已表现出差异。以HAstV(human astrovirus)已验证表位为参考，依据抗原抗体结合模型，结合生信方法推测以下4段序列可能为GAstV的抗原表位：453～467aa(PQADSRSRYNANITF)、508～513aa(VCNTLA)、525～553aa(TAVLRVNTSTTSTGGQITELRNRLNIADG)和585～597aa(DSNPGETFQSFKM)。结果表明，GAs... 相似文献
11.
鸡败血支原体接种鸡体液免疫的变化规律 总被引：1，自引：0，他引：1
SPF鸡接种鸡败血支原体R株、F株和油乳剂苗后，用ELISA检测IgM、IgG和IgA的变化规律，发现特异性IgM出现时间存在差异；强毒株感染后IgM始终存在，因此可作为临诊感染的指证。油乳剂苗能产生IgA，证明油乳剂苗能诱导产生局部免疫。 相似文献
12.
A Mycoplasma gallisepticum (MG) isolate from an atypically mild outbreak in turkey breeders was found to be similar to house finch isolates by DNA analyses. A preliminary study in turkeys showed that this isolate (K5054) caused very mild lesions and protected turkeys against subsequent challenge with a virulent MG strain. In this study, K5054 was further evaluated as a potential vaccine strain in commercial layer-type chickens and turkeys. The safety of K5054 was evaluated by aerosol challenge followed by evaluation of gross and histopathologic lesions as well as serologic reactions and isolation of MG from the trachea and air sacs. Infection of chickens (trial 1) and turkeys (trial 2) with K5054 resulted in little evidence of MG lesions. There was weak seroconversion, and K5054 was consistently reisolated from the tracheas of chickens and turkeys. The efficacy of K5054 as a vaccine was evaluated by aerosol challenge of vaccinated chickens (trial 3) and turkeys (trial 4) with virulent R strain. There was evidence of protection from lesions associated with MG. 相似文献
13.
Mycoplasma gallisepticum (MG) strains showing marked variation in pathogenicity were examined for virulence in ovo. No correlation was found between in ovo pathogenicity and other in vivo or in vitro methods for pathogenicity evaluation. For certain highly pathogenic strains, there was a clear relationship between the titer of MG inoculated and the embryo mortality and time of death; an LD50 for these strains could be calculated by yolk-sac inoculation. However, not every strain that caused lesions in the respiratory tract in vivo caused embryo mortality. Less pathogenic strains that grow well and colonize the respiratory tract usually caused embryo mortality during the later stages of incubation, and there was no strict correlation between titer of inoculum and embryo mortality. It appeared that embryo death in these cases may have resulted from generalized stress due to mass multiplication of the MG. Embryo mortality due to virulent MG was completely blocked in eggs containing maternal antibody to MG, although the mycoplasma could be reisolated from the yolk-sac membrane of the live embryonated egg after 17 days of incubation. Attempts to mimic the effect of maternal antibody by injecting exogenous MG antiserum were not successful. 相似文献
14.
15.
E K Barbour J A Newman J Sasipreeyajan A C Caputa M A Muneer 《Veterinary immunology and immunopathology》1989,21(2):197-206
The antibody response to different proteins of Mycoplasma gallisepticum (MG) was studied in chickens experimentally infected with virulent MG R strain. The chickens were challenged at 8 weeks of age by the intranasal route. Each cockerel received 1.3 X 10(6) colony-forming units (CFU). MG strains (R and F) were banded by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE). The banding pattern was distinctively different between the two strains in the range of 92.5 to 200 kilodaltons (kD). Chicken sera collected at different times following challenge were analyzed by Western blot to determine the patterns of antibodies raised to specific MG proteins (R versus F strains). Early in infection (2 weeks postchallenge), antibodies to 60-kD and 75-kD polypeptides of MG R strain were produced. Subsequently (greater than or equal to 4 weeks postchallenge), antibodies recognized a larger number of MG antigens in both strains. The immunoblot patterns remained the same in the period 8-11 weeks postinfection in each of the two strains; however, the patterns were different when the two strains were compared. The early response recognized the 75-kD protein in the R strain while it recognized the 80-kD protein in the F strain. The late response recognized the 130-kD protein and the protein slightly heavier than 200 kD in the R strain. These two bands did not appear in the immunoblot performed against the F strain of MG. Electroeluted protein of MG R strain, namely adhesin (75 kD), showed a hemagglutination activity (HA) on chicken red blood cells. With the appearance of antibodies specific to the 60-kD and 75-kD polypeptides, there was a significant rise in hemagglutination-inhibition geometric mean titer of chicken sera. 相似文献
16.
Ten-week-old Hy-Line Commercial W-36 pullets were spray-vaccinated with MYCOVAC-L at the manufacturer's recommended dosage (1x) or at 15 times that rate (15x). At 22 or 45 wk of age, subsets of 1x- and 15x-vaccinated pullets were challenged with the virulent Mycoplasma gallisepticum (MG) strain Rlow. Percent hen-day egg production was determined through week 55. Analyses for treatment effects on overall (22-56 wk) percent hen-day egg production revealed no significant differences between nonchallenged 1x and nonchallenged 15x MYCOVAC-L treatments. Among 1x MYCOVAC-L-vaccinated groups, Rlow challenge at 45 wk corresponded to significantly (P < or = 0.01) lower overall egg production compared with the unchallenged 1x-vaccinated control (70.88% vs. 79.15%, respectively). Conversely, at the 15x MYCOVAC-L dosage level, overall egg production was not significantly affected by virulent MG challenge at 45 wk compared with its unchallenged counterpart (84.09% vs. 81.03%, respectively) and could indicate increased protection from virulent MG challenge. Serologic monitoring indicated the virulent MG challenge was consistently (100%) associated with seroconversion. Comparisons among the nonchallenged experimental treatments indicated that vaccinations at the 15x MYCOVAC-L dosage rate were associated with a greater seroconversion rate at weeks 21, 27, and 44, but not at week 50. 相似文献
17.
O'Connor RJ Turner KS Sander JE Kleven SH Brown TP Gómez L Cline JL 《Avian diseases》1999,43(4):640-648
Mycoplasma gallisepticum (MG) has been isolated from wild house finches. The pathogenic effects of MG finch strain (K4058) and MG R-strain were compared after exposure of chickens and turkeys. Gross and histologic lesions, reisolation of the organism, serology, and clinical disease were evaluated. Milder histologic and gross lesions, in addition to lower serologic titers, occurred in birds inoculated with the finch strain. Mortality, concurrent with clinical and gross respiratory signs and lesions, was observed only in chickens challenged with R-strain. Both the MG finch strain and MG R-strain were recovered from the respective challenge groups at 14 and 28 days postexposure. The results show that MG isolated from wild house finches may infect domestic poultry species but causes only mild disease and is less virulent than MG R-strain. Commercial enzyme-linked immunosorbent assay kits best detected the serologic response of chickens and turkeys to the MG finch strain. 相似文献
18.
用大肠杆菌BL21表达了马立克氏病病毒（MDV）强毒GA株的囊膜糖蛋白B（gB)基因，通过SDS－聚丙烯酰胺凝胶龟泳（SDS－PAGE）分离表达蛋白条带，切下并碾碎后作为免疫原制备单克隆抗体。通过酶联免疫吸附试验（ELISA）和间接免疫荧光试验（IFA），得到1株GA株阳性的单克隆抗体杂交瘤细胞株7C8。该单抗腹水的ELISA效价为1：2^12，IFA效价为1：800，与MDV不同致病型毒株CVI988、GA、RB1B、MD11、648A株感染的鸡胚成纤维细胞（CEF）均呈IFA阳性。1：100稀释时与GA感染的CEF在斑点酶联免疫吸附试验（dot-ELISA)中呈阳性。 相似文献
19.
应用RT-PCR方法从鸭源Ⅰ型副黏病毒DP1/02株中扩增F基因并克隆入pMD18-T载体,经序列测定、分析,DP1/02株F基因与鸡新城疫病毒（NDV）国家标准强毒F48E9株的核苷酸、氨基酸序列同源性均达到99%。随后将F基因克隆入真核表达载体pCI-neo,构建真核表达质粒pCI-F,将阳性质粒体外转染Vero细胞,通过间接免疫荧光对真核质粒的表达进行鉴定,利用pCI-F质粒进行动物试验。结果表明构建的真核表达质粒pCI-F能够在Vero细胞中表达,雏鸭免疫14d后在体内可检测到特异性抗体,二次免疫雏鸭后,对NDV强毒的攻毒保护率为73%。本试验为利用F基因构建的核酸疫苗提供了重要的技术支持。 相似文献