鸭源H5亚型禽流感全禽源分子标记疫苗候选株的构建

为了开发用于南方水禽且适合血清学监测的H5亚型禽流感疫苗,作者通过反向遗传技术,删除A/mallard/Huadong/S/2005(H5N1,S株)病毒HA编码多碱性氨基酸序列,使之成为低致病特征,分别与A/duck/England/1/1956(H11N6,E株)和A/Chicken/Shanghi/F/98(H9N2,F株)的NA组合,再以本室禽源高产病毒F株的6个内部片段为骨架,构建全部基因都来自禽流感的疫苗株.成功拯救出2株重组病毒,分别命名为rH5N6/F和rH5N2/F,并引入分子标记N6和N2.重组病毒在鸡胚和MDCK细胞上均具有较好的繁殖能力,且rH5N6/F更适合在鸡胚中生产,对SPF鸡和鸡胚无致病性.重组病毒在clade2.3.4毒株中具有很好的抗原代表性,引入的分子标记有利于血清学监测的区分,为防控水禽H5亚型禽流感提供了良好的疫苗候选株.     

鸡柔嫩艾美耳球虫3-1E和CDPK双抗原DNA疫苗的免疫保护效果观察

将构建的含鸡柔嫩艾美耳球虫(Eimeria tenella)CDPK和3-1E双抗原的真核重组质粒proEC,在14日龄和21日龄分别免疫AA肉鸡,28日龄感染5×104个E.tenella孢子化卵囊,观察其免疫保护效果.结果显示,攻虫后1周,与proC组相比,proEC组能显著增强淋巴细胞转化和血清抗体水平(P＜0.05);与proE组和proC组相比,proEC组卵囊产量最低但差异不显著(P＞0.05),其相对增重低于proE组和proC组.结果表明,proEC双抗原DNA疫苗对E.tenella攻虫表现出一定双抗原协同保护效应.     

益生素雏鸡新城疫疫苗免疫后局部黏膜组织T淋巴细胞数量变化

100只艾维因雏鸡随机分成益生素组、新城疫(ND)疫苗免疫组、益生素ND疫苗组和对照组,采用组织石蜡切片及酸性a-醋酸萘酯酶(acid nonspecifica-naphthyl acetate esterase,ANAE)染色法分别测定ND疫苗首次免疫后第0、7、14、28天和第42天各组雏鸡盲肠扁桃体、哈德尔氏腺、十二指肠和回肠派伊尔结T淋巴细胞数量的动态变化,结果发现:益生素ND疫苗免疫雏鸡,ND疫苗单独免疫雏鸡上述免疫组织T淋巴细胞数量于ND疫苗免疫后14d明显高于未免疫的对照雏鸡和益生素雏鸡;益生素ND疫苗免疫雏鸡又不同程度高于ND疫苗单独免疫雏鸡;益生素单独应用雏鸡上述被检指标高于对照雏鸡.表明益生素可增强雏鸡消化道和呼吸道局部黏膜组织的细胞免疫及对ND疫苗的免疫应答.     

不同剂量的猪瘟活疫苗单次免疫效果评价及疫苗存留试验

用1 200 RID、6 000 RID和24 000 RID 3种不同剂量的猪瘟活疫苗单次免疫9头30日龄的断奶仔猪,检测试验猪的抗体消长和疫苗毒核酸在猪体内的存留时间,并用6头猪进行攻毒保护试验.结果表明:不同免疫剂量的试验猪其抗体水平的动态变化没有显著差异,免疫后21 d试验猪的猪瘟抗体均成阳性,63 d后至578 d猪瘟抗体阻断率仍然高于85％,应用荧光定量RT-PCR技术检测,猪瘟疫苗毒核酸在猪血液和扁桃体中的检出时间分别达28 d和42 d;免疫后370 d进行猪瘟强毒攻击后,免疫猪没有出现明显的临床症状,存活且不带毒.本研究证实,没有其他疫病和母源抗体的仔猪单次接种合理剂量的猪瘟活疫苗就能产生坚强的保护力,提出加强种猪场各种病原监测,淘汰病原阳性种猪,净化种猪群对提高猪瘟疫苗免疫效果,最终控制猪瘟具有重要意义.     

北京动物园圈养绿孔雀新城疫免疫实验研究

通过圈养绿孔雀新城疫免疫实验研究,对疫苗的安全性以及免疫效果进行了评估。单苗实验组结果：低毒活苗LASOTA可以使抗体水平在4LOG2以上的时间持续6个月;灭活油苗可以使抗体水平保持在4LOG2以上8个月。联苗实验组接种LASOTA疫苗同时肌肉注射灭活油苗后,抗体水平保持4LOG2以上15个月,表明圈养绿孔雀宜采用联合疫苗免疫方法。联合疫苗的应用不仅表现在较高抗体水平维持时间较长,低毒活疫苗还有产生黏膜免疫的重要意义。滴鼻或点眼接种LASOTA疫苗,要保证疫苗能够作用于哈氏腺,以激发动物机体产生黏膜免疫。此外免疫接种时机很重要,对该病的预防工作不应在动物机体较高抗体水平的时候进行免疫接种,也不应在动物机体已经失去保护力或隐性感染后盲目接种,应选择绿孔雀在健康无病情况下进行。同时为了有效地控制新城疫,必须加强禽群免疫监测。     

黄芪多糖对接种NDⅣ雏鸡红细胞免疫功能的影响

以50日龄内健康海兰白雏鸡为研究对象,将黄芪多糖（APS）按0 mg/只、5 mg/只和10 mg/只经滴鼻点眼、肌肉注射等方式分别与鸡NDⅣ系疫苗同时免疫接种适龄雏鸡。结果表明,雏鸡C3b受体花环率（E-C3bRR）和红细胞C3b受体花环促进率（ERER）显著升高,红细胞免疫复合物花环率（E-ICRR）和红细胞C3b受体花环抑制率（ERIR）则降低,即APS可显著提高雏鸡的红细胞免疫功能,且APS 10 mg/只组效果优于5 mg/只组;对NDⅣ系苗免疫雏鸡来说,以APS 10 mg/只肌肉注射,NDⅣ滴鼻点眼对红细胞免疫功能的增强作用最显著。     

牛传染性鼻气管炎病毒LN01/08株灭活疫苗的研制

为研制牛传染性鼻气管炎病毒(IBRV)灭活疫苗,本研究以国内分离鉴定的IBRV LN01/08株为种毒,优化病毒增殖条件,获得病毒滴度达108.0TCID50/mL,将其灭活制备疫苗.为比较不同免疫佐剂的效果,分别以矿物质白油和Montanide ISA206佐剂配制灭活疫苗,进行牛体免疫试验.临床观察和血清中和抗体检测结果表明,Montanide ISA206佐剂乳化的疫苗在降低副反应和增强免疫效果方面优于矿物质白油佐剂.应用Montanide ISA206佐剂制备3批灭活疫苗,并对其安全性和免疫保护效果进行测定.结果表明该疫苗安全可靠,对强毒攻击可产生较好的抵抗力,攻毒保护率达80%.疫苗在2℃～8℃保存12个月后仍能保持良好的免疫效果.     

Immunisation of pigs with a major envelope protein sub-unit vaccine against porcine reproductive and respiratory syndrome virus (PRRSV) results in enhanced clinical disease following experimental challenge

Disease exacerbation was observed in pigs challenged with virulent porcine reproductive and respiratory syndrome virus (PRRSV) following immunisation with a recombinant GP5 sub-unit PRRSV vaccine (rGP5) produced in E. coli. Eighteen animals were divided into three experimental groups: group A were immunised twice IM with rGP5, 21 days apart; group B acted as positive controls (challenged but not immunised); and group C were negative controls. Pigs in groups A and B were challenged 21 days after the second immunisation of the group A animals. Following challenge, three pigs given rGP5 exhibited more severe clinical signs than the positive controls, including respiratory distress and progressive weight-loss. Although not statistically significant, the more severe disease exhibited by group A animals may suggest previous immunisation as a contributory factor. The mechanisms of these findings remain unclear and no association could be established between the severity of disease, non-neutralising antibody concentrations and tissue viral loads.     

Evaluation of glycoproteins purified from adult and larval camel ticks (Hyalomma dromedarii) as a candidate vaccine

In order to identify antigens that can help prevent camel tick infestations, three major glycoproteins (GLPs) about 97, 66 and 40 kDa in size were purified from adult and larval Egyptian ticks, Hyalomma (H.) dromedarii, using a single-step purification method with Con-A sepharose. The purified GLPs were evaluated as vaccines against camel tick infestation in rabbits. The rabbits received three intramuscular inoculations of GLPs (20 µg/animal) on days 0, 14, and 28. In the immunoblot analysis, Sera from the immunized rabbits recognized the native GLPs and other proteins from larval and adult H. dromedarii ticks along with those from other tick species such as Rhipicephalus sanguineus but not Ornithodoros moubata. The effects of immunity induced by these GLPs were determined by exposing rabbits to adult H. dromedarii ticks. These results demonstrated that GLP immunization led to a slightly decreased reproductive index and significantly reduced rates of egg hatchability. These results demonstrated that immunization with the purified GLPs can provide protection against infestation by H. dromedarii and some other tick species. Further studies are needed to confirm the effectiveness of immunization with GLPs against other tick species.