中药对人工感染IBDV鸡产生免疫抑制的调节作用

２２０只非免疫鸡随机分为Ａ,Ｂ,Ｃ,Ｄ,Ｅ５组,每组４４只。Ａ组给中药２次,Ｂ组５次,Ｃ、Ｄ、Ｅ组不给中药。于１４日龄对Ａ,Ｂ,Ｃ组人工感染传染性法氏囊病毒（ＩＢＤＶ）,于２１日龄对Ａ,Ｂ,Ｃ,Ｄ组接种新城疫（ＮＤ）Ⅱ系疫苗,于４６日龄每组随机抽取１５只鸡均攻ＮＤ强毒。结果表明：攻ＩＢＤＶ后一周,Ｃ组的死亡率显著高于Ａ组和Ｂ组（Ｐ〈０．０５）,新城疫Ⅱ系苗免疫后,Ｂ组鸡新城疫血凝抑制（ＨＩ）抗体效     

传染性法氏囊病病毒VP2/VP0基因在重组鸡痘病毒中的表达

以鸡痘病毒复制非必需区ＴＫ基因为侧翼,在牛痘病毒Ａ型包涵体晚期启动子（ＡＴＩ）与１６个串联的突变型早期痘苗病毒ｐ７．５启动子组成的复合启动子的下游,分别插入编码传染性法氏囊病病毒（ＩＢＤＶ）结构蛋白ＶＰ２和ＶＰ２－４－３（ＶＰ０）的基因片段后,进行了同源重组和蓝斑筛选,获得２株重组病毒ｖＵＴＡＬａｃＶＰ２－７和ｖＵＴＡＬａｃＶＰ０－１０。经ＥＬＩＳＡ、ＳＤＳ－ＰＡＧＥ和Ｗｅｓｔｅｒｎｂｌｏｔ检测表明,重组病毒ｖＵＴＡＬａｃＶＰ２－７能表达ＶＰ２,ｖＵＴＡＬａｃＶＰ０－１０能表达ＶＰ２和ＶＰ３,ＶＰ２和ＶＰ３的Ｍｒ分别为４１０００和３２０００。     

Protection of chicken against very virulent IBDV provided by in ovo priming with DNA vaccine and boosting with killed vaccine and the adjuvant effects of plasmid-encoded chicken interleukin-2 and interferon-��

The aim of this study was to examine the efficacy of in ovo prime-boost vaccination against infectious bursal disease virus (IBDV) using a DNA vaccine to prime in ovo followed by a killed-vaccine boost post hatching. In addition, the adjuvant effects of plasmid-encoded chicken interleukin-2 and chicken interferon-γ were tested in conjunction with the vaccine. A plasmid DNA vaccine (pcDNA-VP243) encoding the VP2, VP4, and VP3 proteins of the very virulent IBDV (vvIBDV) SH/92 strain was injected into the amniotic sac alone or in combination with a plasmid encoding chicken IL-2 (ChIL-2) or chicken IFN-γ (ChIFN-γ) at embryonation day 18, followed by an intramuscular injection of a commercial killed IBD vaccine at 1 week of age. The chickens were orally challenged with the vvIBDV SH/92 strain at 3 weeks of age and observed for 10 days. In ovo DNA immunization followed by a killed-vaccine boost provided significantly better immunity than the other options. No mortality was observed in this group after a challenge with the vvIBDV. The prime-boost strategy was moderately effective against bursal damage, which was measured by the bursa weight/body weight ratio, the presence of IBDV RNA, and the bursal lesion score. In ovo DNA vaccination with no boost did not provide sufficient immunity, and the addition of ChIL-2 or ChIFN-γ did not enhance protective immunity. In the ConA-induced lymphocyte proliferation assay of peripheral blood lymphocyte collected 10 days post-challenge, there was greater proliferation responses in the DNA vaccine plus boost and DNA vaccine with ChIL-2 plus boost groups compared to the other groups. These findings suggest that priming with DNA vaccine and boosting with killed vaccine is an effective strategy for protecting chickens against vvIBDV.     

传染性法氏囊病病毒自然重配株全基因组序列分析

从具有新的流行病学特征的传染性法氏囊病（IBD）发病鸡群中分离到2株传染性法氏囊病病毒（IBDV）,分别命名为QL和ZZ—ll,对4周龄SPF鸡的致死率分别为94％和86％。为分析该毒株的分子生物学特征,对其全基因组序列进行了测定,2个病毒株基因组A节段长度为3260bp、B节段长度2827bp。病毒演化分析结果显示2个病毒基因组A节段的核苷酸序列与已发表的强毒株序列的同源性分别为96．8％～98．1％和96．9％～98．4％,处在IB—DV超强毒株分支上;而B节段与已发表的弱毒株序列的同源性分别为89．7％～90．4％和90．0％～90．7％,位于弱毒株分支上。IBDV超强毒株和弱毒株序列特征氨基酸残基与基序分析表明,QL和ZZ—11两个病毒株的A节段VP2基因的氨基酸残基为222A、249Q、253Q、254G、256I、294I和299S,七肽基序为SWSASGS,均符合超强毒株的分子特征;而B节段777～782位核苷酸序列为GGTGCC,没有KpnI酶切位点,具有弱毒株的序列特点。以上分析结果表明,QL和ZZ—11为IBDV自然重配株,A节段源于超强毒株,而B节段源于弱毒株。     

紫锥菊、黄芪对感染IBDV雏鸡胸腺、小肠中CD4~＋、CD8~＋ T淋巴细胞动态分布的影响

将14日龄雏鸡随机分为3组,A组灌服1 mL的紫锥菊、黄芪合剂,B、C组灌服生理盐水,连续灌服7 d。21日龄时A、B组雏鸡接种传染性法氏囊病病毒（IBDV）,用免疫组化法观察雏鸡胸腺、小肠中CD4＋、CD8＋T淋巴细胞动态分布的变化。结果表明,用药组和攻毒对照组相比较,CD4＋T淋巴细胞差异显著（P〈0.05）,但是CD8＋T淋巴细胞差异不显著（P〉0.05）,与空白对照组相比CD4＋淋巴细胞显著增多。胸腺、小肠中24日龄时CD4＋、CD8＋T细胞数量较其他日龄差异显著（P〈0.05）。总试验期胸腺中CD4＋、CD8＋含量是所测总数的60%。表明紫锥菊、黄芪对机体免疫有显著增强作用,以胸腺中CD4＋、CD8＋含量多于小肠,能显著降低IBDV对机体造成的损伤。     

IBDV VP2/4/3、ChIL-18共表达载体的构建及在Vero细胞上的表达

为提高传染性法氏囊病病毒(IBDV)多聚蛋白(VP2/4/3)DNA疫苗的免疫效果,应用重叠延伸剪切技术(splicing by overlapping extension)将IBDV VP2/4/3基因与鸡白细胞介素18(ChIL-18)基因分别经3次PCR获得融合基因片段VP2/4/3-ChIL-18和ChIL-18-VP2/4/3,将融合基因片段定向插入真核表达载体pCI中,获得重组质粒pCI-VP2/4/3-ChIL-18和pCI-ChIL-18-VP2/4/3;应用PCR法,在本实验室已成功构建的重组真核表达载体pCI-VP2/4/3和pCI-ChIL-18的基础上,构建VP2/4/3基因和ChIL-18基因的共表达载体co-pCI-VP2/4/3-ChIL-18。在脂质体介导下将上述重组真核表达载体转染Vero细胞,间接免疫荧光证实重组质粒能正常表达目的蛋白,表达的蛋白具有免疫反应性。这为进一步研究ChIL-18的分子免疫佐剂作用及研制高效、价廉的IBDV DNA疫苗提供了实验依据。     

Oral administration of Allium sativum extract protects against infectious bursal disease in chickens

Garlic (Allium sativum, Liliaceae) has been safely used for more than 5000 years, and research on garlic extract is rapidly increasing because of its multiple biological functions. The in vivo effects of oral administration of garlic mixture (GM, water-soluble extract) on infectious bursal disease virus (IBDV)-infected specific pathogen free male white leghorn chicken were examined through histopathological, immunohistochemical, and Western blot analyses, and enzyme-linked immunosorbent assay. The results confirmed the protective effects of oral administration of 5 mg·kg⁻¹ BW GM (Group GM1) on bursal lesions after IBDV infection. In particular, protein expression of IBDV in the bursa decreased in Group GM1, indicating that GM administration decreased IBDV replication in the bursa. Furthermore, immunoglobulin M- and A-bearing B lymphocytes significantly increased 7 days post infection in bursae in Group GM1 (P<0.01), suggesting that the oral administration of 5 mg·kg⁻¹ GM offers moderate protection against B cell destruction after IBDV infection. During infection, the concentration of bursal interferon gamma (IFN-g) increased and peaked in Group GM1 earlier than in Group T (IBDV-exposed), demonstrating that GM administration prompted the production of IFN-g to protect against IBDV infection.     

鸡传染性法氏囊病病毒VP2蛋白及其疫苗的研究进展

传染性法氏囊病病毒(IBDV)是鸡传染性法氏囊病(IBD)的病原。近年来IBDV变异毒株和超强毒株的流行,严重威胁着世界养鸡业的发展,传统疫苗已不能控制IBDV的流行,迫切需要研制新型疫苗。IBDV VP2蛋白是重要的结构蛋白,能诱导机体产生中和抗体,因此,利用VP2蛋白制备IBDV重组疫苗成为国内外研究的热点。综述了IBDV VP2蛋白的作用及在不同表达系统中用VP2蛋白制备疫苗的研究进展,以期为IBDV新型疫苗的开发提供参考。     

鸡传染性法氏囊病的实验研究

将１２０只白来航雏鸡随机分成４个实验组和对照组,分别于第１、２、３和４周龄感染传染性法氏囊病病毒和生理盐水。在感染后第７ｄ,外周血液中白细胞数、血糖和胰高血糖素含量明显低于对照组;在感染后第１４ｄ,上述指标虽有所升高,但仍低于同期对照组。表明ＩＢＤＶ对体内淋巴组织有明显损伤,胰高血糖素的变化及血糖的降低可能是由于胰腺实质细胞变性坏死所致。     

中药复方提取物对IBDV感染SPF鸡抗氧化和抗炎能力的影响

将150羽SPF雏鸡随机分为5组,即对照组(CK)、病毒感染模型组(MC)、中药提取物高、中、低剂量组(T1、T2、T3),T1、T2、T3组试验鸡分别按照10.0、5.0、2.5 g/L的剂量在饮水中添加中药提取物(由2∶2∶1∶1质量比的女贞子、黄芪、枸杞子、菟丝子组成),连续添加7 d,CK和MC不添加任何药物,给药完成后,对照组滴鼻生理盐水,其他各组雏鸡分别通过滴鼻接种IBDV,攻毒后连续观察7 d,检测抗氧化指标(T–SOD、GSH–Px、T–AOC、MDA)和炎性因子(NO、TNF–ɑ、IL–1β、IL–6)的分泌量,检测脾淋巴细胞iNOS、NF–κB、MCP–1基因mRNA表达量。结果显示：T1和T2试验鸡抗氧化能力均提高,血清中GSH–Px活力和T–AOC极显著高于MC的(P<0.01),MDA含量显著低于MC的(P<0.05),T2试验鸡血清中T–SOD活力显著高于MC的(P<0.05);T1和T2试验鸡炎症反应明显减少,血清中NO、TNF–ɑ、IL–1β含量均极显著低于MC的(P<0.01),NO和TNF–ɑ含量显著低于T3的(P<0.05),IL–1β含量显著或极显著低于T3的,IL–6含量显著高于T3和MC的(P<0.05);T1和T2试验鸡脾淋巴细胞中iNOS mRNA表达量显著低于MC的(P<0.05),NF–κB和MCP–1 mRNA表达量极显著低于MC的(P<0.01)。表明中药提取物可能通过增强雏鸡的抗氧化能力,促进炎性相关因子的分泌和调节基因表达实现抗炎效果来抵抗IBDV。