Transcellular transport characteristics of huperzine alone or in combination with ginkgolide B across Caco-2 and Madin-Darby canine kidney cell monolayer

Objective:To study the various processes involved in transcellular transport(TT) of huperzine A alone or in combination with ginkgolide B in Caco-2 and Madin-Darby canine renal(MDCK)cell monolayer.Methods:The transepithelial passage was assayed in the apical-to-basolateral(AP to BL) direction and opposite direction(BL to AP) in both cell lines.The determination of huperzine A and ginkgolide B were performed by high performance liquid chromatography(HPLC).The passage rates of huperzine A and ginkgolide B were calculated.Bi-directional TT(absorption and secretion) were taken in huperzine A and ginkgolide B in Caco-2 and MDCK cell monolayer.Results:TT absorption and secretion kinetics of huperzine A and ginkgolide B across two cells existed at the same time.The passage rates of huperzine A were increased significantly with adding different concentrations of ginkgolide B.Conclusions:The compound preparations of HA in combination with CB for dementia caused by cerebral ischemic have synergistic effects on the pharmacodynamics,and improve the bioavailability through BBB.

表达外源基因SPAM1重组CAV-2溶瘤病毒的构建与拯救

旨在研究犬腺病毒-2型(canine adenovirus type 2,CAV-2)作为溶瘤病毒的潜力并进一步探索精子黏附因子(SPAM1)协同CAV-2重塑肿瘤微环境在肿瘤免疫治疗中的应用价值。本研究以P15A-CAV-2反向遗传操作平台为基础,使用RED/ET同源重组系统构建携带SPAM1外源基因的中间载体,使用中间载体将CAV-2骨架载体E3区域缺失并替换SPAM1外源基因表达盒。再利用合成引物敲除kmccdB反向筛选表达盒构建P15A-CAV-2-mCMV-SPAM1-SV40 polyA感染性克隆质粒并在MDCK-E1A细胞系中拯救重组溶瘤病毒,对重组病毒体外溶瘤效应进行验证。根据测序与酶切验证结果证明,本研究成功构建并拯救出稳定表达外源基因SPAM1的重组溶瘤病毒1株;IFA试验证明,重组毒株能够高水平稳定表达外源基因且外源蛋白具有可弥散分布于细胞间的特点。缺失E3区域表达外源基因SPAM1的重组溶瘤病毒通过光镜观察和CCK8检测发现具有对犬癌细胞系A72强烈的杀伤效应。综上,本研究成功构建1株具有良好溶瘤效应的重组CAV-2,为后续应用于宠物肿瘤治疗奠定了基础。

Cloning and Prokaryotic Expression of Canine IL-2 Gene

[ Objective] To clone and express canine IL-2 gene and thus to provide theoretical support for the development of novel immune enhancers and genetic engineering vaccines. [ Method] Leukocytes separated from canine whole blood were stimulated by concanavalin for 20 h, and then total RNA was extracted. According to the sequence of canine IL-2 gene published in the GenBank, a pair of primers was designed. After PCR am- plificetion, the target fragment was cloned into prokaryotic expression vector pET-28a. The recombinants were transformed into the host bacteria BL21. After IPTG induction, the expression products were analyzed by SDS-PAGE. [ Result] A 500 bp band with the expected size appeared in the RT-PCR products. After the pMD18-T-IL2 was identified by double digestion, an approximately 500 bp fragment was produced, which indicated successful cloning of the gene. After the pET-28a-lL2 was identified by restriction enzyme digestion and PCR, a 500 bp fragment was produced, which indicated successful construction of the expression vector. As revealed by the SDS-PAGE analysis, a protein band with molecular weight of about 20 kDa appeared. [ Conclusion] The canine IL-2 gene was cloned and expressed.

Localization of the VP2 Protein of Canine Parvovirus Type 2 on the Baculovirus Envelop and Its Immunogenicity in a Mouse Model

In this study, the full-length VP2 gene of canine parvovirus type 2 (CPV-2) was cloned into the pBacSC vector which possesses baculovirus transmembrane domain (gp64 TM) gene, baculovirus cytoplasmic domain (gp64 CTD) gene, and green florescence protein (GFP) gene. Baculovirus gp64 TM and gp64 CTD in the pBacSC vector were designed to display heterologous proteins on the baculovirus envelope. After cloning the VP2 gene of CPV-2 into pBacSC vector, the recombinant plasmid pBacSC-VP2 was transformed into E. coli DH10Bac competent cells to form recombinant bacmid DNA. One recombinant baculovirus BacSC-VP2 that expresses the VP2 protein of CPV-2 was obtained. Confocal microscopy and immunogold electron microscopy were used to verify whether VP2 expressing on baculovirus envelope or cell membrane. Immunization of BALB/c mice with recombinant baculovirus BacSC-VP2, demonstrated that serum from the BacSC-VP2 treated models had higher levels of virus neutralization titers than the control groups. The results show that the recombinant baculovirus BacSC-VP2 can induce a strong immune response in a mouse model, suggesting that the pseudotyped baculovirus BacSC-VP2 can serve as a potential vaccine against CPV infections.

犬腺病毒2型的分离鉴定和致病性分析

为了解湖北省犬腺病毒2型(CAV-2)的基因遗传变异特征,本试验从武汉市某比格犬养殖场采集免疫过犬四联活疫苗的临床发病犬的眼、鼻和肛拭子,将经PCR检测为CAV-2阳性的病料接种犬肾细胞(MDCK细胞)进行病毒分离,对CAV-2分离株进行电子显微镜观察和间接免疫荧光鉴定,E3、Fiber、Penton和E1b基因PCR扩增和测序分析以及致病性试验。结果显示:经分离和鉴定共获得3株CAV-2,分别命名为HB404株、HB405株和HB078株。3株CAV-2分离株的E3、Fiber、Penton和E1b基因与国外疫苗毒株相似性分别为98.4%~99.6%、99.3%~99.9%、99.8%~99.9%和99.5%~99.7%;3株分离株的E3、Fiber和Penton基因与国内流行毒株相似性分别为96.6%~97.5%、98.5%~99.7%和99.4%~99.9%。且3株CAV-2分离株与国外疫苗毒株在同一分支,与国内流行毒株不在同一分支。HB405株能使犬出现精神不振、食欲减退、眼鼻有分泌物、打喷嚏和咳嗽等临床症状。结果表明,3株分离株的亲缘关系与国外疫苗毒株较近,HB405株为强毒株,能够使犬发病。本试验结果可为CAV-2的诊断和预防提供参考依据。

犬流感病毒H_(3)N_(2)和H_(3)N_(8)亚型流行病学研究进展

自2004年首次在美国发现犬流感病毒(canine influenza virus,CIV)以来,经过不断的演变进化和跨物种的传播,CIV已在全球范围内广泛传播。由于犬对多种流感病毒易感,流感病毒对犬的影响及其产生人畜共患的大流行性流感的风险不容忽视。文章就CIV的病原学及较稳定传播的两种亚型CIV(H_(3)N_(2)和H_(3)N_(8))的流行病学进行综述,旨在为CIV的预防、诊断以及疫苗研发等提供参考。

Role of Selective Cyclo-Oxygenase-2 Inhibitor Celecoxib in Canine Osteosarcoma Cell Culture

Background: Experimental studies have shown that cyclo-oxygenase-2 (Cox2) is related to the development and progression of tumors, since this enzyme is induced and expressed by cells such as macrophages, osteoblasts, “activated” endothelial cells, and tumor cells. The activity in tumors includes proliferation, cell transformation, tumor growth, invasion and metastasis and may play an important role in carcinogenesis of the canine osteosarcoma, since it has high expression in tissue fragments. The combination of selective Cox2 inhibitors and other treatment modalities is the basis for a new anti-cancer therapy strategy. This in vitro study exposed primary cells of five different canine osteosarcoma cultures to selective Cox2 inhibitor at increasing concentrations and times. Results: For Cox2 negative cultures, despite the absence of differences, greater sensitivity of cells to treatment was observed. For Cox2 positive cultures, a higher number of necrotic cells were observed (P ≤ 0.05), when compared with negative cultures. For exposure times with Celecoxib doses, no difference (P > 0.05) was found between the three times analyzed for living, apoptotic and apoptotic/necrotic cells. There are similarities in the values of 24 h and 48 h, with slight reduction of living cells, increasing those undergoing apoptosis and apoptosis/necrosis. There was significance for necrosis (P ≤ 0.05). In 72 hours, a significant difference was observed between the other two previous values (P ≤ 0.05). It was found for the group of 100 μML-1, that there was a numerically greater signaling for apoptosis and lower (P = 0.08) for necrosis, and this point was the onset of the pharmacodynamic phenomenon, with drop in the values for living cells and increased number of necrotic cells, with a tendency (P = 0.08) for reducing the percentage of necrotic cells for the group of 100 μML-1 when compared to that of 10 μML-1. Conclusions: For Cox2 positive and negative cultures, there was difference for necrotic cells and there was no difference between Cox2 positive and Cox2 negative groups in relation to the percentage of living cells and apoptotic and apoptotic/necrotic cells. At time of 72 hours, higher percentage of living cells, lower percentage of apoptotic cells and increased percentage of necrotic cells in relation to groups of 24 and 48 hours was observed. A tendency for reducing the percentage of necrotic cells for the group of 100 μML-1 when compared to that of the group of 10 μML-1 was observed.

己糖激酶2在犬乳腺肿瘤中的表达及预后研究

本研究旨在探究己糖激酶2(hexokinase 2,HK2)在犬乳腺肿瘤(canine mammary tumor,CMT)中的表达情况及与患犬预后的相关性。将临床收集的121例犬乳腺肿块样本制作石蜡切片,经组织病理学分析判读后随机抽取恶性乳腺肿瘤与正常乳腺组织样本各3份进行高通量转录组测序,筛选差异表达基因。使用实时荧光定量PCR(quantitative real time PCR,qPCR)和免疫组织化学法检测HK2在犬全身组织及乳腺肿瘤组织中的表达情况,对术犬长期随访调查并分析HK2与乳腺肿瘤患犬临床特征及预后的相关性。结果表明:1)本研究中收集到的121例犬乳腺肿块临床样本中良性乳腺肿瘤33例,恶性乳腺肿瘤78例;2)经高通量转录组测序筛选出HK2、MEST、GDF5等36个显著差异表达基因,其中,HK2经qPCR验证以及基于其在细胞代谢中的关键作用且在人类某些肿瘤中异常表达,故将HK2作为研究对象;3)HK2 mRNA与蛋白表达水平在犬正常乳腺组织中均表现为低表达,而CMT中HK2 mRNA与蛋白表达水平均显著升高(P<0.01);4)同时HK2的表达水平与肿瘤组织类型、肿瘤大小、脉管浸润、Ki-67指数以及预后显著相关(P<0.01)。HK2在CMT组织中呈高表达,并与肿瘤的临床特征及预后显著相关。HK2具有作为CMT的诊断与预后评估因子的潜力。

Generation of a Canine-origin Neutralizing scFv Against Canine Parvovirus

Canine parvovirus(CPV)is a high morbidity and lethality virus which causes severe enteric disease in dogs.In an attempt to gain canine-origin neutralizing antibodies against CPV,single chain variable fragment(scFv)bacteria display libraries against the protective antigen VP2 were constructed and screened.VP2 specific scFvs were selected following three rounds of screening procedures.Selected scFvs were characterized by FCM and ELISA.Seven scFvs showed high affinity and specific binding to CPV.Moreover,the neutralizing activity of the antibody was preliminarily identified by CPV(100 TCID_(50))in vitro and scFv-2 showed the neutralizing ability with a titer of 32768.This study generated the first canine-origin neutralizing scFv against CPV.The neutralizing scFv would be constructed into full-length antibody in the future.This study laid the foundation for the generation of an effective therapeutic reagent with long half-life and no immunological rejection for the prevention and treatment of CPV infection.

犬腺病毒2型E3基因自然缺失毒株的分离鉴定及其致病性

犬腺病毒2型(canine adenovirus type 2,CAV-2)是重要的犬呼吸道病原,本试验旨在调查CAV-2在川渝部分地区的流行情况及其分离毒株致病性。采用检测CAV-2的特异性PCR方法,对2021—2022年采集自川渝部分地区的121份患呼吸道疾病的犬鼻咽拭子进行检测,分离流行毒株并研究其基因组特征及致病性。结果显示:CAV-2的阳性率为29.8%,值得注意的是,69.4%的阳性样本在E3基因存在9个核苷酸连续缺失(1035—1043 nt),导致4个氨基酸缺失(345—348 aa)。成功分离出1株E3基因自然缺失毒株,噬斑纯化后的细胞半数感染值为10-9.46TCID50·0.1 mL^(-1);该毒株经口鼻感染幼犬后,幼犬出现体温升高、打喷嚏、流鼻涕及咳嗽等典型呼吸道症状。该分离毒株基因组全长31786 bp,与GenBank中CAV-2基因组的核苷酸相似性为98.8%~98.9%。与已知的CAV-2基因组相比,本研究分离毒株除了E3基因的独特突变外,还在Fiber、Hexon和E1A等蛋白有独特的氨基酸突变,使得该毒株在基因组进化树上区别于已知的CAV-2毒株。本试验首次获得了中国CAV-2毒株的基因组序列,发现了E3基因的自然缺失现象,有助于了解CAV-2的流行及遗传进化。

Research on Electrical Remodeling After Short Term Pacing in Canine Model

Objectives To evaluate the changes in atrial effective refractory period （AERP） proprieties and in ionic currents in PVs myocytes from dogs subjected to rapid atrial pacing in PVs and right atrial appendage （RAA） and to relate these changes to the ability to induce AF. Methods Twelve mongrel dogs in normal sinus rhythm were paced from the superior left PVs or RAA at 500 bpm for 4 hours. Electrophysiologic studies conducted to determine changes in AERP, dispersion and rhythm. Ionic currents were studies with the patch clamp technique in single PVs myocytes in sham operated dogs and compared with those from PVs pacing and RAA pacing groups. Results The presence of rapid atrial pacing was associated with a marked shortening in AERP in both PVs and RAA pacing group with a marked increase of AERP dispersion in PVs pacing. Both L-type calcium current （Ica L ） and the transient outward current （ Ito ） were reduced in both groups with an increased significance in PVs pacing group. The density of ICa-L was decreased significantly from （ - 6. 03 ± 0. 63 ） pA./pF in the control group to （ -3.21 ±0. 34） pA/pF in PVs pacing group and （ - 4. 75 ± 0. 41 ） pA./pF in RAA pacing group （ n = 6, P 〈 0. 05 ） while the density of Ito was decreased significantly from （8.45 ± 0. 71 ） pA./pF in the control group to （ 5.21 ± 0. 763 ） pA./pF in PVs pacing group and （6. 84 ±0. 69 ） pA./pF in RAA pacing group （ n = 6, P 〈 0. 05 ）. Conclusions Our findings provide likely ionic mechanisms of shortened repolarization in induced atrial tachycardia with a decrease in Ica L and /tocurrent densities which is the likely mechanism for a decrease in Action potential duration （APD） rate adaptation in the canine rapid pacing model more pronounced in PVs pacing group underlying the crucial role of PVs in initiating AF.

犬2型腺病毒的分离鉴定

研究旨在通过对采集自辽宁省辽阳某犬专业合作社犬传染性肝炎患犬病料进行分离和鉴定,了解犬腺病毒(CAV)的生物学特性。试验通过分子生物学鉴定、病毒分离、抗性测定、电镜观察、病毒特异性鉴定和动物回归试验等对分离毒株的生物学特性及致病力进行研究。结果显示,通过PCR扩增可得到1019 bp的特异性的核酸片段,命名为CAV A22株。通过核苷酸序列分析,分离株与GenBank上登录的国内外已发表CAV参考序列的核苷酸序列同源性最高达100%。由遗传进化树可知,分离株与U77082亲缘关系较近,处于同一分支;该分离株可在MDCK细胞上连续传代,病毒含量可达105.5TCID50/0.1 mL以上;电镜观察可见圆形、无囊膜、直径约80 nm的典型病毒粒子。病毒特异性鉴定表明分离株为犬2型腺病毒(CAV-2)。病毒回归试验表明,分离株致病力较弱,加以驯化可成为一株良好的疫苗毒株。

表达狂犬病病毒糖蛋白膜外区重组犬2型腺病毒的构建及其免疫原性研究

为研制 1种以犬 2型腺病毒为载体的狂犬病疫苗 ,以狂犬病病毒SRV9株基因组为模板 ,通过RT_PCR技术扩增得到狂犬病病毒糖蛋白膜外区序列 ;以其为目的基因构建以CMV为启动子、SV4 0polyA为终止信号的表达盒。将犬 2型腺病毒的E3区克隆入中间质粒中 ,然后对其进行部分缺失 ,并将表达盒克隆入缺失处 ,再以此重组的E3区置换犬 2型腺病毒的E3区。以重组的犬 2型腺病毒基因组转染MDCK细胞 ,最终获得了表达盒分正向和反向插入E3区的重组犬 2型腺病毒。用两株重组腺病毒免疫幼犬 ,均在犬体内产生了针对狂犬病病毒的抗体。

感染性犬2型腺病毒全基因组克隆及鉴定

以犬 2型腺病毒 (canine adenovirus type- 2 ,CAV- 2 )自然弱毒株 YCA18基因组 DNA为模板 ,经 PCR扩增分别获得其双链两末端 10 13bp(U)和 972 bp(D)的 DNA序列 ,以首尾相接方式克隆入载体 p Poly2 ,获得重组质粒p Poly2 - UD。以 Hind 和 Bst B 双酶切 p Poly2 - UD,回收含载体和部分 U、D的大片段并与 CAV- 2 DNA共转化感受态 E.coli Sure TM,经菌体内同源重组 ,获得含有 CAV- 2全基因组序列的重组质粒 p Poly2 - CAV- 2。后者以 Cla 和 Asc 双酶切 ,释放 CAV- 2全基因组 ,通过脂质体介导转染 MDCK细胞 ,盲传 3代后重复转染 1次 ,4d后 ,出现腺病毒典型病变。细胞上清血凝效价为 1∶ 6 40 ,并可被 CAV- 2抗血清有效抑制。以上结果表明 ,本研究获得了具有感染性的CAV- 2全基因组重组质粒 ,为以 CAV- 2作为重组疫苗载体的系列研究奠定了重要基础。

复方参芩对犬细小病毒致心肌组织Bcl-2和Bax mRNA的影响

为了探讨复方参芩对犬细小病毒致犬心肌组织Bcl-2和Bax基因表达的影响,将丹参、黄芩、甘草等中药配伍并制备成为复方参芩针剂,人工感染犬细小病毒建立模型;将犬分为空白对照组、模型组、黄芪多糖组、复方参芩组;给药7d后,接种病毒,观察各组犬临床症状,取心肌组织,电镜观察心脏组织超微结构变化,采用荧光实时定量PCR法检测Bcl-2和Bax mRNA表达。结果表明,模型组犬死亡率高,心肌组织结构损伤严重,与空白对照组比较,心肌组织细胞Bcl-2mRNA表达下调(P<0.05),Bax mRNA表达增加(P<0.01)。复方参芩组犬存活率较高,心肌组织损伤轻,与模型组相比,心肌组织细胞Bax mRNA表达下调(P<0.01),Bcl-2mRNA表达上调(P<0.01)。通过本试验证明复方参芩可通过上调犬心肌组织细胞Bcl-2mRNA表达,下调Bax mRNA的表达,抑制细小病毒引起的心肌细胞凋亡,保护犬心肌组织免受细小病毒损害。

表达狂犬病毒糖蛋白抗原的重组犬2型腺病毒的构建及鉴定

为研制一种预防犬科动物狂犬病的新型疫苗,将含有狂犬病毒ERA株糖蛋白基因(Rabies glycoprotein,Rgp)表达盒的穿梭质粒pVAXΔE3Rgp中的Rgp表达盒克隆入犬2型腺病毒(Canine adenovirus type2,CAV2)骨架质粒pPoly2-CAV2中,获得重组质粒pPoly2-CAV2-ΔE3-Rgp,释放其基因组,转染MDCK细胞系,获得E3缺失区(Deletion of early protein3,ΔE3)含有Rgp表达盒的重组病毒CAV2-ΔE3-Rgp。该重组病毒能在MDCK细胞上产生典型的腺病毒细胞病变。通过酶切、PCR、基因测序,表明该重组病毒含有完整的Rgp表达盒。通过RT-PCR、Western blot等检测,表明该重组病毒能够表达Rgp抗原。用该重组病毒免疫犬,3次免疫后,可以诱导犬产生特异的抗CAV2HI抗体,其效价超过1∶256和抗狂犬病病毒(Rabies virus,RV)中和抗体,其效价超过0.50IU/mL。试验结果表明,获得的重组病毒免疫犬后,能够产生抗狂犬病毒和腺病毒的高效价保护性抗体,是一种有潜力的犬科动物狂犬病毒腺病毒二联疫苗候选株。

CDV、CPV、CAV-2及CPIV多重PCR的建立及应用

为建立一种快速检测犬瘟热病毒(CDV)、犬细小病毒(CPV)、犬腺病毒Ⅱ型(CAV-2)和犬副流感病毒(CPIV)的多重PCR方法,参照Gen Bank中的相关病毒基因序列,分别设计了4对引物,用于特异性扩增CDV H基因、CPV VP2基因、CAV-2 E3基因和CPIV NP基因上的目的片段。通过优化反应条件,建立了同时扩增CDV(410 bp)、CPV(253 bp)、CVA-2(655 bp)和CPIV(868 bp)的多重PCR方法。利用建立的多重PCR方法,对CDV、CPV、CAV-2、CPIV、CDV+CPV+CAV-2+CPIV和犬冠状病毒(CCV)的DNA或c DNA模板进行扩增,发现该方法的特异性良好。利用建立的多重PCR方法与单一PCR方法进行敏感性比较,发现两者敏感性相差10倍,证明多重PCR方法敏感性良好。利用该方法对从北京市采集的30份犬病料样品进行检测,发现CDV阳性率为63.33%(19/30)、CPV阳性率为33.33%(10/30)、CAV-2阳性率为6.66%(2/30)、CPIV阳性率为0(0/30)。检测结果证明建立的多重PCR方法可用于临床诊断。

犬细小病毒VP2蛋白的原核表达与纯化

为了研究犬细小病毒(canine parovirus,CPV)VP2蛋白的结构和功能,本试验对CPV VP2蛋白进行表达和纯化。采用大肠杆菌表达外源蛋白的方法,将CPVVP2基因插入原核表达载体pET-32a(+)中构建重组原核表达载体pET-VP2,转化至大肠杆菌BL21(DE3)感受态细胞中,在不同IPTG浓度、诱导温度和诱导时间条件下进行原核表达,确定最佳诱导条件。最佳条件下的诱导产物经超声破碎离心后,利用镍柱对重组蛋白进行纯化并用SDS-PAGE和Western blotting进行双重鉴定。结果显示,重组质粒pET-VP2经双酶切鉴定分别获得大小为5 900bp左右的载体条带和1 755bp左右的目的基因条带,成功构建了pET-VP2重组质粒;重组VP2蛋白的分子质量约为64ku,与预期大小一致,且在37℃、1.0mmol/L IPTG、诱导5h条件下表达量最高,条带最亮;蛋白超声破碎后经SDS-PAGE发现,只在沉淀中出现了目的条带,而上清中并未出现相应条带,说明重组蛋白均以包涵体的形式存在;纯化后获得的重组蛋白,经SDS-PAGE和Western blotting双重鉴定,均在64ku处出现条带,说明纯化后的蛋白为重组蛋白pET-VP2。本试验通过对CPV VP2蛋白的原核表达及纯化成功获得了大量纯度较高的CPV VP2蛋白,为今后制备CPV VP2蛋白多克隆抗体及进一步研究该蛋白在对治疗犬细小病毒病中的临床应用价值提供了基础理论依据。

犬瘟热病毒和犬腺病毒2型双重PCR方法的建立及应用

根据犬瘟热病毒(canine distemper virus,CDV)和犬腺病毒2型(Canineadenovirus type2,CAV-2)GeneBank登陆的基因序列各设计一对引物,经试验条件优化,建立了检测CAV-2的PCR方法和CDV的RT-PCR方法,CAV-2可扩增1108bp片段、CDV可扩增560bp的目的片段,特异性试验表明建立的方法只能特异扩增CAV-2和CDV,不能扩增犬细小病毒、犬冠状病毒、犬副流感病毒、犬钩端螺旋体和犬黄胆出血群、狂犬病病毒。敏感性试验表明,所建立的双重PCR方法可以扩增4.63ng总核酸量。在上述试验基础上继续优化条件建立了能同时检测CAV-2和CDV两种病毒的双重PCR检测方法,并用该方法检测来自辽宁、吉林等15家动物医院134份鼻液和眼眵样品,与商品化试纸条检测结果相比,本方法更加敏感和方便。研究结果表明,本实验建立的方法敏感、特异,适用于动物犬瘟热病毒和犬腺病毒2型的快速检测和鉴别诊断。

犬2型腺病毒通用载体的构建及鉴定

为了获得能够携带较大外源基因的犬2型腺病毒E3区缺失性载体,以犬2型腺病毒全基因组质粒pPolyⅡ-CAV-2及E3区重组质粒pVAX-E3为基础,缺失1381bp的E3区片段(92.6%的E3区全序列),插入Linker-NF(内含NotⅠ、ClaⅠ、FseⅠ多克隆位点),获得重组载体质粒pPolyⅡ-CAV-2-ΔE3(NF)(31.9kb)。以AscⅠ和PmeⅠ双酶切,游离重组基因组,在脂质体LipofectamineTM2000介导下,转染MDCK细胞系,获得了E3区缺失的重组病毒CAV-2-ΔE3(NF)。通过病毒的形态学观察,血凝性、生长特性、感染性实验证明,该重组病毒与母源病毒没有差异。重组病毒CAV-2-ΔE3(NF)可以作为载体表达外源基因,其外源基因插入片段不小于3.3kb。