慢病毒载体法制备转基因动物研究进展

慢病毒能够感染分裂细胞和非分裂细胞,因而被发展成为重要的转基因载体,已成为制备转基因动物的一种工具,转基因效率明显提高。该文介绍了制备转基因动物的技术方法,比较了慢病毒载体制备转基因动物的特点和优势,介绍了慢病毒载体安全设计的发展,并将近年来国内外利用慢病毒载体法制备转基因动物的研究进行了概述。     

Viral vectors for targeting the canine retina: a review

Clinical trials are currently underway using gene therapy to treat retinal disease such as Leber congenital amaurosis (LCA). Viral vectors that have been utilized to target retinal cells include adenoviruses, lentiviruses, and recombinant adeno-associated viruses (rAAV). Of the three classes, rAAV vectors show the greatest promise for retinal gene therapy. Recent developments in virus technology such as the development of hybrid and capsid mutant rAAV vectors mean that specific retinal cells can be targeted and faster stronger transgene expression is now possible compared to that achieved with the first generation of vectors. Gene therapy trials in dogs have been very important in the development of therapy for RPE65 LCA which is currently in phase I/II clinical trials in humans. Recent successes in using gene therapy to treat canine achromatopsia, X-linked progressive retinal atrophy (PRA) and the more severe rapid degenerations such as rod-cone dysplasia type 3 may lead also to the translation to human clinical trials. Dogs have played and continue to play an important role as animal models for proof-of-concept studies of retinal gene therapy. As modifications and improvements in gene therapy protocols are made from experience gathered from human clinical trials perhaps gene therapy for the treatment of canine clinical patients will become available to veterinary ophthalmologists.     

转基因动物制作技术及其基因载体研究进展

论文概述了家畜转基因动物的制作方法,初步分析了用于转基因技术的基因载体种类,深入探讨了不同载体的优缺点,并展望了基因载体的发展趋势。     

动物腺病毒载体的研究进展

腺病毒载体已成为近年来在基因治疗和重组疫苗研究方面的热点 ,文章较详细地叙述了腺病毒载体的构建基础、腺病毒载体的构建方法和各类动物腺病毒载体的研究现状以及腺病毒载体在应用时遇到的免疫学问题。并依据现有的腺病毒活载体的研究现状 ,讨论了动物腺病毒载体的发展趋势 ,提出在人类腺病毒载体应用遇到的免疫学问题上 ,某些动物腺病毒载体将具有独特的潜力     

Epizootiology and vectors of African horse sickness virus

African horse sickness (AHS) virus causes a non-contagious, infectious, arthropod-borne disease of equines and is enzootic in sub-Saharan Africa. The major vectors are species of Culicoides but mosquitoes and ticks may be involved. Periodically the virus makes excurisons beyond its enzootic zones but until recently has not been able to maintain itself outside these areas for more than 2–3 consecutive years. This is probably due to a number of factors including the absence of a long term vertebrate reservoir, the prevalence and seasonal incidence of the vectors and the efficiency of control measures. The recent AHS epizootics in Iberia and North Africa seem to have established a new pattern in AHS virus persistence. This is probably linked to the continuous presence of adult C. imicola in the area. Culicoides imicola is basically an Afro-Asiatic insect and prefers warm climates. Therefore its continuous adult presence in parts of Iberia may be due to some recent moderation of the climate in these areas.     

奶牛新病毒——施马伦贝格病毒

本文从病原、流行病学、诊断和预防控制等方面简要介绍了2011年底发生在德国奶牛的一种新病毒病——施马伦贝格病毒,主要感染猪、牛、羊和野牛,该病毒主要由昆虫如蚊蠓等小虫传播,也可通过胎盘垂直传播。截至2012年5月,已经有8个国家相继报道该病的发生。许多国家纷纷采取禁止从受该病毒感染国家进口活动物及其产品的措施防止该病的传入。目前该病毒还没有特异治疗措施和疫苗预防方案。     

利用转基因RNA干涉提高家蚕对BmNPV的抗性初探

基于探讨利用转基因RNA干涉技术使家蚕获得对核型多角体病毒抗性的目的,将家蚕核型多角体病毒(BmNPV)的DNA聚合酶基因、蛋白激酶(PK1)基因以及bro-d和orf1629基因的部分编码片段,分别以其反向重复的形式与家蚕Actin3启动子连接,构建了基于piggyBac转座子载体的转基因表达载体,通过显微注射于家蚕卵,获得了36~107个G1蛾区,得到了20~23头转基因阳性家蚕。经Southern杂交及RT-PCR分析表明,BmNPV的4个反向重复片段都已经导入家蚕基因组中,并且可以进行转录。攻毒实验结果表明,BmNPV的DNA聚合酶基因和PK1基因反向重复片段对病毒的增殖有抑制作用,从而使家蚕对BmNPV具有一定抗性;而BmNPV的bro-d和orf1629基因反向重复片段对病毒的增殖没有抑制作用。针对特定病毒的转基因RNAi技术有望使家蚕获得对该病毒的抗性。     

RNAi靶向N基因抑制猪繁殖与呼吸综合征病毒的复制

根据编码猪繁殖与呼吸综合征病毒(PRRSV)核衣壳蛋白(N)基因的序列,设计3个干扰靶位(N12、N23、N26),构建siRNA表达载体,转染Marc-145细胞后接毒,测定病毒TCID50、CPE,并利用实时荧光定量PCR及间接免疫荧光检测病毒在Marc-145细胞上的复制情况。结果表明,利用RNAi技术靶向N基因,其中N12干扰靶位可以高效抑制PRRSV的增殖,证实N基因可能是病毒复制所必需的结构基因,所选的干扰靶位是病毒复制的关键性位点。     

Human gene therapy vectors derived from feline lentiviruses

Lentiviral vectors are useful for gene transfer to dividing and nondividing cells. Feline immunodeficiency virus (FIV) vectors transduce most human cell types with good efficiency and may have advantages for clinical gene therapy applications. This article reviews significant progress in the development and refinement of FIV vector systems.     

精子载体转基因的研究进展

精子载体法培养转基因动物是目前操作最简便，成本低廉且危险隐患相对较低的一种转基因方法。近10年来的研究结果表明，精子载体法可得到转基因阳性动物，并且引起了更多科研人员的关注。     

Rodent hosts and flea vectors in Brazilian plague foci: a review

Plague, caused by the Yersinia pestis bacterium, has several foci scattered throughout a large area from the Brazilian territory that ranges from the Northeastern State of Ceará to the Southeastern State of Minas Gerais and another separated area at the State of Rio de Janeiro. This review gathers data from plague control and surveillance programs on the occurrence and geographic distribution of rodent hosts and flea vectors in the Brazilian plague areas during the period of from 1952 to 2019. Furthermore, we discuss how the interaction between Y. pestis and some rodent host species may play a role in the disease dynamics. The absence of human cases nowadays in Brazil does not mean that it was eradicated. The dynamics of plague in Brazil and in other countries where it was introduced during the 3rd pandemic are quite alike, alternating epidemics with decades of quiescence. Hence, it remains an important epidemic disease of global concern. The existence of a large animal reservoir and competent vectors demonstrate a need for continuous surveillance to prevent new outbreaks of this disease in humans.     

Mosquito vectors of dog heartworm in the United States: vector status and factors influencing transmission efficiency

Dog heartworm (Dirofilaria immitis) is dependent on mosquito vectors for its maintenance and transmission among vertebrate hosts. Consequently, D. immitis abundance and distribution are closely linked with mosquito vector biology and ecology. Information on the important dog heartworm vectors in the United States is limited and no comprehensive surveillance of dog heartworm in US mosquitoes has been undertaken to date. Here, we review information gleaned from a number of field surveys documenting heartworm presence in wild mosquito populations as well as laboratory assessments of mosquito vector capacity. Various biological and ecological factors likely contribute to the relative importance of different vector species. We describe some of these factors, rank the leading criteria for efficient vectors, and present the most likely vector species found across the United States. Considering the recent emergence of drug resistance among D. immitis strains, practical knowledge of heartworm vector biology and control should be incorporated into heartworm disease management programs. We conclude by proposing that heartworm control would benefit by targeting mosquito vectors, and we suggest ways in which veterinarians can incorporate the recognition of vector importance into heartworm prevention recommendations imparted to clients.     

From genes to complex structures of bluetongue virus and their efficacy as vaccines.

Bluetongue virus-like and core-like structures consisting of multiproteins in different molar ratios, have been synthesized using baculovirus multiple expression vectors. These particles lacking genetic materials, mimic the single- and double-shelled authentic virus particles and have been shown to be highly immunogenic and protective for sheep challenged with infectious virus. The formation of virus-like particles, using this new technology, offers a novel approach to vaccine development.     

猪场重要虫媒及其传播病原研究进展

近年来,非洲猪瘟、牛结节性皮肤病等外来可由虫媒传播的疫病肆虐中国,而一些已在国外流行的虫媒传播病原如非洲马瘟等传入中国的风险也越来越高,严重危害中国畜牧养殖业的发展和公共卫生安全。特别是2018年8月以来非洲猪瘟在中国的流行给养猪业带来重要警示信息,即防止猪场媒介生物进入并阻断其携带病原的传播将成为猪场生物安全的重点。蚊、蝇、蠓及蜱等是猪场和发病猪群传播疫病的重要虫媒因素,虫媒种类及从虫媒中分离到的病毒、细菌、寄生虫等病原种类繁杂,虫媒生物特性的差异对病原的传播方式和传播能力也不尽相同。鉴于此,作者详细归纳了猪场存在的主要虫媒种类及其传播的重要猪病病原,包括猪乙型脑炎病毒、猪繁殖与呼吸综合征病毒、非洲猪瘟病毒、盖塔病毒、猪肠道冠状病毒、大肠杆菌、猪链球菌等,并探讨其危害性和传播风险,以降低猪场虫媒传播疾病所带来的经济损失。     

细菌活载体及其在寄生虫疫苗研究上的应用

随着重组DNA技术的发展和应用,基因工程疫苗的研究取得了快速的进展。减毒或无毒的活微生物作为疫苗载体能够激起持久的系统和黏膜免疫反应,且具有易于接种、安全和廉价等特点,近年来已成为疫苗研究领域的热点。作者对细菌活载体及其在寄生虫疫苗研究上的应用作一概述,从而为研制新型寄生虫疫苗提供参考。     

FIP: a novel approach to vaccination. Proceedings from the 2nd International FCoV/FIP Symposium, Glasgow, 4-7 August 2002

Feline infectious peritonitis (FIP) is a fatal disease of cats. Early attempts at vaccination have been unsuccessful, some even serving to exacerbate the disease through antibody-dependent enhancement. Replication-incompetent feline foamy virus (FFV) transducing vectors are being developed as potential vaccine agents, into which immunogenic fragments of feline coronavirus (FCoV) proteins will be inserted. To use a recombinant viral vector to express FCoV proteins, the agent chosen should be apathogenic and replication incompetent within the host following gene delivery. Spumaviruses confer several advantages over the more traditionally explored retroviral vectors. Stable helper cell line clones have been established by transfection of CRFK cells with FFV tas and assessed using beta-galactosidase assays, PCR, immunofluorescence and western blotting. The generation of infectious virions using these cell lines has been investigated using tas-deleted FFV vectors containing the enhanced green fluorescent protein (eGFP) cassette.     

应用于兽用疫苗研发的病毒载体研究进展

对应用于兽用疫苗研发的病毒载体,包括痘病毒载体、疱疹病毒载体、腺病毒载体、杆状病毒载体、副粘病毒载体、弹状病毒载体、甲病毒载体、冠状病毒载体、反转录病毒载体、黄病毒载体等DNA和RNA病毒载体的研究进展进行了综述,以期为我国基因工程活载体疫苗研发工作提供参考.     

Nematode antigens in protection, diagnosis and pathology

A thorough study of parasite antigens is a prerequisite for control programmes based on protection by vaccination, accurate serodiagnosis and perhaps immune modulation to diminish pathological sequelae. Stage specific surface secreted and somatic antigens may be of particular value in proceeding towards these goals. The design of vaccines is most appropriately focused on surface antigens. With respect to pathology, certain antigens must stimulate humoral and, or cellular immune responses which are responsible for the undesirable immunopathologic consequences of the disease. The ultimate objective, therefore, is identification of those particular antigens followed by appropriate down regulation of the immune system in order to delete such potentially harmful immunological reactions. The relevant illustration presented in this context is an interesting correlation between one particular clinical condition of onchocerciasis ("sowda") and the serological response, defined both in terms of the parasite antigen and an immunoglobulin class restricted antibody response. Current parasitological methods of diagnosis consistently underestimate parasite prevalence. Failure to detect low level patent infections incurs the risk of having a reservoir capable of perpetuating infections. There is, then, an urgent requirement for accurate serodiagnosis, to be used in association with, and for the evaluation of, drug treatment and vector elimination in parasite control programmes. Given the high sensitivity of current immunoassay technology, the only bar to establishing the necessary immunological tests is the choice of suitably specific antibody-antigen systems. Once these are identified, a combination of recombinant nucleic acid biochemistry and hybridoma technology should provide the necessary reagents for inexpensive, robust and specific diagnostic tests. In addition, it may not be many years before the ubiquitous RIA and ELISA technology gives way to the newly developing biosensor systems. Finally, given the sensitivity and specificity of today's nucleic acid hybridization techniques, we may soon expect to see specific identification of infective larvae in their vectors of this, a cloned DNA probe specific for Onchocerca volvulus, and with potential for the detection of infective larvae in blackflies is described.     

Foot-and-mouth disease: susceptibility of domestic poultry and free-living birds to infection and to disease--a review of the historical and current literature concerning the role of birds in spread of foot-and-mouth disease viruses

Ruminants and pigs are the dominant natural hosts of food-and-mouth disease (FMD) viruses. Approximately 70 additional mammalian species are found to be susceptible under natural or experimental conditions. Reptilia, amphibia, and fish are probably naturally resistant to infection. According to the reviewed literature, domestic birds (chickens, turkeys, guinea fowl, ducks and geese) have been experimentally infected with some strains of FMD viruses and may develop lesions suggestive of FMD such as vesicular lesions on the comb, wattles, eye lids, and feet. Since chickens are to some extent coprophagous, chickens get infected by ingestion of virus under conditions of natural exposure or their plumage gets contaminated in an infectious environment. Thus, domestic birds kept in free-run systems may serve as virus vectors for short distances. Free-living birds, especially starlings (Sturnus vulgaris), sea gulls (Larus canus), house-sparrows (Passer domesticus) have been successfully experimentally infected and developed vesicular lesions on the skin and mucosal membranes of the mouth. During epizootics of FMD the plumage of these free-living birds can be contaminated with FMD viruses and the virus is spread over long distances during migration periods in spring and autumn. Thus migrating birds may assume an active role in long distance dissemination of FMD viruses.