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1.
Vaccinia virus recombinant expressing herpes simplex virus type 1 glycoprotein D prevents latent herpes in mice 总被引：28，自引：0，他引：28
K J Cremer M Mackett C Wohlenberg A L Notkins B Moss 《Science (New York, N.Y.)》1985,228(4700):737-740
In humans, herpes simplex virus causes a primary infection and then often a latent ganglionic infection that persists for life. Because these latent infections can recur periodically, vaccines are needed that can protect against both primary and latent herpes simplex infections. Infectious vaccinia virus recombinants that contain the herpes simplex virus type 1 (HSV-1) glycoprotein D gene under control of defined early or late vaccinia virus promoters were constructed. Tissue culture cells infected with these recombinant viruses synthesized a glycosylated protein that had the same mass (60,000 daltons) as the glycoprotein D produced by HSV-1. Immunization of mice with one of these recombinant viruses by intradermal, subcutaneous, or intraperitoneal routes resulted in the production of antibodies that neutralized HSV-1 and protected the mice against subsequent lethal challenge with HSV-1 or HSV-2. Immunization with the recombinant virus also protected the majority of the mice against the development of a latent HSV-1 infection of the trigeminal ganglia. This is the first demonstration that a genetically engineered vaccine can prevent the development of latency. 相似文献
2.
Mapping of herpes simplex virus-1 neurovirulence to gamma 134.5, a gene nonessential for growth in culture 总被引：49，自引：0，他引：49
The gene designated gamma 134.5 maps in the inverted repeats flanking the long unique sequence of herpes simplex virus-1 (HSV-1) DNA, and therefore it is present in two copies per genome. This gene is not essential for viral growth in cell culture. Four recombinant viruses were genetically engineered to test the function of this gene. These were (i) a virus from which both copies of the gene were deleted, (ii) a virus containing a stop codon in both copies of the gene, (iii) a virus containing after the first codon an insert encoding a 16-amino acid epitope known to react with a specific monoclonal antibody, and (iv) a virus in which the deleted sequences were restored. The viruses from which the gene was deleted or which carried stop codons were avirulent on intracerebral inoculation of mice. The virus with the gene tagged by the sequence encoding the epitope was moderately virulent, whereas the restored virus reacquired the phenotype of the parent virus. Significant amounts of virus were recovered only from brains of animals inoculated with virulent viruses. Inasmuch as the product of the gamma 134.5 gene extended the host range of the virus by enabling it to replicate and destroy brain cells, it is a viral neurovirulence factor. 相似文献
3.
[目的]对比狂犬病毒固定强毒株CVS-24、广西街毒株GX074、弱毒株rRC-HL和重组毒株rRC-HL△G感染小鼠后的临床症状及脑组织病理学变化,为揭示狂犬病毒的致病机理提供参考依据.[方法]将CVS-24、GX074、rRC-HL和rRC-HL△G分别通过脑内注射SPF级昆明小鼠,以注射DMEM为对照,每只小鼠注射30μL,攻毒后连续观察测量小鼠的体重和死亡情况,采取濒临死亡小鼠的脑组织制作石蜡切片,经HE染色后观察脑组织的病理变化.[结果]与DMEM组的小鼠相比,rRC-HL组小鼠攻毒后的体重先下降后恢复正常,而其他攻毒组小鼠的体重迅速下降直至死亡.DMEM组和rRC-HL组的小鼠在整个试验周期内未见死亡;CVS-24组、GX074组和rRC-HL△G组的小鼠在攻毒后全部发病死亡,其中,CVS-24组小鼠出现死亡的时间最早(攻毒后第5 d),且在攻毒后第6 d全部死亡.通过观察小鼠脑组织的病理学变化,发现rRC-HL组小鼠脑组织的炎症反应最严重,其神经纤维紊乱,神经元细胞变形,细胞边缘不清晰,少量细胞固缩甚至消失,海马回神经胶质细胞浸润,嗜神经现象明显,血管套现象严重;rRC-HL△G组次之;GX074组和CVS-24组小鼠的脑组织病变轻微,可见少量嗜神经现象.[结论]rRC-HL△G、GX074和CVS-24等3株狂犬病毒强毒株的临床症状更明显,发病死亡率达100%,但与弱毒株相比,其炎症反应较轻微,说明狂犬病毒强毒株可能是通过抑制机体脑组织中促炎因子的产生而抑制炎症反应出现,阻断其固有免疫反应,不利于机体对病毒的清除. 相似文献
4.
用斑马鱼检测猪链球菌2型的致病力 总被引：7，自引：0，他引：7
【目的】猪链球菌2型（Streptococcus suis type 2，SS2）菌株致病力各异，以斑马鱼为实验动物，建立了较为简便可靠的SS2致病力检测方法。【方法】选用1 005尾AB系斑马鱼（Danio rerio）以检测SS2不同分离株的致病力。检测8株基因型均为mrp+ef+、对猪有致病力的SS2菌株。【结果】结果斑马鱼接种菌株12 h后呈败血症病变，96 h内对斑马鱼的半数致死量（LD50）在5.36×103至5.01×104 cfu之间。上述接种菌株的斑马鱼均从体内重新分离到接种菌。同时检测1株基因型为mrp-ef-、对猪无致病力的SS2菌株，斑马鱼接种后96 h内不表现任何病变，亦不出现死亡，对斑马鱼的LD50>106 cfu。SS2有毒力株和无毒力株对斑马鱼的LD50差异极显著（P＜0.01）。【结论】斑马鱼可作为研究猪链球菌2型菌株感染的动物模型。 相似文献
5.
K. N. Slinina E. A. Liskova Z. G. Vorob’yeva A. L. Lazovskaya N. P. Tarabukina E. A. Vasil’eva 《Russian Agricultural Sciences》2011,37(3):258-260
A method is developed for studying the antagonistic activity of the spore probiotics Sakhabactisubtil and Irilis in vivo against
a virulent Rhodococcus equi. Intraperitoneal injection of sterile filtrates of these spore probiotics into mice that received the antibiotic Ampiox and
were infected with a lethal dose of the virulent R. equi strain promotes the survival of 70–100% of the animals and reduced the number of rhodococci in internal organs by 6–9 times. 相似文献
6.
新城疫病毒JZ05株F基因重组pGAPZα的构建 总被引：1，自引：0，他引：1
以RT-PCR扩增新城疫病毒JZ05株,基因F1片段和F2片段,以核酸内切酶κpnI和XbaI对目的基因片段及质粒pGAPZαA进行酶切,连接酶切产物,转化Eacterium coli DH5α.以PCR方法确定JZ05 F1的阳性重组子为2个,JZ05 F2的阳性重组子为4个.对阳性重组子进行酶切鉴定及序列分析,结果发现,重组质粒pGAPZαA-F1、pGAPZαA-F2及质粒pGAPZαA的酶切电泳条带与试验设计大小相符;基因测序得到的重组子中F1和F2序列长度分别为1198bp、269bp,与新域疫病毒JZ05株F基因序列比对,其序列长度和核苷酸排列完全一致.这表明重组质粒中目的基因片段的核苷酸序列、大小和插入位置是正确的,为以酵母表达系统表达F1和F2、研究强毒株与弱毒株F蛋白的抗原性差异程度及研制重组亚单位疫苗打下了基础. 相似文献
7.
V. N. Gerasimov I. A. Dyatlov M. V. Khramov L. I. Marinin E. A. Golov R. I. Mironova A. M. Smirnov M. P. Butko 《Russian Agricultural Sciences》2010,36(3):211-215
It has been established that all anthrax bacteria in an infected organism have the same morphology and fine structure typical
for Bacillus anthracis cells. Anthrax bacteria under conditions of a macroorganism form a capsule and slime. A massive bacterial capsule 0.1–0.4
μm thick is characteristic for bacteria of highly virulent and virulent B. anthracis strains. Microbes of avirulent, weakly virulent, and many virulent strains of the anthrax pathogen form a capsule 0.05–0.75
μm thick. 相似文献
8.
Toxoplasma gondii is a common human pathogen causing serious, even fatal, disease in the developing fetus and in immunocompromised patients. Despite its ability to reproduce sexually and its broad geographic and host range, Toxoplasma has a clonal population structure comprised principally of three lines. We have analyzed 15 polymorphic loci in the archetypal type I, II, and III strains and found that polymorphism was limited to, at most, two rather than three allelic classes and no polymorphism was detected between alleles in strains of a given type. Multilocus analysis of 10 nonarchetypal isolates likewise clustered the vast majority of alleles into the same two distinct ancestries. These data strongly suggest that the currently predominant genotypes exist as a pandemic outbreak from a genetic mixing of two discrete ancestral lines. To determine if such mixing could lead to the extreme virulence observed for some strains, we examined the F(1) progeny of a cross between a type II and III strain, both of which are relatively avirulent in mice. Among the progeny were recombinants that were at least 3 logs more virulent than either parent. Thus, sexual recombination, by combining polymorphisms in two distinct and competing clonal lines, can be a powerful force driving the natural evolution of virulence in this highly successful pathogen. 相似文献
9.
Protection from genital herpes simplex virus type 2 infection by vaccination with cloned type 1 glycoprotein D 总被引：22，自引：0，他引：22
Guinea pigs were vaccinated with truncated herpes simplex virus type-1 (HSV-1) glycoprotein D produced in the genetically engineered mammalian cell line gD10.2. Vaccinated animals formed antibodies that neutralized both HSV-1 and herpes simplex virus type 2 (HSV-2) in an in vitro neutralization assay. Vaccinated animals were challenged with HSV-2 by intravaginal infection. Animals that received the immunogen in Freund's complete adjuvant were completely protected from the clinical manifestations of genital HSV-2 infection. Animals that received the immunogen incorporated in alum adjuvants were partly protected from clinical disease; the infections that did develop were significantly less severe than those that occurred in control animals injected with adjuvant alone. The results demonstrate that immunization with a purified viral protein can provide significant protection against primary genital infection by HSV-2 in guinea pigs. 相似文献
10.
11.
Treatment of an avirulent strain of Trichomonas gallinae with a cellfree homogenate of a virulent strain resulted in enhanced virulence as evidenced by the size of lesions produced in mice. Addition of deoxyribonuclease to the homogenate cell mixture blocked the transformation. 相似文献
12.
H F Clark 《Science (New York, N.Y.)》1978,199(4333):1072-1075
Several strains of attenuated rabies virus lacking the capacity to kill adult mice acquired a high lethal potential for mice after one to five serial passages in murine or human neuroblastoma cells. The virulence acquired after passage in neuroblastoma cells is a stable genetic trait retained during subsequent passage of viruses in nonneuroblastoma cell systems. 相似文献
13.
SW Lee PF Markham MJ Coppo AR Legione JF Markham AH Noormohammadi GF Browning N Ficorilli CA Hartley JM Devlin 《Science (New York, N.Y.)》2012,337(6091):188
Recombination between herpesviruses has been seen in vitro and in vivo under experimental conditions. This has raised safety concerns about using attenuated herpesvirus vaccines in human and veterinary medicine and adds to other known concerns associated with their use, including reversion to virulence and disease arising from recurrent reactivation of lifelong chronic infection. We used high-throughput sequencing to investigate relationships between emergent field strains and vaccine strains of infectious laryngotracheitis virus (ILTV, gallid herpesvirus 1). We show that independent recombination events between distinct attenuated vaccine strains resulted in virulent recombinant viruses that became the dominant strains responsible for widespread disease in Australian commercial poultry flocks. These findings highlight the risks of using multiple different attenuated herpesvirus vaccines, or vectors, in the same populations. 相似文献
14.
Rapid identification of nonessential genes of herpes simplex virus type 1 by Tn5 mutagenesis 总被引：27，自引：0，他引：27
The large genome of herpes simplex virus type of (HSV-1) encodes at least 80 polypeptides, the majority of which have no recognized function. A subgroup of these gene products appears to be nonessential for virus replication in cell culture, but contributes to the complex life cycle of the virus in the host. To identify such functions, a simple insertional mutagenesis method has been used for selective inactivation of individual HSV-1 genes. The bacterial transposon Tn5 was allowed to insert randomly into cloned restriction fragments representing the entire short unique (US) region of the HSV-1 genome. Of the 12 open reading frames that were mutagenized with Tn5, mutant derivatives of US2, US4, and US5 were recombined into the virus. These three genes proved to be nonessential for HSV-1 replication in Vero (African Green monkey kidney) cells and the US4 gene appeared to be involved in viral pathogenesis in the central nervous system of mice. This rapid mutagenesis procedure should prove useful in exploring the entire HSV-1 genome as well as the genomes of other complex animal viruses. 相似文献
15.
Lack of enhanced oxygen consumption by polymorphonuclear leukocytes on phagocytosis of virulent Salmonella typhi 总被引：10，自引：0，他引：10
Human polymorphonuclear leukocytes exhibit an enhanced rate of oxygen consumption during phagocytosis of relatively avirulent strains of Salmonella typhi or Staphylococcus aureus. However, phagocytosis of a virulent strain of Salmonella typhi is not associated with augmented oxygen consumption. The ability of a bacterial strain to alter the postphagocytic rate of oxygen consumption of polymorphonuclear leukocytes may be related to its in vivo virulence. 相似文献
16.
Recombination of influenza A viruses of human and animal origin 总被引：11，自引：0，他引：11
E D Kolbourne 《Science (New York, N.Y.)》1968,160(823):74-76
Simultaneous infection of the allantoic sac of the chick embryo with influenza A/equine 1/56 and any of three recombinants derived from human influenza viruses produced stable hybrids with antigens from each parent strain. These hybrids contain the hemagglutinin protein of the equine virus and the neuraminidase of the human strains. The experiments demonstrate genetic homology of human and equine influenza A viruses and suggest the possibility of their recombination in nature. 相似文献
17.
根据GenBank中已发表的鸭瘟病毒TK基因序列,设计一对引物,对1株鸭瘟病毒强毒和1株鸭瘟病毒疫苗毒进行PCR扩增。将扩增的目的片段分别克隆到pMD18-T载体,经EcoRⅠ和HindⅢ双酶切鉴定,获得阳性重组质粒,然后对阳性重组质粒进行序列测定及分析。结果表明,本实验所扩增的鸭瘟病毒TK基因及侧翼UL24基因大小为1 995 bp,鸭瘟强、弱毒株TK基因及侧翼UL24基因序列完全相同,该病毒TK基因与鸭瘟病毒其它毒株AY911509与AY963569,四川株DQ640611,AV1221株EF173464,sd-01株EF417996同源性分别为99.5%,99.9%,100%,99.9%,100%,而该病毒UL24基因与鸭瘟病毒其它毒株AY911511,DQ227739,EF417996同源性为99.9%,99.8%,99.9%,表明鸭瘟病毒强弱毒株TK基因及侧翼UL24基因高度保守。为构建鸭瘟病毒TK基因缺失的转移载体奠定了基础。 相似文献
18.
Sindbis virus mutants selected for rapid growth in cell culture display attenuated virulence in animals 总被引：16，自引：0，他引：16
Mutants of Sindbis virus were selected for rapid growth in baby hamster kidney (BHK) cell cultures and screened for attenuation of virulence in suckling mice. Comparisons among independently isolated virulent and attenuated strains, as well as a classical reversion analysis, showed that accelerated penetration of BHK cells was correlated with attenuation in vivo. Both phenotypic changes resulted from a reorganization of virion structure as detected by monoclonal antibodies. These results suggest that mutants selected for rapid growth in cell culture may be useful as attenuated vaccines and for studies of the molecular basis of virus pathogenesis. 相似文献
19.
以临床分离得到的2株鸭（Anas domestica）源肠球菌（Enteroco ccns）分别接种小白鼠,观察感染后小白鼠的主要临床症状和病变特点,测定感染小白鼠的发病率、死亡率及半数致死量,并制作切片,光镜下观察各组织病变,以探讨这2个菌株对小白鼠的致病性。结果表明,2株肠球菌均能造成小白鼠发病,其中北京株致病性较强。该病原主要侵害小白鼠肝脏、脾脏和肾脏,最明显的病变特征为脾肿大、淤血,镜下见脾脏淋巴细胞明显减少、脾巨细胞增多、脾小体萎缩等;肝脏淤血、出血,甚至坏死,镜下见肝窦状隙扩张,聚集有细菌团块或淋巴细胞,窦上皮细胞肿胀;肾间质血管淤血,肾小管上皮细胞变性、坏死以及肾小管的蛋白管型等。揭示肠球菌可引起小鼠感染发病并导致组织病变而死亡。 相似文献
20.
In a wild plant-pathogen system, host resistance and pathogen virulence varied markedly among local populations. Broadly virulent pathogens occurred more frequently in highly resistant host populations, whereas avirulent pathogens dominated susceptible populations. Experimental inoculations indicated a negative trade-off between spore production and virulence. The nonrandom spatial distribution of pathogens, maintained through time despite high pathogen mobility, implies that selection favors virulent strains of Melampsora lini in resistant Linum marginale populations and avirulent strains in susceptible populations. These results are consistent with gene-for-gene models of host-pathogen coevolution that require trade-offs to prevent pathogen virulence increasing until host resistance becomes selectively neutral. 相似文献