Viral shedding and transmission between hosts determined by reovirus L2 gene

Two reovirus isolates (type 1 Lang and type 3 Dearing) differ in their transmissibility between littermates of newborn mice. They also differ in the amounts of virus excreted by the gastrointestinal tract. With the use of reassortant viruses, these properties were mapped to the L2 gene. Thus environmental spread of reovirus is a genetic property.     

Viral receptors on isolated murine and human ependymal cells

Viruses that infect ependyma cause ependymitis in humans and hydrocephalus in experimental animals. We report that reovirus type 1 (which induces hydrocephalus in mice) binds to the surface of isolated human and murine ciliated ependymal cells. With the use of recombinant viral clones, the binding property was mapped to the type 1 viral hemagglutinin, which also determines in vivo the affinity of reovirus type 1 for ependyma. Mumps virus, measles virus, parainfluenza type 3, and herpes simplex virus type 1 bind to murine ependyma cells, whereas reovirus type 3, herpes simplex virus type 2, and poliovirus type 2 do not.     

Vaccinia dermal infection and methylcholanthrene in cortisone-treated mice

Cortisone-treated mice were inoculated with vaccinia virus, and then five paintings of methylcholanthrene were applied over the site of inoculation. In 70 percent of the mice, tumors developed at the site of inoculation, and 35 percent of the mice, with and without skin tumors, also developed lymphomas. Identically treated control mice that were vacciniaimmune developed a significantly lower incidence (38 percent) of both skin tumors and lymphomas     

Latency of herpes simplex virus in absence of neutralizing antibody: model for reactivation

Mice inoculated with herpes simplex virus (type 1) by the lip or corneal route and then passively immunized with rabbit antibody to herpes simplex virus developed a latent infection in the trigeminal ganglia within 96 hours. Neutralizing antibody to herpes simplex virus was cleared from the circulation and could not be detected in most of these mice after 2 months. Examination of ganglia from the antibody-negative mice revealed latent virus in over 90 percent of the animals, indicating that serum neutralizing antibody is not necessary to maintain the latent state. When the lips or corneas of these mice were traumatized, viral reactivation occurred in up to 90 percent of the mice, as demonstrated by the appearance of neutralizing antibody. This study provides a model for identifying factors that trigger viral reactivation.     

Hemagglutinin variants of reovirus type 3 have altered central nervous system tropism

Variants of the Dearing strain of reovirus type 3 with antigenically altered hemagglutinin proteins are much less neurovirulent than the parental virus. When injected intracerebrally into mice these variants infected a subset of the brain neurons that were infected by the parental virus. When injected intraperitoneally, the variants did not spread to the brain. These results indicate that minor modifications of the reovirus hemagglutinin dramatically alter the ability of the virus to spread into and injure the central nervous system.     

异育银鲫呼肠孤病毒的分离与鉴定

【目的】发现异育银鲫Carassius auratus gibelio新病原,为其病害防控提供理论基础。【方法】从吉林省某养殖场采集异育银鲫出血病疑似病样,对其进行细菌分离及寄生虫观察、鲤疱疹病毒Ⅱ型的PCR检测和人工感染试验,然后用感染滤液接种鲤上皮瘤细胞(EPC),并对其进行电镜观察。对病毒基因组进行SDS-PAGE电泳分析、RT-PCR鉴定及序列测定。【结果】发病异育银鲫无细菌及寄生虫感染,鲤疱疹病毒Ⅱ型的PCR检测无特异性条带,将过滤后的患病鱼组织滤液感染健康异育银鲫,7 d内死亡率高达86.7%。盲传4代后出现明显的细胞病变。负染后电镜下可观察到病毒粒子,直径约70 nm,病毒颗粒近球形,无囊膜结构,初步判断为呼肠孤病毒(暂命名JL-4)。SDS-PAGE结果揭示,JL-4基因组由11条dsRNA组成,呈现水生呼肠孤病毒基因组典型特征。将RT-PCR扩增产物的序列进行聚类分析,结果显示,JL-4与呼肠孤病毒HZ08株S6序列相似性高达99%,证明该分离株为呼肠孤病毒。【结论】从患病异育银鲫中分离到1株呼肠孤病毒。     

Rapid viral induction of plasmacytomas in pristane-primed BALB-c mice

Strain BALB/c mice were injected intraperitoneally with 0.5 milliliter of pristane, and 39 to 56 days later they were infected with Abelson murine leukemia virus, which is a lymphosarcomagenic variant of Moloney virus. Fifty-eight percent of the mice developed lymphosarcoma, and 28 percent developed immunoglobulin-producing plasmacytomas within 20 to 93 days (77 to 149 days after the pristane injection). Two of 57 control mice developed plasmacytomas at days 138 and 166 after a single injection of pristane; no plasmacytomas were found in mice treated with virus alone.     

Intestinal microbiota promote enteric virus replication and systemic pathogenesis

Intestinal bacteria aid host health and limit bacterial pathogen colonization. However, the influence of bacteria on enteric viruses is largely unknown. We depleted the intestinal microbiota of mice with antibiotics before inoculation with poliovirus, an enteric virus. Antibiotic-treated mice were less susceptible to poliovirus disease and supported minimal viral replication in the intestine. Exposure to bacteria or their N-acetylglucosamine-containing surface polysaccharides, including lipopolysaccharide and peptidoglycan, enhanced poliovirus infectivity. We found that poliovirus binds lipopolysaccharide, and exposure of poliovirus to bacteria enhanced host cell association and infection. The pathogenesis of reovirus, an unrelated enteric virus, also was more severe in the presence of intestinal microbes. These results suggest that antibiotic-mediated microbiota depletion diminishes enteric virus infection and that enteric viruses exploit intestinal microbes for replication and transmission.     

新型鸭呼肠孤病毒病灭活疫苗的制备及免疫原性分析

鸭出血性坏死性肝炎是新型鸭呼肠孤病毒引起的危害养鸭业的一种新传染病。为防制该病,本研究以NDRV JM85株为种毒研制成油佐剂灭活苗,并通过免疫血清学检测及攻毒保护试验评价疫苗效果。结果表明,该疫苗安全性好,免疫原性强,麻鸭二免后28d产生较高的中和抗体,并能维持较长时间。种番鸭免疫后的子代雏番鸭具有一定的母源抗体,能够抵抗强毒的感染,可用于防制鸭新型呼肠孤病毒病。     

Virus-induced autoimmunity: monoclonal antibodies that react with endocrine tissues

Mice infected with reovirus type 1 develop an autoimmune polyendocrine disease. Spleen cells from these mice were fused with myeloma cells and the culture fluids were screened by indirect immunofluorescence for autoantibodies reactive with normal mouse tissues. A large panel of cloned, stable antibody-producing hybridomas has been obtained. Fourteen of the hybridomas make autoantibodies that react with cells in the islets of Langerhans, 24 with cells in the anterior pituitary, 11 with cells in gastric mucosa, and 5 with nuclei. Except for the antibodies to nuclei, the monoclonal autoantibodies are organ-specific. Some, however, show broad cross-species reactivity, recognizing similar antigenic determinants in mouse, rat, pig, and human organs, whereas other recognize determinants only in rodent tissues. Several of the antigens recognized by these monoclonal autoantibodies have been identified as hormones (for example, glucagon, growth hormone, and insulin).     

Distinct pathways of viral spread in the host determined by reovirus S1 gene segment

The genetic and molecular mechanisms that determine the capacity of a virus to utilize distinct pathways of spread in an infected host were examined by using reoviruses. Both reovirus type 1 and reovirus type 3 spread to the spinal cord following inoculation into the hindlimb or forelimb footpad of newborn mice. For type 3 this spread is through nerves and occurs via the microtubule-associated system of fast axonal transport. By contrast, type 1 spreads to the spinal cord through the bloodstream. With the use of reassortant viruses containing various combinations of double-stranded RNA segments (genes) derived from type 1 and type 3, the viral S1 double-stranded RNA segment was shown to be responsible for determining the capacity of reoviruses to spread to the central nervous system through these distinct pathways.     

番鸭呼肠孤病毒的分离与鉴定

从番鸭肝“白点病”患鸭的肝脾匀浆中分离到 7个病毒分离株 .在电镜下观察到病毒粒子呈球形 ,无囊膜 ,有可见的双层衣壳结构 ,外壳直径 75nm,内核直径 50 nm;病毒核酸型为 RNA;不凝集鸡、鸭、兔、豚鼠红细胞 ,与禽呼肠孤病毒有一定的抗原相关性 ;对番鸭胚和鸡胚成纤维细胞可致感染细胞圆缩、融合 ,出现多核细胞和巨细胞 ,胞浆内有近核包涵体 ;试验感染 1日龄敏感雏番鸭死亡率达 10 0 % ,临床及病理变化与自然感染发病的番鸭基本一致 ,并可回收到该病毒 .结果表明 ,目前国内流行的番鸭肝“白点病”病原为呼肠孤病毒科正呼肠孤病毒属番鸭呼肠孤病毒     

Human sickle hemoglobin in transgenic mice

DNA molecules that contain the human alpha- and beta s-globin genes inserted downstream of erythroid-specific, deoxyribonuclease I super-hypersensitive sites were coinjected into fertilized mouse eggs and a transgenic mouse line was established that synthesizes human sickle hemoglobin (Hb S). These animals were bred to beta-thalassemic mice to reduce endogenous mouse globin levels. When erythrocytes from these mice were deoxygenated, greater than 90 percent of the cells displayed the same characteristic sickled shapes as erythrocytes from humans with sickle cell disease. Compared to controls the mice have decreased hematocrits, elevated reticulocyte counts, lower hemoglobin concentrations, and splenomegaly, which are all indications of the anemia associated with human sickle cell disease.     

抗番鸭呼肠孤病毒(MDRV)单克隆抗体的制备及应用

【目的】制备抗番鸭呼肠孤病毒（MDRV）的单克隆抗体,建立番鸭呼肠孤病毒病的间接免疫荧光（IFA）快速诊断方法。【方法】制备MDRV抗原,用之免疫Babl/c小鼠,取免疫小鼠脾细胞和SP2/0骨髓瘤细胞进行融合,采用IFA和ELISA筛选阳性杂交瘤细胞株,体内诱生腹水法制备单克隆抗体,检测其生物学特性,应用制备的单克隆抗体建立MDRV IFA快速诊断方法。【结果】筛选到237-11,45-12和3-H3 3株特异性好并能稳定分泌抗MDRV单克隆抗体的杂交瘤细胞株,其中45-12株单抗为IgM亚型,237-11和3-H3株单抗为IgG3亚型。45-12和3-H3 2株单抗具有ELISA特性,效价分别为10-4和10-5;237-11株单抗具有IFA特性,效价达10³。特异性测定结果显示,3株单抗仅与MDRV反应,而与正常细胞培养物（MDEF）、番鸭细小病毒（MPV）、鹅细小病毒(GPV)、禽呼肠孤病毒(ARV) 、鸭副黏病毒（PMV）和鸭肝炎病毒（DHV）均无交叉反应。应用抗MDRV单抗建立的IFA方法与病毒分离法（VI）的符合率为91%。【结论】筛选到2株具有ELISA特性、1株具有IFA特性且能分泌抗MDRV单克隆抗体的杂交瘤细胞株,建立了MDRV IFA快速诊断方法,为番鸭呼肠孤病毒病的快速诊断奠定了基础。     

基于纳米材料电化学免疫传感器检测禽呼肠孤病毒研究

【目的】构建一种用于检测禽呼肠孤病毒(ARV)的新型电化学免疫传感器。【方法】将石墨烯(G)和甲壳胺(Chi)分散在乙酸溶液中得到均匀的混合物后,加入HAuCl4溶液于80℃还原成金纳米粒子（AuNPs）,得到石墨烯-甲壳胺-金纳米粒子(G-Chi-AuNPs)纳米复合物。将石墨烯(G)和甲壳胺(Chi)分散在乙酸溶液中得到均匀的混合物后,先加入AgNO3溶液于80℃还原成银纳米粒子（AgNPs）,再加入禽呼肠孤病毒单克隆抗体(ARV-MAb),得到石墨烯-甲壳胺-银纳米粒子-禽呼肠孤病毒单克隆抗体（G-Chi-AgNPs-ARV-MAb）纳米复合物。将G-Chi- AuNPs纳米复合物修饰金电极作为传感器平台,固定待检测样品,然后加入G-Chi-AgNPs-ARV-MAb纳米复合物,并对G-Chi-AgNPs-ARV-MAb纳米复合物的孵育时间进行优化,构建了ARV电化学免疫传感器。使用构建的ARV电化学免疫传感器,对禽流感（H5N1、H3N6和H9N2亚型）、新城疫病毒（NDV）、喉气管炎病毒（LTV）、传染性支气管炎病毒（IBV）和传染性法氏囊病毒(IBDV)进行检测,以确定ARV电化学免疫传感器的特异性。使用构建的ARV电化学免疫传感器,对106.5-100.5 TCID50/mL的病毒进行检测,以确定ARV电化学免疫传感器的敏感性试验。使用构建的ARV电化学免疫传感器,对临床样品进行检测,其确定ARV电化学免疫传感器的实用性。【结果】所建立的ARV电化学免疫传感器,G-Chi-AgNPs-ARV-MAb纳米复合物的最佳孵育时间为40 min。当检测的样品为阳性时,ARV与ARV-MAb特异结合,G-Chi-AgNPs-ARV-MAb纳米复合物被固定到电极的表面使其线性伏安曲线出现AgNPs的氧化峰;当检测样品为阴性时,其线性伏安曲线不出现AgNPs的氧化峰。特异性结果表明,所建立的方法仅对ARV的检测为阳性（出现AgNPs的氧化峰）,而对非目标禽流感（H5N1、H3N6和H9N2亚型）、NDV、LTV、IBV和 IBDV的检测为阴性（不出现AgNPs的氧化峰）。敏感性结果表明,所构建的ARV电化学免疫传感器,具有很高的敏感性,对ARV检测的敏感性达101.5 TCID50/mL。使用建立的ARV电化学免疫传感器对22份临床样品进行检测,结果与病毒分离方法相符。【结论】所建立的ARV电化学免疫传感器,具有特异性强、敏感度高及快速的特点,为有效检测诊断禽呼肠孤病毒提供了一种新的快速检测诊断技术。     

Engraftment and development of human T and B cells in mice after bone marrow transplantation.

A model for human lymphocyte ontogeny has been developed in a normal mouse. Human bone marrow, depleted of mature T and B lymphocytes, and bone marrow from mice with severe combined immunodeficiency were transplanted into lethally irradiated BALB/c mice. Human B and T cells were first detected 2 to 4 months after transplantation and persisted for at least 6 months. Most human thymocytes (30 to 50 percent of total thymocytes) were CD3+CD4+CD8+. Human immunoglobulin was detected in some chimeras, and a human antibody response to dinitrophenol could be generated after primary and secondary immunization.     

Survival of mouse embryos frozen to -196 degrees and -269 degrees C

Mouse embryos survived freezing to -196 degrees C. Survival required slow cooling (0.3 degrees to 2 degrees C per minute) and slow warming (4 degrees to 25 degrees C per minute). Depending on the specific rates used, 50 to 70 percent of more than 2500 frozen and thawed early embryos developed into blastocysts in culture after storage at -196 degrees C for up to 8 days. When approximately 1000 of the survivors, including some frozen to -269 degrees C (4 degrees K), were transferred into foster mothers, 65 percent of the recipients became pregnant. More than 40 percent of the embryos in these pregnant mice gave rise to normal, living full-term fetuses or newborn mice.     

Leukemogenic activity of filtrates from radiation-induced lymphoid tumors of mice

Cell-free filtrates of x-ray-induced lymphoid tumors of strain C57BL/ Ka mice have elicited, on injection into newborn isologous hosts, a lymphoma incidence of 15 to 19 percent. In control mice of the same subline, the incidence of spontaneous lymphoma is about 1 percent. No leukemogenic activity could be detected in filtrates from thymi harvested at 2 to 32 days following completion of x-ray treatment. Activity was evident at 64 days and was perhaps somewhat greater at 128 days. Serial cell-free passage of filtrates in newborn F(1) hybrid mice resulted in a marked increase in lymphoma incidence (69 percent), coupled with a shortening of the median latency. Supplementary x-irradiation failed to enhance the activity of filtrates after neonatal injection.     

Adenovirus endocarditis in mice

Viral endocarditis developed in 24 percent of 50 newborn mice 6 to 8 days after intraperitoneal inoculation with murine adenovirus. Typical adenovirus intranuclear inclusions were seen in heart-valve lesions, and high titers of virus were recovered from heart tissue. Furthermore, adenovirions were directly visualized by electron microscopy within endothelial cells and fibroblasts of the heart valves.