流行性出血热病毒感染乳小白鼠的病理组织学与病毒抗原定位研究

流行性出血热病毒感染乳小白鼠的病理组织学与病毒抗原定位研究郭广松,肖红,程丽,文莉,杨占秋（湖北医科大学病理学教研室,武汉４３００７１）（湖北医科大学病毒研究所,武汉４３００７１）关键词病毒抗原,流行性出血热,乳小白鼠,病理变化Ｈｕｇｇｉｒｌｓ（１９...     

Bovine Epizootic Fever

A virus, the Yamaguchi strain, was serially propagated in suckling hamsters, mice and rats, and hamster kidney BHK21-WI2 cells from a natural case in the 1966 outbreak of bovine epizootic fever, an acute febrile disease of cattle, resembling ephemeral fever, known in Japan since 1949. An acute phase blood from the natural case was first passaged in calves by intravenous inoculation, and a blood specimen at the second passage was used to initiate serial hamster passage. Infected hamsters died with nervous symptoms, and serial passage was readily accomplished by intracerebral inoculation with brain emulsions. The hamster passage line of virus was serially passaged by intracerebral inoculation in 1- or 2-day-old mice, and then in rats 1 or 2 days after birth, which developed fatal encephalitis. The hamster passage virus was also serially propagated with cytopathic effect in cultures of BHK21-WI2 cell cultures. These viral lines were shown to be neutralized by, and to produce specific complement-fixing antigen reactive with, convalescent sera of calves infected with the original Yamaguchi strain, confirming the identity of these lines as the Yamaguchi strain. The hamster passage line, when inoculated intravenously in calves, induced an acute febrile illness which was similar to bovine epizootic fever; all the inoculated calves had viremia and developed neutralizing and complement-fixing antibodies against the virus. Serological evidence for infection with this virus was obtained in natural cases in the 1966 outbreak. These findings seem to justify this virus to be the causative agent of bovine epizootic fever.     

Localization of specific antigen in the organs of newborn animals vaccinated with liver smallpox vaccine]

Of 20 suckling rabbits, 4-5-days old, inoculated with live smallpox vaccine intradermally 6 displayed symptoms of generalized pox virus and neuroparalysis complications. Intensive accumulation of specific antigen in the brain, lungs, spleen, and the lymph glands was revealed by immunofluorescent method. The smallpox vaccine virus was isolated from these organs. Prolonged persistance of the attenuated smallpox virus was observed in the brain, spinal cord, lungs, spleen, and the lymph glands of 14 suckling rabbits showing no signs of any disease; specific antigen was revealed by immunofluorescent test. Vascular disturbances and slight cell changes were observed in the brain tissue of the inoculated animals. These changes were more severe in the sick animals.     

Pathogenesis of mouse hepatitis virus infection. The role of nasal epithelial cells as a primary target of low-virulence virus, MHV-S.

The pathogenesis of mouse hepatitis virus (MHV-S) infection in suckling and weanling mice was comparatively studied after intranasal inoculation. In sucklings, infectious virus as well as specific antigen was first detected in the nasal mucosa at 12 hr, then in the nerve cells of the olfactory bulbs. At this stage viral particles were demonstrated both in the supporting cells and olfactory cells of the nasal mucosa. In the posterior part of the brain and spinal cord, virus was detected on days 3 to 4 postinoculation when viral growth was clearly demonstrable in the liver, spleen and intestines. In weanlings too, infection was first established in the nasal mucosa, shedding infectious virus in the nasal washing until day 6 postinoculation, and later infection spread to the brain and spinal cord. In weanling mice, however, neither infectious virus nor viral antigen was detected in the liver or other visceral organs, while serum neutralizing antibody became detectable on day 5 postinoculation, increasing in titer thereafter. Histopathologically degenerative and necrotic changes were observed in the nasal mucosa and central nervous system of both age groups of animals coincidentally with the presence of viral specific antigen, while inflammatory response was much less prominent in sucklings. In the liver, spleen and intestines, however, some lesions were observed only in sucklings.     

Immune therapy of a persistent and disseminated viral infection.

The mechanism of viral clearance was studied by using the mouse model of chronic infection with lymphocytic choriomeningitis virus. Distinct patterns of viral clearance and histopathology were observed in different organs after adoptive immune therapy of persistently infected (carrier) mice. Clearance from the liver occurred within 30 days and was accompanied by extensive mononuclear cell infiltrates and necrosis of hepatocytes. Infectious virus and viral antigen were eliminated concurrently. This pattern of viral clearance was also seen in most other tissues (i.e., lung, spleen, lymph nodes, pancreas, etc.). In contrast, a different pattern of clearance was observed in the brain. Infectious virus was eliminated within 30 days, but viral antigen persisted in the central nervous systems of treated carrier mice for up to 90 days. The urinary system was the most resistant to immune therapy. Elimination of infectious virus and viral antigen from the kidney took greater than 200 days and even then was not complete; trace levels of infectious virus were still present in the kidneys of some treated carrier mice. After immune therapy, viral antigen in the kidney was located within renal tubules that costained for intracellular mouse immunoglobulin G. This unusual staining pattern, coupled with the observation of large numbers of plasma cells within the kidney, suggests that virus-immunoglobulin G complexes found in the tubules may represent in situ immune complex formation as opposed to deposition of circulating immune complexes. In conclusion, these results suggest that the site (organ) of viral persistence is an important consideration in developing treatment strategies for controlling chronic viral infections.     

双单克隆抗体ELISA间接夹心法检测流行性出血热病毒抗原

建立了检测流行性出血热(EHF)病毒抗原的双单克隆抗体(McAb)ELISA同接夹心法,用本法和间接荧光抗体技术(IFAT)相比较,IFAT检出感染细胞内病毒抗原的高峰在感染后第8天,而ELISA检测感染上清中病毒抗原的高峰在第14天,两方法检测179份人工感染EHF病毒的乳鼠脑和肺组织标本,阳性检出率分别为72.1％和68.2％,实验结果表明,本法特异,敏感,简便,不仅可用于EHF病原学研究,也适用于流行病学调查检测大量鼠肺标本。     

Propagation of nephropathia epidemica virus in Mongolian gerbils.

Nephropathia epidemica virus, the etiological agent of hemorrhagic fever with renal syndrome in Scandinavia, was serially propagated in Mongolian gerbils (Meriones unguiculatus). Intracerebrally inoculated suckling gerbils developed subclinical infections, with viral antigen found in lung, brain, liver and spleen. The distribution of viral antigen was similar to that seen in experimentally infected bank voles (Clethrionomys glareolus), the principal wild rodent reservoir of nephropathia epidemica virus. This model provides a readily available animal host for the study of experimental nephropathia epidemica virus infection.     

Viral RNA kinetics is associated with changes in trace elements in target organs of Coxsackie virus B3 infection

Trace elements are pivotal for the host defense, as well as potentially important for viral replication and virulence. Studies of sequential changes in viral replication in target organs of infection are sparse and a possible association with changes in specific trace elements is unknown. In this study Balb/c mice were infected with Coxsackie virus B3 (CVB3). Results indicated that sequential changes in viral replication (RT-PCR) were related to changes in trace element (arsenic, copper, iron, selenium and zinc) concentrations (as determined by ICP-MS) on days 3, 5 and 7 of the infection in serum, heart, lung, liver, pancreas, kidney, spleen, intestine and brain. After an initial viral peak on day 3, viral load drastically decreased in all organs, i.e. by >99% (serum), 97% (lung), 98% (liver), 60% (pancreas), 95% (kidney) and 93% (spleen), except in the heart, intestine and brain in which viral load increased after day 3. Selenium decreased in all organs except the heart while arsenic decreased in all organs except the kidney, spleen and brain. Moreover, selenium was negatively correlated to viral load in serum, liver, pancreas and intestine. To conclude, these findings give evidence that trace elements are directly involved in the replication of CVB3.     

BK virus-transformed inbred hamster brain cells. I. Status of the viral DNA and the association of BK virus early antigens with purified plasma membranes

Inbred LSH hamster brain cells were transformed in vitro by the GS strain of BK virus (BKV), and transplantable tumors classified as undifferentiated glioblastomas were induced in the syngeneic host. The viral status in the transformed cells, designated LSH-BR-BK, was established. About 46 genome equivalents per cell of viral DNA was detected, with the majority of sequences in a free form. The transformed cells expressed large quantities of tumor (T) antigen as well as surface (S) antigen as demonstrated by indirect immunofluorescence. Sixty-three percent of tumor-bearing hamsters produced high-titer antibodies against T, whereas 3 of 14 (21%) hamsters also produced antibodies against the BKV-specific S antigen. Furthermore, the relatedness of BKV early gene products, including T, S, and tumor-specific transplantation antigen, was established by the production of a rabbit antiserum against highly purified plasma membranes of LSH-BR-BK cells and by the induction of a BKV-specific tumor-specific transplantation antigen response by these plasma membranes in the syngeneic host.     

Hemagglutinin-neuraminidase glycoprotein as a determinant of pathogenicity in mumps virus hamster encephalitis: analysis of mutants selected with monoclonal antibodies.

With the aid of monoclonal antibodies directed against a specific site on the hemagglutinin-neuraminidase surface glycoprotein, four mutants of the Kilham neurotropic strain of mumps virus were isolated. All four mutants had increased neuraminidase activity. Two mutants (M10 and M12) lost their hemagglutination capacity with human O erythrocytes but retained their ability to agglutinate guinea pig erythrocytes at 4 degrees C. A third mutant (M11) showed a change in the molecular weight of the hemagglutinin-neuraminidase glycoprotein. These three mutants (M10, M11, and M12) showed unaltered capacity to infect tissue cultures and to cause encephalitis in newborn hamsters. A fourth mutant (M13) retained its hemagglutination activity and capacity to infect Vero cell cultures but showed significantly lower neurovirulence in the suckling hamster brain than did the parental Kilham strain and the other three mutants. Both the number of infected neurons and the amount of infectious virus in the brain was reduced. On the other hand, there were no apparent differences in the occurrence of viral antigen in ependymal cells, indicating a selective change in affinity for neurons in the brain. These results suggest that certain changes in the hemagglutinin-neuraminidase glycoprotein may lead to an alteration of the neuropathogenicity of the Kilham strain of mumps virus.