• Applied Microscopy
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• 제52권
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• pp.11.1-11.9
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• 2022

Zoonotic poxvirus infections pose significant threat to human health as we have witnessed recent spread of monkeypox. Therefore, insights into molecular mechanism behind poxvirus replication cycle are needed for the development of efficient antiviral strategies. Virion assembly is one of the key steps that determine the fate of replicating poxviruses. However, in-depth understanding of poxvirus assembly is challenging due to the complex nature of multi-step morphogenesis and heterogeneous virion structures. Despite these challenges, decades of research have revealed virion morphologies at various maturation stages, critical protein components and interactions with host cell compartments. Transmission electron microscopy has been employed as an indispensable tool for the examination of virion morphology, and more recently for the structure determination of protein complexes. In this review, we describe some of the major findings in poxvirus morphogenesis and the contributions of continuously advancing electron microscopy techniques.

• 대한수의학회지
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• 제56권1호
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• pp.41-43
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• 2016

A dead dove was found on the road and submitted for diagnosis. The bird was severely emaciated, with deformation in its facial area. Grossly, white coalescing nodules were seen on the cut surface of the nasal cavity. Histopathologically, epithelial cells of the upper respiratory tract were markedly proliferated, with ballooning degeneration, down growth of the rete ridge, and large eosinophilic intracytoplasmic inclusion bodies. Parakeratotic hyperkeratosis and focal necrotic focus was present in the proliferative area. The facial bones showed partial bone resorption. Transmission electron microscopy revealed numerous viral particles in epithelial cells with dumbbell-shaped bodies, consistent with poxvirus.

• 대한수의학회지
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• 제15권1호
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• pp.57-67
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• 1975

The poxvirus group is considered to be a typical cytoplasmic inclusion forming virus. Every poxvirus has been reported to produce only one kind of inclusion in the infected tissues. A vague concept that inclusions of poxviruses are eosinophilic or acidophilic has prevailed. Although many papers and theories about the nature of the inclusion have been presented, most of them are not quite convincing on the point of the relations with virus multiplication, and an analysis of papers published showed that there seem to be many discrepancies in the descriptions of the nature of the poxvirus inclusions. Comparative studies on host-virus interaction with cowpox, orf, swinepox and fowlpox viruses which selected from each Group (I-IV) of poxviruses were performed from the morphological and virological standpoints. At first, in cowpox virus-FL cell system, as a comparative model, cytoplasmic inclusion, nucleic acid metabolism by autoradiography and detection of viral antigen by immunofluorescence were studied and obtained the results as follows: 1. The focus-like cytopathic effect (CPE) at early stage developed to entire culture at terminal stage of infection, and also the developing status of CPE was correlated to viral doses for inoculation. Two kinds of cytoplasmic inclusions which named A and B type were easily observed by Giemsa, hematoxylin-eosin (H & E) and May-Greenwald Giemsa (MGG) stainings in the infected cells. The B type inclusions were formed at early stage of infection and the A type inclusions were produced subsequently the B type formation. The B type which common type inclusion in poxviruses was a small compact or aggregate at early stage and developed to a large diffuse body at terminal stage of infection. On the other hand, the A type inclusion which depend upon the kind of virus was appeared as round and discrete shape, and its size and number was increased gradually during the culture period. It was characteristic to form distinct halos around the both types of inclusions in acid fixed, H & E stained preparations of infected cultures. The B type inclusion was always positive in Feulgen reaction and showed as DNA containing body but the A type inclusion was not. 2. In the relationship between inclusion and DNA metabolism of infected cells by the qualitative autoradiography using 3H-thymidine, the appearance of silver grains was coincided with B type inclusion but not with A type inclusion. This showed that the DNA synthesis was proceeded in all B type inclusions except those in the terminal stage with a diffuse form. This suggested that the B type inclusions are only sites of DNA synthesis and this was proceeded after the cell infection independently. The activity of DNA synthesis of the inclusions was nearly the same as that of the nucleic of normal cells and non-inclusion bearing cells. and non-inclusion bearing cells. Regardless of the size of the degree of DNA synthesis of the B type inclusion, inclusion bearing cells all showed remarkable suppression of nuclear DNA synthesis. 3. By the direct fluorescent antibody technique viral antigen in infected cells was detected. The B type inclusions have been proved to contain a great deal of viral antigen, whereas the basic substance of A type inclusion did not show antigenicity except the round edge. It was suggested that the round edge fluorescence might be caused by the glare of cytoplasmic viral antigen which pushed out and concentrated by the A type inclusion development. 4. Hemorrhagic red pock formations on chorioallantoic membrane of embryonated chicken egg had proved the characteristic of used viral strain. 5. By the above studies on the nature of two types of inclusions and the role they play in virus multiplication, it was concluded that the B type inclusion must be the site of the synthesis of viral DNA and protein as well as the site of the virus.

• 한국임상수의학회지
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• 제28권5호
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• pp.530-532
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• 2011

기면 및 호흡곤란 상태로 서울대공원 동물병원으로 내원하여 다음날 폐사한 체중 90 g의 어치를 검사한 결과 양쪽 눈 모두 건조한 딱지로 덮여 눈을 떨 수 없는 상태로 눈꺼풀이 붙어 있었으며, 혀 및 구강내부 점막에 누런 치즈 양 물질이 붙어 있어 계두로 의심되어 PCR 검사를 실시한 결과 국내에서 자연 발생한 계두의 첫 증례로 진단되었다.

• Fisheries and Aquatic Sciences
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• 제26권7호
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• pp.437-446
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• 2023

Cyprinids are popular species for aquaculture worldwide, with Asia being a significant contributor to their production. In Korea, common carp (Cyprinus carpio), koi carp (Cyprinus rubrofuscus), and goldfish (Carassius auratus) are cultivated domestically and imported for ornamental or human consumption purposes. Among the viruses that infect cyprinids, cyprinid herpesvirus-2 (CyHV-2), koi herpesvirus (KHV, also known as cyprinid herpesvirus-3), and carp edema virus (CEV) are of particular concern as they cause substantial economic losses to the aquaculture industry. In this study, we investigated these viruses in both of domestic and imported cyprinids. Our results revealed that CyHV-2 was only detected in imported goldfish from Thailand. To further investigate the genetic characteristics of them, the marker A region was analyzed. Despite belonging to the same cluster with isolates from China, France, Poland, and Israel, CyHV-2 detected in this study showed distinct differences in their repetitive sequence sizes. Furthermore, two different forms of KHV/CEV coinfection were identified from domestic koi carp, both of which exhibited typical symptoms. Phylogenetic analysis showed that one KHV isolate (ScKc-2105-K) was of the Asian type and closely related to isolates from Japan, Indonesia, Belgium, Taiwan, and China. Two CEV isolates (ScKc-2105-CE and GhKc-2207-CE) be- longed to the IIa type and showed high similarity with isolates from the USA, France, and Korea. Notably, koi carp injected with cultured KHV (ScKc-2105-K) showed 78.0% cumulative mortality within 14 days post-injection (dpi). Our findings support the importance of regular surveillance of viral diseases in cyprinids.

• 대한바이러스학회지
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• 제28권1호
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• pp.71-78
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• 1998

Vaccinia virus is the prototype orthopoxvirus that has been used as a vaccine strain for small pox. This virus has been used to express a variety of cellular and viral genes in mammalian cells at high levels. Interleukin-4 (IL-4) has been found to stimulate the proliferation of T cells and enhance the cytolytic activity of cytotoxic T lymphocytes. To test the immunotherapeutic potential of IL-4 delivered in vivo by poxvirus, a recombinant vaccinia virus expressing the murine IL-4 gene (RVVmIL-4) was constructed. A high level of IL-4 production was confirmed by infecting HeLa cells and measuring IL-4 in cell culture supernatant by ELISA. As a tumor model, two cell lines were used; the murine T leukemic line P388 and the murine breast cancer line TS/A. CDF1 mice were intraperitoneally inoculated with $1\;{\times}\;10^5$ cells of P388. Mice were injected at the same site with $5\;{\times}\;10^5\;PFU$ of recombinant vaccinia virus; first, 3 days after the injection of tumor cells and thereafter once every week for 3 weeks. Intraperitoneal injections of RVVmIL-4 significantly prolonged the survival time of mice inoculated with tumor cells. All mice injected with RVVmIL-4 remained alive for 30 days after the postinoculation of tumor cells, while 100% and 70% of the animals injected with saline or wild type vaccinia virus died, respectively. In another tumor model using TS/A, tumor was established by subcutaneously inoculating $2{\times}10^5$ tumor cells to BALB/c mice. After tumor formation was confirmed on day 4 in all mice, $5\;{\times}\;10^6\;PFU$ of RVVmIL-4 was inoculated subcutaneously three times, once every week for 3 weeks. The TS/A tumor was eradicated in two of the nine mice. Seven of the nine mice treated with RVVmIL-4 developed a tumor, but tumor growth was significantly delayed compared to those treated with saline or wild type vaccinia virus. These results indicate that recombinant vaccinia viruses may be used as a convenient tool for delivering immunomodulator genes to a variety of tumors.