• Journal of Microbiology and Biotechnology
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• 제30권12호
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• pp.1843-1853
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• 2020

COVID-19, caused by the novel coronavirus SARS-CoV-2, has spread globally and caused serious social and economic problems. The WHO has declared this outbreak a pandemic. Currently, there are no approved vaccines or antiviral drugs that prevent SARS-CoV-2 infection. Drugs already approved for clinical use would be ideal candidates for rapid development as COVID-19 treatments. In this work, we screened 1,473 FDA-approved drugs to identify inhibitors of SARS-CoV-2 infection using cell-based assays. The antiviral activity of each compound was measured based on the immunofluorescent staining of infected cells using anti-dsRNA antibody. Twenty-nine drugs among those tested showed antiviral activity against SARS-CoV-2. We report this new list of inhibitors to quickly provide basic information for consideration in developing potential therapies.

• 한국어병학회지
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• 제36권2호
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• pp.191-211
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• 2023

Rock bream iridovirus (RBIV) causes high mortality and economic losses in rock bream (Oplegnathus fasciatus) aquaculture industry in Korea. Although, the immune responses of rock bream under RBIV infection have been studied, there is not much information at the different stages of infection (initial, middle and recovery). Gene expression profiling of rock bream under different RBIV infection stages was investigated using a microarray approaches. In total, 5699 and 6557 genes were significantly up- or down-regulated over 2-fold, respectively, upon RBIV infection. These genes were grouped into categories such as innate immune responses, adaptive immune responses, complements, lectin, antibacterial molecule, stress responses, DNA/RNA binding, energy metabolism, transport and cell cycle. Interestingly, hemoglobins (α and β) appears to be important during pathogenesis; it is highly up-regulated at the initial stage and is gradually decreased when the pathogen most likely multiplying and fish begin to die at the middle or later stage. Expression levels were re-elevated at the recovery stage of infection. Among up-regulated genes, interferon-related genes were found to be responsive in most stages of RBIV infection. Moreover, X-linked inhibitor of apoptosis (XIAP)-associated factor 1 (XAF1) expression was high, whereas expression of apoptosis-relate genes were low. In addition, stress responses were highly induced in the virus infection. The cDNA microarray data were validated using quantative real-time PCR. Our results provide novel inslights into the broad immune responses triggered by RBIV at different infection stages.

• Parasites, Hosts and Diseases
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• 제31권1호
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• pp.31-36
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• 1993

Toxoplasmn감염 마우스에 있어서 $interferon-{\gamma}(IFN-{\gamma})$ 투여 시기에 따른 T세포 아형 변화를 관찰하였다. T. gondii Beverley주를 감염시킨 마우스(마우스당 약 100개의 씨스트)에 recombinantmouse $IFN-{\gamma}$(마우스당 $5{\;}{\times}{\;}10^4$ Units)를 감염 4일전/2일전, 감염 2일전/감염일, 감염일/감염후 2일, 감염후 2일/4일에 각각 투여한 다음, 이들 4군의 비장 림프구 T 세포 아형 변화를 매주 1회씩 4주 동안 단세포군 항체를 이용하여 flow cytometry로 분석하였다. Thy-1, 2 세포 (전체 T 세포)는 감염 1주부터 감소하여 2주에 가장 적었으며, 감염대조군에 비해 $IFN-{\gamma}$를 감염 2 일전/감염일 또는 감염일/감염후 2일 투여군에서 유의하게 증가하였다. L3T4 세포(helper/lnducer T 세포)는 유의한 차이가 없었으며, Ly-2 세포($cytotoxic$pressor T 세포)는 $IFN-{\gamma}$투여시 감염 2주까지는 감염대조군과 유사하였으나 감염 3, 4주에는 모두 감소하였다. L3T4/Ly-2 세포 비율은 감염 1주 이후부터 감소하였으며, $IFN-{\gamma}$를 감염 2일전/감염일 또는 감염일/감염후 2일 투여군에서 유의하게 증가하였다. 이상의 성적으로 보아 Toxoplasma 감염 마우스에 $IFN-{\gamma}$ 투여시 변화된 T 세포 아형이 정상 상태로 회복되었으며, $IFN-{\gamma}$를 감염 직후 투여시 더욱 현저한 효과를 나타냄을 알 수 있었다.

• Fisheries and Aquatic Sciences
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• 제19권9호
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• pp.37.1-37.5
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• 2016

Human immunodeficiency virus (HIV) is the causative agent of acquired immune deficiency syndrome (AIDS). Anti-HIV agents targeting various steps in HIV life cycle have been developed; however, so far, no effective drugs have been found. We show here that a peptide isolated from Spirulina maxima (SM-peptide) inhibits HIV-1 infection in a human T cell line MT4. SM-peptide inhibited $HIV-1_{IIIB}$-induced cell lysis with a half-maximal inhibitory concentration ($IC_{50}$) of 0.691 mM, while its 50 % cytotoxic concentration ($CC_{50}$) was greater than 1.457 mM. Furthermore, the SM-peptide inhibited the HIV-1 reverse transcriptase activity and p24 antigen production. This suggests that SM-peptide is a novel candidate peptide, which may be developed as a therapeutic agent for acquired immunodeficiency syndrome patients.

• IMMUNE NETWORK
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• 제13권4호
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• pp.157-162
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• 2013

Application of vaccine materials through oral mucosal route confers great economical advantage in animal farming industry due to much less vaccination cost compared with that of injection-based vaccination. In particular, oral administration of recombinant protein antigen against foot-and- mouth disease virus (FMDV) is an ideal strategy because it is safe from FMDV transmission during vaccine production and can induce antigen-specific immune response in mucosal compartments, where FMDV infection has been initiated, which is hardly achievable through parenteral immunization. Given that effective delivery of vaccine materials into immune inductive sites is prerequisite for effective oral mucosal vaccination, M cell-targeting strategy is crucial in successful vaccination since M cells are main gateway for luminal antigen influx into mucosal lymphoid tissue. Here, we applied previously identified M cell-targeting ligand Co1 to VP1 of FMDV in order to test the possible oral mucosal vaccination against FMDV infection. M cell-targeting ligand Co1-conjugated VP1 interacted efficiently with M cells of Peyer's patch. In addition, oral administration of ligand-conjugated VP1 enhanced the induction of VP1-specific IgG and IgA responses in systemic and mucosal compartments, respectively, in comparison with those from oral administration of VP1 alone. In addition, the enhanced VP1-specific immune response was found to be due to antigen-specific Th2-type cytokine production. Collectively, it is suggested that the M cell-targeting strategy could be applied to develop efficient oral mucosal vaccine against FMDV infection.

• 한국수의병리학회지
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• 제6권1호
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• pp.41-48
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• 2002

Oval cell is considered as facultative precursor cells for both hepatocytes and biliary cells, as well as origin of hepatocellar and cholangiocellular carcinoma (CCC) during carcinogenesis or toxic liver injury. To clarify the cellular origin or differentiation of cholagiocarcinogensis, the fate of carcinogen-induced oval cells was pathologically and phenotypically chased in Syrian golden hamster liver after Clonorchis sinensis (CS) infection which would give rise to a promoting effect. Two week treatment of hamsters with 0.005% diethylnitrosamine (DEN) followed by 2 week treatment of 1% 2-acetylaminofluorene (AAF) under choline deficient diet resulted in massive proliferation of BrdU labeleed and PCNA positive oval cells showing various distinct morphology, histochemical and immunohistochemical phenotypes for GGT, cytokeratin 19 and OV-6. Oval cells also frequently form ductular-like structures or phenotypically show hepatocyte-like characteristics. After CS infection, the oval cells showed sequential morphological changes to atypicl proliferating bile ductules and all hamsters thereafter developed well differentiated and anaplastic CCC at 16 week after CS infection. In electron microscopy, some bile ductules were constructed by intermediate oval cells and bile ductular cells surrounded by basement membrane. The results of this study strongly suggest that CCC developed in the present study were originated from hepatic stem-like oval cells, supporting the theory of stem cell origin of cancers. In addition, this hamster model would be valuable for the molecular mechanistic study during chemical-triggered cholangiocarcinogenesis.

• 대한수의학회지
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• 제34권2호
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• pp.321-326
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• 1994

돼지 유행성 설사 바이러스(KPEDV-9)주를 이용하여 세포내 증식성을 비롯한 혈청학적 역학조사를 수행하였던 바 다음의 결과를 얻었다. 돼지 유행성 설사바이러스 국내 분리주는 Vero 세포에 연속계대시 증식성이 증가되었으며 90대 계대시 $10^{5.5}TCID_{50}/ml$의 역가를 나타내었다. 조직배양 순화주를 이용하여 간염세포내에서 20Kb 이상의 RNA가 존재함을 확인할수 있었으며 전자현미경 검사시 5~10nm의 외피항원 및 80~300nm크기의 coronavirus특징을 나타내었다. 설사증상을 나타내는 돼지의 장가검재료를 이용하여 유행성 설사 바이러스의 감염실태를 조사하였던 바 18%에 상당하는 감염 양성율을 확인하였으며 ELISA법에 의한 항체검사결과 전국적으로 약 45%의 항체 양성율을 나타내었다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2008년도 International Meeting of the Microbiological Society of Korea
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• pp.62-64
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• 2008

A major hurdle to the development of RNA interference as therapy for HIV infection is the delivery of siRNA to T lymphocytes which are difficult cells to transfect even in vitro. We have employed a single chain antibody to the pan T cell surface antigen CD7 was conjugated to an oligo-9-arginine peptide (scFvCD7-9R) for T cell-specific siRNA delivery in NOD/SCIDIL2${\gamma}$-/- mice reconstituted with human peripheral blood lymphocytes (Hu-PBL). Using a novel delivery, we first show that scFvCD7-9R efficiently delivered CD4 siRNA into human T cells in vitro. In vivo administration to Hu-PBL mice resulted in reduced levels of surface CD4 expression on T cells. Mice infected with HIV-1 and treated on a weekly basis with scFvCD7-9R-siRNA complexes targeting a combination of viral genes and the host coreceptor molecule CCR5 successfully maintained CD4/CD3 T cell ratios up to 4 weeks after infection in contrast to control mice that displayed a marked reduction in CD4 T cell numbers. p24 antigen levels were undetectable in 3 of the 4 protected mice. scFvCD7-9R/antiviral siRNA treatment also helped maintain CD4 T cell numbers with reduced plasma viral loads in Hu-PBL mice reconstituted with PBMC from donors seropositive for HIV, indicating that this method can contain viral replication even in established HIV infections. Our results show that scFvCD7-9R could be further developed as a potential therapeutic for HIV-1 infection.

• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.844-850
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• 2000

The specific binding and internalization of viral particles is an essential step for the successful infection of viral pathogens. In the case of the hepatitis B virus (HBV), virions bind to the host cell via the preS domain of the viral surface antigen and are subsequently internalized by endocytosis. HBV-preS specific receptors are primarily expressed on hepatocytes, however, viral DNA and proteins have also been detected in extrahepatic sites, suggsting that celluar recepators for HBV may also exist on extrahepatic cells. Recently, an EBV-transformed B-cell line was identified onto which the preS region binds in a receptor-ligand specific manner. In this study, this specific interaction was further characterized, and the binding region within the preS protein was locaized. Also the internalization after host cell attachment was visualized and analyzed by fluorescence-labeled HBV-preS1 proteins using confocal microscopy. Energy depletion by sodium azide treatment effectively inhibited the internalization of the membrane-bound preS1 ligands, thereby indicating an energy-dependent receptor-mediated endocytotic pathway. Accordingly, the interaction of HBV-pres! with this specific B-cell line may serve as an effective model for an infection pathway in extrahepatic cells.

• 대한수학회보
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• 제48권3호
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• pp.555-574
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• 2011

It is well known that the mathematical models provide very important information for the research of human immunodeciency virus type. However, the infection rate of almost all mathematical models is linear. The linearity shows the simple interaction between the T-cells and the viral particles. In this paper, a differential equation model of HIV infection of $CD4^+$ T-cells with Crowley-Martin function response is studied. We prove that if the basic reproduction number $R_0$ < 1, the HIV infection is cleared from the T-cell population and the disease dies out; if $R_0$ > 1, the HIV infection persists in the host. We find that the chronic disease steady state is globally asymptotically stable if $R_0$ > 1. Numerical simulations are presented to illustrate the results.