• Title/Summary/Keyword: Viral infections

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Clinical profile of Asian and African strains of Zika virus in immunocompetent mice

  • Shin, Minna;Kim, Jini;Park, Jeongho;Hahn, Tae-Wook
    • Korean Journal of Veterinary Research
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    • v.61 no.2
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    • pp.12.1-12.9
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    • 2021
  • The mosquito-borne pathogen Zika virus may result in neurological disorders such as Guillain-Barré syndrome and microcephaly. The virus is classified as a member of the Flaviviridae family and its wide spread in multiple continents is a significant threat to public health. So, there is a need to develop animal models to examine the pathogenesis of the disease and to develop vaccines. To examine the clinical profile during Zika virus infection, we infected neonatal and adult wild-type mice (C57BL/6 and Balb/c) and compared the clinical signs of African-lineage strain (MR766) and Asian-lineage strain (PRVABC59, MEX2-81) of Zika virus. Consistent with previous reports, eight-week-old female Balb/c mice infected with these viral strains showed no changes in body weight, survival rate, and neurologic signs, but demonstrated increases in the weights of spleens and hearts. However, one-day-old neonates showed significantly lower survival rate and body weight with the African-lineage strain than the Asian-lineage strain. These results confirmed the pathogenic differences between Zika virus strains. We also evaluated the clinical responses in neonatal and adult mice of different strains. Our findings suggest that these are useful mouse models for characterization of Zika virus for vaccine development.

Nonstructural Protein of Severe Fever with Thrombocytopenia Syndrome Phlebovirus Inhibits TBK1 to Evade Interferon-Mediated Response

  • Lee, Jae Kyung;Shin, Ok Sarah
    • Journal of Microbiology and Biotechnology
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    • v.31 no.2
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    • pp.226-232
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    • 2021
  • Severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging phlebovirus of the Phenuiviridae family that has been circulating in the following Asian countries: Vietnam, Myanmar, Taiwan, China, Japan, and South Korea. Despite the increasing infection rates and relatively high mortality rate, there is limited information available regarding SFTSV pathogenesis. In addition, there are currently no vaccines or effective antiviral treatments available. Previous reports have shown that SFTSV suppresses the host immune response and its nonstructural proteins (NSs) function as an antagonist of type I interferon (IFN), whose induction is an essential part of the host defense system against viral infections. Given that SFTSV NSs suppress the innate immune response by inhibiting type I IFN, we investigated the mechanism utilized by SFTSV NSs to evade IFNmediated response. Our co-immunoprecipitation data suggest the interactions between NSs and retinoic acid inducible gene-I (RIG-I) or TANK binding kinase 1 (TBK1). Furthermore, confocal analysis indicates the ability of NSs to sequester RIG-I and related downstream molecules in the cytoplasmic structures called inclusion bodies (IBs). NSs are also capable of inhibiting TBK1-interferon regulatory factor 3 (IRF3) interaction, and therefore prevent the phosphorylation and nuclear translocation of IRF3 for the induction of type I IFN. The ability of SFTSV NSs to interact with and sequester TBK1 and IRF3 in IBs demonstrate an effective yet unique method utilized by SFTSV to evade and suppress host immunity.

Clinical Benefit of Vaccinating Male Against HPV-related Disease (인유두종바이러스 관련 질환의 예방을 위한 남성 대상 백신의 임상적 유용성)

  • Lee, Sei Young
    • Korean Journal of Head & Neck Oncology
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    • v.38 no.1
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    • pp.11-16
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    • 2022
  • HHPV (Human Papillomavirus) is a DNA virus that can cause benign lesions, genitourinary cancer, and oropharyngeal cancer by penetrating the mucous membrane and skin. It is widely known to be transmitted mainly through sexual contact. As with many viral infections, vaccines have been developed to prevent infection with HPV. Currently, in many countries, HPV vaccines are mainly used for national immunization for women to prevent diseases that traditionally occur frequently in women, especially cervical cancer. However, since the vaccination rate is relatively low, many countries are struggling with ways to increase the vaccination rate. Meanwhile, the incidence of oropharyngeal cancer caused by HPV in men has been increasing recently. In the United States, the annual number of oropharyngeal cancers in men already exceeds the number of cervical cancers in women, so HPV infection in men has emerged as a major problem. Accordingly, interest in HPV vaccination in men has also increased, and studies on the effectiveness and necessity of vaccination of both women and men compared to women alone are being actively conducted. In this paper, the evidence of HPV vaccination for men will be reviewed through previous studies, and its validity and cost-effectiveness will be analyzed to bolster the clinical usefulness of HPV vaccination for men.

Placental Histopathology in COVID-19-Positive Mothers

  • Sherwani, Nikita;Singh, Neha;Neral, Arvind;Jaiswal, Jyoti;Nagaria, Tripti;Khandwal, Onkar
    • Journal of Microbiology and Biotechnology
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    • v.32 no.9
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    • pp.1098-1102
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    • 2022
  • The placenta is a captivating multifunctional organ of fetal origin and plays an essential role during pregnancy by intimately connecting mother and baby. This study explicates placental pathology and information about 25 placentas collected from the mothers infected with novel coronavirus (SARS-COV-2). So far, congenital transmission of SARS-CoV-2 seems to be remarkably uncommon in spite of many cases of COVID-19 during pregnancy. Out of the 25 placental tissue samples collected, none has shown gene expression of SARS-CoV-2 when confirmed by RT-PCR. At the same time, nasal and throat swab samples collected from newborns of SARS-CoV-2-positive mothers correspondingly tested negative by RT-PCR. The shielding properties of placental barriers against viral infections from mothers to newborns remains a mystery. Major histopathological findings have been recorded as choriodecidual tissue with necrosis, intramural fibrin deposition, chorionic villi with fibrosis, and calcification. Moreover, although recent findings are insufficient to prove direct placental transmission of COVID-19, the abundance of angiotensin-converting enzymes-2 (ACE-2) on the placental surface could potentially contribute to unpleasant outcomes during pregnancy as SARS-CoV-2 gains access to human cells via ACE-2. Finally, the significance of these findings is vague and needs further study.

A study on the design and implementation of a virus spread prevention system using digital technology (디지털 기술을 활용한 바이러스 확산 방지 시스템 설계 및 구현에 관한 연구)

  • Ji-Hyun, Yoo
    • Journal of IKEEE
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    • v.26 no.4
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    • pp.681-685
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    • 2022
  • Including the COVID-19 crisis, humanity is constantly exposed to viral infections, and efforts are being made to prevent the spread of infection by quickly isolating infected people and tracing contacts. Passive epidemiological investigations that confirm contact with an infected person through contact have limitations in terms of accuracy and speed, so automatic tracking methods using various digital technologies are being proposed. This paper verify contact by utilizing Bluetooth Low Energy (BLE) technology and present an algorithm that identifies close contact through analysis and correction of RSSI (Received Signal Strength Indicator) values. Also, propose a system that can prevent the spread of viruses in a centralized server structure.

Characterization of a Peptide Antibody Specific to the Adenylyl Cyclase-Associated Protein of Acanthamoeba castellanii

  • Kim, Min-Jeong;Lee, Hae-Ahm;Quan, Fu-Shi;Kong, Hyun-Hee;Moon, Eun-Kyung
    • Parasites, Hosts and Diseases
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    • v.60 no.1
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    • pp.7-14
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    • 2022
  • Acanthamoeba keratitis (AK) is a rare infectious disease and accurate diagnosis has remained arduous as clinical manifestations of AK were similar to keratitis of viral, bacterial, or fungal origins. In this study, we described the production of a polyclonal peptide antibody against the adenylyl cyclase-associated protein (ACAP) of A. castellanii, and evaluated its differential diagnostic potential. Enzyme-linked immunosorbent assay revealed high titers of A. castellanii-specific IgG and IgA antibodies being present in low dilutions of immunized rabbit serum. Western blot analysis revealed that the ACAP antibody specifically interacted with A. castellanii, while not interacting with human corneal epithelial (HCE) cells and other causes of keratitis such as Fusarium solani, Pseudomonas aeruginosa, and Staphylococcus aureus. Immunocytochemistry (ICC) results confirmed the specific detection of trophozoites and cysts of A. castellanii co-cultured with HCE cells. The ACAP antibody also specifically interacted with the trophozoites and cysts of 5 other Acanthamoeba species. These results indicate that the ACAP antibody of A. castellanii can specifically detect multiple AK-causing members belonging to the genus Acanthamoeba and may be useful for differentially diagnosing Acanthamoeba infections.

Antiviral effects of Korean Red Ginseng on human coronavirus OC43

  • Chi Hwan Jeong;Jisu Kim;Bo Kyeong Kim;Kang Bin Dan;Hyeyoung Min
    • Journal of Ginseng Research
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    • v.47 no.2
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    • pp.329-336
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    • 2023
  • Background: Panax ginseng Meyer is a medicinal plant well-known for its antiviral activities against various viruses, but its antiviral effect on coronavirus has not yet been studied thoroughly. The antiviral activity of Korean Red Ginseng (KRG) and ten ginsenosides against Human coronavirus OC43 (HCoV-OC43) was investigated in vitro. Methods: The antiviral response and mechanism of action of KRG extract and ginsenoside Rc, Re, Rf, Rg1, Rg2-20 (R) and -20 (S), Rg3-20 (R) and -20 (S), and Rh2-20 (R) and -20 (S), against the human coronavirus strain OC43 were investigated by using plaque assay, time of addition assay, real-time PCR, and FACS analysis. Results: Virus plaque formation was reduced in KRG extract-treated and HCoV-OC43-infected HCT-8 cells. KRG extract decreased the viral proteins (Nucleocapsid protein and Spike protein) and mRNA (N and M gene) expression, while increased the expression of interferon genes. Conclusion: KRG extract exhibits antiviral activity by enhancing the expression of interferons and can be used in treating infections caused by HCoV-OC43.

In silico investigation of Panax ginseng lead compounds against COVID-19 associated platelet activation and thromboembolism

  • Yixian Quah;Yuan Yee Lee;Seung-Jin Lee;Sung Dae Kim;Man Hee Rhee;Seung-Chun Park
    • Journal of Ginseng Research
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    • v.47 no.2
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    • pp.283-290
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    • 2023
  • Hypercoagulability is frequently observed in patients with severe coronavirus disease-2019 (COVID-19). Platelets are a favorable target for effectively treating hypercoagulability in COVID-19 patients as platelet hyperactivity has also been observed. It is difficult to develop a treatment for COVID-19 that will be effective against all variants and the use of antivirals may not be fully effective against COVID-19 as activated platelets have been detected in patients with COVID-19. Therefore, patients with less severe side effects often turn toward natural remedies. Numerous phytochemicals are being investigated for their potential to treat a variety of illnesses, including cancer and bacterial and viral infections. Natural products have been used to alleviate COVID-19 symptoms. Panax ginseng has potential for managing cardiovascular diseases and could be a treatment for COVID-19 by targeting the coagulation cascade and platelet activation. Using molecular docking, we analyzed the interactions of bioactive chemicals in P. ginseng with important proteins and receptors involved in platelet activation. Furthermore, the SwissADME online tool was used to calculate the pharmacokinetics and drug-likeness properties of the lead compounds of P. ginseng. Dianthramine, deoxyharrtingtonine, and suchilactone were determined to have favorable pharmacokinetic profiles.

Current Status of Epidemiology, Diagnosis, Therapeutics, and Vaccines for the Re-Emerging Human Monkeypox Virus

  • Wooseong Lee;Yu-Jin Kim;Su Jin Lee;Dae-Gyun Ahn;Seong-Jun Kim
    • Journal of Microbiology and Biotechnology
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    • v.33 no.8
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    • pp.981-991
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    • 2023
  • Monkeypox (Mpox) virus, a member of the Poxviridae family, causes a severe illness similar to smallpox, which is characterized by symptoms such as high fever, rash, and pustules. Human-to-human transmission cases have been reported but remained low since the first recorded case of human infection occurred in the Congo in 1970. Recently, Mpox has re-emerged, leading to an alarming surge in infections worldwide since 2022, originating in the United Kingdom. Consequently, the World Health Organization (WHO) officially declared the '2022-23 Mpox outbreak'. Currently, no specific therapy or vaccine is available for Mpox. Therefore, patients infected with Mpox are treated using conventional therapies developed for smallpox. However, the vaccines developed for smallpox have demonstrated only partial efficacy against Mpox, allowing viral transmission among humans. In this review, we discuss the current epidemiology of the ongoing Mpox outbreak and provide an update on the progress made in diagnosis, treatment, and development of vaccines for Mpox.

The Role of Plasmacytoid Dendritic Cells in Gut Health

  • Hye-Yeon Won;Ju-Young Lee;Dahye Ryu;Hyung-Taek Kim;Sun-Young Chang
    • IMMUNE NETWORK
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    • v.19 no.1
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    • pp.6.1-6.14
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    • 2019
  • Plasmacytoid dendritic cells (pDCs) are a unique subset of cells with different functional characteristics compared to classical dendritic cells. The pDCs are critical for the production of type I IFN in response to microbial and self-nucleic acids. They have an important role for host defense against viral pathogen infections. In addition, pDCs have been well studied as a critical player for breaking tolerance to self-nucleic acids that induce autoimmune disorders such as systemic lupus erythematosus. However, pDCs have an immunoregulatory role in inducing the immune tolerance by generating Tregs and various regulatory mechanisms in mucosal tissues. Here, we summarize the recent studies of pDCs that focused on the functional characteristics of gut pDCs, including interactions with other immune cells in the gut. Furthermore, the dynamic role of gut pDCs will be investigated with respect to disease status including gut infection, inflammatory bowel disease, and cancers.