• 한국군사과학기술학회지
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• 제27권1호
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• pp.107-115
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• 2024

Various vaccines were rapidly developed during the COVID-19 pandemic to prevent and treat infections but global infections continue, and concerns about new mutations and infectious diseases persist. Thus, active research focuses on developing, producing, and supplying vaccines and treatments for various infectious diseases and potential pandemics. Natural killer(NK) cells, as innate immune cells, can recognize and eliminate abnormal cells like virus-infected and cancer cells. Hence, their development as anticancer and antiviral treatments is rapidly advancing. In this study, optimal short-term culture conditions were identified for allogeneic NK cells by simplifying the culture process through the isolation of NK cells(referred to as NKi cells) and eliminating CD3+ cells(referred to as CD3- cells). NK cells demonstrated reduced viral titer in injection of NK cells into SARS-CoV-2 infected ACE-tg mice increased survival. The study's findings could form the basis for an antiviral treatment platform that swiftly responds to new viral disease pandemics.

• 농업과학연구
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• 제35권2호
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• pp.177-182
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• 2008

Type I Interferons (IFNs) are potent antiviral cytokines that modulate both innate immunity and adaptive immunity. Type I IFNs are immediately induced by viral infection, and stimulate production of a broad range of gene products such as double-stranded RNA-activated protein kinase (PKR), 2' 5'-oligoadenylate synthetase (OAS)/RNaseL and Mx GTPases. These proteins inhibit viral replication in host cells. Type I IFNs, in turn, lead to antiviral state at early phase of viral infection. We provide an overview of the knowledge of IFN-inducible antiviral proteins conserved in vertebrates.

• Journal of Microbiology and Biotechnology
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• 제29권8호
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• pp.1184-1192
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• 2019

The influenza A virus is a highly infectious respiratory pathogen that sickens many people with respiratory disease annually. To prevent outbreaks of this viral infection, an understanding of the characteristics of virus-host interaction and development of an anti-viral agent is urgently needed. The influenza A virus can infect mammalian species including humans, pigs, horses and seals. Furthermore, this virus can switch hosts and form a novel lineage. This so-called zoonotic infection provides an opportunity for virus adaptation to the new host and leads to pandemics. Most influenza A viruses express proteins that antagonize the antiviral defense of the host cell. The non-structural protein 1 (NS1) of the influenza A virus is the most important viral regulatory factor controlling cellular processes to modulate host cell gene expression and double-stranded RNA (dsRNA)-mediated antiviral response. This review focuses on the influenza A virus NS1 protein and outlines current issues including the life cycle of the influenza A virus, structural characterization of the influenza A virus NS1, interaction between NS1 and host immune response factor, and design of inhibitors resistant to the influenza A virus.

• Food Science and Biotechnology
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• 제17권5호
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• pp.1074-1078
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• 2008

To investigate the antiviral activity of marine algae against fish pathogenic viruses, which are often the causes of viral disease in aquaculture, the 80% methanolic extracts of 21 species collected from the coast of Korea were screened for their in vitro antiviral activities on infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV), using a flounder spleen (FSP) cell-line. Among them, Monostroma nitidum (10 ${\mu}g/mL$) exhibited the strongest inactivation on IHNV, showing a 2 log reduced virus titre as compared to the control in the determination of direct virucidal activity. In addition, Polysiphonia morrowii (100 ${\mu}g/mL$) remarkably reduced the virus titres of treated cells by 2-2.5 log, for both IHNV and IPNV, in the determination of cellular protective activity, implying the existence of substances that may modulate innate host defense mechanisms against viral infections. These results reveal that some marine algae could be promising candidates as sources of antiviral agents or as health-promoting feeds for aquaculture.

• 셀메드
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• 제6권4호
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• pp.22.1-22.19
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• 2016

The biologically active compounds derived from different natural organisms such as animals, plants, and microorganisms like algae, fungi, bacteria and merine organisms. These natural compounds possess diverse biological activities like anthelmintic, antibacterial, antifungal, antimalarial, antiprotozoal, antituberculosis, and antiviral activities. These biological active compounds were acted by variety of molecular targets and thus may potentially contribute to several pharmacological classes. The synthesis of natural products and their analogues provides effect of structural modifications on the parent compounds which may be useful in the discovery of potential new drug molecules with different biological activities. Natural organisms have developed complex chemical defense systems by repelling or killing predators, such as insects, microorganisms, animals etc. These defense systems have the ability to produce large numbers of diverse compounds which can be used as new drugs. Thus, research on natural products for novel therapeutic agents with broad spectrum activities and will continue to provide important new drug molecules.

• Archives of Pharmacal Research
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• 제17권2호
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• pp.93-99
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• 1994

Macrtophages play an important role in defense against virus infection by intrinsic resistance and by extrinsic resistance. Since interferon-induced enzymes which are 2'-5' oligoadenylate synthetase and p1/eIF-2 protein kinase have been shown to be involved in the inhibition of viral replication, I examined the mechanism by which poly I:C, an interferon inducer, exerts its antiviral effects in inflammatory macrophages infected with herpes simplex virus type 1 (HSV-1). The data presented here demonstrate that poly I:C-induced antiviral activity is partially due to the activation of 2'-5' pligoadenylate synthetase. The activation of 2'-5' oligoadenlate A synthetase by poly I:C is also at least mediated via the production of interferon-.betha.. Taken together, these data indicate that interferon-.betha. produced in response to poly I:C acts in an autocrine manner to activate the 2'-5' oligoadenylate synthetase and to induce resistance to HSV-1.

• 한국군사과학기술학회지
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• 제24권3호
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• pp.348-355
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• 2021

Hantaan virus(HTNV) causes hemorrhagic fever with renal syndrome(HFRS) with a case fatality rate ranging from <1 to 15 % in human. Hantavax^Ⓡ is a vaccine against the Hantavirus, which has been conditionally approved by the Ministry of Food and Drug Safety(MFDS). However, only 50 % of volunteers had neutralizing antibodies 1 year following the boost. Effective antiviral treatments against HTNV infection are limited. Hantaviruses generally cause asymptomatic infection in adult mice. On the other hand, infection of suckling and newborn mice with hantaviruses causes lethal neurological diesease or persistant infection, which is different from the disease in humans. The development of vaccines and antiviral strategies for HTNV has been partly hampered by the lack of an efficient lethal mouse model to evaluate the efficacy of the candidate vaccines or antivirals. In this report, we established a lethal mouse model for HTNV, which may facilitate in vivo studies on the evaluation of candidate drugs against HTNV. The median lethal dose value of HTNV was calculated by probit analysis of deaths occurring within two weeks. Five groups of ten ICR mice were injected intracranially with serial 2-fold dilutions (from 50 to 3.125 PFU/head) of HTNV. Mice injected with HTNV began to die at 8 days post-infection. The lethal dose required to kill 50 % of the mice (LD₅₀) was calculated to be 2.365 PFU/head.

• 한국어병학회지
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• 제17권2호
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• pp.75-82
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• 2004

인터페론은 바이러스에 감염된 세포에서 생성되어 다른 세포로 하여금 바이러스의 증식을 억제하는 단백질을 합성하게 하는 사이토카인의 일종으로서 바이러스에 대한 방어작용에서 중요한 역할을 담당한다. 본 연구 결과 강력한 인터페론 유도물질로 알려져 있는 poly inosinic : cytidylic acid (poly I:C)를 잉어에 주사한 결과 SVCV에 대한 항바이러스 활성을 확인할 수 있었다. 즉, Poly I:C 주사구에서 대조구에 비해 누적폐사율이 감소하였으며, 또한 두신백혈구를 분리하여, poly I:C를 처리한 결과 interferon-like cytokine (ILC)이 생성되었다. Crude ILC의 항바이러스 활성을 cytopathic effect reduction (CPER) assay로 조사한 결과, 적정 HKLs 농도는 1×$10^6$cells/ml으로 나타났으며, 20~50$\mu{g}$/ml 농도의 poly I:C를 처리했을 때 유의적으로 증가하였다. ILC 생성을 위한 적정온도 및 FBS의 농도는 각각 20$20^\circ{C}$와 5%로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제27권10호
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• pp.1727-1735
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• 2017

Hepatitis E virus (HEV) infections cause epidemic or sporadic acute hepatitis, which are mostly self-limiting. However, viral infection in immunocompromised patients and pregnant women may result in serious consequences, such as chronic hepatitis and liver damage, mortality of the latter of which reaches up to 20-30%. Type I interferon (IFN)-induced antiviral immunity is known to be the first-line defense against virus infection. Upon HEV infection in the cell, the virus genome is recognized by pathogen recognition receptors, leading to rapid activation of intracellular signaling cascades. Expression of type I IFN triggers induction of a barrage of IFN-stimulated genes, helping the cells cope with viral infection. Interestingly, some of the HEV-encoded genes seem to be involved in disrupting signaling cascades for antiviral immune responses, and thus crippling cytokine/chemokine production. Antagonistic mechanisms of type I IFN responses by HEV have only recently begun to emerge, and in this review, we summarize known HEV evasion strategies and compare them with those of other hepatitis viruses.

• IMMUNE NETWORK
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• 제16권5호
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• pp.261-270
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• 2016

The human immune system has evolved to fight against foreign pathogens. It plays a central role in the body's defense mechanism. However, the immune memory geared to fight off a previously recognized pathogen, tends to remember an original form of the pathogen when a variant form subsequently invades. This has been termed 'original antigenic sin'. This adverse immunological effect can alter vaccine effectiveness and sometimes cause enhanced pathogenicity or additional inflammatory responses, according to the type of pathogen and the circumstances of infection. Here we aim to give a simplified conceptual understanding of virus infection and original antigenic sin by comparing and contrasting the two examples of recurring infections such as influenza and dengue viruses in humans.