• Archives of Pharmacal Research
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• v.17 no.2
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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.

• Journal of fish pathology
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• v.31 no.2
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• pp.109-113
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• 2018

The purpose of the present study was to determine whether the scuticocidal activity of olive flounder (Paralichthys olivaceus) head-kidney leucocytes can be enhanced by stimulation with polyinosine-polycytosine [poly (I:C)]. The growth of Miamiensis avidus was not affected by exposure to unstimulated or poly (I:C)-stimulated leucocytes alone, heat-inactivated immune serum alone, or unstimulated leucocytes plus heat-inactivated immune serum. However, leucocytes stimulated with poly (I:C) showed clearly high scuticocidal activity against M. avidus in the presence of heat-inactivated immune serum. Furthermore, numerous poly (I:C)-stimulated leucocytes occupied the surface of scuticociliates in the presence of the heat-inactivated immune serum, which led to lysis of scuticociliates. These results suggest that both of the stimulation of leukocytes and the immobilization of scuticociliates are necessary to kill scuticociliates by leukocytes.

• Journal of fish pathology
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• v.17 no.2
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• pp.75-82
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• 2004

Interferons are kinds of cytokines that play an important role in antiviral defense mechanisms during viral infection by converting cells to synthesize proteins that inhibit viral replication. In the present study, an antiviral response against Spring viremia of carp virus (SVCV) was developed in common carp, Cyprinus carpio following stimulation with the potent interferon inducer, poly inosinic : cytidylic acid (poly I:C). Poly I:C injected fish showed lower cumulative mortalities against SVCV than untreated fish did. Moreover, in vitro study showed that head kidney leucocytes (HKLs) produced an interferon-like cytokine (ILC) after stimulation with poly I:C. According cytopathic effect reduction (CPER) assay to examine antiviral activity of crude ILC, the capacity of HKLs for ILC production was highest at 1×$10^6$cells/ml and significantly enhanced when treated with 20~50$\mu{g}$/ml of poly I:C. The optimal temperature and concentration of FBS to induce the highest ILC production were $20^\circ{C}$ and 5%, respectively.

• Journal of Animal Science and Technology
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• v.62 no.3
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• pp.385-395
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• 2020

Polyinosinic:polycytidylic acid (poly[I:C]) can stimulate Toll-like receptor 3 (TLR3) signaling pathways. In this study, DF-1 cells were treated with poly(I:C) at various concentrations and time points to examine the comparative expression patterns of innate immune response genes. The viability of DF-1 cells decreased from 77.41% to 38.68% when cells were treated different dose of poly(I:C) from 0.1 ㎍/mL to 100 ㎍/mL for 24 h respectively. The expressions of TLR3, TLR4, TLR7, TLR15, TLR21, IL1B, and IL10 were increased in dose- and time-dependent manners by poly(I:C) treatment. On the contrary, the expression patterns of interferon regulatory factors 7 (IRF7), Jun proto-oncogene, AP-1 transcription factor subunit (JUN), Nuclear Factor Kappa B Subunit 1 (NF-κB1), and IL8L2 were varied; IRF7 and IL8L2 were increasingly expressed whereas the expressions of JUN and NF-κB1 were decreased in a dose-dependent manner after they were early induced. In time-dependent analysis, IRF7 expression was significantly upregulated from 3 h to 24 h, whereas JUN and NF-κB1 expressions settled down from 6 h to 24 h after poly(I:C) treatment although they were induced at early time from 1 h to 3 h. Poly(I:C) treatment rapidly increased the expression of IL8L2 from 3 h to 6 h with a plateau at 6 h and then the expression of IL8L2 was dramatically decreased until 24 h after poly(I:C) treatment although the expression level was still higher than the non-treated control. These results may provide the basis for understanding host response to viral infection and its mimicry system in chickens.

• Journal of fish pathology
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• v.20 no.2
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• pp.189-200
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• 2007

To investigate the innate immune response involved in early stage of anti-viral defence, carps were injected with UV-inactivated spring viraemia of carp virus (SVCV), poly inosinic:cytidylic acid (Poly I:C) and concanavalin A (Con A), respectively and examined lysozyme activity, serum complement activity and chemiluminescent (CL) response of leucocytes isolated from head kidney at 3 days post-injection. There was no significant difference in plasma lysozyme activities among all experimental groups. However, lysozyme activities of head kidney in the groups injected with antiviral activity inducers were significantly higher than those of the control injected with physiological saline. Bactericidal activities of serum of the groups injected with antiviral activity inducers were not significantly different from control group. However, the CL responses were significantly higher at lower dose of Poly I:C and Con A, whilst dose-dependent increase was shown in UV-inactivated SVCV-injected group. In the challenge test with 1×104 TCID50/fish of SVCV at 4 days post-injection, UV-inactivated SVCV- and Poly I:C-injected groups showed higher relative percent survival (RPS) than Con A-injected group. Furthermore, strong protection was observed in the group injected higher dose of Poly I:C although showed lower activities in lysozyme and CL response. These results suggested that Poly I:C might stimulate other factors belonging to non-specific immune system have induced protective immunity against the SVCV challenged.

• Journal of Plant Biology
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• v.35 no.4
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• pp.415-423
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• 1992

Chlamydomonas reinhardtii 21 gr(mt+) strain의 배우체로부터 두 종류의 DNA methylase를 부분 분리하여 몇가지 기질 DNA에 대한 효소 활성을 측정하였다. DNA methylase I과 II는 동일한 pH와 ionic strength에서 서로 상이한 물리적인 성질과 서로 다른 분자량을 가지며 DNA methylase I과 II는 모두가 DNA 염기 중 adenine보다는 cytosine에 methylation을 수행하는 것으로 생각된다. 합성 DNA를 사용한 실험에서 DNA methylase I과는 달리 DNA methylase II는 poly(dA-dC)·poly(dG-dT)에서 보다 poly(dG-dC)·poly(dG-dC)의 oligonucleotide에서 더 높은 효소활성을 나타내었다. Chlamydomonas reinhardtii에서 추출한 엽록체 DNA를 기질로 사용하였을 때 DNA methylase I과 II 모두가 배우체기 보다는 영양생장기의 엽록체 DNA에 더 높은 활성을 나타내었다.

• BMB Reports
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• v.50 no.1
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• pp.25-30
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• 2017

In the central nervous system, viral infection can induce inflammation by up-regulating pro-inflammatory mediators that contribute to enhanced infiltration of immune cells into the central nervous areas. Celastrol is known to exert various regulatory functions, including anti-microbial activities. In this study, we investigated the regulatory effects and the mechanisms of action of celastrol against astrocytes activated with polyinosinic-polycytidylic acid (poly(I:C)), a synthetic dsRNA, as a model of pro-inflammatory mediated responses. Celastrol significantly inhibited poly(I:C)-induced expression of adhesion molecules, such as ICAM-1/VCAM-1, and chemokines, such as CCL2, CXCL8, and CXCL10, in CRT-MG human astroglioma cells. In addition, celastrol significantly suppressed poly(I:C)-induced activation of JNK MAPK and STAT1 signaling pathways. Furthermore, celastrol significantly suppressed poly(I:C)-induced activation of the $NF-{\kappa}B$ signaling pathway. These results suggest that celastrol may exert its regulatory activity by inhibiting poly(I:C)-induced expression of pro-inflammatory mediators by suppressing activation of JNK MAPK-STAT1/$NF-{\kappa}B$ in astrocytes.

• Biomolecules & Therapeutics
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• v.25 no.6
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• pp.641-647
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• 2017

Galangin (3,5,7-trihydroxyflavone) is a polyphenolic compound abundant in honey and medicinal herbs, such as Alpinia officinarum. In this study, we investigated the anti-inflammatory effects of galangin under in vitro and in vivo neuroinflammatory conditions caused by polyinosinic-polycytidylic acid (poly(I:C)), a viral mimic dsRNA analog. Galangin suppressed the production of nitric oxide, reactive oxygen species, and pro-inflammatory cytokines in poly(I:C)-stimulated BV2 microglia. On the other hand, galangin enhanced anti-inflammatory interleukin (IL)-10 production. Galangin also suppressed the expression of pro-inflammatory markers in poly(I:C)-injected mouse brains. Further mechanistic studies showed that galangin inhibited poly(I:C)-induced nuclear factor (NF)-${\kappa}B$ activity and phosphorylation of Akt without affecting MAP kinases. Interestingly, galangin increased the expression and transcriptional activity of peroxisome proliferator-activated receptor (PPAR)-${\gamma}$, known to play an anti-inflammatory role. To investigate whether PPAR-${\gamma}$ is involved in the anti-inflammatory function of galangin, BV2 cells were pre-treated with PPAR-${\gamma}$ antagonist before treatment of galangin. We found that PPAR-${\gamma}$ antagonist significantly blocked galangin-mediated upregulation of IL-10 and attenuated the inhibition of tumor necrosis factor (TNF)-${\alpha}$ and IL-6 in poly(I:C)-stimulated microglia. In conclusion, our data suggest that PI3K/Akt, NF-${\kappa}B$, and PPAR-${\gamma}$ play a pivotal role in mediating the anti-inflammatory effects of galangin in poly(I:C)-stimulated microglia.

• The Korea Journal of Herbology
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• v.36 no.5
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• pp.117-123
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• 2021

Objectives : The aim of this study is to investigate the effect of wogonin on the production of hydrogen peroxide in polyinosinic:polycytidylic acid (poly I:C)-stimulated TM4 mouse sertoli cells. Methods : TM4 were treated with poly I:C (50 ug/mL) and wogonin at concentrations of 5, 10, 25, and 50 µM for 30 min, 2 hr, 12 hr, 18 hr, and 24 hr. The production of intracellular hydrogen peroxide was measured by dihydrorhodamine 123 assay. Results : For 30 min, 2 hr, 12 hr, 18 hr, and 24 hr treatment, wogonin significantly inhibited intracellular hydrogen peroxide productions of TM4 at the concentration of 5, 10, 25, and 50 µM (p<0.05). In details, production of hydrogen peroxide in poly I:C-stimulated TM4 treated for 30 min with wogonin at concentrations of 5, 10, 25, and 50 µM was 95.67%, 92.69%, 92.05%, and 91.97% of the control group treated with poly I:C only, respectively; the production of hydrogen peroxide for 2 hr was 94.44%, 94.41%, 93%, and 92.98%, respectively; production of hydrogen peroxide for 12 hr was 96.78%, 95.32%, 94.33%, and 93.17%, respectively; production of hydrogen peroxide for 18 hr was 94.7%, 93.4%, 93.38%, and 93.35%, respectively; and production of hydrogen peroxide for 24 hr was 95.75%, 94.77%, 94.58%, and 92.8%, respectively. Conclusions : Wogonin might have anti-viral property related with its inhibition of intracellular hydrogen peroxide production in poly I:C-stimulated TM4 cells.

• The Korea Journal of Herbology
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• v.36 no.1
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• pp.97-102
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• 2021

Objectives : Virus infection through the respiratory tract causes various inflammatory diseases such as pneumonia, cystic fibrosis, and obstructive pulmonary disease, causing enormous social damage. Therefore, it is very important to develop a treatment and prevention of infectious diseases. In this study, we investigated the effect of water extracts of Liriope muscari (WELM), known to improve lung function, on the inflammatory response of lung carcinoma cell line A549 cells induced by the viral double stranded RNA mimetic Polyinosinic:polycytidylic acid (Poly I:C). Methods : The cell viability by WELM treatment was analyzed using MTS assay in A549 cells. After inducing an inflammatory response to WELM-treated A549 cells with Poly I:C, the degree of apoptosis was confirmed through bright field microscopy. Interferon beta (IFN-β) mRNA expression level in A549 cells was analyzed by quantitative reverse transcription PCR (qRT-PCR). Results : WELM treatment has no significant effect on cell viability of A549 cells. We confirmed that pre-treatment of WELM effectively reduces the Poly I:C-induced apoptotic cell death in A549 cells. In addition, it was confirmed that the mRNA expression level of IFN-β, a pro-inflammatory cytokine increased by Poly I:C treatment, was significantly suppressed by WELM treatment in A549 cells. Conclusions : These results provide the evidence that WELM is effective at inhibiting inflammation on respiratory viral infections and suggest that Liriope muscari might be a valuable natural substance in the prevention and treatment of infectious diseases.