• Journal of Microbiology
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• 제40권3호
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• pp.224-229
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• 2002

The effect of human cytomegalovirus (HCMV) on three human monocyte cell lines at different stages of differentiation was investigated. While the viability of HL-60 cells or U-937 cells was not significantly affected by HCMV infection, the viability of THP-1 cells was reduced. Acridine orange/ethidiurn bromide staining revealed that the reduction of THP-1 cell viability was due to increased apoptotic death following HCMV infection. Apoptosis in HL-60 cells was not affected by HCMV infection, and induction of apoptosis of U-937 cells by HCMV was intermediate between HL-60 and THP-1 cells. Since HL-60 cells are the least differentiated and THP-1 cells are the most differentiated, the induction of apoptosis of human monocytes appears to be related to the degree of cell differentiation. Flow cytometric and confocal microscopic studies using fluorescent calcium indicator Fluo-3 suggested a significant increase in intracellular free calcium concentration (［Ca$\^$2+/］i) in THP-1 cells undergoing apoptosis by HCMV infection. Again ［Ca$\^$2+/］i in HCMV-infected HL-60 cells was not critically altered, and that in HCMV-infected U-937 cells was intermediate between THP-1 cells and HL-60 cells. Calcium influx blockers such as verapamil and nifedipine partially reversed HCMV-induced apoptosis in THP-1 cells.

• 미생물학회지
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• 제37권2호
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• pp.145-150
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• 2001

Human cytomegalovirus (HCMV)의 잠복감염으로 부터의 재활성환느 면역기능이 저하된 사람에게 높은 치사율을 가져오며, 재활성화가 기전의 규명은 매우 중요한 연구과제의 하나이다. HCMV의 잠복감염 부위 중 하나라고 생각되고 있는 인체단핵세포에 대한 HCMV의 영향을 알아보기 위해 여러 분화 단계에 있는 THP-1과 HL-60 세포에 HCMV를 감염시킨 후 생존 세포의 수와 형태적 변화를 살펴보았다. HL-60 세포가 HCMV 감염에 의해 세포 생존이나 형태에 큰 영향을 받지 않는 반면, 좀 더 분화된 세포인 THP-1은 HCMV 감염에 의해 생존 세포의 수가 감소하였고, 형태적 변화도 나타났다. 이러한 형태적 변화는 세포의 응집력의 증가에 의한 것으로 HCMV 감염에 따른 THP-1 세포 표면의 CD11b 발현 증가와 밀접한 관계가 있는 것으로 생각된다. THP-1 세포에 HCMV를 감염시킨 후 잠복감염이 이루어진 것을 확인하고, 세포 분화 유도제인 TPA와 hydrocortisone을 처리하였을 경우 방러스가 재활성화하여 증식하는지 알아보았다. 바이러스 감염 2일째에 분화시킨 THP-1 세포에서는 분화 5일째부터 다량의 바이러스가 검출되었고, 감염 17일째 분화시킨 세포에서는 분화 후 15일째부터 바이러스가 검출됨을 관찰하였다. 이는 HCMV를 THP-1 세포에 감염 후 분화를 시키면 잠복감염해 있는 HCMV가 재활성화 되는 것이라 생각되고, 감복해 있던 기간이 길어질수록 바이러스의 재활성화정도는 지연된다는 것을 의미한다.

• Journal of Microbiology
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• 제35권2호
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• pp.152-157
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• 1997

Infection of human fibroblast (HF) cells with human cytomegalovirus (HCMV) result in changes in the intracellular level of second messengers. Since nitric oxide (NO) production has been known to be related with other second messengers, it is probable that HCMV infection of HF cells may involve NO. To test this possibility, the amount of NO was measured following ogenous addition of NO generators such as sodium nitroprusside (SNP) or S-nitroso-N-a-cetylpenicillamine (SNAP) immediately after HCMV infection, however, inhibited virus multiplication. Furthermore, immunoblot experiment using monoclonal antibody to HCMV major immediate early (MIE) proteins or CAT assay using pCMVIE/CAT (plasmid containing CAT gene driven by HCMV MIE promoter) revealed that SNP or SNAP blocked the MIE gene expression. SNP was more effective than SNAP in hibiting HCMV multiplication or MIE gene expression. SNP produced more NO than SNAP in inhibiting HCMV multiplication or MIE gene expression. SNP produced more NO than SNAP. Although the mechanism for the inhibition of HCMV multiplication and MIE gene expression by NO is still elusive some correlation with NO-mediated inhibition of HCMV-induced increase in cytosolic free Ca$\^$2+/ concentration ([Ca$\^$2+/]) was observed. The increase of [Ca$\^$2+/] following HCMV infection was inhibited by SNP, and less effectively by SNAP. Raising [Ca$\^$2+/ with bromo-A23187 partially reversed the SNP block of MIE gene expression. Thus, there appear to e some relationships among NO. [Ca$\^$2+/], and HCMV MIE gene expression.

• 미생물학회지
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• 제29권1호
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• pp.25-33
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• 1991

Antiviral activities of papaverine and nucleoside analogs, 9-[(1,3-dihydroxy-2-propoxy)methyl]guanine (DHPG) and acyclovir, against human cytomegalovirus (HCMV) infection were compared in vitro. Papaverine and DHPG were effective in reducing infectious HCMV yields with $ED_{50}{\s}$ (effective dose 50: the concentraion at which 50% of virus yields was obtained) of approximately 1.02 and $0.45{\mu}{\M}$, respectively; while acyclovir was less effective with an $ED_{50}$ of about $10.4{\mu}{\M}$The relative cytotoxicity of these drugs was evaluated under the same conditions used to measure infectious HCMV yields. Papaverine and DHPG demonstrated little cellular toxicity as measured by their effect on the viability of confluent cells at concentrations in the range of those demonstrating potent inhibition of HCMV replication. Similarly, protein synthesis was largely unaffected by these drugs in stationary mock-infected cells as measured by the incorporation of isotopically labelled amino acids. In contrast, cellular DNA synthesis was invariably reduced in the presence of either drug. HCMV-specific DNA synthesis was also strongly inhibited by papaverine and DHPG.

• Journal of Microbiology and Biotechnology
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• 제23권11호
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• pp.1627-1635
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• 2013

Mitochondria often play central roles in apoptotic pathways, and disruption of the mitochondrial transmembrane potential (${\Delta}{\psi}m$) has been observed in various cells undergoing apoptosis. Human cytomegalovirus (HCMV) infection induces apoptosis in permissive cells; however, investigations of mitochondria-targeted apoptosis in HCMV-infected human foreskin fibroblast (HFF) cells have been limited. Here, we investigated the mitochondrial apoptosis pathway in HCMV-infected HFF cells. Flow cytometry analysis using JC-1 revealed that HCMV infection induces disruption of ${\Delta}{\psi}m$ in HFF cells when administered 24 h post-infection (hpi), and this disruption was maximized at 48 hpi. Moreover, cytochrome c, normally a mitochondrial inner membrane protein, was detected in cytoplasmic extracts of HCMV-infected cells, but not mock-infected cells, by western blot analysis at 24 hpi. A caspase activity assay based on fluorescence spectrophotometry using a fluorogenic substrate revealed an increase in caspase-3 activity at 48 hpi in HCMV-infected cells. Caspase-8 activity was increased at 72 hpi in HCMV-infected cells. These results imply that HCMV infection induces mitochondria-mediated apoptosis in HFF cells.

• Parasites, Hosts and Diseases
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• 제30권1호
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• pp.53-58
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• 1992

환자는 54세 광부로 1991년 1월 낙반사고로 인해 가벼운 골반 골절상을 받았었고, 골절상은 완치되었으나 설사가 지속하고 체중이 심하게 감소하였다. 발병 약 9 개월만에 시행한 대변검사 및 조직 검사에서 분선충중(strongyloidiasis), 포자충중(isosporiasis) 및 인형 세포거대바이러스(heman cytomegalovirus)에 감염된 사실이 확인되었다. Albendazole로 치료하였으나 약 2개월 후 근로복지공사 장성병원에서 난치 상환 하에 퇴원하였으며, 퇴원 1주 후 사망하였다.

• Journal of Microbiology
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• 제38권4호
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• pp.255-259
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• 2000

For rapid and sensitive measurement of antiviral activities, application of a recombinant virus containing firefly luciferase gene was attempted. Recombinant human cytomegalovirus (HCMV) containing luciferase gene driven by HCMV late gene pp28 promoter (HCMV/pp28-luc) was used to test the antiviral activities of three known compounds and the result was compared with results from the conventional plaque assay for measuring the production of infectious viruses. When human fibroblast cells were infected with HCMV/pp28-luc, luciferase activity was observed at 2 days after infection and reached maximum at 6 days after infection, whereas the production of infectious virus was maximal at 4 days after infection. The antiviral activities of ganciclovir, acyclovir, and papaverine were measured in HFF cells infected with HCMV/PP28-luc and the luciferase activity was compared with the infectious virus titers. Luciferase activity decreased as the concentration of ganciclovir or papaverine increased, while there was a slight decrease in luciferase activity with acyclovir. The level of the decrease in Luciferase activity was comparable to the level of decrease in the production of infectious virus. Therefore, the antiviral assay using recombinant virus HCMV/pp28-luc resulted in sensitivity similar to the conventional plaque assay with a significant reduction in assay time.

• Biomolecules & Therapeutics
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• 제25권1호
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• pp.69-79
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• 2017

Viruses continue to evolve a new strategy to take advantage of every aspect of host cells in order to maximize their survival. Due to their central roles in transducing a variety of transmembrane signals, GPCRs seem to be a prime target for viruses to pirate for their own use. Incorporation of GPCR functionality into the genome of herpesviruses has been demonstrated to be essential for pathogenesis of many herpesviruses-induced diseases. Here, we introduce US28 of human cytomegalovirus (HCMV) as the best-studied example of virally-encoded GPCRs to manipulate host GPCR signaling. In this review, we wish to summarize a number of US28-related topics including its regulation of host signaling pathways, its constitutive internalization, its structural and functional analysis, its roles in HCMV biology and pathogenesis, its proliferative activities and role in oncogenesis, and pharmacological modulation of its biological activities. This review will aid in our understanding of how pathogenic viruses usurp the host GPCR signaling for successful viral infection. This kind of knowledge will enable us to build a better strategy to control viral infection by normalizing the virally-dysregulated host GPCR signaling.

• Archives of Pharmacal Research
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• 제22권6호
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• pp.542-548
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• 1999

The UL47 gene (b 60390-b 60388) located in the unique long region of the human cytomegalovirus (HCMV) AD169 strain genome was analyzed RNA mapping. Northern blot analysis showed that the UL47 gene was expressed at late times after infection (72 h postinfection). The 9.7-kb transcript was expressed in the infected cells but not in phosphonoformate-treated cells at 72 hpi, indicating that the UL47 gene was only expressed at late times after infection. To map the 5'-end and 3'-end of UL47 transcripts, primer at late times after infection. To map the 5'-end and 3'-end of UL47 transcripts, primer extension and RNase protection analysis were performed. Primer extension analysis revealed that the transcription initiation site of UL47 was located in 27 bp downstream (b 60323) of the TATA box motif. The sizes of UL47 ORF (approximately 2.9-kb) and UL48 ORF (approximately 6.7-kb) deduced from computer sequence analysis suggest that the expressed 9.7-kb transcript of UL47 uses the 3'-end polyadenylation signal of Ul48. The result of RNase protection determined that the 3'-end of UL47 RNA utilized the 3'-end polyadenylation signal of UL48, which is located in HCMV genome b 70082.

• Journal of Microbiology
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• 제38권1호
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• pp.24-30
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• 2000

US3 gene is a member of the human cytomegalovirus (HCMV) immediate early gene. Although the precise functions of the US3 gene in HCMV replication and pathogenesis are not known, it has been reported to play a role in inhibiting major histocompatibility class I antigen presentation. For further knowledge of US3 gene expression, rabbit polyclonal antiserum of the US3 gene product was used for indirect immunofluorescence assay. In permissive human foreskin fibroblast (HFF) cells, US3 gene expression was detectable as crescent or half-moon shape in the perinuclear region at immediate early times after virus infection. HFF cells infected with mutant HCMV lacking US3 open reading frames were negative for US3 immunofluorescence assay. Double immunofluorescence assay using monoclonal antibody to gamma adaptin (specific for the Golgi complex) and rabbit anti-US3 antiserum revealed that US3 gene product could be localized to the Golgi complex. At later time after HCMV infection, US3 gene products were detected as globular aggregates in the cytosol. These aggregates were positive for gamma adaptin and stained with preimmune serum, suggesting a nonspecific reaction to the Golgi complex. Northern blot analysis revealed that transcription of US3 was observed only during immediate early times after virus infection (until 6 h postinfection). Therefore US3 gene expression appears to be confined to immediate early time and its gene products are localized to the Golgi complex as crescent shaped forms in the perinuclear cytoplasm.