• Journal of Microbiology and Biotechnology
• /
• v.28 no.6
• /
• pp.849-859
• /
• 2018

Herpes simplex virus type 2 (HSV-2) infection has been a public health concern worldwide. It is the leading cause of genital herpes and a contributing factor to cervical cancer and human immunodeficiency virus (HIV) infection. No vaccine is available yet for the treatment of HSV-2 infection, and routinely used synthetic nucleoside analogs have led to the emergence of drug resistance. The small molecule $Retro-2^{cycl}$ has been reported to be active against several pathogens by acting on intracellular vesicle transport, which also participates in the HSV-2 lifecycle. Here, we showed that Retro-2.1, which is an optimized, more potent derivative of $Retro-2^{cycl}$, could inhibit HSV-2 infection, with 50% inhibitory concentrations of $5.58{\mu}M$ and $6.35{\mu}M$ in cytopathic effect inhibition and plaque reduction assays, respectively. The cytotoxicity of Retro-2.1 was relatively low, with a 50% cytotoxicity concentration of $116.5{\mu}M$. We also preliminarily identified that Retro-2.1 exerted the antiviral effect against HSV-2 by a dual mechanism of action on virus entry and late stages of infection. Therefore, our study for the first time demonstrated Retro-2.1 as an effective antiviral agent against HSV-2 in vitro with targets distinct from those of nucleoside analogs.

• Journal of Life Science
• /
• v.30 no.3
• /
• pp.221-229
• /
• 2020

Distylium racemosum is an evergreen tree growing wild on Jeju Island, which has been reported to exert biological activity. Obesity is induced by genetic, metabolic, environmental, and other factors. Among these, certain bacterial and viral infections have been shown to cause obesity, which is known as infectobesity. Human adenovirus (HAdV)-36 is one of the viruses that are known to cause infectobesity in humans. Unlike extensive research on preventing obesity and developing anti-obesity drugs, little research has been conducted specifically on the prevention and treatment of infectobesity. Therefore, this study aimed to evaluate the effects of phytochemicals from D. racemosum on the replication of HAdV-36. A549 cells infected with HAdV-36 were treated with an ethyl acetate fraction of a D. racemosum leaf extract (DRE), and the virus titer was calculated based on the hemagglutination (HA) titer. The results showed a concentration-dependent inhibitory effect of DRE treatment on HA titers. DRE treatment was also found to inhibit the cytopathic effects of the virus and the expression of viral genes. Quercitrin was identified as the constituent of DRE exerting an inhibitory effect on HAdV-36 replication. This study shows that DRE can be used as a candidate substance for the development of treatment for HAdV-36 infections. In addition, this study provides a basis to further investigate DRE for the development of anti-infectobesity medication.

• Journal of Korean Medicine Rehabilitation
• /
• v.24 no.3
• /
• pp.11-27
• /
• 2014

Objectives This study was designed to evaluate the effects of Ephedra Sinica and Fibrosum Gypsum extract on obesity by using 3T3-L1 cells and high fat diet rats. Methods In vitro, Ephedra Sinica and Fibrosum Gypsum extract (50, 100, 200, $500{\mu}g/ml$) were added in 3T3-L1 cells. Cytotoxicity was measured by MTT assasy. Adipocyte differentiation was measured by Oil Red O staining, GPDH activity and $C/EBP{\alpha}$ protein expression. In vivo, Sprague-Dawley rats were divided into 5 groups : Normal diet group (Normal group), taken high fat diet and no treatment group (Control group), taken high fat diet and orally administered Ephedra Sinica and Fibrosum Gypsum extract daily (Group I: 50 mg/kg, Group II: 100 mg/kg, Group III : 200 mg/kg, oral). For 6 weeks of administration, body weight and the amount of food intake were measured once a week. After administration, blood analysis (AST, ALT, T-Bilirubin, BUN, RBC, Hb, HCT), serum lipid level (triglyceride, Total cholesterol, HDL, LDL), serum leptin level, epididymal adipose tissue weight and histological finding of liver were estimated. Results In vitro, The cytotoxicity was not significant. 3T3-L1 cell's differentiation was significantly decreased in Oil Red O staining, GPDH activity and $C/EBP{\alpha}$ protein expression. In vivo, Body weight and the amount of food intake, AST, ALT, Total cholesterol, TG, LDL, serum leptin, epididymal adipose tissue weight showed significant decrease in group I, group II and group III. There were no significant difference in T-bilirubin, BUN, RBC, Hb and HCT between all groups. HDL showed significant increase in group I, group II and group III. In histological finding of liver tissue, there were decreased adiposity and cytopathic effect in group I, group II and group III. Conclusions It is suggested that Ephedra Sinica and Fibrosum Gypsum extract can be used in the treatment of obesity.

• Microbiology and Biotechnology Letters
• /
• v.27 no.5
• /
• pp.419-425
• /
• 1999

Prophylactic effects of Bifidobacterium longum HY8001, Korean isolate, against Escherichia coli O157:H7 and Salmonella typhimurium DT104 enteric infection were examined at four groups of specific pathogen free(SPF)-ICR mouse for each pathogen. B. longum HY8001+B. typhimurium DT104+B. longum HY8001(BL+ST+BL) group and B. longum HY8001+E. coli O157:H7+B. longum HY8001(BL+E+BL) group were fed with B. longum HY8001 before and after E. coli O157:H7 or s. typhimurium DT104 challenge, while B. longum HY8001+S. typhimurium DT104(BL+ST) and B. longum HY8001+e. coli O157:H7(BL+E) groups were fed with B. longum HY8001 only before E. coli O157:H7 or S. typhimurium DT104 challenge. E. coli O157:H7(E) and S. typhimurium DT104(ST) groups were challenged with each pathogen without B. longum HY8001 administration and control groups were administered with phosphate buffered solution(PBS). After the oral administration with B. longum HY8001(109cfu), th emice were challenged with E. coli O157:H7(2$\times$1010cfu) or S. typhimurium DT104(108cfu) and the mortality rate and the fecal shedding of challenged pathogen were also examined define the reactivity of the B. longum HY8001. Production of toxin neutralizing substance(s) of B. longum HY8001 was determined by cell cytotoxicity assay using Vero cells. Fecal shedding of th eS. typhimurium DT104 was significantly decreased in BL+ST+BL group fed with B. longum HY8--1 before and after challenge(p<0.05), while the fecal shedding s of S. typhimurium DT104 in BL+ST and St groups remained more than 106cfu. the protective effect of the B. longum HY8001 against E. coli O157:H7 was significantly high only in BL+E+BL group fed with b. longum Hy8001 before and after E. coli O157:H7 challenge from the result of fecal E. coli O157:H7 isolation rate, mortality rate, and intestinal contents culture to detect E. coli O157:H7. the mortality rate of the BL+e and E groups. The cytopathic effect (CPE) of the Vero cytotoxin (Shiga like toxin I & II) in Vero cell was neutralized in B. longum HY8001 culture supernatant added wells which indicate the presence of soluble Vero cytotxin neutralizing substance(s) in B. longum HY8001 culture suprnatant.

• Proceedings of the Microbiological Society of Korea Conference
• /
• 2000.05a
• /
• pp.23-36
• /
• 2000

Japanese encephalitis virus (JEV) is the causative agent of a mosquito-borne encephalitis and is transmitted to human via persistently infected mosquito vectors. Although the virus is known to cause only acute infection, there were reports that showed neurological sequelae, latent infection in peripheral mononuclear cells, and recurrence of the disease after acute encephalitis. Innate resistance of certain cell lines, abnormal SN1 expression of the virus, and anti-apoptotic effect of cullular bcl-2 have been suggested as probable causes of JEV persistence even in the absence of defective interfering (DI) particles. Although possible involvement of DI particles in JEV persistence was suggested, neither has a direct evidence for DI presence nor its molecular characterization been made. Two questions asked in this study are whether the DI virus plays any role in JEV persistent infection if it is associated with and what type of change(s) can be made in persistently infected cells to avoid apoptosis even with the continuous virus replication, DI-free standard stock of JEV was infected in BHK-21, Vero, and SW13 cells and serial high multiplicity passages were performed in order to generate DI particles. There different-sized DI RNA species which were defective in both structural and nonstructural protein coding genes. Rescued ORFs of the DI genome maintained in-frame and the presence of replicative intermediate or replicative form RNA of the DI particles confirmed their replication competence. On the other hand, several clones with JEV persistent infection were established from the cells survived acute infections during the passages. Timing of the DI virus generation during the passages seemed coincide to the appearance of persistently infected cells. The DI RNAs were identified in most of persistently infected cells and were observed throughout the cell maintenance. One of the cloned cell line maintained the viral persistence without DI RNA coreplication. The cells with viral persistence released the reduced but continuous infectious JEV particle for up to 9 months and were refractory to homologous virus superinfection but not to heterologous challenges. Unlike the cells with acute infection these cells were devoid of characteristic DNA fragmentation and JEV-induced apoptosis with or without homologous superinfection. Therefore, the DI RNA generated during JEV undiluted serial passage on mammalian cells was shown to be biologically active and it seemed to be responsible, at least in part, for the establishment and maintenance of the JEV persistence in mammalian cells. Viral persistence without DI RNA coreplication, as in one of the cell clones, supports that JEV persistent infection could be maintained with or without the presence of DI particles. In addition, the fact that the cells with JEV persistence were resistant against homologous virus superinfection, but not against heterologous one, suggests that different viruses have their own and independent pathway for cytopathogenesis even if viral cytopathic effect could be converged to an apoptosis after all.

• Journal of Life Science
• /
• v.26 no.7
• /
• pp.835-846
• /
• 2016

Chemo-resistance is the biggest issue of effective cancer therapy. ABCG2 is highly correlated with multi-drug resistance, and represent a typical phenotype of multiple cancer stem-like cells. Accumulating evidence recently reported that oncolytic viruses represent a new strategy for multiple aggressive cancers and drug resistant cancers including cancer stem cell-like cells and ABCG2 expressing cells. In this study, we generated an evolutionally engineered vaccinia virus, SLJ-496, for drug-resistant cancer therapy. We first showed that SLJ-496 treatment enhanced tumor affinity using cytopathic effect assay, plaque assay, as well as cell viability assay. Next, we clearly demonstrated that in vitro SLJ-496 treatment represents significant cytotoxic effect in multiple cancers including colorectal cancer cells (HT-29, HCT-116, HCT-8), gastric cancer cells (AGS, NCI-N87, MKN-28), Hepatocellular carcinoma cells (SNU-449, SNU-423, SNU-475, HepG2), as well as mesothelioma cell (NCI-H226, NCI-H28, MSTO-221h). Highly ABCG2 expressing HT-29 cells represent cancer stem like phenotype including stem cell marker expression, and self-renewal bioactivities. Interestingly, we demonstrated that in vitro treatment of SLJ-496 showed significant cytotoxicity effect, as well as viral replication capacity in ABCG2 overexpressing cell. In addition, we also demonstrated the cytotoxic effect of SLJ-496 in Adriamycin-resistant cell lines, SNU-620 and ADR-300. Taken together, these findings provide us a pivotal clue that cancer therapy using SLJ-496 vaccinia virus might be new therapeutic strategy to overcome ABCG2 expressing cancer stem-like cell and multiple chemo-resistance cancer cells.

• The Journal of Korean Society of Virology
• /
• v.26 no.2
• /
• pp.215-225
• /
• 1996

Aseptic meningits, an acute inflammation of the meninges, is a common illness during childhood. Virus is the most important cause of aseptic meningitis. Especially enterovirus causes approximately above 85% of all cases of aseptic meningitis. In 1993, there was a big epidemic of aseptic meningitis by ECHO 9 and ECHO 30 viruses. And ECHO 3 virus was isolated as a causative agent of aseptic meningitis in 1994. This study was aimed to detect the causative agent of aseptic meningitis in 1995 and to analyze the 5'-noncoding region which was used to detect virus. Virus was isolated from 87 stools and cerebrospinal fluid specimens of the patients by cultured RD and HEp-2 cell. Neutralizing antibody tests using enterovirus serum pool were performed on the specimens with cytopathic effect. 3 of ECHO 7 viruses and 5 of Coxsackie B3 viruses were isolated from stool specimens and 1 of ECHO 7 and Coxsackie B3 mixed type was confirmed from cerebrospinal fluid specimens. RNA was isolated from the culture supernatants of infected cells and general primers were selected in highly conserved part of the 5'-noncoding region of the enteroviral genome for RT-PCR. PCR product from this virus showed a 152bp band on gel electrophoresis. Sequence of obtained DNA was compared with prototype sequences by accessing to the Genebank database. 5'-noncoding region of isolated Coxsackie B3 virus, which has point mutations in nucleotide sequence positions 493, 497, 502, 523, was closely related to that of polio virus type 1, Mahoney strain. In case of isolated ECHO 7 virus, nucleotide has been changed from cytosine to thymine at position 581 and from thymine to cytosine at position 583. We concluded the causative agents of the outbreak of aseptic meningitis during June to July in 1995 were both ECHO 7 and Coxsackie B3 virus, and the primer used in this study could allow a rapid diagnosis of enteroviruses by PCR.

• KSBB Journal
• /
• v.13 no.3
• /
• pp.231-237
• /
• 1998

An attenuated Japanese encephalitis virus (JEV) clone SA-14-14-2(Vero) was obtained through successive adaptation of a primary cell adapted strain, SA-14-14-2(PDK) to Vero cell, a continuous line of monkey kidney cells. The virus titer reached above the 107 plaque forming unit (pfu) per mL of culture supernatant with 3 passages in Vero cells and was maintained close to this level in the further passages. The optimum temperature for the virus growth was $35^{\circ}C$. Growth pattern of the virus indicated that optimum time for the virus harvest is 4 days post infection and the virus accomplished rapid initial propagation even in medium containing no serum supplement. The roller bottle (RB) system and the spinner flask (SF) system using micro-carrier (Cytodex-1) for the JEV cultivation were explored. When RB, SF, and T-flask culture system were compared, there was no significant difference in virus yield. Furthermore, the results indicated that virus could be harvested multiple times from 3 days to 9 days post infection; neither severe cytopathic effect (CPE) in the infected cells nor the decrease in the titer was observed on duration of 9 days.

• Journal of Microbiology
• /
• v.42 no.1
• /
• pp.25-31
• /
• 2004

Sf9 cells have obvious advantages for the conventional production technology of vaccine. They are useful tools for high concentration and large-scale cultures. Sf9 cells were grown to maximal concentration, 8${\times}$l0$\^$6/ cells/$m\ell$ in a 500$m\ell$ spinner flask, with a doubling time at the exponentially growing phase of 24.5 hours, using serum-free media. To explore the ability of Sf9 cells to be infected by the Japanese encephalitis (JE) virus Beijing-l strain, Sf9 cells were infected with the virus. By 4-5 days post-infection, 10-15 % of the Sf9 cells showed cytopathic effect (CPE), from granularity to the formation of syncytia and multinucleated giant cells continuously observed over a period of 35 days. Positive fluorescent reactions were detected in 30-40% of cells infected with the JE virus Beijing-l strain, and the uninfected Sf9 cells were completely negative. Virus particles, propagated in Sf9 and Vero cells, were concentrated by sedimentation on 40% trehalose cushions by ultracentrifugation, and showed identical patterns of viral morphogenesis. Complete virus particles, 40 to 50 nm in diameter, were observed, and JE virus envelope (E) proteins, at 53 kDa, were found in the western blot analysis to the anti-JE virus E protein monoclonal antibody and reacted as a magenta band in the same position to the glycoprotein staining. To evaluate whether the infectious virus was produced in Sf9 cells inoculated with the JE virus Beijing-l stain, Sf9 cells were inoculated with the virus, and sample harvested every 5 days. The titers of the JE virus Beijing-l strain rose from 1.0${\times}$l0$\^$5/ to 1.5${\times}$l0$\^$6/ pfu/$m\ell$. The infected Sf9 cells could be subcultured in serum-free medium, with no change in the plaque sizes formed by the JE virus Beijing-l strain in the plaque assay. It is suggested that the ability of the JE virus Beijing-l strain to infect Sf9 cells in serum-free media will provide a useful insect cell system, where the JE virus replication, cytopathogenicity and vaccine immunogen can be studied.

• Pediatric Infection and Vaccine
• /
• v.3 no.2
• /
• pp.154-162
• /
• 1996

Purpose : Adenoviruses(Ad) have been shown to play an important role in the etiology of severely acute respiratory diseases, particulary in infants and young children, and the occurrence of fatal outcome and chronic pulmonary sequelae in association with adenoviral infection has been a cause of great interest and concern. This report presents the resul of a retrospective analysis on 30 cases of lower respiratory infection from which adenovirus was isolated. Patients & Methods : The 30 patients in this study represent all detected cases of adenovial infection out of 240 children who were admitted to Sang Sung Medical Center between February to June 1996 showing signs and symptoms of lower respiratory tract infection. The diagnosis of adenovirus infection was based on microscopic visualization of typical cytopathic effect in HEp-2 tissue culture and used monoclonal Ab with nasopharyngeal aspiration. Results : The male/female ratio was 2:1 and the majority of age range was below 36months. Clinical diagnoses in all 30 patients were pneumonia(n=21), bronchitis and Bronchiolitis(n=5) and ARDS(n=4). We recieved the most of patients in the month of May. The chief complaints were fever(93.3%) and cough(80%) and extrapulmonary symptoms were diarrhea(n=5), seizure(n=4), abdominal pain(n=1). The mean duration of fever was $11.95{\pm}6.54$days. Physical examination on admission were crackles(73.3%), coarse breathing sounds(60%), hepatosplenomegaly(33.3%), decreased brething sounds(30%). In WBC counts, 8cases were below $4000/mm^3$ and 14 cases were above $10,000/mm^3$. In platelets counts, 4cases were below $150,000/mm^3$ and 10 cases were above $450,000/mm^3$. 21 cases were above 1 in CRP. GOT and GPT were abnormal in some cases. Chest X-ray revealed diffuse pulmonary infiltration(n=15), pleural effusion(n=6), consolidation(n=4) and hyperaeration(n=3). Seven patients were treated at the peditric intensive care unit with respiratory support and high dose of gammaglobulin. However, one patients died even through he was treated with NO ventilation and high frequency ventilation. Conclusion : Those with adenoviral pneumonia and respiratory infection having long fever duration and symptoms like bacterial pneumonia must be carefully differentiated in order to provide proper treatement and preventive measures due to possible fatal outcome.