• Title/Summary/Keyword: Viral titer

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TOPICAL GENE DELIVERY TO NORMAL ORAL EPITHELIUM USING ADENOVIRUS IN ORGAN CULTURE MODEL (조직 배양 모형에서 정상 구강 점막 상피에 대한 국소 유전자 요법)

  • Kim, Tae-Hwan;Kwak, Myung-Ho;Lee, Choon-Ho;Park, Jun-Woo;Park, Young-Wook;Kim, Seong-Gon
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.31 no.3
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    • pp.193-197
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    • 2009
  • Background: Though it is clear that many types of viruses can infect the oral mucosa, its condition for infection is unclear. The purpose of this study was to analyze the conditions for viral infection of normal oral mucosa and explore the possibility of topical gene therapy to oral mucosa using a viral vector. Methods: Freshly taken fragments of the palate and the tongue of mice were used for organ culture. The specimens were exposed to green fluorescent protein (GFP)-adenoviral vector for 1 hour except for the control. Initial viral titer was $6.3{\times}10^{11}\;pfu/ml$ and the virus was diluted to working concentrations. The dilution ratio was 1:1,000 ($6.3{\times}10^8\;pfu/ml$), 1:10,000 ($6.3{\times}10^7\;pfu/ml$), and 1:100,000 ($6.3{\times}10^6\;pfu/ml$). They were then cultured on a stainless steel wire mesh in an organ culture dish. The specimens were stereoscopically examined every 24 hours for 6 days, after which they were fixed and analyzed through immunohistochemical methods Results: There was no visible expression in the control, $6.3{\times}10^6\;pfu/ml$, and $6.3{\times}10^7\;pfu/ml$ groups. Initial expression was observed at 24 hours after infection in both the palate and the tongue in $6.3{\times}10^8\;pfu/ml$ and the expression significantly increased until 3 days in the palate and 2 days in the tongue after infection (P<0.05). In both groups, the expression was mostly observed at the resection margin. Immunohistochemical studies showed that the epithelial cells were positive to GFP. Conclusion: The present study showed that topically applied adenovirus containing specific genetic information of GFP could successfully transduce GFP in normal oral epithelial cells at the resection margin in organ culture in terms of dose and exposure time.

Disinfection effect of corona discharged plasma water on fish pathogens (코로나 방전 플라즈마 처리수에 의한 어류 병원체 소독 효과)

  • You, Jin Ho;Lee, Ji Hyun;Mun, Seong Hee;Kwon, Se Ryun;Park, Tae Sup;Kwon, Joon Yeong
    • Journal of fish pathology
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    • v.33 no.1
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    • pp.63-69
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    • 2020
  • Fish culture is constantly threatened by various infectious diseases which are largely transmitted by water. Plasma technology is being used to sterilize polluted water in many industries. In this study, two bacterial pathogens Aeromonas salmonicida and Streptococcus iniae, and a virus (viral hemorrhagic septicemia virus, VHSV) were subjected to plasma water that was produced by a corona discharge system. Growth of A. salmonicida was greatly inhibited from 105.61 CFU/ml in positive control to 103.51 CFU/ml in treated group by only 60 sec contact with plasma water. Similarly, S. iniae was inhibited from 105.85 CFU/ml to 103.40 CFU/ml. VHSV titer also decreased from 104.1 TCID50/ml to 101.45 TCID50/ml by the same treatment. Activation of water by the plasma was confirmed by the existence of ozone in the plasma water. These results suggest that plasma water could efficiently disinfect fish pathogens, possibly by the action of reactive oxygen species contained in the plasma water.

Study on the Pathogenesis of Hantaan Virus with Monoclonal Antibodies (단일항체를 이용한 한국형출혈열의 병인성 연구)

  • Kim, Gum-Ryong;Kim, Tai-Gyu;Rhyu, Mun-Gan;Lim, Byung-Uk
    • The Journal of the Korean Society for Microbiology
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    • v.22 no.1
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    • pp.1-8
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    • 1987
  • Hantaan virus(HV) 76-118 strain was inoculated into suckling ICR mice by intra-nasal route with an inoculum of $10LD_{50}$. Mortality was 65% at the 3rd week after inoculation, but declined to 35% at the 4th week. Infectivity was determined by the measuring immuno-fluorescent antibody in sera. The peak of infectivity was 80% at the 4'th week after inoculation. Viremia was reached peak level of $1.7{\times}10^4\;PFU/ml$ by day 10. Immunofluorescent antibody and neutralizing antibody appeared by 2 weeks and 15-17 days respectively, but achieved similar titer by 35 days. By using a monoclonal antibody to HV 76-118, viral antigens were initially detected in inguinal and axillary lymph node by 2 days. Viral antigens in bone marrow and lung were delayed much more than in those of lymph node. These were similar with those of intra-peritoneal and intra-muscular route. Immune complex against IgG, IgM and C3 appeared by 16 days, 14 days, and 18 days respectively. The pattern of immunofluorescence in the basement membrane of glomeruli was diffuse membranous. Spotted pattern was also observed in the tissue stained with anti-mouse C3 antibody. By 20 days, control tissue was also shown immune complex in the glomeruli.

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Systemic Analysis of a Novel Coxsackievirus Gene Delivery System in a Mouse Model

  • Kim, Yeon-Jung;Yun, Soo-Hyeon;Lim, Byung-Kwan;Park, Ki-Bum;Na, Ha-Na;Jeong, Soo-Young;Kim, Dae-Sun;Cho, Young-Joo;Jeon, Eun-Seok;Nam, Jae-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.19 no.3
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    • pp.307-313
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    • 2009
  • In order to systemically investigate the possibility of using coxsackievirus B3 (CVB3) to deliver foreign genes in vivo, a recombinant strain of CVB3 encoding the renilla gene (CVB3-renilla) was constructed. The recombinant CVB3 resulted in extensive and transient expression of the renilla protein within mouse organs, especially the pancreas. The level of expression was generally dependent upon the viral titer present. Moreover, the CVB3-renilla strain was completely attenuated. Interestingly, the recombinant CVB3 vector was expressed much more strongly in mouse organs than was a comparable adenoviral vector. The CVB3-renilla strain did not express the renilla gene in mice with pre-existing coxsackievirus-specific neutralizing antibodies, but direct organ-specific administration of the virus during open-peritoneum surgery was able to circumvent this immunity. This coxsackievirus vector may represent a useful means for delivering and expressing foreign genes in mouse models in an acute and extensive fashion.

Enhanced bone morphogenic protein adenoviral gene delivery to bone marrow stromal cells using magnetic nanoparticle

  • Lee, Jung-Tae;Jung, Jae-Whan;Choi, Jae-Yong;Kwon, Tae-Geon
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.39 no.3
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    • pp.112-119
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    • 2013
  • Objectives: This study investigated the question of whether adenoviral magnetofection can be a suitable method for increasing the efficacy of gene delivery into bone marrow stromal cell (BMSC) and for generation of a high level of bone morphogenic protein (BMP) secretion at a minimized viral titer. Materials and Methods: Primary BMSCs were isolated from C57BL6 mice and transduced with adenoviral vectors encoding ${\beta}$ galactosidase or BMP2 and BMP7. The level of BMP secretion, activity of osteoblast differentiation, and cell viability of magnetofection were measured and compared with those of the control group. Results: The expression level of ${\beta}$ galactosidase showed that the cell transduction efficiency of AdLacZ increased according to the increased amount of magnetic nanoparticles. No change in cell viability was observed after magnetofection with 2 ${\mu}L$ of magnetic nanoparticle. Secretion of BMP2 or BMP7 was accelerated after transduction of AdBMP2 and 7 with magnetofection. AdBMP2 adenoviral magnetofection resulted in up to 7.2-fold higher secretion of BMP2, compared with conventional AdBMP2-transduced BMSCs. Magnetofection also induced a dramatic increase in secretion of BMP7 by up to 10-fold compared to the control. Use of only 1 multiplicity of infection (moi) of magnetofection with adenoviral transduction of AdBMP2 or AdBMP7 resulted in significantly higher transgene expression compared to 20 moi of conventional adenoviral transduction. Conclusion: Magnetic particle-mediated gene transudation is a highly efficient method of gene delivery to BMSCs. Magnetofection can lower the amount of viral particles while improving the efficacy of gene delivery.

Construction of a cDNA library of Aphis gossypii Glover for use in RNAi

  • KWON, HyeRi;KIM, JungGyu;LIM, HyounSub;YU, YongMan;YOUN, YoungNam
    • Entomological Research
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    • v.48 no.5
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    • pp.384-389
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    • 2018
  • Aphis gossypii Glover is an important insect pest that functions as a viral vector and mediates approximately 45 different viral diseases. As part of a strategy for control of A. gossypii, we investigated the functions of genes using RNAi. To this end, a cDNA library was constructed for various genes and for selecting appropriate targets for RNAi mediated silencing. The cDNA library was constructed using the Gateway cloning system with site-specific recombination of bacteriophage ${\lambda}$. It was used to carry out single step cloning of A. gossypii cDNAs. As a result, a cDNA library with a titer of $8.4{\times}10^6$ was constructed. Since the sequences in this library carry att sites, they can be cloned into various binary vectors. This library will be of value for various studies. For later screening of selected genes, it is planned to clone the library into virus-induced gene silencing (VIGS) vectors, which makes it possible to analyze gene function and allow subsequent transfection of plants. Such transfection experiments will allow testing of RNAi-induced insecticidal activity or repellent activity to A. gossypii, and result in the identification of target genes. It is also expected that the constructed cDNA library will be useful for analysis of gene functions in A. gossypii.

Development of a Platform for Natural Killer Cell Therapy with Antiviral Efficacy (항바이러스 효능을 가진 자연살해세포 치료제 플랫폼 개발)

  • Dongsoo Kim;Hyeongseok Yun;Jinhui Lee;Dayoung Yeon;Chi Ho Yu;Se Hum Gu;Young-Jo Song;Jung-Eun Kim;Seung-Ho Lee;Yong Han Lee;Gyeung Haeng Hur;Junghwa Kang
    • Journal of the Korea Institute of Military Science and Technology
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    • v.27 no.1
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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.

Experience with Entecavir Therapy for Lamivudine-Resistant Chronic Hepatitis B in Korean Children and Adolescents (라미부딘 내성 소아 청소년 만성 B형 간염에서 Entecavir 치료 경험)

  • Cho, Seung-Man;Choe, Byung-Ho;Chu, Mi-Ae;Kim, Jung-Mi
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.13 no.1
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    • pp.44-50
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    • 2010
  • Purpose: To estimate the viral suppressive effect of entecavir monotherapy in Korean children and adolescents with lamivudine-resistant chronic hepatitis B (CHB). Methods: One milligram of entecavir was administered once daily to 6 patients (4 boys; mean age, 17.5 years; range, 15.10~24.6 years) with lamivudine-resistant CHB for a mean duration of therapy of 13.4 months (range, 1~21.1 months). The therapeutic results were compared with 11 patients who received adefovir (0.3 mg/kg/day [maximal dose 10 mg]) for at least 12 months (mean, 33.4 months; range, 12.4~58.3 months). The serum HBV DNA level and serologic markers were measured every 2 months. Results: The interval to a HBV DNA titer decrement (>1 $log_{10}$) was 1.2${\pm}$0.2 and 4.4${\pm}$5.2 months (p=0.185) for the entecavir and adefovir groups, respectively. The interval to a HBV DNA titer decrement (>2 $log_{10}$) was 2.4${\pm}$2.3 and 9.2${\pm}$7.3 months (p=0.025), for the entecavir and adefovir groups, respectively. Conclusion: The therapeutic efficacy of entecavir was favorable in children and adolescents, especially in shortening the interval to a >2 $log_{10}$ decrement in the HBV DNA titer. Long-term follow up is needed to determine the therapeutic efficacy of entecavir for lamivudine-resistant CHB in children and adolescents.

Validation of a Real-Time RT-PCR Method to Quantify Newcastle Disease Virus (NDV) Titer and Comparison with Other Quantifiable Methods

  • Jang, Juno;Hong, Sung-Hwan;Kim, Ik-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.21 no.1
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    • pp.100-108
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    • 2011
  • A method for the rapid detection and quantification of Newcastle disease virus (NDV) produced in an animal cell culture-based production system was developed to enhance the speed of the NDV vaccine manufacturing process. A SYBR Green I-based real-time RT-PCR was designed with a conventional, inexpensive RT-PCR kit targeting the F gene of the NDV LaSota strain. The method developed in this study was validated for specificity, accuracy, precision, linearity, limit of detection (LOD), limit of quantification (LOQ), and robustness. The validation results satisfied the predetermined acceptance criteria. The validated method was used to quantify virus samples produced in an animal cell culture-based production system. The method was able to quantify the NDV samples from mid- or late-production phases, but not effective on samples from the early-production phase. For comparison with other quantifiable methods, immunoblotting, plaque assay, and tissue culture infectious dose 50 ($TCID_{50}$) assay were also performed with the NDV samples. The results demonstrated that the real-time RT-PCR method is suitable for the rapid quantification of virus particles produced in an animal cell-culture-based production system irrespective of viral infectivity.

Effects of Dexamethasone on the Burden of Marine Birnavirus (MABV) in Olive Flounder, Paralichthys olivaceus (Dexamethasone 투여가 넙치(Paralichthys olivaceus)의 marine birnavirus (MABV) 감염강도에 미치는 영향)

  • Kwon, Se Ryun;Nam, Yoon Kwon
    • Korean Journal of Ichthyology
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    • v.19 no.2
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    • pp.88-92
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    • 2007
  • The effect of dexamethasone injection on the burden of marine birnavirus (MABV) in asymptomatically infected olive flounder (Paralichthys olivaceus) fingerlings was investigated. In real time PCR analysis, the threshold cycle (Ct) value of the fish injected with dexamethasone was significantly lower than that of the fish in the PBS-injected and no-handling groups. The higher amplification of the MABV gene in the dexamethasone-injected group than the 2 control groups was confirmed also by semi-quantitative RT-PCR. The results indicate an increase of MABV burden in olive flounder fingerlings after a single injection with dexamethasone.