• Title/Summary/Keyword: Hepatitis virus

Search Result 698, Processing Time 0.031 seconds

Interaction of Hepatitis C Virus Core Protein with Janus Kinase Is Required for Efficient Production of Infectious Viruses

  • Lee, Choongho
    • Biomolecules & Therapeutics
    • /
    • v.21 no.2
    • /
    • pp.97-106
    • /
    • 2013
  • Chronic hepatitis C virus (HCV) infection is responsible for the development of liver cirrhosis and hepatocellular carcinoma. HCV core protein plays not only a structural role in the virion morphogenesis by encapsidating a virus RNA genome but also a non-structural role in HCV-induced pathogenesis by blocking innate immunity. Especially, it has been shown to regulate JAK-STAT signaling pathway through its direct interaction with Janus kinase (JAK) via its proline-rich JAK-binding motif ($^{79}{\underline{P}}GY{\underline{P}}WP^{84}$). However, little is known about the physiological significance of this HCV core-JAK association in the context of the virus life cycle. In order to gain an insight, a mutant HCV genome (J6/JFH1-79A82A) was constructed to express the mutant core with a defective JAK-binding motif ($^{79}{\underline{A}}GY{\underline{A}}WP^{84}$) using an HCV genotype 2a infectious clone (J6/JFH1). When this mutant HCV genome was introduced into hepatocarcinoma cells, it was found to be severely impaired in its ability to produce infectious viruses in spite of its robust RNA genome replication. Taken together, all these results suggest an essential requirement of HCV core-JAK protein interaction for efficient production of infectious viruses and the potential of using core-JAK blockers as a new anti-HCV therapy.

Large-Scale Culture of Hepatitis A Virus in Human Diploid MRC-5 Cells and Partial Purification of the Viral Antigen for Use as a Vaccine

  • Kim, Hyun-Seok;Chung, Yong-Ju;Jeon, Yeong-Joong;Lee, Sung-Hee
    • Journal of Microbiology and Biotechnology
    • /
    • v.9 no.4
    • /
    • pp.386-392
    • /
    • 1999
  • A large-scale culture of hepatitis A virus in human diploid MRC-5 cells was conducted. In a roller bottle culture, the virus was grown to a maximum titer in 3 weeks after infection. Over 95% of the cell-associated virus was excreted after culturing the infected cells in suspension media without fetal bovine serum for 3 days. The cultured virus was inactivated with formalin, concentrated by ultrafiltration, and partially purified by ultracentrifugation in a non-ionic gradient medium of Renocal. Two separate peak fractions showing high anti-HAY ELISA titer were pooled and about 40% of HAV antigen was recovered by this purification procedure. Of the partially purified vaccine, the protein pattern in SDS-PAGE and immunogenicity in mice were compared with a commercial HAV vaccine. In SDS-PAGE, the purified vaccine in this study and the commercial vaccine showed almost the same protein pattern. The seroconversion rate of the purified vaccine in mice was not different from that of the commercial vaccine. Therefore, we could prepare a good grade of HAV vaccine by a simple purification procedure although the purification itself was not completed.

  • PDF

Comparison on serological reaction between complement fixation test and enzyme-linked immunosorbent assay for detection of antibodies against Sendai virus, mouse hepatitis virus and Mycoplasma pulmonis in mice and rats (마우스 및 랫트의 Sendai virus, mouse hepatitis Virus, Mycoplama pulmonis 감염(感染)에 대한 보체결합반응(補體結合反應)과 효소표식면역흡착측정법(酵素標識免疫吸着測定法)과의 비교(比較))

  • Chung, Yoo-yeul;Lee, Hak-cheul;Lee, Eun;Yoo, Byung-sam
    • Korean Journal of Veterinary Research
    • /
    • v.29 no.4
    • /
    • pp.517-523
    • /
    • 1989
  • This study was undertaken to establish reliable diagnostic-procedures for the microbiological monitoring of laboratory animals. Murine(mice and rats) antibodies against hemagglutinating virus of Japan(HVJ), mouse hepatitis virus(MHV) and Mycoplasma pulmonis(Mp) were detected sensitively and specifically in experimentally and naturally infected animals' sera by an indirect enzyme-linked immunosorbent assay(ELISA), using urease conjugated antimurine immunoglobulin. The sensitivity and specificity of the complement fixation test which has been apllied widely for serodiagnosis of HVJ, MHV and Mp infections were apparently lower than those of ELISA. From these results, the ELISA was found to be available for the serodiagnosis of HVJ, MHV and Mp infections in mice and rats.

  • PDF

Hepatitis C Virus Core Protein Is Efficiently Released into the Culture Medium in Insect Cells

  • Choi, Soo-Ho;Kim, So-Yeon;Park, Kyu-Jin;Kim, Yeon-Joo;Hwang, Soon-Bong
    • BMB Reports
    • /
    • v.37 no.6
    • /
    • pp.735-740
    • /
    • 2004
  • Hepatitis C virus (HCV) is a causal agent of the chronic liver infection. To understand HCV morphogenesis, we studied the assembly of HCV structural proteins in insect cells. We constructed recombinant baculovirus expression vectors consisting of either HCV core alone, core-E1, or core-E1-E2. These structural proteins were expressed in insect cells and were examined to assemble into particles. Neither core-E1 nor core-E1-E2 was capable of assembling into virus-like particles (VLPs). It was surprising that the core protein alone was assembled into core-like particles. These particles were released into the culture medium as early as 2 days after infection. In our system, HCV structural proteins including envelope proteins did not assemble into VLPs. Instead, the core protein itself has the intrinsic capacity to assemble into amorphous core-like particles. Furthermore, released core particles were associated with HCV RNA, indicating that core proteins were assembled into nucleocapsids. These results suggest that HCV may utilize a unique core release mechanism to evade the hosts defense mechanism, thus contributing to the persistence of HCV infection.

Overexpression and Purification of PreS Region of Hepatitis B Virus Antigenic Surface Protein adr Subtype in Escherichia coli

  • Abbas, Naaz;Ahmad, Aftab;Shakoori, Abdul Rauf
    • BMB Reports
    • /
    • v.40 no.6
    • /
    • pp.1002-1008
    • /
    • 2007
  • PreS domain of Hepatitis B virus (HBV) surface antigen is a good candidate for an effective vaccine as it activates both B and T cells besides binding to hepatocytes. This report deals with overexpression and purification of adr subtype of surface antigen that is more prevalent in Pakistan. PreS region, comprising 119 aa preS1 region plus a 55 aa preS2 region plus 11 aa from the N-terminal S region, was inserted in pET21a+ vector, cloned in E. coli $DH5\alpha$ cells and expressed in E. coli BL21 codon+ cells. The conditions for over expression were optimized using different concentrations of IPTG (0.01-5 mM), and incubating the cells at different temperatures (23-$41^{\circ}C$) for different durations (0-6 h). The cells were grown under the given optimized conditions (0.5 mM IPTG concentration at $37^{\circ}C$ for 4 h), lysed by sonication and the protein was purified by ion exchange chromatography. On the average, 24.5 mg of recombinant protein was purified per liter of culture. The purified protein was later lyophilized and stored at $-80^{\circ}C$.

The Comparison of Sequencing Method with Restriction Fragment Mass Polymorphism Method for the Detection of HBV YMDD Mutants (HBV YMDD 돌연변이형 검사 시 염기서열법과 Restriction Fragment Mass Polymorphism 법의 비교)

  • Jung, An-Na;Jung, Hee-Kyoung;Choi, Sam-Kyu;Park, Chung-Oh
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.37 no.3
    • /
    • pp.173-177
    • /
    • 2005
  • YMDD motif mutants of the hepatitis B virus(HBV) emerge in chronic hepatitis B patients after prolonged lamivudine treatment. HBV DNA breakthrough may be accompained by the emergence of YMDD mutants. We compared the performance of the sequencing method with that of RFMP method in chronic hepatitis B patients who had suffered the HBV DNA breakthrough after lamivudine treatment. Both sequencing and RFMP methods were used to detect YMDD variants in 20 chronic hepatitis B patients. YMDD mutants were detected in 17 samples (85.0%) by both methods. Among them, no mutants were detected in two samples(10.0%), while they were detected in the other sample(5.0%) with the RFMP method. The concordance rate between both methods was 95.0%. There was inconsistency in one sample showing mutants detected by the RFMP method, but not by sequencing method. In the sequencing method, the mutants was detected in the major type virus, but not in the minor type virus. However, both sequencing and RFMP methods were highly concordant except in one sample, so it is suggested that both methods are useful to detect YMDD mutants of chronic hepatitis B patients.

  • PDF

Comparative Inactivation of Hepatitis A Virus and Murine Encephalomyocarditis Virus to Various Inactivation Processes (바이러스 불활화 공정에 대한 Hepatitis A Virus와 Murine Encephalomyocarditis Virus의 민감도 비교)

  • Kim, In-Seop
    • Korean Journal of Microbiology
    • /
    • v.39 no.4
    • /
    • pp.242-247
    • /
    • 2003
  • Murine encephalomyocarditis virus (EMCV) has been used as a surrogate for hepatitis A virus (HAV) for the validation of virus removal and/or inactivation during the manufacturing process of biopharmaceuticals. Recently international regulation for the validation of HAV safety has been reinforced because of the reported cases of HAV transmission to hemophiliac patients who had received ntihemophilic factors prepared from human plasma. The purpose of the present study was to compare the resistance of HAV and EMCV to various viral inactivation processes and then to standardize the HAV validation method. HAV was more resistant than EMCV to pasteurization (60oC heat treatment for 10 hr), low pH incubation (pH 3.9 at 25oC for 14 days), 0.1 M NaOH treatment, and lyophilization. EMCV was completely inactivated to undetectable levels within 2 hr of pasteurization, however, HAV was completely inactivated to undetectable levels after 5 hr treatment. EMCV was completely inactivated to undetectable levels within 15 min of 0.1 M NaOH treatment, however, residual infectivity of HAV still remained even after 120 min of treatment. The log reduction factors achieved during low pH incubation were 1.63 for HAV and 3.84 for EMCV. Also the log reduction factors achieved during a lyophilization process of antihemophilic factor VIII were 1.21 for HAV and 4.57 for EMCV. These results indicate that HAV rather than EMCV should be used for the virus validation study and the validation results obtained using EMCV should be precisely reviewed.

Hepatocellular Carcinoma Following Vertical Transmission of Hepatitis B Virus in a Child with X-linked Agammaglobulinemia (범저감마 글로불린혈증 환아에서 B형 간염 바이러스 수직 감염에 의해 발생한 간세포 암종 1례)

  • Oh, Jong-Gon;Kim, Byung-Ju;Kook, Hoon;Woo, Young-Jong;Choi, Young-Youn;Ma, Jae-Sook;Hwang, Tai-Ju;Seo, Jong-Jin
    • Pediatric Gastroenterology, Hepatology & Nutrition
    • /
    • v.3 no.1
    • /
    • pp.105-109
    • /
    • 2000
  • X-linked agammaglobulinemia (XLA) is a primary inherited B-cell immunodeficiency. The prevalence of neoplastic disease in patients with XLA is approximatedly 0.7%. The most frequent tumor is lymphoreticular malignancy. We report a case of hepatocellular carcinoma (HCC) in a 13-year-old boy with XLA, after probable maternal transmission of hepatitis B virus. The authors consider that the vertical transmission of hepatitis B virus might play an important role in the development of HCC in a child with XLA who could not eliminate hepatitis B virus effectively.

  • PDF

Studies on the rabbit viral hepatitis I. Electron microscopic observation of the acute hepatic lesions in experimentally infected rabbit (토끼의 바이러스성(性) 간염(肝炎)에 관(關)한 연구(硏究) I. 실험적(實驗的) 감염토(感染兎)의 급성간염조직(急性肝炎組織)의 전자현미경적(電子顯微鏡的) 관찰(觀察))

  • Lee, Cha-soo;Park, Cheong-kyu
    • Korean Journal of Veterinary Research
    • /
    • v.29 no.4
    • /
    • pp.531-540
    • /
    • 1989
  • A new sudden death in rabbits appeared in China and Korea in 1984 and 1985, respectively, and was recognized to be an acute infectious disease caused by a virus. The disease was reported as a "new viral disease," and thereafter, a tentative name of "viral hemorrhagic disease", "hemorrhagic pneumonia" or "viral hemorrhagic pneumonia" has been described in the case reports. But authors had called the viral disease "rabbit viral hepatitis" due to picornavirus infection, because the principal lesion of the disease was an acute hepatitis. The purpose of this report is to describe the electron microscopic findings on the livers in experimentally infected rabbits. All the livers of the affected rabbits were shown to have degenerative changes of a type that is characteristic of acute hepatitis. In the liver cells, there were dilation of rER and mitochondria, vacuole formation of various sizes, and appearances of many virus-like particles in the vicinity of rER, granular bodies and crystalline arrays of viral particles in the cytoplasm with necrotic changes of the nucleus. Clusters of virus-like particles and viral crystals appeared in the cytoplasm of sinusoid endothelial cells and Kupffer's cells with morphological changes of organelles. Also viral crystals were demonstrated in the cytoplasm of macrophages among the liver cells. On the whole, the liver cells had many virus-like particles and a few crystalline arrays of viral particles. Therefore, this implies that the liver cells are the main site of the viral replication in inducing the viremia. It was concluded that the liver was the primary target organ of this viral disease, and the pathological and the ultrastructural evidence suggest that the virus may be belong to genus enterovirus.

  • PDF

A Case Report of HBsAg Seroclearance in Chronic Hepatitis B Patient

  • Lee, Hyeok Jae;Lee, Min-Hyeok
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.44 no.3
    • /
    • pp.142-146
    • /
    • 2012
  • Hepatitis B surface antigen (HBsAg) seroclearance is a rare event in chronic hepatitis B virus (HBV) infection which acquires the disease early in life. A case study have examined with asymptomatic chronic hepatitis B carrier who exhibits HBsAg seroclearance in anti-HBe positive. We comprehensively studied the biochemical, virological and clinical aspects of a patient with HBsAg seroclearance. Liver biochemistry, serological markers, serum HBV DNA levels, and development of clinical complications were monitored. Mutation of hepatitis B virus is suspected serum HBsAg detected by the HBsAg assay systems of VITROS (OrthoClinical Diagnostics, USA), AxSYM (Abbott Laboratories, USA), Elecsys (Roche Diagnostics, Germany) and ADVIA Centaur (Bayer Diagnostics, USA). These four immunoassays showed negative results. Also, the patient had undetectable serum HBV DNA. Therefore, no mutation within the "a" determinant of HBsAg, which might escape detection from HBsAg immunoassay were found. Natural seroclearance was confirmed.

  • PDF