• Title/Summary/Keyword: Neutralizing antibodies

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Hepatitis C Virus - Proteins, Diagnosis, Treatment and New Approaches for Vaccine Development

  • Keyvani, Hossein;Fazlalipour, Mehdi;Monavari, Seyed Hamid Reza;Mollaie, Hamid Reza
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.12
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    • pp.5917-5935
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    • 2012
  • Background: Hepatitis C virus (HCV) causes acute and chronic human hepatitis infection and as such is an important global health problem. The virus was discovered in the USA in 1989 and it is now known that three to four million people are infected every year, WHO estimating that 3 percent of the 7 billion people worldwide being chronically infected. Humans are the natural hosts of HCV and this virus can eventually lead to permanent liver damage and carcinoma. HCV is a member of the Flaviviridae family and Hepacivirus genus. The diameter of the virus is about 50-60 nm and the virion contains a single-stranded positive RNA approximately 10,000 nucleotides in length and consisting of one ORF which is encapsulated by an external lipid envelope and icosahedral capsid. HCV is a heterogeneous virus, classified into 6 genotypes and more than 50 subtypes. Because of the genome variability, nucleotide sequences of genotypes differ by approximately 31-34%, and by 20-23% among subtypes. Quasi-species of mixed virus populations provide a survival advantage for the virus to create multiple variant genomes and a high rate of generation of variants to allow rapid selection of mutants for new environmental conditions. Direct contact with infected blood and blood products, sexual relationships and availability of injectable drugs have had remarkable effects on HCV epidemiology. Hundreds of thousands of people die each year from hepatitis and liver cancer caused by HCV virus infection. Approximately 80% of patients with acute hepatitis C progress into a chronic disease state leading to serious hepatic disorders, 10-20% of which develop chronic liver cirrhosis and hepatocellular carcinoma. The incubation period of HCV is 6-8 weeks and the infection is often asymptomatic so it is very hard to detect at early stages, making early treatment very difficult. Therefore, hepatitis C is called a "silent disease". Neutralizing antibodies are produced against several HCV proteins during infection but the virus mutates to escape from antibodies. Some patients with chronic hepatitis C may have some symptoms such as fatigue, muscle aches, nausea and pain. Autoimmune and immunecomplex-mediated diseases have also been reported with chronic HCV infection.

The Effects of Pro-inflammatory Cytokines by Cisplatin on the Death of Sensory Hair Cells. (시스플라틴에 의한 염증성 사이토카인의 청각유모세포 사멸 효과)

  • Lee, Jeong-Han;Park, Chan-Ny;Park, Rae-Kil
    • Journal of Life Science
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    • v.18 no.4
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    • pp.542-549
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    • 2008
  • Cisplatin (cis-diamminedichloroplatinum II : CDDP) is the most widely used anticancer drug against a variety of human neoplasms. However, its clinical use is limited by the onset of severe side effects, including ototoxicity and nephrotoxicity. Even though a number of evidences in cytotoxic mechanism of cisplatin have been suggested, the role of pro-inflammatory cytokines in cisplatin cytotoxicity of auditory cells has not yet been demonstrated. Herein our data clearly demonstrated that cisplatin decreased the viability of HEI-OC1 auditory cells, which was inhibited by the addition of neutralizing $anti-TNF-{\alpha}$, $anti-IL-1{\beta}$ and anti-IL-6 antibodies. Consistently, Neutralization with antibodies against pro-inflammatory cytokines ameliorated the cell death and disarrangement of cochlea hair cell layers in the rat primary cochlear explants which were treated with cisplatin. Furthermore, exogeneous supplementation with free radical scavengers, including GSH and NAC, significantly prevented the cytotoxicity of cisplatin in the rat primary cochlea explants. We also observed that $TNF-{\alpha}$ was predominantly expressed in Deiters and Hensen's cells located in hair cell zone of cisplatin-treated cochlear explants. These findings suggest that pro-inflammatory cytokines, including $TNF-{\alpha}$, $IL-1{\beta}$ and IL-6, may play a pivotal role in the pathophysiology of hair cell damages caused by ototoxic drug cisplatin.

Comparative Analysis of Screening Results from Various ELISA Formats Used for Detection of Anti-Erythropoietin Antibodies in Korean Patients

  • Ha, Sung-Kyu;Yang, Seung-Ju;Shin, Sug-Kyun;Jo, Young-Il;Baek, Kyung-Min;Hong, Seung-Hwa;Pack, Seung-Pil;Kim, Sung-Jo;Heo, Tae-Hwe
    • Biomolecules & Therapeutics
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    • v.18 no.2
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    • pp.184-190
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    • 2010
  • Clinical cases of pure red cell aplasia (PRCA) have been reported during the recombinant human erythropoietin (EPO) therapy for the anemia patients. PRCA is a rare hematological disorder leading to a severe anemia due to an almost complete stop of red blood cell production. Antibody (Ab)-associated PRCA is caused by the EPO-neutralizing Abs that eliminate the biological activity of EPO. In order to detect anti-EPO Abs in human sera, we performed conventional ELISA, directly coated bridging ELISA, and streptavidin coated bridging ELISA, and compared their sensitivity and specificity. Some false positive results were obtained in the conventional ELISA. One positive sample was detected successfully by streptavidin coated bridging ELISA, which was not appeared in the directly coated bridging ELISA. In conclusion, streptavidin coated bridging ELISA was substantially sensitive and specific format and one out of sixty-eight serum samples was proved to be anti-EPO positive.

Fusion Peptide Improves Stability and Bioactivity of Single Chain Antibody against Rabies Virus

  • Xi, Hualong;Zhang, Kaixin;Yin, Yanchun;Gu, Tiejun;Sun, Qing;Shi, Linqing;Zhang, Renxia;Jiang, Chunlai;Kong, Wei;Wu, Yongge
    • Journal of Microbiology and Biotechnology
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    • v.27 no.4
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    • pp.718-724
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    • 2017
  • The combination of rabies immunoglobulin (RIG) with a vaccine is currently effective against rabies infections, but improvements are needed. Genetic engineering antibody technology is an attractive approach for developing novel antibodies to replace RIG. In our previous study, a single-chain variable fragment, scFv57R, against rabies virus glycoprotein was constructed. However, its inherent weak stability and short half-life compared with the parent RIG may limit its diagnostic and therapeutic application. Therefore, an acidic tail of synuclein (ATS) derived from the C-terminal acidic tail of human alpha-synuclein protein was fused to the C-terminus of scFv57R in order to help it resist adverse stress and improve the stability and half-life. The tail showed no apparent effect on the preparation procedure and affinity of the protein, nor did it change the neutralizing potency in vitro. In the ELISA test of molecular stability, the ATS fusion form of the protein, scFv57R-ATS, showed an increase in thermal stability and longer half-life in serum than scFv57R. The protection against fatal rabies virus challenge improved after fusing the tail to the scFv, which may be attributed to the improved stability. Thus, the ATS fusion approach presented here is easily implemented and can be used as a new strategy to improve the stability and half-life of engineered antibody proteins for practical applications.

Expression of porcine circovirus type 2 capsid protein fused with partial polyhedrin using baculovirus

  • Lee, Jun Beom;Bae, Sung Min;Shin, Tae Young;Woo, Soo Dong
    • International Journal of Industrial Entomology and Biomaterials
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    • v.30 no.2
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    • pp.50-57
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    • 2015
  • Porcine circovirus type 2 (PCV2) is an important infectious swine virus causing postweaning multisystemic wasting syndrome (PMWS). PCV2 capsid protein, encoded by ORF2 has type-specific epitopes, is very immunogenic, and is associated with the induction of neutralizing antibodies. For the efficient production of capsid protein, recombinant Autographa californica nucleopolyhedroviruses were generated to express ORF2 fused with two forms of a partial polyhedrin. Recombinant capsid protein was produced successfully with the partial polyhedrin fusion form and the yield was high, as was shown by SDS-PAGE. Production of recombinant capsid proteins in insect cells was confirmed by Western blot analysis using anti-His monoclonal antibody, anti-ORF2 monoclonal antibody, and anti-PCV2 porcine serum. Fusion expression with amino acids 19 to 110 of the polyhedrin increased the production of recombinant capsid protein, but fusion with amino acids 32 to 85 did not. Additionally, PCV2 capsid protein is a glycoprotein; however, the glycosylation of recombinant protein was not observed. The results of an Enzyme-linked immunosorbent assay (ELISA) showed that recombinant capsid proteins could be utilized as antigens for fast, large-scale diagnosis of PCV2-infected pigs. Our results suggest that the fusion expression of partial polyhedrin is able to increase the production of recombinant PCV2 capsid protein in insect cells.

Serological survey of the rabies virus in dogs reared in the area around the Pukhansan National Park (북한산 국립공원 주변지역 사육견의 광견병 항체 분포조사)

  • 조성범;박최규;임홍규;조미영;이달주;이은동;이정학;이병동
    • Korean Journal of Veterinary Service
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    • v.24 no.2
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    • pp.109-116
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    • 2001
  • This study was conducted to investigate the prevalence rate for rabies antibody (PRRA) of dogs near the Pukhansan National Park and in some other districts in Seoul Metropolitan city. From April to July 2000, a total of 414 serum samples were taken from dogs for breeding (92), pet dogs (162), and unclaimed/stray dogs (162). Rabies virus antibodies were detected by neutralizing peroxidase-linked assay (NPLA). Of 414 sera tested, 145 (35%) were positive to rabies virus antibody. PRRA in Pukhansan National Park area and in the other districts of Seoul city were 34.8% and 35.4%, respectively. There was no significant difference in the prevalence rate between these two districts. PRRA in pet dogs, unclaimed/stray dogs, and dogs for breeding were 39.5%, 35%, and 27.2% respectively. PRRA in dogs from residential areas, apartments, animal hospitals, and farms were 32.5%, 60%, 35.3%, and 26.7% respectively. Especially, the dogs reared in apartments had a significantly higher seroprevalence (60%) than those in residential or farm areas. PRRA in less than 1 year, 1~<2 years, 2~<3 years, and over 3 years old dogs were 14.7%, 40.4%, 38.4%, and 53% respectively, and overall 35% in the dog population. In addition, we found that dogs less than 1 year of age had lower antibody prevalence than those over 1 year of age. It was concluded that enhancement of vaccination is important in the prevention of the rabies, and that rabies vaccines should not be less supplied than the population of the dog.

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Production of Monoclonal Antibody to Newcastle Disease Virus and its Diagnostic Use (뉴켓슬병 바이러스에 대한 단크론성 항체생산 및 진단에 이용)

  • Chung Ok Choi;Chung Gil Lee;Sung Man Cho;Jin Soo Na;Soo Hwan An;Joon Hun Kwon
    • Korean Journal of Poultry Science
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    • v.15 no.3
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    • pp.207-210
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    • 1988
  • A total of 3 hybridoma clones producting menoclonal antibody (MCA) against Newcastle disease virus(NDV) was raised by cell fusion method. The MCAs did not cross react against other avian or mammalian viruses tested. However, these antibodies reacted with all strains of velogenic and lentogenic NDVs tested indicating that they are unable to discriminate the possible antigenic differences among NDVs. All. the MCAs were classified as IgG type and did not show neutralizing and hemagglutination inhibition (HAI) activity except one clone which has low HAI activity. One of these MCA raised in mouse ascites revealed the titer of $10^6$ by indirect immunofluorescent antibody (IFA) test Using the MCA, virulent NDV could easily be detected from tracheal and conjunctival smears made 2 to 3 days after experimental infection.

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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.

Lipoteichoic Acid from Lactobacillus plantarum Inhibits the Expression of Platelet-Activating Factor Receptor Induced by Staphylococcus aureus Lipoteichoic Acid or Escherichia coli Lipopolysaccharide in Human Monocyte-Like Cells

  • Kim, Hangeun;Jung, Bong Jun;Jeong, Jihye;Chun, Honam;Chung, Dae Kyun
    • Journal of Microbiology and Biotechnology
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    • v.24 no.8
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    • pp.1051-1058
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    • 2014
  • Platelet-activating factor receptor (PAFR) plays an important role in bacterial infection and inflammation. We examined the effect of the bacterial cell wall components lipopolysaccharide (LPS) and lipoteichoic acid (LTA) from Lactobacillus plantarum (pLTA) and Staphylococcus aureus (aLTA) on PAFR expression in THP-1, a monocyte-like cell line. LPS and aLTA, but not pLTA, significantly increased PAFR expression, whereas priming with pLTA inhibited LPS-mediated or aLTA-mediated PAFR expression. Expression of Toll-like receptor (TLR) 2 and 4, and CD14 increased with LPS and aLTA treatments, but was inhibited by pLTA pretreatment. Neutralizing antibodies against TLR2, TLR4, and CD14 showed that these receptors were important in LPS-mediated or aLTA-mediated PAFR expression. PAFR expression is mainly regulated by the nuclear factor kappa B signaling pathway. Blocking PAF binding to PAFR using a PAFR inhibitor indicated that LPS-mediated or aLTA-mediated PAF expression affected TNF-${\alpha}$ production. In the mouse small intestine, pLTA inhibited PAFR, TLR2, and TLR4 expression that was induced by heat-labile toxin. Our data suggested that pLTA has an anti-inflammatory effect by inhibiting the expression of PAFR that was induced by pathogenic ligands.