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Resistance to influenza A virus infection in transformed cell lines expressing an anti-PB2 monoclonal antibody. Vet J 2013; 198:487-93. [PMID: 24140339 DOI: 10.1016/j.tvjl.2013.09.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2013] [Revised: 09/11/2013] [Accepted: 09/13/2013] [Indexed: 11/24/2022]
Abstract
The polymerase basic 2 (PB2) protein is one of four proteins that make up the influenza A virus replication complex, which is responsible for viral gene transcription and replication. To assess the antiviral potential of an anti-PB2 monoclonal antibody that inhibits RNA transcription of influenza A viruses, Mardin-Darby canine kidney (MDCK) cells were transformed with two transgenes that encode the light and heavy chains of the monoclonal antibody. The transformed cell lines expressing this monoclonal antibody displayed resistance to several subtypes of influenza A virus infection. In the transformed cell lines infected with influenza A virus, the level of viral RNA transcription was decreased and the effective nuclear transportation of the PB2 protein was also inhibited. These results demonstrate that the anti-PB2 intrabody is potentially able to interfere with the effective nuclear transportation of PB2 protein, resulting in the observed resistance to influenza A virus infection in vitro.
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Gal-Tanamy M, Zemel R, Bachmatov L, Jangra RK, Shapira A, Villanueva R, Yi M, Lemon SM, Benhar I, Tur-Kaspa R. Inhibition of protease-inhibitor-resistant hepatitis C virus replicons and infectious virus by intracellular intrabodies. Antiviral Res 2010; 88:95-106. [PMID: 20705106 PMCID: PMC4418563 DOI: 10.1016/j.antiviral.2010.08.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 06/16/2010] [Accepted: 08/04/2010] [Indexed: 12/15/2022]
Abstract
Hepatitis C virus (HCV) infection is a common cause of chronic liver disease and a serious threat to human health. The HCV NS3/4A serine protease is necessary for viral replication and innate immune evasion, and represents a well-validated target for specific antiviral therapy. We previously reported the isolation of single-chain antibodies (scFvs) that inhibit NS3/4A protease activity in vitro. Expressed intracellularly (intrabodies), these scFvs blocked NS3-mediated proliferation of NS3-transfected cells. Here we show that anti-NS3 scFvs suppress HCV RNA replication when expressed intracellularly in Huh7 hepatoma cells bearing either subgenomic or genome-length HCV RNA replicons. The expression of intrabodies directed against NS3 inhibited the autonomous amplification of HCV replicons resistant to small-molecule inhibitors of the NS3/4A protease, and replicons derived from different HCV genotypes. The combination of intrabodies and interferon-α had an additive inhibitory effect on RNA replication in the replicon model. Intrabody expression also inhibited production of infectious HCV in a cell culture system. The NS3 protease activity was inhibited by the intrabodies in NS3-expressing cells. In contrast, cell-free synthesis of HCV RNA by preformed replicase complexes was not inhibited by intrabodies, suggesting that the major mode of inhibition of viral replication is inhibition of NS3/4A protease activity and subsequent suppression of viral polyprotein processing.
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Affiliation(s)
- Meital Gal-Tanamy
- Molecular Hepatology Research Laboratory, Felsenstein Medical Research Center, Sackler School of Medicine, Tel-Aviv University, Petah Tikva, Israel
- Department of Molecular Microbiology and Biotechnology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat Aviv Israel
- Center for Hepatitis Research, Institute for Human Infections and Immunity, and the Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Romy Zemel
- Molecular Hepatology Research Laboratory, Felsenstein Medical Research Center, Sackler School of Medicine, Tel-Aviv University, Petah Tikva, Israel
| | - Larissa Bachmatov
- Molecular Hepatology Research Laboratory, Felsenstein Medical Research Center, Sackler School of Medicine, Tel-Aviv University, Petah Tikva, Israel
| | - Rohit K. Jangra
- Center for Hepatitis Research, Institute for Human Infections and Immunity, and the Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Assaf Shapira
- Department of Molecular Microbiology and Biotechnology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat Aviv Israel
| | - Rodrigo Villanueva
- Center for Hepatitis Research, Institute for Human Infections and Immunity, and the Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - MinKyung Yi
- Center for Hepatitis Research, Institute for Human Infections and Immunity, and the Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Stanley M. Lemon
- Center for Hepatitis Research, Institute for Human Infections and Immunity, and the Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Itai Benhar
- Department of Molecular Microbiology and Biotechnology, The George S. Wise Faculty of Life Sciences, Tel-Aviv University, Ramat Aviv Israel
| | - Ran Tur-Kaspa
- Molecular Hepatology Research Laboratory, Felsenstein Medical Research Center, Sackler School of Medicine, Tel-Aviv University, Petah Tikva, Israel
- Department of Medicine D and Liver Institute, Rabin Medical Center, Beilinson Campus, Petah Tikva, Israel
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Serruys B, Van Houtte F, Verbrugghe P, Leroux-Roels G, Vanlandschoot P. Llama-derived single-domain intrabodies inhibit secretion of hepatitis B virions in mice. Hepatology 2009; 49:39-49. [PMID: 19085971 DOI: 10.1002/hep.22609] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
UNLABELLED Hepatitis B virus (HBV) infections cause 500,000 to 700,000 deaths per year as a consequence of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Efficient and safe antivirals to treat chronically infected patients and consequently to prevent development of hepatocellular carcinoma are still awaited. We isolated five single-domain antibodies (VHHs) that recognize the most abundant envelope protein (S) of HBV. VHHs, when expressed and retained in the endoplasmic reticulum as intrabodies, reduced levels of secreted hepatitis B surface antigen (HBsAg) particles in a cellular HBV model. In a hydrodynamics-based HBV mouse model, these intrabodies caused a marked reduction in HBsAg concentrations and a 10- to >100-fold reduction in the concentration of HBV virions in plasma. CONCLUSION VHHs potently inhibited secretion of HBV virions in vivo, showing that this approach might be useful in the treatment of HBV. To our knowledge, this is the first report of intrabody-mediated inhibition of viral secretion in mammals.
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Affiliation(s)
- Benedikte Serruys
- Center for Vaccinology, Ghent University and Hospital, Ghent, Belgium
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Jin YH, Hong SH, Kim K, Shin HJ, Park S. Intracellular antibody fragment against hepatitis B virus X protein does not inhibit viral replication. Yonsei Med J 2006; 47:721-8. [PMID: 17066517 PMCID: PMC2687759 DOI: 10.3349/ymj.2006.47.5.721] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Replication of the hepatitis B virus is suppressed by deficiency of the X protein. Although several molecules that block cellular targets of X protein reduce the production of hepatitis B virus progeny, the effect of a specific inhibitor of X protein on viral replication has not been investigated. To block X protein specifically, we adopted an intracellular expression approach using H7 single chain variable fragment (H7scFv), an antibody fragment against X protein. We previously demonstrated that cytoplasmic expression of H7scFv inhibits X protein-induced tumorigenicity and transactivation. In this study, intracellular H7scFv expression inhibits reporter gene transactivation but not viral replication determined by endogenous hepatitis B virus polymerase activity assay and real-time PCR. Our findings imply that intracellular expression of antibody fragment against X protein may not be an alternative therapeutic modality for inhibition of hepatitis B virus replication.
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Affiliation(s)
- Young-Hee Jin
- Department of Microbiology, Ajou University School of Medicine, Suwon, Korea
| | - Seung-Ho Hong
- Department of Microbiology, Ajou University School of Medicine, Suwon, Korea
| | - Kyongmin Kim
- Department of Microbiology, Ajou University School of Medicine, Suwon, Korea
| | - Ho Joon Shin
- Department of Microbiology, Ajou University School of Medicine, Suwon, Korea
| | - Sun Park
- Department of Microbiology, Ajou University School of Medicine, Suwon, Korea
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Bose B, Sinha S. Problems in using statistical analysis of replacement and silent mutations in antibody genes for determining antigen-driven affinity selection. Immunology 2005; 116:172-83. [PMID: 16162266 PMCID: PMC1817819 DOI: 10.1111/j.1365-2567.2005.02208.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The analysis of molecular signatures of antigen-driven affinity selection of B cells is of immense use in studies on normal and abnormal B cell development. Most of the published literature compares the expected and observed frequencies of replacement (R) and silent (S) mutations in the complementarity-determining regions (CDRs) and the framework regions (FRs) of antibody genes to identify the signature of antigenic selection. The basic assumption of this statistical method is that antigenic selection creates a bias for R mutations in the CDRs and for S mutations in the FRs. However, it has been argued that the differences in intrinsic mutability among different regions of an antibody gene can generate a statistically significant bias even in the absence of any antigenic selection. We have modified the existing statistical method to include the effects of intrinsic mutability of different regions of an antibody gene. We used this method to analyse sequences of several B cell-derived monoclonals against T-dependent antigens, T-independent antigens, clones derived from lymphoma and amyloidogenic clones. Our sequence analysis indicates that even after correcting for the intrinsic mutability of antibody genes, statistical parameters fail to reflect the role of antigen-driven affinity selection in maturation of many clones. We suggest that, contrary to the basic assumption of such statistical methods, selection can act both for and against R mutations in the CDR as well as in the FR regions. In addition we have identified different methodological difficulties in the current uses of such statistical analysis of antibody genes.
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Affiliation(s)
- Biplab Bose
- Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, India
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Schilling R, Ijaz S, Davidoff M, Lee JY, Locarnini S, Williams R, Naoumov NV. Endocytosis of hepatitis B immune globulin into hepatocytes inhibits the secretion of hepatitis B virus surface antigen and virions. J Virol 2003; 77:8882-92. [PMID: 12885906 PMCID: PMC167249 DOI: 10.1128/jvi.77.16.8882-8892.2003] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Hepatitis B immunoglobulin is used for prophylaxis against hepatitis B virus (HBV) and is thought to act by neutralization of virions and hepatitis B virus surface antigen (HBsAg)-containing particles in circulation. Using a panel of hepatocyte-derived cell lines, the present study investigated in vitro whether HBs-specific immunoglobulin G (IgG) is internalized in hepatocytes and whether it interacts with HBsAg in the cells. By immunoelectron microscopy and immunoblotting, human IgG and FcRn receptor for IgG were demonstrated on cellular membranes and in cytoplasmic extracts, irrespective of the HBsAg status of the cells. Furthermore, HBsAg and anti-HBs were shown to be colocalized in the same cellular compartment by two-color confocal microscopy. Endocytosis of HBs-specific IgG caused intracellular accumulation of HBsAg in a dose-dependent manner and inhibited the secretion of HBsAg and HBV virions from the cells. These effects were not observed with F(ab)(2) fragments or nonimmune IgG as controls. The specificity of intracellular HBsAg- anti-HBs interaction was further investigated in cells transfected with HBV genomes expressing wild-type HBsAg or immune escape HBsAg (with a G145R mutation). Monoclonal anti-HBs markedly reduced the secretion of wild-type HBsAg, while the secretion of mutant HBsAg was not affected. These results suggest that HBs-specific IgG binds to hepatocytes and interacts with HBsAg within the cells. This may be relevant for the selection of surface antibody escape mutations.
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Affiliation(s)
- Ralf Schilling
- Institute of Hepatology, Department of Medicine, University College London, London WC1E 6HX, United Kingdom
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Zhang J, Liu YF, Yang SJ, Qiao Q, Zhang SZ, Cheng H. Targeting therapeutic of humanized scFv25 and the fusion to mutant TNFα against hepatocellular carcinoma: a preliminary study. Shijie Huaren Xiaohua Zazhi 2003; 11:285-288. [DOI: 10.11569/wcjd.v11.i3.285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To explore the cytotoxic effects of humanized scFv25 and the fusion to mutant TNFα on HCC xenografts in nude mice.
METHODS: The mice with HCC xenografts were injected the purified recombinant immunotoxin through tail vain and executed after two weeks. The bulk and weight of tumor were observed. Expression of TNFα was detected by immunohistochemical staining in the tumor tissues.
RESULTS: The tumor regression trials of hscFv25-mTNFα showed 5/5 effective, with 2/5 completely remission and 3/5 partly remission. The therapeutic result of hscFv25-mTNFα was better than that of mutant TNFα (Xh2 = 6.62, P < 0.05). The HCC tissue treated by hscFv25-mTNFα expressed TNFα, and the positive granules were mainly existed in cytoplasm.
CONCLUSION: Recombinant immunotoxin the hscFV25-mTNFα can regress the growth of HCC with a great potential.
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Jia ZS, Chen L, Hao CQ, Feng ZH, Li JG, Wang JP, Cao YZ, Zhou YX. Intracellular immunization by hammerhead ribozyme against HCV. Shijie Huaren Xiaohua Zazhi 2003; 11:148-150. [DOI: 10.11569/wcjd.v11.i2.148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To evaluate the effect of hammerhead ribozyme 213 (Rz 213) against hepatitis C virus (HCV) infection.
METHODS: Rz213 cleaving 5'oncoding region (5'CR) of HCV was beforehand transfected in a human hepatic carcinoma cell (HHCC) line and selected for G418 resistance. Cells stably expressing Rz213 were retransfected with pCMVNCRluc containing 5扤CR-luc fusion genes by lipofectAMINE; luciferase activity in lysate of transfactant was measured in scintillation counter.
RESULTS: HHCC cells stably expressing Rz213 exhibited significant resistance to retransfection of targeting gene.
CONCLUSION: Stably transfected cells with Rz213 were selected and expressed in HHCC, and thus exerted the intracellular immunity against infection of HCV.
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Kriangkum J, Xu B, Nagata LP, Fulton RE, Suresh MR. Bispecific and bifunctional single chain recombinant antibodies. BIOMOLECULAR ENGINEERING 2001; 18:31-40. [PMID: 11535414 DOI: 10.1016/s1389-0344(01)00083-1] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Bispecific and bifunctional monoclonal antibodies as second generation monoclonals, produced by conventional chemical or somatic methods, have proved useful in the immunodiagnosis and immunotherapy of cancer and other diseases. Recombinant antibodies produced by genetic engineering techniques have also become available for use in preclinical and clinical studies. Furthermore, through genetic engineering, it is possible to remove or add on key protein domains in order to create designer antibody molecules with two or more desired functions. This review summarizes the strategies for development of single chain variable fragment (scFv) bifunctional and bispecific antibodies. The advantages and disadvantages as well as the problems of generating the various bispecific and bifunctional antibody constructs are reported and discussed. Since conventionally prepared bispecific and bifunctional monoclonal antibodies have already shown promise in clinical trials and results from preclinical studies of recombinant bispecific antibodies are encouraging, clinical trials in humans of recombinant bispecific and bifunctional antibodies, as a new generation of biologicals, are likely to be the thrust in the next decade and beyond.
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Affiliation(s)
- J Kriangkum
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2N8
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Affiliation(s)
- W A Marasco
- Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, Harvard Medical School, 44 Binney Street, Jimmy Fund Building, Room 824, Boston, MA 02115, USA
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Zoulim F. Therapy of chronic hepatitis B virus infection: inhibition of the viral polymerase and other antiviral strategies. Antiviral Res 1999; 44:1-30. [PMID: 10588330 DOI: 10.1016/s0166-3542(99)00056-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Chronic hepatitis B infection remains a major public health problem worldwide. The hepatitis B virus belongs to the family of hepadnaviruses that replicate their DNA genome via a reverse transcription pathway. The chronicity of infection in infected hepatocytes is maintained by the persistence of the viral covalently closed circular DNA. The main strategies to combat chronic HBV infection rely on the stimulation of the specific antiviral immune response and on the inhibition of viral replication. While the prolonged administration of reverse transcriptase inhibitors is most often associated with a control of viral replication rather than eradication, it may select for resistant mutants. The search for new viral targets is therefore mandatory to design combination strategies to prevent the emergence of resistant mutants and eventually clear viral infection.
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