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Hansen TJ, Fong SL, Day JK, Capra JA, Hodges E. Human gene regulatory evolution is driven by the divergence of regulatory element function in both cis and trans. CELL GENOMICS 2024; 4:100536. [PMID: 38604126 PMCID: PMC11019363 DOI: 10.1016/j.xgen.2024.100536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 01/03/2024] [Accepted: 03/10/2024] [Indexed: 04/13/2024]
Abstract
Gene regulatory divergence between species can result from cis-acting local changes to regulatory element DNA sequences or global trans-acting changes to the regulatory environment. Understanding how these mechanisms drive regulatory evolution has been limited by challenges in identifying trans-acting changes. We present a comprehensive approach to directly identify cis- and trans-divergent regulatory elements between human and rhesus macaque lymphoblastoid cells using assay for transposase-accessible chromatin coupled to self-transcribing active regulatory region (ATAC-STARR) sequencing. In addition to thousands of cis changes, we discover an unexpected number (∼10,000) of trans changes and show that cis and trans elements exhibit distinct patterns of sequence divergence and function. We further identify differentially expressed transcription factors that underlie ∼37% of trans differences and trace how cis changes can produce cascades of trans changes. Overall, we find that most divergent elements (67%) experienced changes in both cis and trans, revealing a substantial role for trans divergence-alone and together with cis changes-in regulatory differences between species.
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Affiliation(s)
- Tyler J Hansen
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Sarah L Fong
- Vanderbilt Genetics Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Bakar Computational Health Sciences Institute, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Jessica K Day
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - John A Capra
- Bakar Computational Health Sciences Institute, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Epidemiology and Biostatistics, University of California, San Francisco, CA 94143, USA.
| | - Emily Hodges
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Vanderbilt Genetics Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Vanderbilt Ingram Cancer Center, Nashville, TN 37232, USA.
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Hansen T, Fong S, Capra JA, Hodges E. Human gene regulatory evolution is driven by the divergence of regulatory element function in both cis and trans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.14.528376. [PMID: 36824965 PMCID: PMC9949080 DOI: 10.1101/2023.02.14.528376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Gene regulatory divergence between species can result from cis-acting local changes to regulatory element DNA sequences or global trans-acting changes to the regulatory environment. Understanding how these mechanisms drive regulatory evolution has been limited by challenges in identifying trans-acting changes. We present a comprehensive approach to directly identify cis- and trans-divergent regulatory elements between human and rhesus macaque lymphoblastoid cells using ATAC-STARR-seq. In addition to thousands of cis changes, we discover an unexpected number (~10,000) of trans changes and show that cis and trans elements exhibit distinct patterns of sequence divergence and function. We further identify differentially expressed transcription factors that underlie >50% of trans differences and trace how cis changes can produce cascades of trans changes. Overall, we find that most divergent elements (67%) experienced changes in both cis and trans, revealing a substantial role for trans divergence-alone and together with cis changes-to regulatory differences between species.
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Affiliation(s)
- Tyler Hansen
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37212, USA
| | - Sarah Fong
- Vanderbilt Genetics Institute, Vanderbilt University School of Medicine, Nashville, TN 37212, USA
- Bakar Computational Health Sciences Institute, University of California, San Francisco, San Francisco, CA 94143, USA
| | - John A. Capra
- Bakar Computational Health Sciences Institute, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Emily Hodges
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37212, USA
- Vanderbilt Genetics Institute, Vanderbilt University School of Medicine, Nashville, TN 37212, USA
- Lead contact
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Primate innate immune responses to bacterial and viral pathogens reveals an evolutionary trade-off between strength and specificity. Proc Natl Acad Sci U S A 2021; 118:2015855118. [PMID: 33771921 PMCID: PMC8020666 DOI: 10.1073/pnas.2015855118] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Humans and our close evolutionary relatives respond differently to a large number of infections. Such differences are thought to result, at least in part, from interspecies differences in immune function. Here, we report on the whole-genome expression of blood leukocytes from four primate species responding to bacterial and viral stimulation. We show that apes mount a markedly stronger early transcriptional response to both viral and bacterial stimulation when compared to African and Asian monkeys. In addition, our findings suggest that apes activate a broader array of defense molecules that may be beneficial for early pathogen killing at the potential cost of increased energy expenditure and tissue damage. Our results provide insight into the evolution of immune responses in primates. Despite their close genetic relatedness, apes and African and Asian monkeys (AAMs) differ in their susceptibility to severe bacterial and viral infections that are important causes of human disease. Such differences between humans and other primates are thought to be a result, at least in part, of interspecies differences in immune response to infection. However, because of the lack of comparative functional data across species, it remains unclear in what ways the immune systems of humans and other primates differ. Here, we report the whole-genome transcriptomic responses of ape species (human and chimpanzee) and AAMs (rhesus macaque and baboon) to bacterial and viral stimulation. We find stark differences in the responsiveness of these groups, with apes mounting a markedly stronger early transcriptional response to both viral and bacterial stimulation, altering the transcription of ∼40% more genes than AAMs. Additionally, we find that genes involved in the regulation of inflammatory and interferon responses show the most divergent early transcriptional responses across primates and that this divergence is attenuated over time. Finally, we find that relative to AAMs, apes engage a much less specific immune response to different classes of pathogens during the early hours of infection, up-regulating genes typical of anti-viral and anti-bacterial responses regardless of the nature of the stimulus. Overall, these findings suggest apes exhibit increased sensitivity to bacterial and viral immune stimulation, activating a broader array of defense molecules that may be beneficial for early pathogen killing at the potential cost of increased energy expenditure and tissue damage.
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Sasikumar S, Chameettachal S, Kingshott P, Cromer B, Pati F. 3D hepatic mimics - the need for a multicentric approach. ACTA ACUST UNITED AC 2020; 15:052002. [PMID: 32460259 DOI: 10.1088/1748-605x/ab971c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The liver is a center of metabolic activity, including the metabolism of drugs, and consequently is prone to drug-induced liver injury. Failure to detect hepatotoxicity of drugs during their development will lead to the withdrawal of the drugs during clinical trials. To avoid such clinical and economic consequences, in vitro liver models that can precisely predict the toxicity of a drug during the pre-clinical phase is necessary. This review describes the different technologies that are used to develop in vitro liver models and the different approaches aimed at mimicking different functional aspects of the liver at the fundamental level. This involves mimicking of the functional and structural units like the sinusoid, the bile canalicular system, and the acinus.
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Affiliation(s)
- Shyama Sasikumar
- Department of Biomedical Engineering, Indian Institute of Technology Hyderabad, Sangareddy 502285, Telangana, India. Department of Chemistry and Biotechnology, School of Science, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia
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5
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Abstract
Hepatitis C virus (HCV) species tropism is incompletely understood. We have previously shown that at the level of entry, human CD81 and occludin (OCLN) comprise the minimal set of human factors needed for viral uptake into murine cells. As an alternative approach to genetic humanization, species barriers can be overcome by adapting HCV to use the murine orthologues of these entry factors. We previously generated a murine tropic HCV (mtHCV or Jc1/mCD81) strain harboring three mutations within the viral envelope proteins that allowed productive entry into mouse cell lines. In this study, we aimed to characterize the ability of mtHCV to enter and infect mouse hepatocytes in vivo and in vitro. Using a highly sensitive, Cre-activatable reporter, we demonstrate that mtHCV can enter mouse hepatocytes in vivo in the absence of any human cofactors. Viral entry still relied on expression of mouse CD81 and SCARB1 and was more efficient when mouse CD81 and OCLN were overexpressed. HCV entry could be significantly reduced in the presence of anti-HCV E2 specific antibodies, suggesting that uptake of mtHCV is dependent on viral glycoproteins. Despite mtHCV’s ability to enter murine hepatocytes in vivo, we did not observe persistent infection, even in animals with severely blunted type I and III interferon signaling and impaired adaptive immune responses. Altogether, these results establish proof of concept that the barriers limiting HCV species tropism can be overcome by viral adaptation. However, additional viral adaptations will likely be needed to increase the robustness of a murine model system for hepatitis C. At least 150 million individuals are chronically infected with HCV and are at risk of developing serious liver disease. Despite the advent of effective antiviral therapy, the frequency of chronic carriers has only marginally decreased. A major roadblock in developing a vaccine that would prevent transmission is the scarcity of animal models that are susceptible to HCV infection. It is poorly understood why HCV infects only humans and chimpanzees. To develop an animal model for hepatitis C, previous efforts focused on modifying the host environment of mice, for example, to render them more susceptible to HCV infection. Here, we attempted a complementary approach in which a laboratory-derived HCV variant was tested for its ability to infect mice. We demonstrate that this engineered HCV strain can enter mouse liver cells but does not replicate efficiently. Thus, additional adaptations are likely needed to construct a robust animal model for HCV.
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Thomas E, Liang TJ. Experimental models of hepatitis B and C - new insights and progress. Nat Rev Gastroenterol Hepatol 2016; 13:362-74. [PMID: 27075261 PMCID: PMC5578419 DOI: 10.1038/nrgastro.2016.37] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Viral hepatitis is a major cause of morbidity and mortality, affecting hundreds of millions of people worldwide. Hepatitis-causing viruses initiate disease by establishing both acute and chronic infections, and several of these viruses are specifically associated with the development of hepatocellular carcinoma. Consequently, intense research efforts have been focusing on increasing our understanding of hepatitis virus biology and on improving antiviral therapy and vaccination strategies. Although valuable information on viral hepatitis emerged from careful epidemiological studies on sporadic outbreaks in humans, experimental models using cell culture, rodent and non-human primates were essential in advancing the field. Through the use of these experimental models, improvement in both the treatment and prevention of viral hepatitis has progressed rapidly; however, agents of viral hepatitis are still among the most common pathogens infecting humans. In this Review, we describe the important part that these experimental models have played in the study of viral hepatitis and led to monumental advances in our understanding and treatment of these pathogens. Ongoing developments in experimental models are also described.
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Affiliation(s)
- Emmanuel Thomas
- Schiff Center for Liver Diseases and Sylvester Cancer Center, Room
PAP514, Papanicolaou Building, 1550 NW 10th Avenue, Miami, Florida 33136, USA
| | - T. Jake Liang
- Liver Diseases Branch, NIH, Building 10-9B16, Bethesda, Maryland
20892–1800, USA
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7
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Determinants Involved in Hepatitis C Virus and GB Virus B Primate Host Restriction. J Virol 2015; 89:12131-44. [PMID: 26401036 DOI: 10.1128/jvi.01161-15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 09/17/2015] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Hepatitis C virus (HCV) only infects humans and chimpanzees, while GB virus B (GBV-B), another hepatotropic hepacivirus, infects small New World primates (tamarins and marmosets). In an effort to develop an immunocompetent small primate model for HCV infection to study HCV pathogenesis and vaccine approaches, we investigated the HCV life cycle step(s) that may be restricted in small primate hepatocytes. First, we found that replication-competent, genome-length chimeric HCV RNAs encoding GBV-B structural proteins in place of equivalent HCV sequences designed to allow entry into simian hepatocytes failed to induce viremia in tamarins following intrahepatic inoculation, nor did they lead to progeny virus in permissive, transfected human Huh7.5 hepatoma cells upon serial passage. This likely reflected the disruption of interactions between distantly related structural and nonstructural proteins that are essential for virion production, whereas such cross talk could be restored in similarly designed HCV intergenotypic recombinants via adaptive mutations in NS3 protease or helicase domains. Next, HCV entry into small primate hepatocytes was examined directly using HCV-pseudotyped retroviral particles (HCV-pp). HCV-pp efficiently infected tamarin hepatic cell lines and primary marmoset hepatocyte cultures through the use of the simian CD81 ortholog as a coreceptor, indicating that HCV entry is not restricted in small New World primate hepatocytes. Furthermore, we observed genomic replication and modest virus secretion following infection of primary marmoset hepatocyte cultures with a highly cell culture-adapted HCV strain. Thus, HCV can successfully complete its life cycle in primary simian hepatocytes, suggesting the possibility of adapting some HCV strains to small primate hosts. IMPORTANCE Hepatitis C virus (HCV) is an important human pathogen that infects over 150 million individuals worldwide and leads to chronic liver disease. The lack of a small animal model for this infection impedes the development of a preventive vaccine and pathogenesis studies. In seeking to establish a small primate model for HCV, we first attempted to generate recombinants between HCV and GB virus B (GBV-B), a hepacivirus that infects small New World primates (tamarins and marmosets). This approach revealed that the genetic distance between these hepaciviruses likely prevented virus morphogenesis. We next showed that HCV pseudoparticles were able to infect tamarin or marmoset hepatocytes efficiently, demonstrating that there was no restriction in HCV entry into these simian cells. Furthermore, we found that a highly cell culture-adapted HCV strain was able to achieve a complete viral cycle in primary marmoset hepatocyte cultures, providing a promising basis for further HCV adaptation to small primate hosts.
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Scull MA, Shi C, de Jong YP, Gerold G, Ries M, von Schaewen M, Donovan BM, Labitt RN, Horwitz JA, Gaska JM, Hrebikova G, Xiao JW, Flatley B, Fung C, Chiriboga L, Walker CM, Evans DT, Rice CM, Ploss A. Hepatitis C virus infects rhesus macaque hepatocytes and simianized mice. Hepatology 2015; 62:57-67. [PMID: 25820364 PMCID: PMC4482775 DOI: 10.1002/hep.27773] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 03/01/2015] [Indexed: 12/31/2022]
Abstract
UNLABELLED At least 170 million people are chronically infected with hepatitis C virus (HCV). Owing to the narrow host range of HCV and restricted use of chimpanzees, there is currently no suitable animal model for HCV pathogenesis studies or the development of a HCV vaccine. To identify cellular determinants of interspecies transmission and establish a novel immunocompetent model system, we examined the ability of HCV to infect hepatocytes from a small nonhuman primate, the rhesus macaque (Macaca mulatta). We show that the rhesus orthologs of critical HCV entry factors support viral glycoprotein-dependent virion uptake. Primary hepatocytes from rhesus macaques are also permissive for HCV-RNA replication and particle production, which is enhanced when antiviral signaling is suppressed. We demonstrate that this may be owing to the diminished capacity of HCV to antagonize mitochondrial antiviral-signaling protein-dependent innate cellular defenses. To test the ability of HCV to establish persistent replication in vivo, we engrafted primary rhesus macaque hepatocytes into immunocompromised xenorecipients. Inoculation of resulting simian liver chimeric mice with either HCV genotype 1a or 2a resulted in HCV serum viremia for up to 10 weeks. CONCLUSION Together, these data indicate that rhesus macaques may be a viable model for HCV and implicate host immunity as a potential species-specific barrier to HCV infection. We conclude that suppression of host immunity or further viral adaptation may allow robust HCV infection in rhesus macaques and creation of a new animal model for studies of HCV pathogenesis, lentivirus coinfection, and vaccine development.
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Affiliation(s)
- Margaret A. Scull
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065, USA
| | - Chao Shi
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065, USA
| | - Ype P. de Jong
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065, USA,Division of Gastroenterology and Hepatology, Center for the Study of Hepatitis C, Weill Cornell Medical College, New York, New York 10065, USA
| | - Gisa Gerold
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065, USA
| | - Moritz Ries
- AIDS Vaccine Research Laboratory, Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI 53711, USA
| | - Markus von Schaewen
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA
| | - Bridget M. Donovan
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065, USA
| | - Rachael N. Labitt
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065, USA
| | - Joshua A. Horwitz
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065, USA
| | - Jenna M. Gaska
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA
| | - Gabriela Hrebikova
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA
| | - Jing W. Xiao
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065, USA
| | - Brenna Flatley
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065, USA
| | - Canny Fung
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065, USA
| | - Luis Chiriboga
- Department of Pathology, New York University Medical Center, New York, New York, USA
| | | | - David T. Evans
- AIDS Vaccine Research Laboratory, Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, WI 53711, USA
| | - Charles M. Rice
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065, USA
| | - Alexander Ploss
- Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Diseases, The Rockefeller University, New York, New York 10065, USA,Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA,Correspondence to: Alexander Ploss, Ph.D., Department of Molecular Biology, Princeton University, Washington Road, LTL 110, Princeton, NJ 08544, Phone: (609) 258-7128, Fax: (609) 258-1701,
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9
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Abstract
The investigation of virus-induced liver disease and hepatocellular carcinoma needs small animal models modeling hepatitis C virus (HCV) infection and liver disease biology. A recent study published in Cell Research reports a novel mouse model which is permissive for chronic HCV infection and shows chronic liver injury including inflammation, steatosis and fibrosis.
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Affiliation(s)
- Rajiv G Tawar
- Inserm, U1110, Strasbourg, France
- Université de Strasbourg, Strasbourg, France
| | - Laurent Mailly
- Inserm, U1110, Strasbourg, France
- Université de Strasbourg, Strasbourg, France
| | - Thomas F Baumert
- Inserm, U1110, Strasbourg, France
- Université de Strasbourg, Strasbourg, France
- Pôle Hépato-digestif, Institut Hospitalo-Universitaire, Strasbourg, France
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Abstract
Because of their strong similarities to humans across physiologic, developmental, behavioral, immunologic, and genetic levels, nonhuman primates are essential models for a wide spectrum of biomedical research. But unlike other animal models, nonhuman primates possess substantial outbred genetic variation, reducing statistical power and potentially confounding interpretation of results in research studies. Although unknown genetic variation is a hindrance in studies that allocate animals randomly, taking genetic variation into account in study design affords an opportunity to transform the way that nonhuman primates are used in biomedical research. New understandings of how the function of individual genes in rhesus macaques mimics that seen in humans are greatly advancing the rhesus macaques utility as research models, but epistatic interaction, epigenetic regulatory mechanisms, and the intricacies of gene networks limit model development. We are now entering a new era of nonhuman primate research, brought on by the proliferation and rapid expansion of genomic data. Already the cost of a rhesus macaque genome is dwarfed by its purchase and husbandry costs, and complete genomic datasets will inevitably encompass each rhesus macaque used in biomedical research. Advancing this outcome is paramount. It represents an opportunity to transform the way animals are assigned and used in biomedical research and to develop new models of human disease. The genetic and genomic revolution brings with it a paradigm shift for nonhuman primates and new mandates on how nonhuman primates are used in biomedical research.
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von Schaewen M, Ding Q, Ploss A. Visualizing hepatitis C virus infection in humanized mice. J Immunol Methods 2014; 410:50-9. [PMID: 24642425 DOI: 10.1016/j.jim.2014.03.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 03/06/2014] [Indexed: 12/20/2022]
Abstract
Hepatitis C virus (HCV) establishes frequently persistent infections. Chronic carriers can develop severe liver disease. HCV has been intensely studied in a variety of cell culture systems. However, commonly used cell lines and primary hepatocyte cultures do not or only in part recapitulate the intricate host environment HCV faces in the liver. HCV infects readily only humans and chimpanzees, which poses challenges in studying HCV infection in vivo. Consequently, tractable small animal models are needed that are not only suitable for analyzing HCV infection but also for testing novel therapeutics. Here, we will focus our discussion on humanized mice, i.e. mice engrafted with human tissues or expressing human genes, which support HCV infection. We will further highlight novel methods that can be used to unambiguously detect HCV infected cells in situ, thereby facilitating a spatio-temporal dissection of HCV infection in the three dimensional context of the liver.
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Affiliation(s)
- Markus von Schaewen
- Department of Molecular Biology, Princeton University, 110 Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544, United States
| | - Qiang Ding
- Department of Molecular Biology, Princeton University, 110 Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544, United States
| | - Alexander Ploss
- Department of Molecular Biology, Princeton University, 110 Lewis Thomas Laboratory, Washington Road, Princeton, NJ 08544, United States.
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12
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Murine models of hepatitis C: what can we look forward to? Antiviral Res 2014; 104:15-22. [PMID: 24462693 DOI: 10.1016/j.antiviral.2014.01.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 01/10/2014] [Accepted: 01/12/2014] [Indexed: 12/11/2022]
Abstract
The study of interactions between hepatitis C virus (HCV) with its mammalian host, along with the development of more effective therapeutics and vaccines has been delayed by the lack of a suitable small animal model. HCV readily infects only humans and chimpanzees, which poses logistic, economic and ethical challenges with analyzing HCV infection in vivo. Progress has been made in understanding the determinants that dictate HCV's narrow host range providing a blueprint for constructing a mouse model with inheritable susceptibility to HCV infection. Indeed, genetically humanized mice were generated that support viral uptake, replication and production of infectious virions--albeit at low levels. These efforts are complemented with attempts to select for viral variants that are inherently more capable of replicating in non-human species. In parallel, engraftment of relevant human tissues into improved xenorecipients is being continuously refined. Incorporating advances in stem-cell-biology and tissue engineering may allow the generation of patient-specific humanized mice. Construction of such mouse "avatars" may allow analyzing functionally patient-specific differences with respect to susceptibility to infection, disease progression and responses to treatment. In this review, we discuss the three, before mentioned approaches to overcome current species barriers and generate a small animal model for HCV infection, i.e. genetic modification of mice to increase their susceptibility to the virus; genetic modification of HCV, to increase its pathogenicity for mice; and the introduction of human liver and immune cells into immunodeficient mice, to create "humanized" mice. Although in the foreseeable future there will not be a single model that perfectly mimics the natural course of HCV in humans there is reason for optimism. The spectrum of murine animal models for hepatitis C provides a broad arsenal for analyzing the disease. These models may play an important role by prioritizing vaccine candidates and possibly refining combination anti-viral drug therapies. This article forms part of a symposium in Anti-viral Research on "Hepatitis C: next steps toward global eradication."
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Setia S, Gambhir R, Kapoor V, Jindal G, Garg S, Setia S. Attitudes and Awareness Regarding Hepatitis B and Hepatitis C Amongst Health-care Workers of a Tertiary Hospital in India. Ann Med Health Sci Res 2013; 3:551-8. [PMID: 24380007 PMCID: PMC3868122 DOI: 10.4103/2141-9248.122105] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background: Hepatitis is an inflammatory disease of the liver. In sever cases, it may lead to permanent liver damage including liver cirrhosis or hepato-cellular carcinoma and may ultimately lead to death. Health-care workers (HCWs), due to their regular contact with patients are at a high-risk of acquiring this disease. Aim: The aim of this study was to assess the knowledge and attitude toward hepatitis B and C infection among the health-care interns and correlate the level of awareness to the attitude they behold toward the disease. Subjects and Methods: A closed ended questionnaire consisting of questions to evaluate the knowledge regarding hepatitis B and C infection and attitude of the (HCWs/interns) was duly filled by 255 participants including, 100 dental, 100 medical, and 55 nursing interns. Statistical analysis was carried out using the Chi-square test, ANOVA test, post-hoc test and Pearson's correlation. Results: Although most of the interns were aware of the existence of hepatitis B and C infection, the level of awareness regarding the modes of transmission and vaccination was found to be dissatisfactory. Awareness level regarding the infection among nursing interns was statistically significantly lower than the dental and medical interns. A direct positive correlation as found between awareness score and behavior score, which reveals that interns with better awareness level had better attitudes toward the infection and prevention of its transmission. Conclusion: There is an urgent need to increase the level and quality of training among HCWs to prevent the spread of hepatitis B virus and hepatitis C virus.
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Affiliation(s)
- S Setia
- Department of Public Health Dentistry, Gian Sagar Dental College and Hospital, Rajpura, Punjab, India
| | - Rs Gambhir
- Department of Public Health Dentistry, Gian Sagar Dental College and Hospital, Rajpura, Punjab, India
| | - V Kapoor
- Department of Oral Surgery, Gian Sagar Dental College and Hospital, Rajpura, Punjab, India
| | - G Jindal
- Department of Oral Surgery, Gian Sagar Dental College and Hospital, Rajpura, Punjab, India
| | - S Garg
- Department of Oral Surgery, Gian Sagar Dental College and Hospital, Rajpura, Punjab, India
| | - S Setia
- Department of Radiology, Government Multispeciality Hospital, Chandigarh, India
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14
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Deest M, Westhaus S, Steinmann E, Manns MP, von Hahn T, Ciesek S. Impact of single nucleotide polymorphisms in the essential HCV entry factor CD81 on HCV infectivity and neutralization. Antiviral Res 2013; 101:37-44. [PMID: 24211330 DOI: 10.1016/j.antiviral.2013.10.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 10/22/2013] [Accepted: 10/30/2013] [Indexed: 12/22/2022]
Abstract
End stage liver disease caused by chronic infection with the hepatitis C virus (HCV) is a leading indication for liver transplantation, yet outcomes are poor since the liver graft is rapidly re-infected by HCV. Antibodies against the essential HCV receptor CD81 have been shown to inhibit HCV cell entry in vitro and in vivo and may represent an attractive treatment option. However, several CD81 variants exist at low levels in human populations. We aimed to investigate to what extent these variants function as HCV receptors and would be amenable to therapeutic interventions with CD81 antibodies. We used lentiviral expression to introduce wildtype or variant CD81 in the CD81(low) Lunet N4 cell line. HCV replication cycle steps and neutralization by CD81 antibodies were then investigated using full length HCV reporter viruses (HCVcc) as well as HCV pseudoparticles (HCVpp). We found that all tested CD81 variants support cell entry by HCVpp and HCVcc with an efficiency similar to wildtype CD81. Other replication cycle steps, namely intracellular RNA replication and release of new particles, were also unaffected by the presence of CD81 variants. Importantly, four neutralizing antibodies directed against the CD81 LEL (5A6, JS81, 1D6 and 1.3.3.22) retained their ability to inhibit HCV infection when wildtype CD81 on target cells was replaced with any of the CD81 variants. These data indicate that CD81 variants that exist in the human population are fully functional as HCV receptors and their presence would not diminish the efficacy of therapeutic regimens that include CD81-antibodies.
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Affiliation(s)
- Maximilian Deest
- Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Germany; German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Germany
| | - Sandra Westhaus
- Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Germany; German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Germany; Institute for Molecular Biology, Medical School Hannover, Hannover, Germany
| | - Eike Steinmann
- Division of Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, A Joint Venture Between the Medical School Hannover (MHH) and the Helmholtz Centre for Infection Research (HZI), Hannover, Germany
| | - Michael P Manns
- Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Germany; German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Germany
| | - Thomas von Hahn
- Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Germany; German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Germany; Institute for Molecular Biology, Medical School Hannover, Hannover, Germany
| | - Sandra Ciesek
- Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Germany; German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig, Germany.
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Vogt A, Scull MA, Friling T, Horwitz JA, Donovan BM, Dorner M, Gerold G, Labitt RN, Rice CM, Ploss A. Recapitulation of the hepatitis C virus life-cycle in engineered murine cell lines. Virology 2013; 444:1-11. [PMID: 23777661 DOI: 10.1016/j.virol.2013.05.036] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 04/05/2013] [Accepted: 05/26/2013] [Indexed: 01/13/2023]
Abstract
Hepatitis C virus (HCV) remains a major medical problem. In-depth study of HCV pathogenesis and immune responses is hampered by the lack of suitable small animal models. The narrow host range of HCV remains incompletely understood. We demonstrate that the entire HCV life-cycle can be recapitulated in mouse cells. We show that antiviral signaling interferes with HCV RNA replication in mouse cells. We were able to infect mouse cells expressing human CD81 and occludin (OCLN)-the minimal set of entry factor factors required for HCV uptake into mouse cells. Infected mouse cells sustain HCV RNA replication in the presence of miR122 and release infectious particles when mouse apoE is supplied. Our data demonstrate that the barriers of HCV interspecies transmission can be overcome by engineering a suitable cellular environment and provide a blue-print towards constructing a small animal model for HCV infection.
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Affiliation(s)
- Alexander Vogt
- Center for the Study of Hepatitis C, The Rockefeller University, New York, NY 10065, USA
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