1
|
Replication of Hepatitis E Virus (HEV) in Primary Human-Derived Monocytes and Macrophages In Vitro. Vaccines (Basel) 2020; 8:vaccines8020239. [PMID: 32455708 PMCID: PMC7349946 DOI: 10.3390/vaccines8020239] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/15/2020] [Accepted: 05/18/2020] [Indexed: 12/16/2022] Open
Abstract
HEV is the most causative agent of acute viral hepatitis globally. HEV causes acute, chronic, and extrahepatic manifestations. Chronic HEV infection develops in immunocompromised patients such as organ transplant patients, HIV-infected patients, and leukemic patients. The source of chronic HEV infection is not known. Also, the source of extrahepatic manifestations associated with HEV infection is still unclear. Hepatotropic viruses such as HCV and HBV replicate in peripheral blood mononuclear cells (PBMCs) and these cells become a source of chronic reactivation of the infections in allograft organ transplant patients. Herein, we reported that PBMCs and bone marrow-derived macrophages (BMDMs), isolated from healthy donors (n = 3), are susceptible to HEV in vitro. Human monocytes (HMOs), human macrophages (HMACs), and human BMDMs were challenged with HEV-1 and HEV-3 viruses. HEV RNA was measured by qPCR, the marker of the intermediate replicative form (ds-RNA) was assessed by immunofluorescence, and HEV capsid protein was assessed by flow cytometry and ELISA. HEV infection was successfully established in primary HMOs, HMACs, and human BMDMs, but not in the corresponding cells of murine origin. Intermediate replicative form (ds RNA) was detected in HMOs and HMACs challenged with HEV. The HEV load was increased over time, and the HEV capsid protein was detected intracellularly in the HEV-infected cells and accumulated extracellularly over time, confirming that HEV completes the life cycle inside these cells. The HEV particles produced from the infected BMDMs were infectious to naive HMOs in vitro. The HEV viral load was comparable in HEV-1- and HEV-3-infected cells, but HEV-1 induced more inflammatory responses. In conclusion, HMOs, HMACs, and human BMDMs are permissive to HEV infection and these cells could be the source of chronic and recurrent infection, especially in immunocompromised patients. Replication of HEV in human BMDMs could be related to hematological disorders associated with extrahepatic manifestations.
Collapse
|
2
|
Kindler E, Gil-Cruz C, Spanier J, Li Y, Wilhelm J, Rabouw HH, Züst R, Hwang M, V’kovski P, Stalder H, Marti S, Habjan M, Cervantes-Barragan L, Elliot R, Karl N, Gaughan C, van Kuppeveld FJM, Silverman RH, Keller M, Ludewig B, Bergmann CC, Ziebuhr J, Weiss SR, Kalinke U, Thiel V. Early endonuclease-mediated evasion of RNA sensing ensures efficient coronavirus replication. PLoS Pathog 2017; 13:e1006195. [PMID: 28158275 PMCID: PMC5310923 DOI: 10.1371/journal.ppat.1006195] [Citation(s) in RCA: 167] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 02/15/2017] [Accepted: 01/20/2017] [Indexed: 12/11/2022] Open
Abstract
Coronaviruses are of veterinary and medical importance and include highly pathogenic zoonotic viruses, such as SARS-CoV and MERS-CoV. They are known to efficiently evade early innate immune responses, manifesting in almost negligible expression of type-I interferons (IFN-I). This evasion strategy suggests an evolutionary conserved viral function that has evolved to prevent RNA-based sensing of infection in vertebrate hosts. Here we show that the coronavirus endonuclease (EndoU) activity is key to prevent early induction of double-stranded RNA (dsRNA) host cell responses. Replication of EndoU-deficient coronaviruses is greatly attenuated in vivo and severely restricted in primary cells even during the early phase of the infection. In macrophages we found immediate induction of IFN-I expression and RNase L-mediated breakdown of ribosomal RNA. Accordingly, EndoU-deficient viruses can retain replication only in cells that are deficient in IFN-I expression or sensing, and in cells lacking both RNase L and PKR. Collectively our results demonstrate that the coronavirus EndoU efficiently prevents simultaneous activation of host cell dsRNA sensors, such as Mda5, OAS and PKR. The localization of the EndoU activity at the site of viral RNA synthesis-within the replicase complex-suggests that coronaviruses have evolved a viral RNA decay pathway to evade early innate and intrinsic antiviral host cell responses.
Collapse
Affiliation(s)
- Eveline Kindler
- Department of Infectious Diseases and Pathobiology, University of Bern, Bern, Switzerland
- Federal Department of Home Affairs, Institute of Virology and Immunology, Bern and Mittelhäusern, Switzerland
| | - Cristina Gil-Cruz
- Institute of Immunobiology, Kantonsspital St.Gallen, St.Gallen, Switzerland
| | - Julia Spanier
- Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School, Hannover, Germany
| | - Yize Li
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Jochen Wilhelm
- Universities Giessen & Marburg Lung Center (UGMLC), Deutsches Zentrum für Lungenforschung (DZL), Giessen, Germany
| | - Huib H. Rabouw
- Virology Division, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | | | - Mihyun Hwang
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States of America
| | - Philip V’kovski
- Department of Infectious Diseases and Pathobiology, University of Bern, Bern, Switzerland
- Federal Department of Home Affairs, Institute of Virology and Immunology, Bern and Mittelhäusern, Switzerland
- Graduate School for Biomedical Science, University of Bern, Bern, Switzerland
| | - Hanspeter Stalder
- Department of Infectious Diseases and Pathobiology, University of Bern, Bern, Switzerland
- Federal Department of Home Affairs, Institute of Virology and Immunology, Bern and Mittelhäusern, Switzerland
| | - Sabrina Marti
- Department of Infectious Diseases and Pathobiology, University of Bern, Bern, Switzerland
- Federal Department of Home Affairs, Institute of Virology and Immunology, Bern and Mittelhäusern, Switzerland
| | | | | | - Ruth Elliot
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Nadja Karl
- Institute for Medical Virology, Justus-Liebig-University, Giessen, Germany
| | - Christina Gaughan
- Department of Cancer Biology, Lerner Research Institute, Cleveland, Ohio, United States of America
| | - Frank J. M. van Kuppeveld
- Virology Division, Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Robert H. Silverman
- Department of Cancer Biology, Lerner Research Institute, Cleveland, Ohio, United States of America
| | - Markus Keller
- Institute of Novel and Emerging Infectious Diseases, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Burkhard Ludewig
- Institute of Immunobiology, Kantonsspital St.Gallen, St.Gallen, Switzerland
| | - Cornelia C. Bergmann
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio, United States of America
| | - John Ziebuhr
- Institute for Medical Virology, Justus-Liebig-University, Giessen, Germany
| | - Susan R. Weiss
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Ulrich Kalinke
- Institute for Experimental Infection Research, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Helmholtz Centre for Infection Research and the Hannover Medical School, Hannover, Germany
| | - Volker Thiel
- Department of Infectious Diseases and Pathobiology, University of Bern, Bern, Switzerland
- Federal Department of Home Affairs, Institute of Virology and Immunology, Bern and Mittelhäusern, Switzerland
- * E-mail:
| |
Collapse
|
3
|
Dotzauer A, Kraemer L. Innate and adaptive immune responses against picornaviruses and their counteractions: An overview. World J Virol 2012; 1:91-107. [PMID: 24175214 PMCID: PMC3782268 DOI: 10.5501/wjv.v1.i3.91] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 02/22/2012] [Accepted: 05/20/2012] [Indexed: 02/05/2023] Open
Abstract
Picornaviruses, small positive-stranded RNA viruses, cause a wide range of diseases which is based on their differential tissue and cell type tropisms. This diversity is reflected by the immune responses, both innate and adaptive, induced after infection, and the subsequent interactions of the viruses with the immune system. The defense mechanisms of the host and the countermeasures of the virus significantly contribute to the pathogenesis of the infections. Important human pathogens are poliovirus, coxsackievirus, human rhinovirus and hepatitis A virus. These viruses are the best-studied members of the family, and in this review we want to present the major aspects of the reciprocal effects between the immune system and these viruses.
Collapse
Affiliation(s)
- Andreas Dotzauer
- Andreas Dotzauer, Leena Kraemer, Department of Virology, University of Bremen, 28359 Bremen, Germany
| | | |
Collapse
|
4
|
Züst R, Cervantes-Barragan L, Habjan M, Maier R, Neuman BW, Ziebuhr J, Szretter KJ, Baker SC, Barchet W, Diamond MS, Siddell SG, Ludewig B, Thiel V. Ribose 2'-O-methylation provides a molecular signature for the distinction of self and non-self mRNA dependent on the RNA sensor Mda5. Nat Immunol 2011; 12:137-43. [PMID: 21217758 PMCID: PMC3182538 DOI: 10.1038/ni.1979] [Citation(s) in RCA: 595] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Accepted: 12/02/2010] [Indexed: 02/07/2023]
Abstract
The 5' cap structures of higher eukaryote mRNAs have ribose 2'-O-methylation. Likewise, many viruses that replicate in the cytoplasm of eukaryotes have evolved 2'-O-methyltransferases to autonomously modify their mRNAs. However, a defined biological role for 2'-O-methylation of mRNA remains elusive. Here we show that 2'-O-methylation of viral mRNA was critically involved in subverting the induction of type I interferon. We demonstrate that human and mouse coronavirus mutants lacking 2'-O-methyltransferase activity induced higher expression of type I interferon and were highly sensitive to type I interferon. Notably, the induction of type I interferon by viruses deficient in 2'-O-methyltransferase was dependent on the cytoplasmic RNA sensor Mda5. This link between Mda5-mediated sensing of viral RNA and 2'-O-methylation of mRNA suggests that RNA modifications such as 2'-O-methylation provide a molecular signature for the discrimination of self and non-self mRNA.
Collapse
Affiliation(s)
- Roland Züst
- Institute of Immunobiology, Kantonal Hospital St. Gallen, St. Gallen, Switzerland
- Present Address: Present address: Singapore Immunology Network, Agency for Science, Technology and Research, Singapore.,
| | | | - Matthias Habjan
- Institute of Immunobiology, Kantonal Hospital St. Gallen, St. Gallen, Switzerland
| | - Reinhard Maier
- Institute of Immunobiology, Kantonal Hospital St. Gallen, St. Gallen, Switzerland
| | | | - John Ziebuhr
- Centre for Infection and Immunity, Queen's University Belfast, Belfast, UK
- Institute of Medical Virology, Justus Liebig University Giessen, Giessen, Germany
| | - Kristy J Szretter
- Department of Medicine, Department of Molecular Microbiology, and Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, Missouri USA
| | - Susan C Baker
- Department of Microbiology and Immunology, Loyola University Stritch School of Medicine, Maywood, Illinois USA
| | - Winfried Barchet
- Institute for Clinical Chemistry and Pharmacology, University Hospital, University of Bonn, Bonn, Germany
| | - Michael S Diamond
- Department of Medicine, Department of Molecular Microbiology, and Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, Missouri USA
| | - Stuart G Siddell
- Department of Cellular and Molecular Medicine, School of Medical and Veterinary Sciences, University of Bristol, Bristol, UK
| | - Burkhard Ludewig
- Institute of Immunobiology, Kantonal Hospital St. Gallen, St. Gallen, Switzerland
- Vetsuisse Faculty, University of Zürich, Zürich, Switzerland
| | - Volker Thiel
- Institute of Immunobiology, Kantonal Hospital St. Gallen, St. Gallen, Switzerland
- Vetsuisse Faculty, University of Zürich, Zürich, Switzerland
| |
Collapse
|
5
|
Briggs CM, Holder RC, Reid SD, Parks GD. Activation of human macrophages by bacterial components relieves the restriction on replication of an interferon-inducing parainfluenza virus 5 (PIV5) P/V mutant. Microbes Infect 2010; 13:359-68. [PMID: 21185944 DOI: 10.1016/j.micinf.2010.12.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 12/04/2010] [Accepted: 12/15/2010] [Indexed: 12/26/2022]
Abstract
Macrophages regulate immune responses during many viral infections, and can be a major determinant of pathogenesis, virus replication and immune response to infection. Here, we have addressed the question of the outcome of infection of primary human macrophages with parainfluenza virus 5 (PIV5) and a PIV5 mutant (P/V-CPI-) that is unable to counteract interferon (IFN) responses. In cultures of naïve monocyte-derived macrophages (MDMs), WT PIV5 established a highly productive infection, whereas the P/V-CPI- mutant was restricted for replication in MDMs by IFN-beta. Restricted replication in vitro was relieved in MDM that had been activated by prior exposure to heat killed Gram positive bacteria, including Listeria monocytogenes, Streptococcus pyogenes, and Bacillus anthracis. Enhanced replication of the P/V mutant in MDM previously activated by bacterial components correlated with a reduced ability to produce IFN-beta in response to virus infection, whereas IFN signaling was intact. Activated MDM were found to upregulate the synthesis of IRAK-M, which has been previously shown to negatively regulate factors involved in TLR signaling and IFN-beta production. We discuss these results in terms of the implications for mixed bacteria-virus infections and for the use of live RNA virus vectors that have been engineered to be attenuated for IFN sensitivity.
Collapse
Affiliation(s)
- Caitlin M Briggs
- Department of Microbiology and Immunology, Wake Forest University, School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157-1064, United States
| | | | | | | |
Collapse
|
6
|
Naturally acquired hepatitis A antibodies after haematopoetic stem cell transplantation. Epidemiol Infect 2010; 139:683-7. [DOI: 10.1017/s0950268810001585] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
SUMMARYHaematopoietic stem cell transplant (HSCT) recipients lose immune memory of exposure to infectious agents and vaccines accumulated throughout their lifetime and therefore need to be revaccinated. We aimed to evaluate the influence of different factors on hepatitis A virus (HAV) immunity in both child and adult HSCT recipients living in an intermediate endemic region, Turkey. Eighty patients (age range 2·5–57 years) who had HAV serology prior to HSCT were evaluated. The prevalence of HAV seropositivity was 85% (n=68) before HSCT. There was no history of HAV vaccination before HSCT in children and HAV vaccine was not available in Turkey 10 years ago, so it was assumed that all seropositive patients reflected natural immunity. After the exclusion of six patients with autologous HSCT, the remaining 62 seropositive and allogeneic patients were included in this retrospective study. The duration of HAV seropositivity was estimated using the Kaplan–Meier method, log-rank analysis and Cox regression models. Estimated mean time to loss of HAV seropositivity was 48·6 months after transplantation. Patients who were older (⩾18 years) at transplantation and who had older (⩾18 years) donors became seronegative later (P<0·05). Cox backward-stepwise regression confirmed that older age of recipient at transplantation was the only significant parameter for HAV seropositivity (P<0·05). HAV-inactivated vaccine might be recommended later to older HSCT recipients in intermediate endemic regions.
Collapse
|
7
|
Perrella A, Vitiello L, Atripaldi L, Sbreglia C, Grattacaso S, Bellopede P, Patarino T, Morelli G, Altamura S, Racioppi L, Perrella O. Impaired function of CD4+/CD25+ T regulatory lymphocytes characterizes the self-limited hepatitis A virus infection. J Gastroenterol Hepatol 2008; 23:e105-10. [PMID: 17645467 DOI: 10.1111/j.1440-1746.2007.05008.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND AIM Hepatitis A virus (HAV) causes a transient illness leaving permanent protection against reinfection. Few data are available on the regulatory mechanisms involved in the CD4+ T helper activation. We aimed to investigate the frequency and function of CD3+/CD4+/CD25+ T cells with regulatory function (Tregs) during acute HAV infection. METHODS We enrolled 35 consecutive patients and 15 healthy donors, enumerated Tregs by flow cytometry assay and evaluated, after immunomagnetical sorting with magnetic beads, their ability to inhibit the proliferation of CD4+/CD25- T lymphocytes at different ratios (1:1, 1:10, 1:20). RESULTS All patients had the usual course of infection. Our immunological analysis showed Tregs frequency in these patients (6.5% [range, 5-8.8%]; 36 [range, 10-87] cells) did not have any statistical difference compared with healthy donors (6% [range, 5-8%]; 48 (range, 23-71) cells), while their ability to suppress CD4+/CD25- was drastically reduced at different ratios (Mann-Whitney U-test; ratio 1:1, 93% vs 72%, z = -3.34, P < 0.0001; ratio 1:10, 86% vs 51%, z = -4.04, P < 0.001; ratio 1:20, 56% vs 30%, z = -3.43, P < 0.0001). After the seroconversion, CD4+/CD25+ frequency and function in HAV-infected patients did not differ from healthy individuals. CONCLUSION CD4+/CD25+ T cells seem to be impaired in their function during the HAV acute infection. This evidence might help to determine an optimal T helper cell immune network that is a predisposing factor for a self-limiting disease.
Collapse
Affiliation(s)
- Alessandro Perrella
- Department of Hepatogastroenterology and Immunology, VII Division of Infectious Disease and Immunology, Hospital D Cotugno, Naples, Italy.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Khatri M, Sharma JM. Modulation of macrophages by infectious bursal disease virus. Cytogenet Genome Res 2007; 117:388-93. [PMID: 17675882 DOI: 10.1159/000103202] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2006] [Accepted: 10/06/2006] [Indexed: 11/19/2022] Open
Abstract
Infectious bursal disease is one of the most important naturally occurring viral diseases of chickens worldwide. The causative agent, infectious bursal disease virus (IBDV), belongs to the family Birnaviridae. This virus causes an acute, highly contagious and immunosuppressive disease in chickens. The virus infects and destroys actively dividing IgM-bearing B cells. Although B cells are the principal targets for IBDV, recent data show that the virus also infects macrophages. IBDV-infected macrophages produce various cytokines and chemokines which may play an important role in the protection and/or pathogenesis of IBDV. In this review, the modulatory effects of IBDV on macrophages will be discussed.
Collapse
Affiliation(s)
- M Khatri
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN 55108, USA.
| | | |
Collapse
|
9
|
Pejawar-Gaddy S, Gitiban-Vaghefi N, Parks GD, Alexander-Miller MA. Distinct pathways for signaling maturation in macrophages and dendritic cells after infection with paramyxovirus simian virus 5. Viral Immunol 2007; 20:76-87. [PMID: 17425423 DOI: 10.1089/vim.2006.0070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Professional antigen-presenting cells are critical components of both the innate and adaptive immune responses. Although dendritic cells (DCs) are generally thought to be the primary activators of naive T cells, macrophages have also been shown to fulfill this role. As with DCs, the capacity to induce optimal activation of T cells requires that macrophages undergo a process that results in the increased expression of costimulatory molecules, such as CD40, CD80, and CD86, and the production of cytokines. In this study we analyzed the effect of infection of macrophages generated from BALB/c mice with the paramyxovirus simian virus 5 (SV5). Here we have shown that bone marrow-derived macrophages (BMMs) are not productively infected at any multiplicity of infection tested. Analysis of activation markers revealed that SV5-infected BMMs robustly upregulated CD40 and modestly upregulated CD86, but did not upregulate the expression of CD80. Further, SV5-infected BMMs secreted low levels of interferon-beta and interleukin (IL)-12p40, but high levels of tumor necrosis factor-alpha and IL-6. Intriguingly, upregulation of these molecules on BMMs, unlike our previous results using bone marrow-derived dendritic cells, was not dependent on live virus. These findings provide evidence that different professional antigen-presenting cells can detect and respond to virus via distinct mechanisms.
Collapse
Affiliation(s)
- Sharmila Pejawar-Gaddy
- Department of Microbiology and Immunology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA
| | | | | | | |
Collapse
|
10
|
Abstract
The termination of the apoptotic programme occurs in most cases via recognition and clearance by phagocytes, especially the professional phagocytes, such as macrophages and immature dendritic cells. Engulfed cells do not simply disappear from the midst of living tissues. The fine-defined presentation of yielded self-antigens to T cells is a central event in the induction or the maintenance of the peripheral immune tolerance to self. Conversely, abnormality in this pathway may contribute to the pathogenesis of systemic and organ-specific autoimmune diseases. We herein reviewed the relationship between phagocytosis of apoptotic cells and immune regulation, especially the effects of engulfed apoptotic cells on immune tolerance and autoimmune diseases.
Collapse
Affiliation(s)
- G Liu
- Transplantation Biology Research Division, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | | | | | | |
Collapse
|
11
|
Abstract
Human wild-type (wt) hepatitis A virus (HAV), the causative agent of acute hepatitis, barely grows in cell culture and in the process accumulates attenuating and cell culture-adapting mutations. This genetic instability of wt HAV in cell culture is a major roadblock to studying HAV pathogenesis and producing live vaccines that are not overly attenuated for humans. To develop a robust cell culture system capable of supporting the efficient growth of wt HAV, we transfected different cell lines with in vitro RNA transcripts of wt HAV containing the blasticidin resistance gene. Blasticidin-resistant colonies grew only in transfected Huh7 cells and produced infectious virus. HAV was genetically stable in Huh7 cells for at least nine serial passages and did not accumulate attenuating or cell culture-adapting mutations. Treatment with alpha interferon A/D cured the blasticidin-resistant Huh7 cells of the HAV infection. The cured cells, termed Huh7-A-I cells, did not contain virus or HAV antigens and were sensitive to blasticidin. Huh7-A-I cells were more permissive than parental cells for wt HAV infection, including a natural isolate from a human stool sample, and produced 10-fold-more infectious particles. This is the first report of a cell line that allows the genetically stable growth of human wt HAV. The viral vectors and cells described here should allow better insight into the pathogenesis of HAV and the development of attenuated vaccines. The cell lines susceptible to wt HAV growth may also be used to detect and isolate infectious virus from patient and environmental samples.
Collapse
Affiliation(s)
- Krishnamurthy Konduru
- Laboratory of Hepatitis and Related Emerging Agents, Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA
| | | |
Collapse
|
12
|
Tseng CTK, Perrone LA, Zhu H, Makino S, Peters CJ. Severe acute respiratory syndrome and the innate immune responses: modulation of effector cell function without productive infection. THE JOURNAL OF IMMUNOLOGY 2005; 174:7977-85. [PMID: 15944304 DOI: 10.4049/jimmunol.174.12.7977] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Severe acute respiratory syndrome (SARS) caused by a novel human coronavirus (CoV), designated SARS-CoV, is a highly contagious respiratory disease with the lungs as a major target. Although the exact mechanism of SARS-CoV pathogenesis remains unknown, an intense, ill-regulated local inflammatory response has been suggested as partially responsible for the devastating lung pathology. We investigated the interaction of SARS-CoV with human macrophages (Mphi) and dendritic cells (DC), two key innate immune cells of the host immune system, by focusing on their susceptibility to viral infection and subsequent responses (e.g., phenotypic maturation, T cell-priming activity, phagocytosis, and cytokine production). We found neither cell to be permissive for SARS-CoV replication. However, incubation of Mphi and DC with live, but not gamma irradiation-inactivated, viruses appeared to better sustain their viability. Also, exposure to infectious SARS-CoV led to the phenotypic and functional maturation of DC, with regard to MHC class II and costimulatory molecule expression, T cell-stimulatory capacity, and cytokine production, respectively. Cytokine production was also observed for Mphi, which were refractory to cell surface phenotypic changes. Strikingly, live SARS-CoV could further prime cell types to respond to a suboptimal dose of bacterial LPS (100 ng/ml), resulting in massive release of IL-6 and IL-12. However, the endocytic capacity (e.g., Ag capture) of Mphi was significantly compromised upon exposure to infectious SARS-CoV. This study is the first demonstration that although SARS-CoV does not productively infect human Mphi or DC, it appears to exert differential effects on Mphi and DC maturation and functions, which might contribute to SARS pathogenesis.
Collapse
Affiliation(s)
- Chien-Te K Tseng
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | | | | | | | | |
Collapse
|
13
|
McIntire JJ, Umetsu DT, DeKruyff RH. TIM-1, a novel allergy and asthma susceptibility gene. ACTA ACUST UNITED AC 2003; 25:335-48. [PMID: 15007635 DOI: 10.1007/s00281-003-0141-3] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2003] [Accepted: 08/26/2003] [Indexed: 12/31/2022]
Abstract
Atopic diseases, including asthma, allergic rhinitis, and atopic dermatitis, are caused by environmental factors in genetically predisposed individuals. Although the prevalence of these diseases has risen dramatically over the past two decades, it has been difficult to identify the underlying causes of these diseases due to the complex interplay between the genetic and environmental factors involved. Using a congenic mouse model of asthma, we simplified this complex trait and identified the novel T cell immunoglobulin domain, mucin-like domain (TIM) gene family, that encodes transmembrane proteins expressed by CD4 T cells. Recent studies demonstrate that the TIM family, particularly TIM-1, plays a critical role in immune responses that regulate the development of atopic diseases. In humans, certain polymorphic variants of TIM-1 are strongly associated with protection against atopy, and this association occurs only in individuals who have had past infection with hepatitis A virus (HAV). Since TIM-1 functions as the cellular receptor for HAV, activation of T cells through TIM-1 by HAV or by its natural ligand may affect T cell differentiation and the development of Th2-driven allergic inflammatory responses. Epidemiologically, HAV infection is associated with a reduced risk of developing atopy, and because the incidence of HAV infection has been significantly reduced in industrialized countries over the past 30 years, the discovery of a genetic interaction between HAV and TIM-1 provides the first molecular genetic evidence for the hygiene hypothesis.
Collapse
Affiliation(s)
- Jennifer J McIntire
- Division of Allergy and Immunology, Department of Pediatrics, Stanford University, CA 94305-5208, USA
| | | | | |
Collapse
|