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Xie Y, Chen C, Zhang D, Jiao Z, Chen Y, Wang G, Tan Y, Zhang W, Xiao S, Peng G, Shi Y. Diversity for endoribonuclease nsp15-mediated regulation of alpha-coronavirus propagation and virulence. Microbiol Spectr 2023; 11:e0220923. [PMID: 37938022 PMCID: PMC10715224 DOI: 10.1128/spectrum.02209-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/24/2023] [Indexed: 11/09/2023] Open
Abstract
IMPORTANCE Understanding the role of the endoribonuclease non-structural protein 15 (nsp15) (EndoU) in coronavirus (CoV) infection and pathogenesis is essential for vaccine target discovery. Whether the EndoU activity of CoV nsp15, as a virulence-related protein, has a diverse effect on viral virulence needs to be further explored. Here, we found that the transmissible gastroenteritis virus (TGEV) and feline infectious peritonitis virus (FIPV) nsp15 proteins antagonize SeV-induced interferon-β (IFN-β) production in human embryonic kidney 293 cells. Interestingly, compared with wild-type infection, infection with EnUmt-TGEV or EnUmt-FIPV did not change the IFN-β response or reduce viral propagation in immunocompetent cells. The results of animal experiments showed that EnUmt viruses did not reduce the clinical presentation and mortality caused by TGEV and FIPV. Our findings enrich the understanding of nsp15-mediated regulation of alpha-CoV propagation and virulence and reveal that the conserved functions of nonstructural proteins have diverse effects on the pathogenicity of CoVs.
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Affiliation(s)
- Yunfei Xie
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Chener Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Ding Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Zhe Jiao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Yixi Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Gang Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Yubei Tan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Wanpo Zhang
- Veterinary Pathology Laboratory, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Shaobo Xiao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Guiqing Peng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
| | - Yuejun Shi
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China
- Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei, China
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Different Mechanisms Are Utilized by Coronavirus Transmissible Gastroenteritis Virus To Regulate Interferon Lambda 1 and Interferon Lambda 3 Production. J Virol 2022; 96:e0138822. [PMID: 36448799 PMCID: PMC9769389 DOI: 10.1128/jvi.01388-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Type III interferons (IFN-λ) are shown to be preferentially produced by epithelial cells, which provide front-line protection at barrier surfaces. Transmissible gastroenteritis virus (TGEV), belonging to the genus Alphacoronavirus of the family Coronaviridae, can cause severe intestinal injuries in porcine, resulting in enormous economic losses for the swine industry, worldwide. Here, we demonstrated that although IFN-λ1 had a higher basal expression, TGEV infection induced more intense IFN-λ3 production in vitro and in vivo than did IFN-λ1. We explored the underlying mechanism of IFN-λ induction by TGEV and found a distinct regulation mechanism of IFN-λ1 and IFN-λ3. The classical RIG-I-like receptor (RLR) pathway is involved in IFN-λ3 but not IFN-λ1 production. Except for the signaling pathways mediated by RIG-I and MDA5, TGEV nsp1 induces IFN-λ1 and IFN-λ3 by activating NF-κB via the unfolded protein responses (UPR) PERK-eIF2α pathway. Furthermore, functional domain analysis indicated that the induction of IFN-λ by the TGEV nsp1 protein was located at amino acids 85 to 102 and was dependent on the phosphorylation of eIF2α and the nuclear translocation of NF-κB. Moreover, the recombinant TGEV with the altered amino acid motif of nsp1 85-102 was constructed, and the nsp1 (85-102sg) mutant virus significantly reduced the production of IFN-λ, compared with the wild strain. Compared to the antiviral activities of IFN-λ1, the administration of IFN-λ3 showed greater antiviral activity against TGEV infections in IPEC-J2 cells. In summary, our data point to the significant role of IFN-λ in the host innate antiviral responses to coronavirus infections within mucosal organs and in the distinct mechanisms of IFN-λ1 and IFN-λ3 regulation. IMPORTANCE Coronaviruses cause infectious diseases in various mammals and birds and exhibit an epithelial cell tropism in enteric and respiratory tracts. It is critical to explore how coronavirus infections modulate IFN-λ, a key innate cytokine against mucosal viral infection. Our results uncovered the different processes of IFN-λ1 and IFN-λ3 production that are involved in the classical RLR pathway and determined that TGEV nsp1 induces IFN-λ1 and IFN-λ3 production by activating NF-κB via the PERK-eIF2α pathway in UPR. These studies highlight the unique regulation of antiviral defense in the intestine during TGEV infection. We also demonstrated that IFN-λ3 induced greater antiviral activity against TGEV replication than did IFN-λ1 in IPEC-J2 cells, which is helpful in finding a novel strategy for the treatment of coronavirus infections.
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Abstract
Pyroptosis, a programmed cell death, functions as an innate immune effector mechanism and plays a crucial role against microbial invasion. Gasdermin D (GSDMD), as the main pyroptosis effector, mediates pyroptosis and promotes releasing proinflammatory molecules into the extracellular environment through pore-forming activity, modifying inflammation and immune responses. While the substantial importance of GSDMD in microbial infection and cancer has been widely investigated, the role of GSDMD in virus infection, including coronaviruses, remains unclear. Enteric coronavirus transmissible gastroenteritis virus (TGEV) and porcine deltacoronavirus (PDCoV) are the major agents for lethal watery diarrhea in neonatal pigs and pose the potential for spillover from pigs to humans. In this study, we found that alphacoronavirus TGEV upregulated and activated GSDMD, resulting in pyroptosis after infection. Furthermore, the fragment of swine GSDMD from amino acids 242 to 279 (242-279 fragment) was required to induce pyroptosis. Notably, GSDMD strongly inhibited both TGEV and PDCoV infection. Mechanistically, the antiviral activity of GSDMD was mediated through promoting the nonclassical release of antiviral beta interferon (IFN-β) and then enhancing the interferon-stimulated gene (ISG) responses. These findings showed that GSDMD dampens coronavirus infection by an uncovered GSDMD-mediated IFN secretion, which may present a novel target of coronavirus antiviral therapeutics. IMPORTANCE Coronaviruses, primarily targeting respiratory and gastrointestinal epithelia in vivo, have a serious impact on humans and animals. GSDMD, a main executioner of pyroptosis, is highly expressed in epithelial cells and involves viral infection pathogenesis. While the functions and importance of GSDMD as a critical regulator of inflammasome activities in response to intracellular bacterial infection have been extensively investigated, the roles of GSDMD during coronavirus infection remain unclear. We here show that alphacoronavirus TGEV triggered pyroptosis and upregulated GSDMD expression, while GSDMD broadly suppressed the infection of enteric coronavirus TGEV and PDCoV by its pore-forming activity via promoting unconventional release of IFN-β. Our study highlights the importance of GSDMD as a regulator of innate immunity and may open new avenues for treating coronavirus infection.
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Guo YL, Feng L, Jiang WD, Wu P, Liu Y, Kuang SY, Tang L, Tang WN, Zhou XQ. Dietary iron deficiency impaired intestinal immune function of on-growing grass carp under the infection of Aeromonas hydrophila: Regulation of NF-κB and TOR signaling. FISH & SHELLFISH IMMUNOLOGY 2019; 93:669-682. [PMID: 31408728 DOI: 10.1016/j.fsi.2019.08.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 08/06/2019] [Accepted: 08/09/2019] [Indexed: 06/10/2023]
Abstract
Iron is an important mineral element for fish. In this study, we investigated the influences of dietary iron deficiency on intestinal immune function as well as underlying signaling of on-growing grass carp (Ctenopharyngodon idella). Fish were fed with six graded level of dietary iron for sixty days, and a fourteen days' challenge test under infection of Aeromonas hydrophila thereafter. Results showed that compared with optimal iron level, iron deficiency increased enteritis morbidity, decreased lysozyme (LZ) and acid phosphatase (ACP) activities, complement 3 (C3), C4 and immunoglobulin M (IgM) concentrations and down-regulated mRNA levels of hepcidin, liver expressed antimicrobial peptide 2A (LEAP-2A), LEAP-2B, Mucin2, β-defensin-1, anti-inflammatory cytokines transforming growth factor β1 (TGF-β1), TGF-β2, interleukin 4/13A (IL-4/13A), IL-4/13B, IL-10, IL-11 and IL-15, inhibitor of κBα (IκBα), target of rapamycin (TOR) and ribosomal protein S6 kinase 1 (S6K1), whereas up-regulated mRNA levels of pro-inflammatory cytokines IL-1β, interferon γ2 (IFN-γ2), IL-8, IL-12p35, IL-12p40 and IL-17D, nuclear factor kappa B (NF-κB) p65, IκB kinases α (IKKα), IKKβ and eIF4E-binding protein (4E-BP) in intestine of on-growing grass carp, indicating that iron deficiency impaired intestinal immune function of fish under infection of A. hydrophila. Besides, iron excess also increased enteritis morbidity and impaired immune function of fish under infection of A. hydrophila. In addition, the effect of ferrous fumarate on intestinal immune function of on-growing grass carp is more efficient than ferrous sulfate. Finally, based on ability against enteritis, LZ activities in mid intestine and distal intestine, we recommended adding 83.37, 86.71 and 85.39 mg iron/kg into diet, respectively.
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Affiliation(s)
- Yan-Lin Guo
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 6111.0930, China
| | - Lin Feng
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 6111.0930, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 6111.0930, China; Key Laboratory of Animal Disease-resistant Nutrition, Sichuan Province, China
| | - Wei-Dan Jiang
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 6111.0930, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 6111.0930, China; Key Laboratory of Animal Disease-resistant Nutrition, Ministry of Education, China
| | - Pei Wu
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 6111.0930, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 6111.0930, China; Key Laboratory of Animal Disease-resistant Nutrition, Ministry of Education, China
| | - Yang Liu
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 6111.0930, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 6111.0930, China; Key Laboratory of Animal Disease-resistant Nutrition and Feed, Ministry of Agriculture and Rural Affairs, China
| | - Sheng-Yao Kuang
- Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu, 610066, China
| | - Ling Tang
- Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu, 610066, China
| | - Wu-Neng Tang
- Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu, 610066, China
| | - Xiao-Qiu Zhou
- Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 6111.0930, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, 6111.0930, China; Key Laboratory of Animal Disease-resistant Nutrition, Sichuan Province, China.
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Renson P, Fablet C, Andraud M, Normand V, Lebret A, Paboeuf F, Rose N, Bourry O. Maternally-derived neutralizing antibodies reduce vaccine efficacy against porcine reproductive and respiratory syndrome virus infection. Vaccine 2019; 37:4318-4324. [PMID: 31248683 PMCID: PMC7115427 DOI: 10.1016/j.vaccine.2019.06.045] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 06/12/2019] [Accepted: 06/14/2019] [Indexed: 01/12/2023]
Abstract
Maternally-derived neutralizing antibodies impair PRRS vaccination immune responses in piglets. Maternally-derived neutralizing antibodies reduce PRRS vaccine efficacy in piglets. IFNa may also interfere with PRRS vaccination.
Modified live virus (MLV) vaccines are commonly used to reduce the impact of porcine reproductive and respiratory syndrome (PRRS) but limited efficacy is achieved in field conditions. Here, we evaluated the impact of maternally-derived neutralizing antibodies (MDNAs) on vaccine efficacy after PRRS virus (PRRSV) challenge. Piglets with low (A−) or high (A+) MDNA levels derived from a commercial pig herd were moved to experimental facilities to be vaccinated (V+) or not (V−) with a PRRSV-1 MLV vaccine at 3 weeks of age (woa). Because of unexpectedly low vaccine detection in A−V+ piglets post-vaccination (pv), all V+ piglets received a second vaccination at 4 woa. Five weeks (W5) pv, piglets were inoculated with a PRRSV-1 field strain to evaluate vaccine protection, and were mingled 24 h later with non-inoculated piglets of similar immune status to assess viral transmission. Vaccine strain was detected at W2 pv in 69% and 6% of A−V+ and A+V+ piglets, and at W5 pv in 50% and 25% of A−V+ and A+V+ piglets, respectively. At W5 pv, 94% of A−V+ and 44% of A+V+ piglets seroconverted, with a significant IFNg response induction in the A−V+ group only. After challenge, compared to the V− inoculated group, viremia was 100-fold lower at 10 days post-infection in A−V+ whereas viremia was not significantly reduced in A+V+ piglets. A lower transmission rate was estimated for the A−V+ group: 0.15 [0.07–0.29] versus 0.44 [0.18–1.76] and 0.32 [0.14–0.68] for the A+V+ and V− groups, respectively. Investigations about the low vaccine strain detection after the first vaccination suggested a relationship between IFNa levels and vaccine strain detection in A−V+ piglets. We showed that MDNAs impair vaccine efficacy against PRRSV both in inoculated and contact piglets, probably by reducing vaccine replication. IFNa may also interfere with PRRSV vaccination. These new data could help improving vaccination protocols.
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Affiliation(s)
- Patricia Renson
- Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail (Anses), Unité Virologie Immunologie Porcines, BP 53, 22440 Ploufragan, France; Union des Groupements de Producteurs de Viande de Bretagne (UGPVB), 104 Rue Eugène Pottier, 35065 Rennes Cedex, France; Université Bretagne Loire, Cité Internationale, 1 Place Paul Ricoeur, CS 54417, 35044 Rennes, France
| | - Christelle Fablet
- Anses, Unité Epidémiologie, Santé et Bien-être, BP 53, 22440 Ploufragan, France; Université Bretagne Loire, Cité Internationale, 1 Place Paul Ricoeur, CS 54417, 35044 Rennes, France
| | - Mathieu Andraud
- Anses, Unité Epidémiologie, Santé et Bien-être, BP 53, 22440 Ploufragan, France; Université Bretagne Loire, Cité Internationale, 1 Place Paul Ricoeur, CS 54417, 35044 Rennes, France
| | - Valérie Normand
- Porc. Spective, Groupe vétérinaire Chêne Vert Conseil, ZA de Gohélève, 56920 Noyal-Pontivy, France
| | - Arnaud Lebret
- Porc. Spective, Groupe vétérinaire Chêne Vert Conseil, ZA de Gohélève, 56920 Noyal-Pontivy, France
| | - Frédéric Paboeuf
- Anses, Service de Production de Porcs Assainis et Expérimental, BP 53, 22440 Ploufragan, France; Université Bretagne Loire, Cité Internationale, 1 Place Paul Ricoeur, CS 54417, 35044 Rennes, France
| | - Nicolas Rose
- Anses, Unité Epidémiologie, Santé et Bien-être, BP 53, 22440 Ploufragan, France; Université Bretagne Loire, Cité Internationale, 1 Place Paul Ricoeur, CS 54417, 35044 Rennes, France
| | - Olivier Bourry
- Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail (Anses), Unité Virologie Immunologie Porcines, BP 53, 22440 Ploufragan, France; Université Bretagne Loire, Cité Internationale, 1 Place Paul Ricoeur, CS 54417, 35044 Rennes, France.
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Poelaert KCK, Van Cleemput J, Laval K, Descamps S, Favoreel HW, Nauwynck HJ. Beyond Gut Instinct: Metabolic Short-Chain Fatty Acids Moderate the Pathogenesis of Alphaherpesviruses. Front Microbiol 2019; 10:723. [PMID: 31024501 PMCID: PMC6460668 DOI: 10.3389/fmicb.2019.00723] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 03/22/2019] [Indexed: 12/14/2022] Open
Abstract
Short-chain fatty acids (SCFA), such as sodium butyrate (SB), sodium propionate (SPr), and sodium acetate (SAc), are metabolic end-products of the fermentation of dietary fibers. They are linked with multiple beneficial effects on the general mammalian health, based on the sophisticated interplay with the host immune response. Equine herpesvirus 1 (EHV1) is a major pathogen, which primarily replicates in the respiratory epithelium, and disseminates through the body via a cell-associated viremia in leukocytes, even in the presence of neutralizing antibodies. Infected monocytic CD172a+ cells and T-lymphocytes transmit EHV1 to the endothelium of the endometrium or central nervous system (CNS), causing reproductive or neurological disorders. Here, we questioned whether SCFA have a potential role in shaping the pathogenesis of EHV1 during the primary replication in the URT, during the cell-associated viremia, or at the level of the endothelium of the pregnant uterus and/or CNS. First, we demonstrated the expression of SCFA receptors, FFA2 and FFA3, within the epithelium of the equine respiratory tract, at the cell surface of immune cells, and equine endothelium. Subsequently, EHV1 replication was evaluated in the URT, in the presence or absence of SB, SPr, or SAc. In general, we demonstrated that SCFA do not affect the number of viral plaques or virus titer upon primary viral replication. Only SB and SPr were able to reduce the plaque latitudes. Similarly, pretreatment of monocytic CD172a+ cells and T-lymphocytes with different concentrations of SCFA did not alter the number of infected cells. When endothelial cells were treated with SB, SPr, or SAc, prior to the co-cultivation with EHV1-inoculated mononuclear cells, we observed a reduced number of adherent immune cells to the target endothelium. This was associated with a downregulation of endothelial adhesion molecules ICAM-1 and VCAM-1 in the presence of SCFA, which ultimately lead to a significant reduction of the EHV1 endothelial plaques. These results indicate that physiological concentrations of SCFA may affect the pathogenesis of EHV1, mainly at the target endothelium, in favor of the fitness of the horse. Our findings may have significant implications to develop innovative therapies, to prevent the devastating clinical outcome of EHV1 infections.
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Affiliation(s)
- Katrien C K Poelaert
- Laboratory of Virology, Department of Virology, Immunology and Parasitology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Jolien Van Cleemput
- Laboratory of Virology, Department of Virology, Immunology and Parasitology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.,301 Schultz Laboratory, Department of Molecular Biology, Princeton University, Princeton, NJ, United States
| | - Kathlyn Laval
- 301 Schultz Laboratory, Department of Molecular Biology, Princeton University, Princeton, NJ, United States
| | - Sarah Descamps
- Laboratory of Virology, Department of Virology, Immunology and Parasitology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Herman W Favoreel
- Laboratory of Virology, Department of Virology, Immunology and Parasitology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Hans J Nauwynck
- Laboratory of Virology, Department of Virology, Immunology and Parasitology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Poelaert KCK, Van Cleemput J, Laval K, Favoreel HW, Soboll Hussey G, Maes RK, Nauwynck HJ. Abortigenic but Not Neurotropic Equine Herpes Virus 1 Modulates the Interferon Antiviral Defense. Front Cell Infect Microbiol 2018; 8:312. [PMID: 30258819 PMCID: PMC6144955 DOI: 10.3389/fcimb.2018.00312] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 08/15/2018] [Indexed: 12/20/2022] Open
Abstract
Equine herpesvirus 1 (EHV1) is considered as a major pathogen of Equidae, causing symptoms from mild respiratory disease to late-term abortion and neurological disorders. Different EHV1 strains circulating in the field have been characterized to be of abortigenic or neurovirulent phenotype. Both variants replicate in a plaque-wise manner in the epithelium of the upper respiratory tract (URT), where the abortigenic strains induce more prominent viral plaques, compared to the neurovirulent strains. Considering the differences in replication at the URT, we hypothesized that abortigenic strains may show an increased ability to modulate the type I IFN secretion/signaling pathway, compared to strains that display the neurovirulent phenotype. Here, we analyze IFN levels induced by abortigenic and neurovirulent EHV1 using primary respiratory epithelial cells (EREC) and respiratory mucosa ex vivo explants. Similar levels of IFNα (~70 U/ml) were detected in explants inoculated with both types of EHV1 strains from 48 to 72 hpi. Second, EREC and mucosa explants were treated with recombinant equine IFNα (rEqIFNα) or Ruxolitinib (Rux), an IFN signaling inhibitor, prior to and during inoculation with abortigenic or neurovirulent EHV1. Replication of both EHV1 variants was suppressed by rEqIFNα. Further, addition of Rux increased replication in a concentration-dependent manner, indicating an IFN-susceptibility for both variants. However, in two out of three horses, at a physiological concentration of 100 U/ml of rEqIFNα, an increase in abortigenic EHV1 replication was observed compared to 10 U/ml of rEqIFNα, which was not observed for the neurovirulent strains. Moreover, in the presence of Rux, the plaque size of the abortigenic variants remained unaltered, whereas the typically smaller viral plaques induced by the neurovirulent variants became larger. Overall, our results demonstrate the importance of IFNα in the control of EHV1 replication in the URT for both abortigenic and neurovirulent variants. In addition, our findings support the speculation that abortigenic variants of EHV1 may have developed anti-IFN mechanisms that appear to be absent or less pronounced in neurovirulent EHV1 strains.
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Affiliation(s)
- Katrien C K Poelaert
- Department of Virology, Immunology and Parasitology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Jolien Van Cleemput
- Department of Virology, Immunology and Parasitology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Kathlyn Laval
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton Neuroscience Institute, Princeton University, Princeton, NJ, United States
| | - Herman W Favoreel
- Department of Virology, Immunology and Parasitology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Gisela Soboll Hussey
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI, United States
| | - Roger K Maes
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI, United States
| | - Hans J Nauwynck
- Department of Virology, Immunology and Parasitology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Yuan P, Yang Z, Song H, Wang K, Yang Y, Xie L, Huang S, Liu J, Ran L, Song Z. Three Main Inducers of Alphacoronavirus Infection of Enterocytes: Sialic Acid, Proteases, and Low pH. Intervirology 2018; 61:53-63. [PMID: 30176660 PMCID: PMC7179561 DOI: 10.1159/000492424] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 07/19/2018] [Indexed: 12/19/2022] Open
Abstract
Transmissible gastroenteritis virus (TGEV) and porcine epidemic diarrhea virus (PEDV) are similar coronaviruses, causing diseases characterized by vomiting, diarrhea, and death from severe dehydration in piglets. Thus, they have caused huge losses to the swine-breeding industry worldwide. Nowadays, they are easily transmitted among the continents via vehicles, equipment, and cargo. Both viruses establish an infection in porcine enterocytes in the small intestine, and their spike (S) proteins play a key role in the virus-cell binding process under unfavorable conditions when the intestine with a low pH is filled with a thick layer of mucus and proteases. Sialic acid, proteases, and low pH are three main inducers of coronavirus infection. However, the details of how sialic acid and low pH affect virus binding to the host cell are not determined, and the functions of the proteases are unknown. This review emphasizes the role of three factors in the invasion of TGEV and PEDV into porcine enterocytes and offers more insights into Alphacoronavirus infection in the intestinal environment.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Zhenhui Song
- *Zhenhui Song, PhD, Department of Veterinary Medicine, College of Animal Science, Southwest University, Chongqing 402460 (People's Republic of China), E-Mail
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The PERK Arm of the Unfolded Protein Response Negatively Regulates Transmissible Gastroenteritis Virus Replication by Suppressing Protein Translation and Promoting Type I Interferon Production. J Virol 2018; 92:JVI.00431-18. [PMID: 29769338 DOI: 10.1128/jvi.00431-18] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 04/30/2018] [Indexed: 01/29/2023] Open
Abstract
Coronavirus replication is closely associated with the endoplasmic reticulum (ER), the primary cellular organelle for protein synthesis, folding, and modification. ER stress is a common consequence in coronavirus-infected cells. However, how the virus-induced ER stress influences coronavirus replication and pathogenesis remains controversial. Here, we demonstrated that infection with the alphacoronavirus transmissible gastroenteritis virus (TGEV) induced ER stress and triggered the unfolded protein response (UPR) in vitro and in vivo, and ER stress negatively regulated TGEV replication in vitro Although TGEV infection activated all three UPR pathways (activating transcription factor 6 [ATF6], inositol-requiring enzyme 1 [IRE1], and protein kinase R-like ER kinase [PERK]), the virus-triggered UPR suppressed TGEV replication in both swine testicular (ST) and IPEC-J2 cells primarily through activation of the PERK-eukaryotic initiation factor 2α (eIF2α) axis, as shown by functional studies with overexpression, small interfering RNA (siRNA), or specific chemical inhibitors. Moreover, we demonstrated that PERK-eIF2α axis-mediated inhibition of TGEV replication occurs through phosphorylated eIF2α-induced overall attenuation of protein translation. In addition to direct inhibition of viral production, the PERK-eIF2α pathway activated NF-κB and then facilitated type I IFN production, resulting in TGEV suppression. Taken together, our results suggest that the TGEV-triggered PERK-eIF2α pathway negatively regulates TGEV replication and represents a vital aspect of host innate responses to invading pathogens.IMPORTANCE The induction of ER stress is a common outcome in cells infected with coronaviruses. The UPR initiated by ER stress is actively involved in viral replication and modulates the host innate responses to the invading viruses, but these underlying mechanisms remain incompletely understood. We show here that infection with the alphacoronavirus TGEV elicited ER stress in vitro and in vivo, and the UPR PERK-eIF2α branch was predominantly responsible for the suppression of TGEV replication by ER stress. Furthermore, the PERK-eIF2α axis inhibited TGEV replication through direct inhibition of viral proteins due to global translation inhibition and type I IFN induction. These findings highlight a critical role of the UPR PERK-eIF2α pathway in modulating host innate immunity and coronavirus replication.
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Type III Interferon Restriction by Porcine Epidemic Diarrhea Virus and the Role of Viral Protein nsp1 in IRF1 Signaling. J Virol 2018; 92:JVI.01677-17. [PMID: 29187542 DOI: 10.1128/jvi.01677-17] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 11/21/2017] [Indexed: 01/16/2023] Open
Abstract
Type III interferons (IFNs) play a vital role in maintaining the antiviral state of the mucosal epithelial surface in the gut, and in turn, enteric viruses may have evolved to evade the type III IFN responses during infection. To study the possible immune evasion of the type III IFN response by porcine epidemic diarrhea virus (PEDV), a line of porcine intestinal epithelial cells was developed as a cell model for PEDV replication. IFN-λ1 and IFN-λ3 inhibited PEDV replication, indicating the anti-PEDV activity of type III IFNs. Of the 21 PEDV proteins, nsp1, nsp3, nsp5, nsp8, nsp14, nsp15, nsp16, open reading frame 3 (ORF3), E, M, and N were found to suppress type III IFN activities, and IRF1 (interferon regulatory factor 1) signaling mediated the suppression. PEDV specifically inhibited IRF1 nuclear translocation. The peroxisome is the innate antiviral signaling platform for the activation of IRF1-mediated IFN-λ production, and the numbers of peroxisomes were found to be decreased in PEDV-infected cells. PEDV nsp1 blocked the nuclear translocation of IRF1 and reduced the number of peroxisomes to suppress IRF1-mediated type III IFNs. Mutational studies showed that the conserved residues of nsp1 were crucial for IRF1-mediated IFN-λ suppression. Our study for the first time provides evidence that the porcine enteric virus PEDV downregulates and evades IRF1-mediated type III IFN responses by reducing the number of peroxisomes.IMPORTANCE Porcine epidemic diarrhea virus (PEDV) is a highly contagious enteric coronavirus that emerged in swine in the United States and has caused severe economic losses. PEDV targets intestinal epithelial cells in the gut, and intestinal epithelial cells selectively induce and respond to the production of type III interferons (IFNs). However, little is known about the modulation of the type III IFN response by PEDV in intestinal epithelial cells. In this study, we established a porcine intestinal epithelial cell model for PEDV replication. We found that PEDV inhibited IRF1-mediated type III IFN production by decreasing the number of peroxisomes in porcine intestinal epithelial cells. We also demonstrated that the conserved residues in the PEDV nsp1 protein were crucial for IFN suppression. This study for the first time shows PEDV evasion of the type III IFN response in intestinal epithelial cells, and it provides valuable information on host cell-virus interactions not only for PEDV but also for other enteric viral infections in swine.
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11
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Zhou Y, Wu W, Xie L, Wang D, Ke Q, Hou Z, Wu X, Fang Y, Chen H, Xiao S, Fang L. Cellular RNA Helicase DDX1 Is Involved in Transmissible Gastroenteritis Virus nsp14-Induced Interferon-Beta Production. Front Immunol 2017; 8:940. [PMID: 28848548 PMCID: PMC5552718 DOI: 10.3389/fimmu.2017.00940] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/24/2017] [Indexed: 12/11/2022] Open
Abstract
Transmissible gastroenteritis virus (TGEV), an enteropathogenic coronavirus (CoV) of porcine, causes lethal watery diarrhea and severe dehydration in piglets and leads to severe economic losses in the swine industry. Unlike most CoVs that antagonize type I interferon (IFN) production, previous studies showed that TGEV infection induces IFN-I production both in vivo and in vitro. However, the underlying mechanism(s) remain largely unknown. In this study, we found that TGEV infection significantly facilitated IFN-β production as well as activation of the transcription factors IFN regulatory factor 3 (IRF3) and nuclear factor-kappaB (NF-κB) in porcine kidney (PK-15) cells. Screening of TGEV-encoded proteins demonstrated that non-structural protein 14 (nsp14) was the most potent IFN-β inducer and induced IFN-β production mainly by activating NF-κB but not IRF3. Further analysis showed that nsp14 interacted with DDX1, a member of the DExD/H helicase family. Knockdown of DDX1 by specific small interfering RNA (siRNA) significantly decreased nsp14-induced IFN-β production and NF-κB activation. Furthermore, TGEV-induced IFN-β production and IFN-stimulated gene (ISG) expression were decreased in cells transfected with DDX1-specific siRNA, indicating the vital role of DDX1 to TGEV-induced IFN-β responses. In summary, our data revealed a potential coactivator role of host RNA helicase DDX1 to the induction of IFN-β response initiated by TGEV and demonstrated that nsp14 is an important IFN inducer among the TGEV-encoded proteins.
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Affiliation(s)
- Yanrong Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Wei Wu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Lilan Xie
- College of Life Science and Technology, Wuhan Institute of Bioengineering, Wuhan, China
| | - Dang Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Qiyun Ke
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Zhenzhen Hou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Xiaoli Wu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Ying Fang
- College of Life Sciences, South-Central University for Nationalities, Wuhan, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Shaobo Xiao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
| | - Liurong Fang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, China
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12
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Inhibition of NF-κB activity by the porcine epidemic diarrhea virus nonstructural protein 1 for innate immune evasion. Virology 2017; 510:111-126. [PMID: 28715653 PMCID: PMC7111422 DOI: 10.1016/j.virol.2017.07.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 06/28/2017] [Accepted: 07/05/2017] [Indexed: 12/29/2022]
Abstract
Porcine epidemic diarrhea virus emerged in the US is known to suppress the type I interferons response during infection. In the present study using porcine epithelial cells, we showed that PEDV inhibited both NF-κB and proinflammatory cytokines. PEDV blocked the p65 activation in infected cells and suppressed the PRD II-mediated NF-κB activity. Of the total of 22 viral proteins, nine proteins were identified as NF-κB antagonists, and nsp1 was the most potent suppressor of proinflammatory cytokines. Nsp1 interfered the phosphorylation and degradation of IκBα, and thus blocked the p65 activation. Mutational studies demonstrated the essential requirements of the conserved residues of nsp1 for NF-κB suppression. Our study showed that PEDV inhibited NF-κB activity and nsp1 was a potent NF-κB antagonist for suppression of both IFN and early production of pro-inflammatory cytokines. PEDV inhibits type I IFNs and NF-κB-mediated pro-inflammatory cytokines. PEDV blocks p65 nuclear translocation in virus-infected cells. Among 22 viral proteins, nsp1, nsp3, nsp5, nsp7, nsp14, nsp15, nsp16, ORF3, and E are NF-κB antagonists. Nsp1 suppresses pro-inflammatory cytokines and p65 activation by blocking IκBα phosphorylation. The conserved residues of nsp1 are crucial for NF-κB suppression.
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13
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Zhang Q, Yoo D. Immune evasion of porcine enteric coronaviruses and viral modulation of antiviral innate signaling. Virus Res 2016; 226:128-141. [PMID: 27212682 PMCID: PMC7111337 DOI: 10.1016/j.virusres.2016.05.015] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/16/2016] [Accepted: 05/17/2016] [Indexed: 12/15/2022]
Abstract
Enteric coronaviruses have evolved to modulate the host innate immunity. Viral IFN antagonists have been identified and they are mostly redundant. For protection of intestinal epithelia from enteric viruses, type III IFN plays a major role.
Porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV) are emerged and reemerging viruses in pigs, and together with transmissible gastroenteritis virus (TGEV), pose significant economic concerns to the swine industry. These viruses infect epithelial cells of the small intestine and cause watery diarrhea, dehydration, and a high mortality in neonatal piglets. Type I interferons (IFN-α/β) are major antiviral cytokines forming host innate immunity, and in turn, these enteric coronaviruses have evolved to modulate the host innate immune signaling during infection. Accumulating evidence however suggests that IFN induction and signaling in the intestinal epithelial cells differ from other epithelial cells, largely due to distinct features of the gut epithelial mucosal surface and commensal microflora, and it appears that type III interferon (IFN-λ) plays a key role to maintain the antiviral state in the gut. This review describes the recent understanding on the immune evasion strategies of porcine enteric coronaviruses and the role of different types of IFNs for intestinal antiviral innate immunity.
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Affiliation(s)
- Qingzhan Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana IL, United States
| | - Dongwan Yoo
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana IL, United States.
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14
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Zhang Q, Shi K, Yoo D. Suppression of type I interferon production by porcine epidemic diarrhea virus and degradation of CREB-binding protein by nsp1. Virology 2016; 489:252-68. [PMID: 26773386 PMCID: PMC7111358 DOI: 10.1016/j.virol.2015.12.010] [Citation(s) in RCA: 141] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2015] [Revised: 10/20/2015] [Accepted: 12/19/2015] [Indexed: 12/25/2022]
Abstract
Type I interferons (IFN-α/β) are the major components of the innate immune response of hosts, and in turn many viruses have evolved to modulate the host response during infection. We found that the IFN-β production was significantly suppressed during PEDV infection in cells. To identify viral IFN antagonists and to study their suppressive function, viral coding sequences for the entire structural and nonstructural proteins were cloned and expressed. Of 16 PEDV nonstructural proteins (nsps), nsp1, nsp3, nsp7, nsp14, nsp15 and nsp16 were found to inhibit the IFN-β and IRF3 promoter activities. The sole accessory protein ORF3, structure protein envelope (E), membrane (M), and nucleocapsid (N) protein were also shown to inhibit such activities. PEDV nsp1 did not interfere the IRF3 phosphorylation and nuclear translocation but interrupted the enhanceosome assembly of IRF3 and CREB-binding protein (CBP) by degrading CBP. A further study showed that the CBP degradation by nsp1 was proteasome-dependent. Our data demonstrate that PEDV modulates the host innate immune responses by degrading CBP and suppressing ISGs expression.
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Affiliation(s)
- Qingzhan Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana 61802, IL, USA
| | - Kaichuang Shi
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana 61802, IL, USA
| | - Dongwan Yoo
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana 61802, IL, USA.
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15
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Lin CM, Annamalai T, Liu X, Gao X, Lu Z, El-Tholoth M, Hu H, Saif LJ, Wang Q. Experimental infection of a US spike-insertion deletion porcine epidemic diarrhea virus in conventional nursing piglets and cross-protection to the original US PEDV infection. Vet Res 2015; 46:134. [PMID: 26589292 PMCID: PMC4654902 DOI: 10.1186/s13567-015-0278-9] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 10/21/2015] [Indexed: 02/08/2023] Open
Abstract
Although the original US porcine epidemic diarrhea virus (PEDV) was confirmed as highly virulent by multiple studies, the virulence of spike-insertion deletion (S-INDEL) PEDV strains is undefined. In this study, 3-4 day-old conventional suckling piglets were inoculated with S-INDEL PEDV Iowa106 (4 pig litters) to study its virulence. Two litters of age-matched piglets were inoculated with either the original US PEDV PC21A or mock as positive and negative controls, respectively. Subsequently, all pigs were challenged with the original US PEDV PC21A on 21-29 days post-inoculation (dpi) to assess cross-protection. All S-INDEL Iowa106- and the original US PC21A-inoculated piglets developed diarrhea. However, the severity of clinical signs, mortality (0-75%) and fecal PEDV RNA shedding titers varied among the four S-INDEL Iowa106-inoculated litters. Compared with the original PC21A, piglets euthanized/died acutely from S-INDEL Iowa106 infection had relatively milder villous atrophy, lower antigen scores and more limited intestinal infection. Two of four S-INDEL Iowa106-infected sows and the original PC21A-infected sow showed anorexia and watery diarrhea for 1-4 days. After the original PC21A challenge, a subset (13/16) of S-INDEL Iowa106-inoculated piglets developed diarrhea, whereas all (5/5) and no (0/4) pigs in the mock and original PC21A-inoculated pigs had diarrhea, respectively. Our results suggest that the virulence of S-INDEL PEDV Iowa106 was less than the original US PEDV PC21A in suckling pigs, with 100% morbidity and 18% (6/33) overall (0-75%) mortality in suckling pigs depending on factors such as the sow's health and lactation and the piglets' birth weight. Prior infection by S-INDEL Iowa106 provided partial cross-protection to piglets against the original PC21A challenge at 21-29 dpi.
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Affiliation(s)
- Chun-Ming Lin
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
| | - Thavamathi Annamalai
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
| | - Xinsheng Liu
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA. .,State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory of China, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.
| | - Xiang Gao
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
| | - Zhongyan Lu
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
| | - Mohamed El-Tholoth
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA. .,Department of Virology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
| | - Hui Hu
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
| | - Linda J Saif
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
| | - Qiuhong Wang
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
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16
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Annamalai T, Saif LJ, Lu Z, Jung K. Age-dependent variation in innate immune responses to porcine epidemic diarrhea virus infection in suckling versus weaned pigs. Vet Immunol Immunopathol 2015; 168:193-202. [PMID: 26433606 PMCID: PMC7112776 DOI: 10.1016/j.vetimm.2015.09.006] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 08/17/2015] [Accepted: 09/12/2015] [Indexed: 01/02/2023]
Abstract
Porcine epidemic diarrhea (PED) is an enteric coronaviral infection that causes severe morbidity and mortality in suckling pigs, but less severe disease in older pigs. Consequently, it causes significant economic losses to the pork industry. There are limited studies on the innate immune responses to PED virus (PEDV) in pigs. The aims of our study were to investigate differences in innate immune responses to PEDV infection in suckling and weaned pigs and to examine if disease severity coincides with reduced innate immune responses. Weaned 26-day-old pigs (n = 20) and 9-day-old nursing pigs (n = 20) were assigned to PEDV inoculated or uninoculated control groups. The pigs were observed daily for clinical signs, virus shedding and were euthanized at post-inoculation days (PIDs) 1 and 5 to assay immune responses. Blood samples were collected at PIDs 1, 3 and 5. The natural killer (NK) cell frequencies, NK cell activities (lysis of target K562 tumor cells in vitro), CD3+CD4+ T cell and CD3+CD8+ T cell frequencies were measured in blood and ileum at PIDs 1 and 5. The PEDV infected suckling pigs showed severe diarrhea and vomiting at PID 1, whereas the PEDV infected weaned pigs showed milder clinical signs starting at PID 3. PEDV infected suckling pigs had significantly higher diarrhea scores, earlier fecal PEDV RNA shedding and significantly higher viremia (viral RNA in serum) compared to weaned pigs. There was no mortality in either infected suckling or infected weaned pigs. The control pigs not inoculated with PEDV did not show any clinical signs and no detectable fecal or serum PEDV RNA. Strikingly, PEDV infected suckling pigs had significantly lower NK cell frequencies, undetectable NK cell activity and lower IFNγ producing NK cells in blood and ileum compared to PEDV infected weaned pigs. Pro-inflammatory cytokine profiles of PEDV infected suckling pigs differed from those of PEDV infected weaned pigs and coincided with onset of fecal PEDV RNA shedding and serum PEDV RNA titers. The infected suckling pigs have higher and earlier increases in serum IFNα, but lower serum IL-8 and TNFα levels compared to infected weaned pigs. CD3+CD4+ T cell frequencies were significantly higher in ileum of suckling pigs than in weaned pigs, whereas there was no difference in CD3+CD8+ T cell frequencies. In conclusion, the observations of impaired lytic activity and IFN-γ production by NK cells in suckling pigs coincided with the increased severity of PEDV infection in the suckling pigs compared with the weaned pigs.
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Affiliation(s)
- Thavamathi Annamalai
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA
| | - Linda J Saif
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
| | - Zhongyan Lu
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA
| | - Kwonil Jung
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
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An K, Fang L, Luo R, Wang D, Xie L, Yang J, Chen H, Xiao S. Quantitative proteomic analysis reveals that transmissible gastroenteritis virus activates the JAK-STAT1 signaling pathway. J Proteome Res 2014; 13:5376-90. [PMID: 25357264 DOI: 10.1021/pr500173p] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Transmissible gastroenteritis virus (TGEV), a porcine enteropathogenic coronavirus, causes lethal watery diarrhea and severe dehydration in piglets. In this study, liquid chromatography-tandem mass spectrometry coupled to isobaric tags for relative and absolute quantification labeling was used to quantitatively identify differentially expressed cellular proteins after TGEV infection in PK-15 cells. In total, 162 differentially expressed cellular proteins were identified, including 60 upregulated proteins and 102 downregulated proteins. These differentially expressed proteins were involved in the cell cycle, cellular growth and proliferation, the innate immune response, etc. Interestingly, many upregulated proteins were associated with interferon signaling, especially signal transducer and activator of transcription 1 (STAT1) and interferon-stimulated genes (ISGs). Immunoblotting and real-time quantitative reverse transcription polymerase chain reaction demonstrated that TGEV infection induces STAT1 phosphorylation and nuclear translocation, as well as ISG expression. This study for the first time reveals that TGEV induces interferon signaling from the point of proteomic analysis.
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Affiliation(s)
- Kang An
- Division of Animal Infectious Diseases, State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University , Wuhan, Hubei China
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Wang Y, Shi H, Rigolet P, Wu N, Zhu L, Xi XG, Vabret A, Wang X, Wang T. Nsp1 proteins of group I and SARS coronaviruses share structural and functional similarities. INFECTION GENETICS AND EVOLUTION 2010; 10:919-24. [PMID: 20609418 PMCID: PMC7106014 DOI: 10.1016/j.meegid.2010.05.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Revised: 05/24/2010] [Accepted: 05/25/2010] [Indexed: 11/01/2022]
Abstract
The nsp1 protein of the highly pathogenic SARS coronavirus suppresses host protein synthesis, including genes involved in the innate immune system. A bioinformatic analysis revealed that the nsp1 proteins of group I and SARS coronaviruses have similar structures. Nsp1 proteins of group I coronaviruses interacted with host ribosomal 40S subunit and did not inhibit IRF-3 activation. However, synthesis of host immune and non-immune proteins was inhibited by nsp1 proteins at both transcriptional and translational levels, similar to SARS coronavirus nsp1. These results indicate that different coronaviruses might employ the same nsp1 mechanism to antagonize host innate immunity and cell proliferation. However, nsp1 may not be the key determinant of viral pathogenicity, or the factor used by the SARS coronavirus to evade host innate immunity.
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Affiliation(s)
- Yongjin Wang
- Laboratory of Wildlife Epidemic Diseases, East China Normal University, Shanghai 200062, China
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Charley B, Laude H, La Bonnardière C. Inhibition of transmissible gastroenteritis coronavirus (TGEV) multiplication in vitro by non-immune lymphocytes. ACTA ACUST UNITED AC 2009; 138:183-194. [PMID: 32288183 PMCID: PMC7134748 DOI: 10.1016/s0769-2617(87)80003-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/1986] [Accepted: 12/10/1986] [Indexed: 11/06/2022]
Abstract
In vitro studies were undertaken to examine the effects of non-immune porcine peripheral blood leukocytes (PBL) on a Coronavirus infection due to transmissible gastroenteritis virus (TGEV). The assay consisted of TGEV-infected epithelial cells expressing viral antigens on the cell surface and producing low amounts of interferon (IFN). Non-immune PBL were found to limit virus replication at an effector-to-target ratio of 100/1 even when effector cells were depleted of phagocytic cells. Neutralizing anti-IFN antibodies did not abrogate the effect. PBL from newborn animals were as effective as adult cells, whereas fibroepithelial cells, human and mouse lymphoid cells did not exert antiviral effects. Under similar conditions, PBL from adult animals could lyse TGEV-infected cells even in the presence of anti-IFN antibodies. However, newborn PBL were not cytotoxic. Moreover, depletion of NK cells by monoclonal antibodies plus complement did not alter the inhibitory effect. These latter observations suggest that virus multiplication-inhibition effects and cytotoxic (or NK) activities are unrelated.
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Affiliation(s)
- B Charley
- INRA, Station de Recherches de Virologie et d'Immunologie, 78850 Thiverval-Grignon (France)
| | - H Laude
- INRA, Station de Recherches de Virologie et d'Immunologie, 78850 Thiverval-Grignon (France)
| | - C La Bonnardière
- INRA, Station de Recherches de Virologie et d'Immunologie, 78850 Thiverval-Grignon (France)
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De l’utilité des animaux domestiques pour la recherche en immunologie. BULLETIN DE L'ACADÉMIE NATIONALE DE MÉDECINE 2008. [PMID: 19235483 PMCID: PMC7111044 DOI: 10.1016/s0001-4079(19)32718-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Les recherches en immunologie des animaux domestiques fournissent des données complémentaires à celles menées chez la souris, du fait des « opportunités » qu’offrent ces espèces. Certaines d’entre elles font l’objet de cette communication: approche chirurgicale du fonctionnement in vivo des organes lymphoïdes, interventions in utero pour l’étude de l’ontogénèse du système immunitaire, pertinence de l’étude physiopathologique des infections sur espèces cibles.
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Charley B, Riffault S, Van Reeth K. Porcine innate and adaptative immune responses to influenza and coronavirus infections. Ann N Y Acad Sci 2007; 1081:130-6. [PMID: 17135502 PMCID: PMC7168046 DOI: 10.1196/annals.1373.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
abstract: Both innate and adaptative immune responses contribute to the control of infectious diseases, including by limiting the spreading of zoonotic diseases from animal reservoirs to humans. Pigs represent an important animal reservoir for influenza virus infection of human populations and are also naturally infected by coronaviruses, an important group of viruses, which includes the recently emerged severe acute respiratory syndrome (SARS) virus. Studies on both innate and adaptative immune responses of pigs to influenza virus and coronaviruses contribute, therefore, to a better control of these infections in their natural hosts and will be briefly reviewed in this article. Pro‐inflammatory cytokines, including type I interferon (IFN), tumor necrosis factor‐α (TNF‐α), and interleukin‐6 (IL‐6), were found in lung secretions of influenza virus infected pigs, and correlated with the intensity of clinical signs, whereas prior vaccination against influenza strongly reduced the production of infectious virus and cytokines in the lungs upon challenge, which was associated with clinical protection. An early type I IFN production was also found in coronavirus infected pigs, including at mucosal sites. IFN induction by coronavirus is shown to involve interaction between a viral glycoprotein and a leukocyte subset, likely equivalent to plasmacytoid dendritic cells, present in the mucosae and associated lymphoid tissues. Given the IFN mediated antiviral and immunomodulatory effects, the use of IFN or IFN inducers may prove an efficient strategy for a better control of influenza virus and coronavirus infections in pigs. Because influenza and coronaviruses target mucosal surfaces, adaptative immune responses have to be characterized at mucosal sites. Thus, nasal and pulmonary antibody responses were analyzed in influenza virus infected or vaccinated pigs showing short‐lived, but potentially protective local IgA and IgG antibody (Ab) responses. Interestingly, primary influenza virus infection induced long‐lived increase of lung CD8+ T cells and local lymphoproliferative responses. Pigs infected by a respiratory coronavirus (PRCV) showed virus‐specific IgG Ab‐secreting cells in the bronchial lymph nodes, whereas the transmissible gastroenteritis coronavirus (TGEV) induced more IgA Ab‐secreting cells in gut tissues, which illustrates the importance of the route of antigen administration for inducing local immune effector mechanisms. Porcine viral infections provide, therefore, valuable models for evaluating the immune parameters that are important for controlling transmission of important viral zoonotic infections.
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Affiliation(s)
- Bernard Charley
- INRA, Virologie Immunologie moléculaires, 78350, Jouy-en-Josas, France.
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La Bonnardière C, Laude H, Berg K. Biological and antigenic relationships between virus-induced porcine and human interferons. ACTA ACUST UNITED AC 2006; 137:171-180. [PMID: 32288182 PMCID: PMC7135696 DOI: 10.1016/s0769-2617(86)80202-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/1985] [Accepted: 02/14/1986] [Indexed: 11/17/2022]
Abstract
Endogenous interferon (IFN) made by the newborn piglet in response to enteric coronavirus TGEV (transmissible gastroenteritis virus) infection was identified as leukocytic IFN (IFN-α). Indeed, the antiviral activity found in the serum and in the urine of infected piglets displayed the same main biological and antigenic properties as the IFN induced in influenza-infected pig leukocytes. It is therefore concluded that most, if not all, circulating IFN activity must be derived from lymphoid cells. Moreover, it was shown that a high degree of antigenic homology exists between porcine and human IFN-α: antibodies to HuIFN-α could efficiently neutralize PorIFN-α, and they were used for its purification by immunoaffinity.
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Affiliation(s)
- C La Bonnardière
- Station de Recherches de Virologie et d'Immunologie, INRA, 78850 Thiverval-Grignon (France)
| | - H Laude
- Station de Recherches de Virologie et d'Immunologie, INRA, 78850 Thiverval-Grignon (France)
| | - K Berg
- Institute of Medical Microbiology, University of Aarhus, DK 8000, Aarhus C (Denmark)
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23
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Haverson K, Riffault S. Antigen presenting cells in mucosal sites of veterinary species. Vet Res 2006; 37:339-58. [PMID: 16611552 DOI: 10.1051/vetres:2006005] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Accepted: 09/15/2005] [Indexed: 11/14/2022] Open
Abstract
The ability of antigen presenting cells, in particular dendritic cells, to integrate a variety of environmental signals, together with their ability to respond appropriately by initiating either tolerance or defensive immune responses make them cells of particular relevance and importance in the mucosal environment. They have been demonstrated in a variety of mucosal tissues in veterinary species and have been characterized to varying degrees, showing that fundamental immunological principles apply throughout all species, but also highlighting some species differences. A major advantage of carrying out immunological research in veterinary species is their size: it is possible to cannulate lymphatic ducts and obtain information about cell migration between different tissues. It is also possible to obtain pure populations of relatively rare cell types such as the plasmacytoid dendritic cells or mucosal dendritic cells ex vivo for the study of immune responses to diseases in their natural host and for other thorough functional studies. Two major myeloid antigen presenting cell (APC) (dendritic cells, DC) cell populations have been described in gut draining lymph and other mucosal sites in ruminants and pigs, characterised by the presence or absence of surface molecules, their enzyme profiles, their ability to phagocytose and their different potential as APC. There is evidence that one of these subsets has migrated from the diffuse mucosal tissue, where it is found as a phagocytic as well as stimulatory APC population, which in turn may be derived from blood macrophages. In addition, the presence and role in viral infection of the IFN-alpha producing plasmacytoid DC in mucosal tissue is discussed, based on studies in pigs.
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Affiliation(s)
- Karin Haverson
- Department of Clinical Veterinary Science, University of Bristol, United Kingdom.
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24
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Van Reeth K, Van Gucht S, Pensaert M. Correlations between lung proinflammatory cytokine levels, virus replication, and disease after swine influenza virus challenge of vaccination-immune pigs. Viral Immunol 2003; 15:583-94. [PMID: 12513929 DOI: 10.1089/088282402320914520] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
During experimental infection of pigs with swine influenza virus (SIV), there is a strong temporal correlation between peak virus titers in the lungs, levels of different proinflammatory cytokines in bronchoalveolar lavage (BAL) fluids, and disease. Vaccination against SIV can greatly reduce or prevent virus replication after challenge and the resulting disease. Here, we took advantage of pigs from vaccination-challenge experiments, with different degrees of virological and clinical protection, to further correlate SIV replication with cytokines and disease. Forty-nine pigs were vaccinated twice with a commercial inactivated SIV vaccine or with experimental vaccines, and 35 control pigs were not vaccinated. Between 2 and 4 weeks after the last vaccination, all pigs were challenged intratracheally with SIV. Twenty-four hours after the challenge, we determined body temperatures, respiratory scores, lung virus titers, and neutrophils and cytokines in BAL fluids. Interferon-alpha (IFN-alpha), tumor necrosis factor (TNF-alpha), interleukin-1 (IL-1), and -6 (IL-6) were determined by bioassay, and IL-8 by a commercial ELISA. The results were analyzed for three comparison groups. The unvaccinated control pigs (group 1, n = 35) were positive for all or most parameters examined. Vaccinated pigs with challenge virus replication in the lungs (group 2, n = 28) had slightly lower virus titers than the challenge control pigs, and clear reductions in disease severity and mean titers of all five cytokines, but neutrophil numbers were not affected. Vaccinated pigs without detectable virus replication (group 3, n = 21) were largely protected against clinical signs and neutrophil infiltration. Mean levels of IFN-alpha, TNF-alpha, and IL-6, but not IL-1 or IL-8, were lower than in both other groups. Virus titers in the lungs of individual pigs showed highly significant correlations with IFN-alpha and IL-6, and lower correlations with TNF-alpha and IL-8. Clinical signs were most closely associated with IFN-alpha, IL-6, and TNF-alpha. The relationship between disease and IL-8 or IL-1 was much weaker. Our data provide further evidence for a role of IFN-alpha, TNF-alpha, and IL-6 in the pathogenesis of SIV. The similarities with cytokine profiles during human influenza virus infection are discussed.
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Affiliation(s)
- K Van Reeth
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
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25
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Cencic A, Henry C, Lefèvre F, Huet JC, Koren S, La Bonnardière C. The porcine trophoblastic interferon-gamma, secreted by a polarized epithelium, has specific structural and biochemical properties. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:2772-81. [PMID: 12047387 DOI: 10.1046/j.1432-1033.2002.02950.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
At the time of implantation in the maternal uterus, the trophectoderm of the pig blastocyst is the source of a massive secretion of interferon-gamma (IFN-gamma), together with lesser amounts of IFN-delta, a unique species of type I IFN. This trophoblastic IFN-gamma (TrIFN-gamma) is an unprecedented example of IFN-gamma being produced spontaneously by an epithelium. We therefore studied some of its structural and biochemical properties, by comparison with pig IFN-gamma from other sources, either natural LeIFN-gamma (from adult leucocytes), or recombinant. Biologically active TrIFN-gamma is a dimeric molecule, of which monomers are mainly composed of a truncated polypeptide chain with two glycotypes, unlike LeIFN-gamma which is formed of at least two polypeptide chains and four glycotypes. TrIFN-gamma collected in the uterus lumen was enzymatically deglycosylated and analysed by mass spectrometry (MALDI-TOF). The data revealed that the more abundant polypeptide has a mass of 14.74 kDa, corresponding to a C-terminal cleavage of 17 residues from the expected 143-residue long mature sequence. A minor polypeptide, with a mass of 12.63 kDa, corresponds to a C-terminal truncation of 36 amino acids. MALDI-TOF analysis of tryptic peptides from the glycosylated molecule(s) identifies a single branched carbohydrate motif, with six N-acetylgalactosamines, and no sialic acid. The only glycan microheterogeneity seems to reside in the number of l-fucose residues (one to three). The lack of the C-terminal cluster of basic residues, and the presence of nonsialylated glycans, result in a very low net charge of TrIFN-gamma molecule. However, the 17-residue truncation does not affect the antiproliferative activity of TrIFN-gamma on different cells, among which is a porcine uterine epithelial cell line. It is suggested that these specific properties might confer on TrIFN-gamma a particular ability to invade the uterine mucosa and exert biological functions beyond the endometrial epithelium.
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Affiliation(s)
- Avrelija Cencic
- Unité de Virologie et d'Immunologie Moléculaires, INRA, Jouy en Josas, France
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26
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Chełmońska-Soyta A, Katska L, Kurpisz M, Stefaniak T, Zimecki M. The effect of Ureaplasma diversum activated mononuclear leukocytes on the development and interferon-tau production by bovine IVF-derived embryos. J Reprod Immunol 2001; 51:145-58. [PMID: 11543853 DOI: 10.1016/s0165-0378(01)00073-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Ureaplasma diversum is an opportunistic pathogen of the bovine genital tract causing herd outbreaks of granular vulvitis, abortion and infertility. Early embryonic death probably contributes to reduction of the reproductive performance in cows, however, pathogenesis of the disease remains obscure. The aim of the study was to examine whether activation of mononuclear leukocytes by U. diversum may affect embryo development and IFN-tau production. Bovine peripheral blood mononuclear leukocytes were cultured with U.diversum antigen for 24 h. The levels of IL-1, TNF-alpha, NO and GM-CSF in the cell culture supernatants were measured. IVF-derived embryos were cultured in the presence of supernatants from activated leukocytes. The development of embryos until day 6 postinsemination and the rate of morulae/blastocysts were determined. IFN-tau production in supernatants of cultured embryos was examined by inhibition of a virally-induced cytopathic effect. The results showed that U. diversum stimulated mononuclear leukocyte production of IL-1, TNF-alpha and NO. Supernatants from U. diversum-activated cells did not impair the rates of the embryo development and blastocyst formation. The products of activated leukocytes increased the IFN-tau production by cultured blastocysts. This suggest that U. diversum infection provides leukocyte-mediated signals for developing embryos for generation of additional production of cytokine - an important component of innate immunity.
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Affiliation(s)
- A Chełmońska-Soyta
- Department of Veterinary Prevention and Immunology, Agriculture University of Wrocław, Faculty of Veterinary Medicine, C.K. Norwida Str.31, 50-375 Wrocław, Poland
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27
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Tråvén M, Näslund K, Linde N, Linde B, Silván A, Fossum C, Hedlund KO, Larsson B. Experimental reproduction of winter dysentery in lactating cows using BCV -- comparison with BCV infection in milk-fed calves. Vet Microbiol 2001; 81:127-51. [PMID: 11376958 PMCID: PMC7117383 DOI: 10.1016/s0378-1135(01)00337-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Infection models were developed for adult cows and for young calves using the same strain of bovine coronavirus (BCV), which for the first time allows experimental reproduction of winter dysentery (WD) in seronegative lactating cows. The cattle were infected through direct contact with an experimentally inoculated calf. All experimental cattle shed faecal BCV with development of diarrhoea, being profusely watery with small amounts of blood in the most severely affected animals, including both cows and calves. The cows, in contrast to the calves, showed depressed general condition and appetite leading to a marked decrease in milk yield. Further age-associated differences were a shorter incubation period in the two youngest calves, but with milder fever and milder decrease in white blood cell counts. These findings shed light on the apparent epidemiological differences between WD and calf BCV diarrhoea suggesting that, (1) the same strains of BCV cause natural outbreaks of calf diarrhoea and WD, (2) seronegative cows are more severely affected by the infection than seronegative conventionally reared calves, and (3) unaffected general condition in diarrhoeic calves may lead to underestimation of the occurrence of calf diarrhoea in WD outbreaks. In response to infection, all cattle produced early interferon type 1 in serum and, except for one calf, in nasal secretions. A finding not previously reported is the detection of interferon type 1 responses in bovine milk. All cattle developed high IgM antibody responses and long-lasting IgA antibody responses both systemically and locally. The serum IgM antibody responses came earlier in most of the calves than in the cows. Prolonged IgM antibody responses were detected in serum and milk, while those in nasal secretions were much shorter. BCV-specific IgA was present in nasal secretions from all cattle throughout the 6 months follow-up. The IgA antibody response in serum was detected up to 17 months post-infection and the duration showed an age-related variation indicating a more prominent IgA memory in the adult cattle and in the older calves than in the younger ones. BCV-specific IgG was detected in all cattle during the experimental period of up to 22 months. In conclusion, WD was reproduced in seronegative lactating cows. The cows showed a more severe general diseases than seronegative calves infected concurrently. Very long-lasting IgA antibody responses were detected both systemically and locally.
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Affiliation(s)
- M Tråvén
- Department of Ruminant Medicine and Veterinary Epidemiology, Swedish University of Agricultural Sciences, Box 7019, S-750 07 Uppsala, Sweden.
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28
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Cencic A, LeFèvre F, Koren S, La Bonnardière C. Tetracycline-controlled expression of glycosylated porcine interferon-gamma in mammalian cells. Anim Biotechnol 2000; 10:63-79. [PMID: 10654431 DOI: 10.1080/10495399909525922] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Tetracycline-controlled expression plasmids that allow inducible expression of proteins in mammalian cells (Gossen & Bujard, 1992), have been used to express porcine interferon-gamma in the RK-13 rabbit kidney cell line. Following neomycin selection, stable clones produced recombinant, glycosylated porcine interferon-gamma (rGPoIFN-gamma) only after removal of tetracycline (Tc). Southern blot analysis of one clone showed that approximately 50 copies of IFN-gamma cDNA were present in the cell genome. In the absence of Tc, stable clones secreted large amounts of rGPoIFN-gamma (up to 16 microg/ml) into the medium supplemented with 10% FCS and high glucose concentration. Molecular weight comparison of 35S-Methionine, labelled rGPoIFN-gamma with natural leukocytic IFN-gamma after immunoprecipitation, revealed 4 major glycoforms with apparent Mr of 27,000; 25,000; 20,000 and 18,500, that are almost identical in both IFN-gamma species. In both cases, all 4 glycoforms resolved into 2 polypeptide monomers with apparent Mr of 16,500 and 14,500 upon deglycosylation with N-glycosydase F. The biological activity of rGPoIFN-gamma was in the same range as that of natural leukocytic PoIFN-gamma (2 x 10(6) U/mg). Eventually, this recombinant mammalian IFN-gamma should constitute a very useful substitute for leukocyte PoIFN-gamma in in vitro or in vivo experiments.
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Affiliation(s)
- A Cencic
- Unité de Virologie et d'Immunologie Moléculaires, I.N.R.A., Jouy-en-Josas, France
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29
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Baudoux P, Carrat C, Besnardeau L, Charley B, Laude H. Coronavirus pseudoparticles formed with recombinant M and E proteins induce alpha interferon synthesis by leukocytes. J Virol 1998; 72:8636-43. [PMID: 9765403 PMCID: PMC110275 DOI: 10.1128/jvi.72.11.8636-8643.1998] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Transmissible gastroenteritis virus (TGEV), an enteric coronavirus of swine, is a potent inducer of alpha interferon (IFN-alpha) both in vivo and in vitro. Incubation of peripheral blood mononuclear cells with noninfectious viral material such as inactivated virions or fixed, infected cells leads to early and strong IFN-alpha synthesis. Previous studies have shown that antibodies against the virus membrane glycoprotein M blocked the IFN induction and that two viruses with a mutated protein exhibited a decreased interferogenic activity, thus arguing for a direct involvement of M protein in this phenomenon. In this study, the IFN-alpha-inducing activity of recombinant M protein expressed in the absence or presence of other TGEV structural proteins was examined. Fixed cells coexpressing M together with at least the minor structural protein E were found to induce IFN-alpha almost as efficiently as TGEV-infected cells. Pseudoparticles resembling authentic virions were released in the culture medium of cells coexpressing M and E proteins. The interferogenic activity of purified pseudoparticles was shown to be comparable to that of TGEV virions, thus establishing that neither ribonucleoprotein nor spikes are required for IFN induction. The replacement of the externally exposed, N-terminal domain of M with that of bovine coronavirus (BCV) led to the production of chimeric particles with no major change in interferogenicity, although the structures of the TGEV and BCV ectodomains markedly differ. Moreover, BCV pseudoparticles also exhibited interferogenic activity. Together these observations suggest that the ability of coronavirus particles to induce IFN-alpha is more likely to involve a specific, multimeric structure than a definite sequence motif.
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Affiliation(s)
- P Baudoux
- Unité de Virologie Immunologie Moléculaires, INRA, 78350 Jouy-en-Josas, France
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30
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Baudoux P, Besnardeau L, Carrat C, Rottier P, Charley B, Laude H. Interferon alpha inducing property of coronavirus particles and pseudoparticles. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 440:377-86. [PMID: 9782306 DOI: 10.1007/978-1-4615-5331-1_49] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Previous work in our laboratory have provided evidence that the membrane glycoprotein M of TGEV is centrally involved in efficient induction of alpha interferon (IFN-alpha) synthesis by non-immune peripheral blood mononuclear cells incubated with fixed, TGEV-infected cells or inactivated virions. Here we report recent completion of studies initiated to get a better understanding of the nature of the interferogenic determinant(s). Transfected cells expressing TGEV M together with the minor structural component E (formerly called sM) were found to trigger IFN-alpha synthesis. Co-expression of these two proteins was shown to be necessary and sufficient for assembly and release of pseudoparticles resembling TGEV virions. Purified pseudoparticles exhibited an interferogenic activity close to that of authentic virions. Chimeric recombinant particles expressing BCV M ectodomain also induced IFN. Examination of cell cultures infected by viruses representative of the three Nidovirales genera revealed that the capacity to act as an efficient IFN-alpha inducer is a common feature of viral particles of the coronavirus genus. Altogether these data bring new insights regarding the putative nature of the viral structure involved in IFN-alpha induction.
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Affiliation(s)
- P Baudoux
- Unité de Virologie Immunologie Moléculaires, INRA, Jouy-en-Josas, France
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31
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Fossum C. Cytokines as markers for infections and their effect on growth performance and well-being in the pig. Domest Anim Endocrinol 1998; 15:439-44. [PMID: 9785048 DOI: 10.1016/s0739-7240(98)80001-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Exposure to micro-organisms commonly elicit the production of cytokines. These soluble factors enhance several innate immune functions that aim to limit the spread of infection. Further, many of the pro-inflammatory cytokines regulate the ensuing specific immune response. In addition to their effects on cells of the immune system, cytokines also are important regulators in the so called immune-neuroendocrine network. The microbial structures that are necessary for induction of cytokine production are not conclusively determined but in general, bacteria preferentially induce the production of IL-1, TNF-alpha, IL-6, and IL-8, whereas virus induce the production of Type 1 interferons (IFN-alpha/beta). The onset of production of these cytokines is rapid, and several of them may reach systemic levels during a short period after infection. Thus, cytokines can serve as markers for ongoing infections and be used for discrimination between infections of bacterial or viral origin. Results from experimental and field studies show that serum IFN-alpha and IL-6 seem to be useful markers for ongoing (subclinical) viral and bacterial infections, respectively, in the pig. Consequently, demonstration of these cytokines can be valuable tools in heard health monitoring programs.
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Affiliation(s)
- C Fossum
- Department of Veterinary Microbiology, SLU, Biomedical Centre, Uppsala, Sweden
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32
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Albina E, Carrat C, Charley B. Interferon-alpha response to swine arterivirus (PoAV), the porcine reproductive and respiratory syndrome virus. J Interferon Cytokine Res 1998; 18:485-90. [PMID: 9712364 DOI: 10.1089/jir.1998.18.485] [Citation(s) in RCA: 197] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We studied the interferon-alpha (IFN-alpha) system in relation to the porcine arterivirus (PoAV), porcine reproductive and respiratory syndrome virus (PRRSV). Recombinant porcine IFN-alpha inhibited the growth of this virus in alveolar macrophage cultures. When pigs were challenged intranasally with PoAV, their serum contained IFN-alpha in relatively low concentrations on the second day after challenge and up to 5 days at the latest. Most animals had no IFN-alpha in their lung secretions, even though PoAV replicates in the respiratory tract. In vitro, PoAV replicates in alveolar macrophages, but neither these nor peripheral blood mononuclear cells (PBMC) produced IFN-alpha in response to infection. This may be because PoAV suppresses IFN-alpha production. When macrophages treated with PoAV were superinfected with swine transmissible gastroenteritis virus (TGEV), a known good inducer of IFN, no IFN-alpha was detected. This suppressive effect was lost when the virus was inactivated by UV light. Our results suggest that downregulation of IFN-alpha production may play an important part in enabling PoAV to replicate in cell cultures and in pigs.
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Affiliation(s)
- E Albina
- CNEVA-Ploufragan, Unité de Virologie et Immunologie Porcines, France.
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33
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Splíchal I, Reháková Z, Sinkora M, Sinkora J, Trebichavský I, Laude H, Charley B. In vivo study of interferon-alpha-secreting cells in pig foetal lymphohaematopoietic organs following in utero TGEV coronavirus injection. RESEARCH IN IMMUNOLOGY 1997; 148:247-56. [PMID: 9300531 PMCID: PMC7135581 DOI: 10.1016/s0923-2494(97)80866-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Non-infectious UV-inactivated transmissible gastroenteritis virus (TGEV) was previously shown to induce interferon alpha (IFN alpha) secretion following in vitro incubation with blood mononuclear cells. In this study, pig foetuses at different stages of gestation were injected in utero with (a) partially UV-inactivated wild TGEV or (b) fully UV-inactivated wild or dm49-4 mutant TGEV coronavirus. Nucleated cells from foetal liver, bone marrow, spleen and blood were isolated 10 or 20 h after injection and assayed ex vivo for IFN alpha secretion by ELISPOT and ELISA techniques. The administration of TGEV induced IFN alpha-secreting cells in foetal lymphohaematopoietic organs at mid-gestation. In contrast, IFN alpha was not detected in control sham-operated foetuses. A specific point mutation in the amino acid sequence of the viral membrane glycoprotein M of TGEV mutant dm49-4 was associated with lower or absent IFN alpha in utero inducibility by mutant virus as compared with wild virus. Flow cytometry analysis did not show differences in leukocyte surface marker expression between control and TGEV- or between dm49-4 and wild virus-treated foetus cells, with the exception of a reduction in percentages of polymorphonuclear cells in TGEV-treated lymphohaematopoietic tissues, which is probably due to IFN alpha secretion. The present data provided in vivo evidence of IFN alpha secretion at the cell level in foetal lymphohaematopoietic organs. Such IFN alpha-secreting cells in lymphohaematopoietic tissues may be the source of IFN alpha detected during foetal infections.
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Affiliation(s)
- I Splíchal
- Division of Immunology and Gnotobiology, Academy of Sciences of the Czech Republic, Nový Hrádek (Czech Republic)
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34
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Gachet Y, Carpentier G, Chousterman S. Purification of an atypical bovine interferon induced in response to heat shock in bovine cultured cells. Characterization in comparison with the classical alpha, beta and gamma interferon. Biochimie 1997; 79:43-52. [PMID: 9195045 DOI: 10.1016/s0300-9084(97)87624-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Heat-shock induced factor (HSIF) was excreted by bovine MDBK cells during their recovery period after a heat shock. This factor has the capacity to induce 2',5' oligoadenylate synthetase activity, an enzyme generally by interferon treatment (J Biol Chem (1987) 262, 4806-4811). We have observed that an antiviral state was also produced in response to heat shock. HSIF was purified 10,000-fold and different techniques showed a copurification of both activities. Certain properties of HSIF were established, such as its molecular mass (45 kDa) and isoelectric point (6.8). This cytokine was acid-sensitive as IFN gamma (type II) and temperature labile contrarily to alpha, beta and gamma bovine IFN. Immunoprecipitation and comparative chromatography on lectines or polynucleotides established that HSIF was structurally different from the three classes of bovine IFN. Moreover, two-dimensional electrophoresis and comparative analysis of [35S] methionine-labeled proteins induced by HSIF alpha, beta or gamma bovine IFN showed that HSIF induces a specific set of proteins. Taken together, all these results strongly suggest that HSIF is a new atypical bovine interferon induced in response to heat shock.
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Affiliation(s)
- Y Gachet
- Unité 471 INSERM Centre INSERM Saint-Antoine, Paris, France
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35
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Antón IM, González S, Bullido MJ, Corsín M, Risco C, Langeveld JP, Enjuanes L. Cooperation between transmissible gastroenteritis coronavirus (TGEV) structural proteins in the in vitro induction of virus-specific antibodies. Virus Res 1996; 46:111-24. [PMID: 9029784 PMCID: PMC7134021 DOI: 10.1016/s0168-1702(96)01390-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Following infection of haplotype defined NIH-miniswine with virulent transmissible gastroenteritis coronavirus (TGEV), isolated mesenteric lymph node CD4+ T-cells mounted a specific proliferative response against infectious or inactivated purified virus in secondary in vitro stimulation. A specific, dose-dependent response to the three major recombinant viral proteins: spike (S), membrane (M), and nucleoprotein (N), purified by affinity chromatography, was characterized. Induction of in vitro antibody synthesis was analyzed. The purified recombinant viral proteins induced the in vitro synthesis of neutralizing TGEV-specific antibodies when porcine TGEV-immune cells were stimulated with each of the combinations made with two of the major structural proteins: S + N, S + M, and to a minor extent with M + N, but not by the individual proteins. S-protein was dissociated from purified virus using NP-40 detergent and then micellar S-protein oligomers (S-rosettes) were formed by removing the detergent. These occurred preferentially by the association of more than 10 S-protein trimmers. These S-rosettes in collaboration with either N or M-proteins elicited TGEV-specific antibodies with titers up to 84 and 60%, respectively, of those induced by the whole virus. N-protein could be partially substituted by a 15-mer peptide that represents a T helper epitope previously identified in N-protein (Antón et al. (1995)). These results indicate that the induction of high levels of TGEV-specific antibodies requires stimulation by at least two viral proteins, and that optimum responses are induced by a combination of S-rosettes and the nucleoprotein.
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Affiliation(s)
- I M Antón
- CSIC, Department of Molecular and Cell Biology, Madrid, Spain
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36
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L'Haridon RM, Huynh L, Assal NE, Martal J. A single intrauterine infusion of sustained recombinant ovine interferon-τ extends corpus luteum lifespan in cyclic ewes. Theriogenology 1995; 43:1031-45. [PMID: 16727690 DOI: 10.1016/0093-691x(95)00067-i] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/1994] [Accepted: 02/01/1995] [Indexed: 11/28/2022]
Abstract
Delivery carriers were developed to permit sustained release of recombinant ovine tau-interferon (roIFN-tau) to increase corpus luteum (CL) lifespan in cyclic ewes following a single intrauterine administration on Day 10 post estrus. A single infusion with 1.7 mg roIFN-tau covalently bound to carboxymethyl biogel agarose (carbodiimide coupling) significantly increased the interestrus interval (P < 0.01) in treated (n = 4) versus control animals (n = 6), whereas liposomally encapsulated roIFN-tau administered to experimental ewes (n = 8) versus control ewes (n = 6) was less effective (P < 0.05). RoIFN-tau covalently bound to trisacryl (glutaraldehyde coupling) was also effective in cyclic ewes (n = 6), but covalent binding to Eupergit C through oxirane bonds yielded ineffective preparations. Ewes that were given 1.7 mg soluble roIFN-tau (n = 8) displayed slight extension of the CL lifespan compared with ewes that were given 1.7 mg soluble BSA (n = 6), but this extension lacked significance in the Mann-Whitney U-test (P > 0.05). These results are consistent with previous data from experiments performed with daily intrauterine infusion of soluble, native or recombinant oIFN-tau. In addition, because CL maintenance requires only a single administration, these methods are efficient and simple to use since they avoid animal catheterization and allow for reduced injection frequency. Moreover, they may permit the use of smaller amounts of IFN. It is concluded that the use of oIFN-tau sustained in some delivery systems may allow for the development of an experimental sheep pseudopregnancy model.
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Affiliation(s)
- R M L'Haridon
- Unité de Virologie et Immunologie, Institut National de la Recherche Agronomique, 78 350, Jouy en Josas, France
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37
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Baudoux P, Charley B, Laude H. Recombinant expression of the TGEV membrane glycoprotein M. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1995; 380:305-10. [PMID: 8830498 DOI: 10.1007/978-1-4615-1899-0_49] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We have previously shown that the membrane protein M of TGEV is involved in efficient induction of alpha interferon (IFN alpha) synthesis by non-immune peripheral blood mononuclear cells incubated with fixed, TGEV-infected cells or inactivated virions. In order to determine whether M protein is able to induce interferon in the absence of other viral factors, we expressed the protein either stably in the porcine ST cells or transiently in the simian COS7 cells. Although showing no obvious difference in intracellular localization or glycosylation compared to its viral counterpart, the recombinant molecule failed to induce significant IFN activity.
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Affiliation(s)
- P Baudoux
- Unite de Virologie et Immunologie Moléculaires, INRA, Jouy-en-Josas, France
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38
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Jordan LT, Derbyshire JB. Antiviral activity of interferon against transmissible gastroenteritis virus in cell culture and ligated intestinal segments in neonatal pigs. Vet Microbiol 1994; 38:263-76. [PMID: 8017030 PMCID: PMC7117254 DOI: 10.1016/0378-1135(94)90007-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/09/1993] [Indexed: 01/28/2023]
Abstract
Segments of jejunum in 5 to 6 days old piglets were surgically ligated, inoculated with transmissible gastroenteritis virus (TGEV) and 18 hours later the segments were fixed for histology or suspensions were prepared for plaque assay in swine testis (ST) cell cultures to determine the yield of virus. When the virulent Purdue strain of TGEV was used, villous atrophy was seen and TGEV antigen was demonstrated immunohistochemically in the villous enterocytes. The Miller M6 strain of virus produced less extensive lesions in the segments, but since it was titratable by plaque assay it was used in the subsequent yield reduction assays to determine the antiviral activity of interferon. When intestinal segments were inoculated simultaneously with either 3200 units of natural porcine interferon-alpha or up to 1000,000 units of recombinant human interferon-alpha 2 a, and TGEV, there no reductions in virus yield, although the same cytokines exerted an antiviral effect in ST cells treated in a similar way. However, virus yields were significantly reduced in intestinal segments in piglets treated parenterally with the synthetic interferon inducer polyinosinic: polycytidylic acid 6 hours before challenge of the segments with TGEV. There was also a trend for the antiviral effects of interferon induction before challenge to be augmented by the inclusion of interferon with the virus inoculum. It was concluded that interferon would be ineffective as a therapeutic for TGEV, although it might be useful prophylactically.
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Affiliation(s)
- L T Jordan
- Department of Veterinary Microbiology and Immunology, Ontario Veterinary, College University of Guelph, Canada
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39
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Charlier M, L'Haridon R, Boisnard M, Martal J, Gaye P. Cloning and structural analysis of four genes encoding interferon-omega in rabbit. JOURNAL OF INTERFERON RESEARCH 1993; 13:313-22. [PMID: 8301151 DOI: 10.1089/jir.1993.13.313] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
By using an ovine interferon-tau (IFN-tau) cDNA probe, four recombinant phages were isolated from a rabbit genomic library and sequenced from nucleotides -450 to 1,300 relative to the CAP site. Each of the four rabbit genes contains an open reading frame of 595 nucleotides and code for proteins that exhibit structural characteristics of the interferon-omega (IFN-omega) family. They display more than 98% identity in their coding regions. The deduced amino acid sequences share > 96% sequence similarity. In contrast, the 5' and 3' noncoding regions have diverged considerably (approximately 50% identity). Amino acid comparisons of rabbit IFN-omega with IFN-omega of other species reveal the highest degree of identity with human (72%), followed by porcine (68%) IFN-omega. Rabbit IFN-omega displays only 57% sequence similarity with ovine IFN-tau. The coding regions of the four genes subcloned in a cytomegalovirus eukaryotic expression vector and transfected in monkey COS-7 cells direct the production of proteins that protect bovine and rabbit cells against vesicular stomatitis virus infection, thus demonstrating that these genes encode fully active IFN proteins. The expression of these genes was studied in Sendai-induced rabbit leukocytes. A single band of poly(A)+RNA hybridized with a rabbit IFN-omega probe under stringent conditions, whereas no IFN-omega transcript was detected with RNA isolated from uninduced leukocytes. Southern blot analysis suggest the existence of at least eight IFN-omega genes or pseudogenes in the rabbit genome.
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Affiliation(s)
- M Charlier
- Unité d'Endocrinologie de l'Embryon, I.N.R.A., Jouy-en-Josas, France
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40
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Vandenbroeck K, Martens E, D'Andrea S, Billiau A. Refolding and single-step purification of porcine interferon-gamma from Escherichia coli inclusion bodies. Conditions for reconstitution of dimeric IFN-gamma. EUROPEAN JOURNAL OF BIOCHEMISTRY 1993; 215:481-6. [PMID: 8344315 DOI: 10.1111/j.1432-1033.1993.tb18057.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Recombinant porcine interferon-gamma, overexpressed in Escherichia coli, was found to accumulate in cytoplasmic inclusion bodies. The influence of various physicochemical parameters on refolding was investigated using 6 M guanidine/HCl-solubilised inclusion bodies which had been purified by ultracentrifugation on a sucrose step gradient. It appeared that the yield of reconstitution of denatured protein reached 60-70% under optimum conditions, i.e. at an intermediary guanidine/HCl concentration of 0.5 M and at a protein concentration of 10-20 microM (0 degrees C). Since intermediary guanidine/HCl concentrations at 0.5-1.65 M increasingly promoted off-pathway formation of soluble aggregates and at 0.5-0.2 M progressively promoted precipitation, maximal recovery of biologically active protein required a twofold transition in the surrounding guanidine/HCl concentration (6 M-->0.5 M-->0 M). A single additional size-exclusion chromatographic step yielded a final product that was > 99.5% pure, had specific antiviral activity > 10(7) U/mg protein and contained < or = 25 pg/ml endotoxin. Cross-linking by means of disulfosuccinimidyl tartarate revealed that the refolded protein possessed a dimeric structure. Furthermore, we have characterized three different molecular species of recombinant porcine interferon-gamma that are formed under non-optimal refolding conditions (1 M guanidine/HCl) and that differ from each other in specific activity, size and stability. One of these converts irreversibly into dimeric interferon-gamma in a temperature-dependent manner and is therefore considered as a productive folding intermediate.
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41
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Nowacki W, Cederblad B, Renard C, La Bonnardière C, Charley B. Age-related increase of porcine natural interferon alpha producing cell frequency and of interferon yield per cell. Vet Immunol Immunopathol 1993; 37:113-22. [PMID: 8236791 PMCID: PMC7119810 DOI: 10.1016/0165-2427(93)90059-d] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Porcine blood mononuclear cells (PBMC) were shown to secrete interferon alpha (IFN-alpha) after induction by a coronavirus, the transmissible gastroenteritis virus (TGEV). IFN-alpha producing cells, referred to as natural interferon alpha producing (NIP) cells, were detected by an ELISPOT assay using anti-porcine IFN-alpha monoclonal antibodies. The frequency of NIP cells among blood cells is low, at most 40-110 per 10(5) PBMC and each NIP cell was found to produce several units of IFN. We have shown that NIP cell frequency and IFN yield per cell gradually increased with the age of the donor animals, from the neonatal period to the adult age, with a significant increase around puberty. Our present results also indicate that NIP cells may be influenced by physiological and genetic factors; thus (1) NIP cell frequency and IFN yield per cell were decreased during lactation; (2) Chinese (Meishan) pigs were found to have higher NIP cell frequency and IFN yield per cell than European (Large White) animals.
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Affiliation(s)
- W Nowacki
- Laboratoire de Virologie et Immunologie Moléculaires, INRA, Jouy en Josas, France
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42
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Nowacki W, Charley B. Enrichment of coronavirus-induced interferon-producing blood leukocytes increases the interferon yield per cell: a study with pig leukocytes. RESEARCH IN IMMUNOLOGY 1993; 144:111-20. [PMID: 8390709 PMCID: PMC7135579 DOI: 10.1016/0923-2494(93)80066-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Porcine peripheral blood mononuclear cells, which secrete IFN alpha in response to a coronavirus, transmissible gastroenteritis virus, were detected by a filter immunoplaque assay (ELISPOT). IFN alpha-producing cells (IPC), which are present at a low frequency in the blood, could be enriched up to 100-fold by sequential depletion of plastic-adherent cells and cell fractionation on metrizamide density gradients. IPC were present in the non-adherent low-density cell subpopulation. Cell selection experiments using antibody (Ab)-coated immunomagnetic beads revealed that porcine IPC could be positively selected by anti-CD4 or -SLA-class-II Ab, but not by anti-CD2 or -CD8 Ab. The estimated IFN yield per IPC was found to increase when IPC were assayed at higher concentrations. These data suggest that IPC represent a unique and distinct cell population in the blood, which could secrete higher amounts of IFN following its accumulation at a site of viral infection.
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Affiliation(s)
- W Nowacki
- Laboratoire de Virologie et Immunologie moléculaires, INRA, Jouy-en-Josas, France
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43
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Degryse E, Dietrich M, Nguyen M, Achstetter T, Charlier M, Charpigny G, Gaye P, Martal J. Addition of a dipeptide spacer significantly improves secretion of ovine trophoblast interferon in yeast. Gene 1992; 118:47-53. [PMID: 1511883 DOI: 10.1016/0378-1119(92)90247-m] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Yeast has been analysed for its potential to secrete an ovine member of the type-I interferon (IFN) family, trophoblastin (oTP-1). The processing potential of the yeast KEX2 gene product (KEX2p) was evaluated using gene oTP-1 fused to the pre-pro sequence encoding the pre-pro peptide of the yeast alpha-factor precursor. High-level accumulation of nonprocessed (unmatured) recombinant oTP-1 (re-oTP-1) was observed in the medium. In order to short-circuit the limiting activity of KEX2p and to obtain a fully matured re-oTP-1, secretion was directed using a pre::oTP-1 fusion, relying only on signal peptidase-dependent processing. However, secretion of oTP-1 was impaired. High-level secretion was restored when the gene product contained a peptide spacer between oTP-1 and the signal peptidase cleavage site. The oTP-1 variant was shown to have an extended N terminus. An N-extended form was examined further and shown to have the correct size. Surprisingly, the variant retained its in vitro and in vivo biological activities. This system is likely to represent a general method for high-level secretion of type-I IFNs.
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Affiliation(s)
- E Degryse
- Department of Molecular Biology, Transgene S.A., Strasbourg, France
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44
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Artursson K, Gobl A, Lindersson M, Johansson M, Alm G. Molecular cloning of a gene encoding porcine interferon-beta. JOURNAL OF INTERFERON RESEARCH 1992; 12:153-60. [PMID: 1640116 DOI: 10.1089/jir.1992.12.153] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A gene encoding the porcine interferon-beta (poIFN-beta) was cloned from a genomic library. The sequence of a potential intronless coding region as well as 1,265 bp of the 5'- and 277 bp of the 3'-flanking regions is presented. The gene is predicted to encode a mature protein of 165 amino acids and a signal peptide of 21 amino acids. This probable poIFN-beta shows high homology (63%) with human (hu) IFN-beta at the amino acid level, but less with porcine (po) IFN-alpha 1 (32%). It contains three cysteines and three potential N-glycosylation sites. A region of the 5' flank (-116 to -159) of the gene is homologous to the IFN gene regulatory element (IRE) of the huIFN-beta gene which mediates virus inducibility. Southern blot analysis indicates that the poIFN-beta gene is present as a single copy in the porcine genome. Its expression in porcine peripheral blood leukocytes stimulated in vitro by pseudorabies virus (PRV) was demonstrated at the RNA level both by Northern blot analysis and by in situ hybridization. The latter approach in addition detected only about one IFN-beta mRNA-containing cell per 2,000 PRV-stimulated porcine leukocytes, a frequency in the same range as that for leukocytes containing IFN-alpha mRNA.
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Affiliation(s)
- K Artursson
- Department of Veterinary Microbiology, Biomedical Center, Uppsala, Sweden
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45
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Naidoo D, Derbyshire JB. Interferon induction in porcine leukocytes with transmissible gastroenteritis virus. Vet Microbiol 1992; 30:317-27. [PMID: 1345591 PMCID: PMC7117433 DOI: 10.1016/0378-1135(92)90019-p] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/07/1991] [Indexed: 12/02/2022]
Abstract
Leukocytes were harvested from the peripheral blood, mesenteric lymph node and small intestinal lamina propria from groups of three piglets before, and 1, 2 and 3 weeks after infection with virulent transmissible gastroenteritis virus (TGEV) at 2 weeks of age. The donor piglets developed clinical signs of transmissible gastroenteritis which persisted for up to 3 days, and they developed peak serum titres of TGEV-neutralizing antibodies 2 weeks post-infection. The leukocytes were cultured in the presence of pokeweed mitogen (PWM), various dilutions of purified TGEV, or control media for 3 or 5 days, and the culture supernatants were tested for antiviral activity in MDBK cells challenged with vesicular stomatitis virus. The antiviral activity was characterized as porcine interferon (IFN)-alpha or porcine IFN-tau on the basis of its stability at pH 2.0 and neutralization by anti-human IFN-alpha antibodies. Viability of the leukocytes in culture, determined by trypan blue exclusion, was highest for the peripheral blood leukocytes and lowest for the mesenteric lymph node leukocytes. There were no consistent differences in antiviral activity between cultures incubated for 3 or 5 days. Porcine IFN-alpha was found in the supernatants of the leukocyte cultures stimulated with TGEV antigen, harvested before or after infection of the donor piglets with TGEV. Porcine IFN-tau was demonstrated in the supernatants of the leukocyte cultures stimulated with PWM, more frequently when the leukocytes were harvested post-infection. This was the first demonstration of IFN induction in vitro in leukocytes from porcine gut-associated lymphoid tissue.
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Affiliation(s)
- D Naidoo
- Department of Veterinary Microbiology and Immunology, University of Guelph, Ontario, Canada
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46
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Mege D, Lefevre F, Labonnardiere C. The porcine family of interferon-omega: cloning, structural analysis, and functional studies of five related genes. JOURNAL OF INTERFERON RESEARCH 1991; 11:341-50. [PMID: 1800582 DOI: 10.1089/jir.1991.11.341] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We report the molecular characterization of the porcine IFN-omega multigenic family which appears to comprise six to seven loci. Five of these loci were cloned and sequenced, revealing two pseudogenes (psi PoIFN-omega 1 and -omega 2) and three genes with an intact reading frame (PoIFN-omega 3, -omega 4, and -omega 5) that could encode preproteins of 179-190 amino acids including a putative signal peptide of 23 residues. By comparison of porcine IFN-omega coding sequences to those of known mammalian counterparts, it appeared that porcine sequences contain an in-frame five-codon deletion (between positions 113 and 117) in a region of relatively high sequence variability. In vitro transcription and translation of the three potentially functional reading frames gave rise to proteins with antiviral activity, showing that the porcine-specific deletion does not abolish the biological activity. Comparative analysis of flanking sequences revealed unique features of the 3' untranslated region of IFN-omega 4 gene: It contained a consensus estrogen-responsive element (ERE) in the vicinity of an extensive A-T-rich sequence known to serve a specific regulatory role in the expression of many genes involved in the inflammatory response. This finding suggests that the expression of the functional members of the porcine IFN-omega family may be mediated through different mechanisms. The expression of these genes was studied by Northern blot analysis of mRNAs from pig conceptus (days 14-20). Five bands of poly(A)+ RNAs hybridized with an IFN-omega probe provided the stringency was low, suggesting that a distinct family of IFN-omega-related genes were expressed by porcine trophoblastic cells during early gestation.
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Affiliation(s)
- D Mege
- I.N.R.A., Laboratoire de Virologie et d'Immunologie Moléculaires, Centre de Jouy, Jouy-en-Josas, France
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47
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Cerutti M, Hue D, Charlier M, L'Haridon R, Pernollet JC, Devauchelle G, Gaye P. Expression of a biologically active ovine trophoblastic interferon using a baculovirus expression system. Biochem Biophys Res Commun 1991; 181:443-8. [PMID: 1659817 DOI: 10.1016/s0006-291x(05)81439-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Ovine trophoblast protein (oTP) an embryonic interferon, which plays a key role in maternal recognition of pregnancy, has been expressed in insect cells using a baculovirus expression system. A cDNA coding for oTP was inserted downstream of the strong polyhedrin promoter. Cells infected with recombinant virus produced biologically active oTP and greater than 90% was secreted into the culture medium during infection. High amount of antiviral activity were produced (up to 5 x 10(5) IU per ml of culture medium). Recombinant oTP (roTP) was purified by immunoaffinity chromatography and found to be identical to authentic oTP with respect to molecular mass and N-terminal amino acid sequence.
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Affiliation(s)
- M Cerutti
- Station de Recherches de Pathologie Comparée, URA CNRS n. 11840, I.N.R.A., Saint-Christol-lez-Alès, France
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48
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Vandenbroeck K, Dijkmans R, van Aerschot A, Billiau A. Engineering by PCR-based exon amplification of the genomic porcine interferon-gamma DNA for expression in Escherichia coli. Biochem Biophys Res Commun 1991; 180:1408-15. [PMID: 1953787 DOI: 10.1016/s0006-291x(05)81353-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Interferon-gamma (IFN-gamma) is coded for by a single gene containing three introns, localized within the coding region. We have previously cloned the IFN-gamma gene from a pig genomic DNA lambda library and have determined its nucleotide sequence. In order to construct the porcine IFN-gamma DNA without intervening sequence, the four exons were separately amplified by the polymerase chain reaction (PCR) using primers matching the exon-termini. From the amplified exon-fragments the complete intron-free DNA was obtained by a strategy consisting of alternate rounds of PCR and ligation. The sequence so-obtained was used for expression in E. coli. The recombinant protein appeared as inclusion bodies which were solubilized and refolded in order to obtain biologically active IFN-gamma.
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Affiliation(s)
- K Vandenbroeck
- Rega Institute for Medical Research, Katholieke Universiteit Leuven, Belgium
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49
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Nicaud JM, Fournier P, La Bonnardière C, Chasles M, Gaillardin C. Use of ars18 based vectors to increase protein production in Yarrowia lipolytica. J Biotechnol 1991; 19:259-70. [PMID: 1367240 DOI: 10.1016/0168-1656(91)90063-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The isolation of ars sequence from the yeast Yarrowia lipolytica has recently been reported (Fournier et al., 1991). Vectors containing ars18 have been used to increase homologous and heterologous protein production. Examples presented are the Yarrowia lipolytica alkaline extracellular protease (AEP), the porcine alpha 1-interferon and the bovine prochymosin. A 2- to 6-fold increase in the corresponding protein production was observed and in several cases it was established that it corresponded to the copy number of plasmid in the cell.
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Affiliation(s)
- J M Nicaud
- Laboratoire de Génétique des Microorganismes, Institut National Agronomique Paris-Grignon, Thiverval-Grignon, France
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50
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Charlier M, Hue D, Boisnard M, Martal J, Gaye P. Cloning and structural analysis of two distinct families of ovine interferon-alpha genes encoding functional class II and trophoblast (oTP) alpha-interferons. Mol Cell Endocrinol 1991; 76:161-71. [PMID: 1820971 DOI: 10.1016/0303-7207(91)90270-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Ovine trophoblast protein (oTP) is a polypeptide secreted by ovine trophectoderm from day 11 to 21, which plays a key role in maternal recognition of pregnancy. Structural analyses established that oTP shares extensive homology with class II alpha-interferon (IFN-alpha II) subfamily. Previous screening of an ovine genomic DNA library probed with an oTP cDNA incidently resulted in the isolation of a functional IFN-alpha II gene and two relevant pseudogenes, as shown by sequence analysis and study of expression in eukaryotic COS cells. The expected oTP gene together with a cognate pseudogene was successfully isolated from the series of clones selected from another genomic library probed with the oTP cDNA, using two specific oligonucleotides, each one complementary to a region of oTP cDNA with little homology with the IFN-alpha II gene and related pseudogenes. Southern blotting of ovine genomic DNA indicated the existence of at least five trophoblast IFN-alpha genes or pseudogenes. Nucleotide sequence comparisons showed that the oTP gene exhibits a higher homology (90%) with bovine trophoblast IFN gene (Stewart et al. (1990) J. Mol. Endocrinol. 4, 275-282) than with oIFN-alpha II gene (70%), thus providing evidence that embryonic IFNs constitute a distinct subfamily of IFN-alpha s.
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Affiliation(s)
- M Charlier
- Unité d'Endocrinologie de l'Embryon, I.N.R.A., Jouy-en-Josas, France
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