1
|
Wang X, Sheng Y, Ji P, Deng Y, Sun Y, Chen Y, Nan Y, Hiscox JA, Zhou EM, Liu B, Zhao Q. A Broad-specificity Neutralizing Nanobody against Hepatitis E Virus Capsid Protein. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2024; 213:442-455. [PMID: 38905108 PMCID: PMC11299488 DOI: 10.4049/jimmunol.2300706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 06/03/2024] [Indexed: 06/23/2024]
Abstract
Hepatitis E virus (HEV) is a worldwide zoonotic and public health concern. The study of HEV biology is helpful for designing viral vaccines and drugs. Nanobodies have recently been considered appealing materials for viral biological research. In this study, a Bactrian camel was immunized with capsid proteins from different genotypes (1, 3, 4, and avian) of HEV. Then, a phage library (6.3 × 108 individual clones) was constructed using peripheral blood lymphocytes from the immunized camel, and 12 nanobodies against the truncated capsid protein of genotype 3 HEV (g3-p239) were screened. g3-p239-Nb55 can cross-react with different genotypes of HEV and block Kernow-C1/P6 HEV from infecting HepG2/C3A cells. To our knowledge, the epitope recognized by g3-p239-Nb55 was determined to be a novel conformational epitope located on the surface of viral particles and highly conserved among different mammalian HEV isolates. Next, to increase the affinity and half-life of the nanobody, it was displayed on the surface of ferritin, which can self-assemble into a 24-subunit nanocage, namely, fenobody-55. The affinities of fenobody-55 to g3-p239 were ∼20 times greater than those of g3-p239-Nb55. In addition, the half-life of fenobody-55 was nine times greater than that of g3-p239-Nb55. G3-p239-Nb55 and fenobody-55 can block p239 attachment and Kernow-C1/P6 infection of HepG2/C3A cells. Fenobody-55 can completely neutralize HEV infection in rabbits when it is preincubated with nonenveloped HEV particles. Our study reported a case in which a nanobody neutralized HEV infection by preincubation, identified a (to our knowledge) novel and conserved conformational epitope of HEV, and provided new material for researching HEV biology.
Collapse
Affiliation(s)
- Xueting Wang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
- Department of Veterinary Medicine, Shandong Vocational Animal Science and Veterinary College, Weifang, Shandong, China
| | - Yamin Sheng
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Pinpin Ji
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Yingying Deng
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Yani Sun
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Yiyang Chen
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Yuchen Nan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Julian A. Hiscox
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - En-Min Zhou
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Baoyuan Liu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Qin Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| |
Collapse
|
2
|
Zhang B, Fan M, Fan J, Luo Y, Wang J, Wang Y, Liu B, Sun Y, Zhao Q, Hiscox JA, Nan Y, Zhou EM. Avian Hepatitis E Virus ORF2 Protein Interacts with Rap1b to Induce Cytoskeleton Rearrangement That Facilitates Virus Internalization. Microbiol Spectr 2022; 10:e0226521. [PMID: 35138149 PMCID: PMC8826821 DOI: 10.1128/spectrum.02265-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 01/05/2022] [Indexed: 12/31/2022] Open
Abstract
Avian hepatitis E virus (HEV) causes liver diseases and multiple extrahepatic disorders in chickens. However, the mechanisms involved in avian HEV entry remain elusive. Herein, we identified the RAS-related protein 1b (Rap1b) as a potential HEV-ORF2 protein interacting candidate. Experimental infection of chickens and cells with an avian HEV isolate from China (CaHEV) led to upregulated expression and activation of Rap1b both in vivo and in vitro. By using CaHEV capsid as mimic of virion to treat cell in vitro, it appears that the interaction between the viral capsid and Rap1b promoted cell membrane recruitment of the downstream effector Rap1-interacting molecule (RIAM). In turn, RIAM further enhanced Talin-1 membrane recruitment and retention, which led to the activation of integrin α5/β1, as well as integrin-associated membrane protein kinases, including focal adhesion kinase (FAK). Meanwhile, FAK activation triggered activation of downstream signaling molecules, such as Ras-related C3 botulinum toxin substrate 1 RAC1 cell division cycle 42 (CDC42), p21-activated kinase 1 (PAK1), and LIM domain kinase 1 (LIMK1). Finally, F-actin rearrangement induced by Cofilin led to the formation of lamellipodia, filopodia, and stress fibers, contributes to plasma membrane remodeling, and might enhance CaHEV virion internalization. In conclusion, our data suggested that Rap1b activation was triggered during CaHEV infection and appeared to require interaction between CaHEV-ORF2 and Rap1b, thereby further inducing membrane recruitment of Talin-1. Membrane-bound Talin-1 then activates key Integrin-FAK-Cofilin cascades involved in modulation of actin kinetics, and finally leads to F-actin rearrangement and membrane remodeling to potentially facilitate internalization of CaHEV virions into permissive cells. IMPORTANCE Rap1b is a multifunctional protein that is responsible for cell adhesion, growth, and differentiation. The inactive form of Rap1b is phosphorylated and distributed in the cytoplasm, while active Rap1b is prenylated and loaded with GTP to the cell membrane. In this study, the activation of Rap1b was induced during the early stage of avian HEV infection under the regulation of PKA and SmgGDS. Continuously activated Rap1b recruited its effector RIAM to the membrane, thereby inducing the membrane recruitment of Talin-1 that led to the activation of membrane α5/β1 integrins. The triggering of the signaling pathway-associated Integrin α5/β1-FAK-CDC42&RAC1-PAK1-LIMK1-Cofilin culminated in F-actin polymerization and membrane remodeling that might promote avian HEV virion internalization. These findings suggested a novel mechanism that is potentially utilized by avian HEV to invade susceptible cells.
Collapse
Affiliation(s)
- Beibei Zhang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Mengnan Fan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Jie Fan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Yuhang Luo
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Jie Wang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Yajing Wang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Baoyuan Liu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Yani Sun
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Qin Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - Julian A. Hiscox
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Yuchen Nan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| | - En-Min Zhou
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, China
| |
Collapse
|
3
|
Gordeychuk I, Kyuregyan K, Kondrashova A, Bayurova E, Gulyaev S, Gulyaeva T, Potemkin I, Karlsen A, Isaeva O, Belyakova A, Lyashenko A, Sorokin A, Chumakov A, Morozov I, Isaguliants M, Ishmukhametov A, Mikhailov M. Immunization with recombinant ORF2 p551 protein protects common marmosets (Callithrix jacchus) against homologous and heterologous hepatitis E virus challenge. Vaccine 2022; 40:89-99. [PMID: 34836660 DOI: 10.1016/j.vaccine.2021.11.042] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 10/18/2021] [Accepted: 11/14/2021] [Indexed: 12/23/2022]
Abstract
BACKGROUND Hepatitis E virus (HEV) is a major causative agent of acute hepatitis worldwide, prompting continuous HEV vaccine efforts. Vaccine development is hampered by the lack of convenient animal models susceptible to infection with different HEV genotypes. We produced recombinant open reading frame 2 protein (pORF2; p551) of HEV genotype (GT) 3 and assessed its immunogenicity and protectivity against HEV challenge in common marmosets (Callithrix jacchus, CM). METHODS p551 with consensus sequence corresponding to amino acid residues 110-660 of HEV GT3 pORF2 was expressed in E. coli and purified by affinity chromatography. CMs were immunized intramuscularly with 20 μg of p551 VLPs with alum adjuvant (n = 4) or adjuvant alone (n = 2) at weeks 0, 3, 7 and 19. At week 27, p551-immunized and control animals were challenged with HEV GT1 or GT3 and thereafter longitudinally screened for markers of liver function, anti-HEV IgG and HEV RNA in feces and sera. RESULTS Purified p551 formed VLPs with particle size of 27.71 ± 2.42 nm. Two immunizations with p551 induced anti-HEV IgG mean titer of 1:1810. Immunized CMs challenged with homologous and heterologous HEV genotype did not develop HEV infection during the follow-up. Control CMs infected with both HEV GT1 and GT3 demonstrated signs of HEV infection with virus shedding and elevation of the levels of liver enzymes. High levels of anti-HEV IgG persisted in vaccinated CMs and control CMs that resolved HEV infection, for up to two years post challenge. CONCLUSIONS CMs are shown to be a convenient laboratory animal model susceptible to infection with HEV GT1 and GT3. Immunization with HEV GT3 ORF2/p551 triggers potent anti-HEV antibody response protecting CMs from homologous and heterologous HEV challenge. This advances p551 in VLPs as a prototype vaccine against HEV.
Collapse
Affiliation(s)
- Ilya Gordeychuk
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia; Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, Moscow 127994, Russia.
| | - Karen Kyuregyan
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia; I.I. Mechnikov Research Institute of Vaccines and Sera, Moscow 105064, Russia; Russian Medical Academy of Continuous Professional Education, Moscow 125993, Russia.
| | - Alla Kondrashova
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia; Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, Moscow 127994, Russia
| | - Ekaterina Bayurova
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia.
| | - Stanislav Gulyaev
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia.
| | - Tatiana Gulyaeva
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia.
| | - Ilya Potemkin
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia; I.I. Mechnikov Research Institute of Vaccines and Sera, Moscow 105064, Russia; Russian Medical Academy of Continuous Professional Education, Moscow 125993, Russia.
| | - Anastasia Karlsen
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia; I.I. Mechnikov Research Institute of Vaccines and Sera, Moscow 105064, Russia; Russian Medical Academy of Continuous Professional Education, Moscow 125993, Russia; N.F. Gamaleya Federal Research Center for Epidemiology & Microbiology, Moscow 123098, Russia
| | - Olga Isaeva
- I.I. Mechnikov Research Institute of Vaccines and Sera, Moscow 105064, Russia; Russian Medical Academy of Continuous Professional Education, Moscow 125993, Russia.
| | - Alla Belyakova
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia.
| | - Anna Lyashenko
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia.
| | - Alexey Sorokin
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia
| | - Alexey Chumakov
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia; Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, Moscow 127994, Russia
| | - Igor Morozov
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia.
| | - Maria Isaguliants
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia; N.F. Gamaleya Federal Research Center for Epidemiology & Microbiology, Moscow 123098, Russia; Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 17177 Stockholm, Sweden.
| | - Aydar Ishmukhametov
- Chumakov Federal Scientific Center for Research and Development of Immune-and-Biological Products of Russian Academy of Sciences, Moscow 108819, Russia; Institute for Translational Medicine and Biotechnology, Sechenov First Moscow State Medical University, Moscow 127994, Russia.
| | - Mikhail Mikhailov
- I.I. Mechnikov Research Institute of Vaccines and Sera, Moscow 105064, Russia; Russian Medical Academy of Continuous Professional Education, Moscow 125993, Russia.
| |
Collapse
|
4
|
Sun Y, Yan W, Chen X, Liu Q, Ji P, Zhu J, Gai L, Li X, Zhao J, Zhang L, Zhang H, Liu B, Zhou EM, Zhao Q. Antigenic cross-reactivity among human, swine, rabbit and avian hepatitis E virus capsid proteins. Vet Microbiol 2022; 265:109331. [PMID: 34999311 DOI: 10.1016/j.vetmic.2022.109331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/29/2021] [Accepted: 01/02/2022] [Indexed: 11/25/2022]
Abstract
Hepatitis E virus (HEV), a zoonotic virus, infects many animal species, including humans. Capsid proteins of human, swine, rabbit and avian HEVs share 48 %-100 % amino acid identity. In the present study, antigenic cross-reactivity among human, swine, rabbit and avian HEV capsid proteins were analyzed in detail using indirect and blocking enzyme-linked immunosorbent assays (ELISAs). The C-terminal 268 amino acids of genotype 1 human, genotype 4 swine, genotype 3 rabbit and genotype B3 avian HEV capsid proteins served as coating antigens for ELISA. Hyperimmune rabbit antisera (against four HEV capsid proteins) and human, pig, rabbit and chicken clinical sera were as primary antibodies. Closely correlated and statistically indistinguishable results were obtained for detection of anti-HEV antibodies in human and pig sera using human, swine and rabbit HEV capsid proteins as coating antigens. Moderately correlated differences in detection of anti-HEV antibodies in rabbit sera were obtained using the three capsid proteins. Statistically significant differences with no correlations were obtained for anti-HEV antibodies detection in chicken sera between avian HEV capsid protein and human, swine and rabbit ones. Blocking ELISA results demonstrated that two common epitopes among the four species HEVs were immunodominant in avian HEV, but were non-immunodominant in human, swine and rabbit HEVs. Nevertheless, three epitopes common to human, swine and rabbit HEVs were all immunodominant epitopes for the three species HEVs. Collectively, these results demonstrate that anti-HEV antibodies in human and pig sera can be detected using human, swine and rabbit HEV capsid proteins. By contrast, for optimal detection of anti-HEV antibodies in rabbit and chicken sera, the respective rabbit and avian HEV capsid proteins should be used. These results provide insights to guide future development of serological assays for diagnosing HEV infections in various animal species.
Collapse
Affiliation(s)
- Yani Sun
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China
| | - Wenlong Yan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China
| | - Xu Chen
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China
| | - Qianqian Liu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China
| | - Pinpin Ji
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China
| | - Jiahong Zhu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China
| | - Lili Gai
- Shandong Bluetown Analysis and Test Co., Ltd, Jinan, Shandong, 250102, China
| | - Xiaoxuan Li
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China
| | - Jiakai Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China
| | - Lu Zhang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China
| | - Hao Zhang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China
| | - Baoyuan Liu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China
| | - En-Min Zhou
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China
| | - Qin Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, Shaanxi, 712100, China.
| |
Collapse
|
5
|
Cancela F, Noceti O, Arbiza J, Mirazo S. Structural aspects of hepatitis E virus. Arch Virol 2022; 167:2457-2481. [PMID: 36098802 PMCID: PMC9469829 DOI: 10.1007/s00705-022-05575-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 06/04/2022] [Indexed: 12/14/2022]
Abstract
Hepatitis E virus (HEV) is a leading cause of acute hepatitis worldwide. Hepatitis E is an enterically transmitted zoonotic disease that causes large waterborne epidemic outbreaks in developing countries and has become an increasing public-health concern in industrialized countries. In this setting, the infection is usually acute and self-limiting in immunocompetent individuals, although chronic cases in immunocompromised patients have been reported, frequently associated with several extrahepatic manifestations. Moreover, extrahepatic manifestations have also been reported in immunocompetent individuals with acute HEV infection. HEV belongs to the alphavirus-like supergroup III of single-stranded positive-sense RNA viruses, and its genome contains three partially overlapping open reading frames (ORFs). ORF1 encodes a nonstructural protein with eight domains, most of which have not been extensively characterized: methyltransferase, Y domain, papain-like cysteine protease, hypervariable region, proline-rich region, X domain, Hel domain, and RNA-dependent RNA polymerase. ORF2 and ORF3 encode the capsid protein and a multifunctional protein believed to be involved in virion release, respectively. The novel ORF4 is only expressed in HEV genotype 1 under endoplasmic reticulum stress conditions, and its exact function has not yet been elucidated. Despite important advances in recent years, the biological and molecular processes underlying HEV replication remain poorly understood, primarily due to a lack of detailed information about the functions of the viral proteins and the mechanisms involved in host-pathogen interactions. This review summarizes the current knowledge concerning HEV proteins and their biological properties, providing updated detailed data describing their function and focusing in detail on their structural characteristics. Furthermore, we review some unclear aspects of the four proteins encoded by the ORFs, highlighting the current key information gaps and discussing potential novel experimental strategies for shedding light on those issues.
Collapse
Affiliation(s)
- Florencia Cancela
- grid.11630.350000000121657640Sección Virología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Ofelia Noceti
- grid.414402.70000 0004 0469 0889Programa Nacional de Trasplante Hepático y Unidad Docente Asistencial Centro Nacional de Tratamiento Hepatobiliopancreatico. Hospital Central de las Fuerzas Armadas, Montevideo, Uruguay
| | - Juan Arbiza
- grid.11630.350000000121657640Sección Virología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Santiago Mirazo
- grid.11630.350000000121657640Sección Virología, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay ,grid.11630.350000000121657640Departamento de Bacteriología y Virología, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay ,Av. Alfredo Navarro 3051, PC 11600 Montevideo, Uruguay
| |
Collapse
|
6
|
Veeranarayanan S, Azam AH, Kiga K, Watanabe S, Cui L. Bacteriophages as Solid Tumor Theragnostic Agents. Int J Mol Sci 2021; 23:402. [PMID: 35008840 PMCID: PMC8745063 DOI: 10.3390/ijms23010402] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/27/2021] [Accepted: 12/28/2021] [Indexed: 12/16/2022] Open
Abstract
Cancer, especially the solid tumor sub-set, poses considerable challenges to modern medicine owing to the unique physiological characteristics and substantial variations in each tumor's microenvironmental niche fingerprints. Though there are many treatment methods available to treat solid tumors, still a considerable loss of life happens, due to the limitation of treatment options and the outcomes of ineffective treatments. Cancer cells evolve with chemo- or radiation-treatment strategies and later show adaptive behavior, leading to failed treatment. These challenges demand tailored and individually apt personalized treatment methods. Bacteriophages (or phages) and phage-based theragnostic vectors are gaining attention in the field of modern cancer medicine, beyond their bactericidal ability. With the invention of the latest techniques to fine-tune phages, such as in the field of genetic engineering, synthetic assembly methods, phage display, and chemical modifications, noteworthy progress in phage vector research for safe cancer application has been realized, including use in pre-clinical studies. Herein, we discuss the distinct fingerprints of solid tumor physiology and the potential for bacteriophage vectors to exploit specific tumor features for improvised tumor theragnostic applications.
Collapse
Affiliation(s)
| | | | | | | | - Longzhu Cui
- Division of Bacteriology, Department of Infection and Immunity, School of Medicine, Jichi Medical University, Shimotsuke-shi 3290498, Japan; (S.V.); (A.H.A.); (K.K.); (S.W.)
| |
Collapse
|
7
|
Development of a competitive ELISA for detecting antibodies against genotype 1 hepatitis E virus. Appl Microbiol Biotechnol 2021; 105:8505-8516. [PMID: 34633486 DOI: 10.1007/s00253-021-11621-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 09/19/2021] [Accepted: 09/26/2021] [Indexed: 10/20/2022]
Abstract
Hepatitis E, a significant global public health issue in China, is caused by sporadic infections with regional hepatitis E virus (HEV) genotypes 1, 3, and 4. To date, most immunoassays currently used to test human sera for the presence of anti-HEV antibodies cannot identify HEV at the genotype level. However, such information would be useful for identifying the source of infecting virus. Therefore, here we describe the development of a competitive enzyme-linked immunosorbent assay (ELISA) for detecting anti-genotype 1 HEV antibodies in human sera. Using recombinant genotype 1 HEV ORF3 protein as immunogen, traditional hybridoma technology was employed to generate seven monoclonal antibodies (mAbs), of which two mAbs specifically reacted with the immunogen. One of these two mAbs, 1D2, was labeled with horseradish peroxidase (HRP) for use in competitive ELISA (cELISA). After cELISA optimization using a checkerboard assay design, the amount of ORF3SAR-55 as coating antigen (100 ng/well), HRP-1D2 mAb concentration (1 μg/mL), and test serum dilution (1:10) were selected and a result ≥ 19.5 was used as the cutoff for a positive result. Importantly, cross-genotype cELISA results indicated that the cELISA could not detect anti-genotype 3 rabbit and 4 swine HEV antibodies. Moreover, human sera confirmed as negative for anti-HEV antibodies using the commercial ELISA kit were all negative via cELISA. However, because the commercial ELISA kit detects anti-all genotypes HEV antibodies and the cELISA only detects anti-genotype 1 HEV antibodies, the consistence rate of two assays detecting positive sera is low. In summary, here a cELISA for detecting anti-genotype 1 HEV antibodies was developed for use in epidemiological investigations of genotype 1 HEV infections in humans. KEY POINTS: • Seven mAbs were produced using genotype 1 HEV ORF3 protein as immunogen. • One mAb that specifically bound to genotype 1 HEV ORF3 protein was selected and labeled for use in a cELISA to detect anti-genotype 1 HEV antibodies. • The competitive ELISA developed here will aid clinical diagnosis of HEV infections and will be useful for large-scale serological testing of genotype 1 HEV infections in humans.
Collapse
|
8
|
A broadly cross-reactive monoclonal antibody against hepatitis E virus capsid antigen. Appl Microbiol Biotechnol 2021; 105:4957-4973. [PMID: 34129082 PMCID: PMC8236046 DOI: 10.1007/s00253-021-11342-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 04/28/2021] [Accepted: 05/09/2021] [Indexed: 12/27/2022]
Abstract
Abstract To generate a hepatitis E virus (HEV) genotype 3 (HEV-3)–specific monoclonal antibody (mAb), the Escherichia coli–expressed carboxy-terminal part of its capsid protein was used to immunise BALB/c mice. The immunisation resulted in the induction of HEV-specific antibodies of high titre. The mAb G117-AA4 of IgG1 isotype was obtained showing a strong reactivity with the homologous E. coli, but also yeast-expressed capsid protein of HEV-3. The mAb strongly cross-reacted with ratHEV capsid protein derivatives produced in both expression systems and weaker with an E. coli–expressed batHEV capsid protein fragment. In addition, the mAb reacted with capsid protein derivatives of genotypes HEV-2 and HEV-4 and common vole hepatitis E virus (cvHEV), produced by the cell-free synthesis in Chinese hamster ovary (CHO) and Spodoptera frugiperda (Sf21) cell lysates. Western blot and line blot reactivity of the mAb with capsid protein derivatives of HEV-1 to HEV-4, cvHEV, ratHEV and batHEV suggested a linear epitope. Use of truncated derivatives of ratHEV capsid protein in ELISA, Western blot, and a Pepscan analysis allowed to map the epitope within a partially surface-exposed region with the amino acid sequence LYTSV. The mAb was also shown to bind to human patient–derived HEV-3 from infected cell culture and to hare HEV-3 and camel HEV-7 capsid proteins from transfected cells by immunofluorescence assay. The novel mAb may serve as a useful tool for further investigations on the pathogenesis of HEV infections and might be used for diagnostic purposes. Key points • The antibody showed cross-reactivity with capsid proteins of different hepeviruses. • The linear epitope of the antibody was mapped in a partially surface-exposed region. • The antibody detected native HEV-3 antigen in infected mammalian cells. Supplementary Information The online version contains supplementary material available at 10.1007/s00253-021-11342-7.
Collapse
|
9
|
Culma MF. Strongyloides stercoralis proteome: A reverse approach to the identification of potential immunogenic candidates. Microb Pathog 2020; 152:104545. [PMID: 33091578 DOI: 10.1016/j.micpath.2020.104545] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 09/28/2020] [Accepted: 09/29/2020] [Indexed: 11/15/2022]
Abstract
Strongyloides stercoralis is a parasite widely distributed in the tropical and subtropical areas in the world. Its treatment and diagnosis have a limitation as many other parasitic diseases. Nowadays, there is a great interest in designing an efficient epitope for vaccines or diagnostic. In this study, a bioinformatics-based screening approach has been incorporated in order to explore potential immunogens in the S. stercoralis proteome. Bioinformatic tools were used to predict diagnostic and vaccinology approaches. 12.851 cell immunology proteins from Uniprot were analyzed. Thirty-four immunogenic candidates were identified, they had higher antigenic activity, less than 2 α-helices, non-allergen activity and they do not have homology with host proteins, all of them have ortholog protein with Strongyloides ratti. Some of them presented a good binding with immunological cell (T and B cell). These proteins could be a good alternative as a candidate for the design of the novel vaccines or diagnostic tests of strongyloides stercoralis.
Collapse
|
10
|
Synthetic Peptides Containing Three Neutralizing Epitopes of Genotype 4 Swine Hepatitis E Virus ORF2 induced Protection against Swine HEV Infection in Rabbit. Vaccines (Basel) 2020; 8:vaccines8020178. [PMID: 32294910 PMCID: PMC7348971 DOI: 10.3390/vaccines8020178] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/05/2020] [Accepted: 04/09/2020] [Indexed: 12/12/2022] Open
Abstract
Genotype 4 hepatitis E virus (HEV) is a zoonotic pathogen transmitted to humans through food and water. Previously, three genotype 4 swine HEV ORF2 peptides (407EPTV410, 410VKLYTS415, and 458PSRPF462) were identified as epitopes of virus-neutralizing monoclonal antibodies that partially blocked rabbit infection with swine HEV. Here, individual and tandem fused peptides were synthesized, conjugated to keyhole limpet hemocyanin (KLH), then evaluated for immunoprotection of rabbits against swine HEV infection. Forty New Zealand White rabbits were randomly assigned to eight groups; groups 1 thru 5 received three immunizations with EPTV-KLH, VKLYTS-KLH, PSRPF-KLH, EPTVKLYTS-KLH, or EPTVKLYTSPSRPF-KLH, respectively; group 6 received truncated swine HEV ORF2 protein (sp239), and group 7 received phosphate-buffered saline. After an intravenous swine HEV challenge, all group 7 rabbits exhibited viremia and fecal virus shedding by 2–4 weeks post challenge (wpc), seroconversion by 4–9 wpc, elevated alanine aminotransferase (ALT) at 2 wpc, and severe liver lymphocytic venous periphlebitis. Only 1–2 rabbits/group in groups 1–4 exhibited delayed viremia, fecal shedding, seroconversion, increased ALT levels, and slight liver lymphocytic venous periphlebitis; groups 5–6 showed no pathogenic effects. Collectively, these results demonstrate that immunization with a polypeptide containing three genotype 4 HEV ORF2 neutralizing epitopes completely protected rabbits against swine HEV infection.
Collapse
|
11
|
Alatortseva GI, Sidorov AV, Nesterenko LN, Luhverchik LN, Dotsenko VV, Amiantova II, Zhukina MV, Kabargina VY, Milovanova AV, Vorobev DS, Ammur YI, Mikhailov MI, Kyuregyan KK, Malinnikova EY, Zhavoronok SV, Blinov VM, Zverev VV. DEVELOPMENT OF HEPATITIS E 3 GENOTYPE RECOMBINANT PROTEIN CAPSID OF: CLONING, EXPRESSION, PURIFICATION, EVALUATION OF THE ANTIGENIC PROPERTIES. ЖУРНАЛ МИКРОБИОЛОГИИ, ЭПИДЕМИОЛОГИИ И ИММУНОБИОЛОГИИ 2019. [DOI: 10.36233/0372-9311-2019-1-10-17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Aim. The development of the hepatitis E virus (HEV) genotype 3 recombinant capsid protein.Materials and methods. E.coli strains, plasmid vectors, serological and clinical samples, ELISA reagent kits, molecular biological, bioinformatic, biotechnological, biochemical and serological methods.Results. Using viruscontaining material from pigs of Belgorod region (Russian Federation) we made E.coli strains producing recombinant capsid protein, containing C-terminal of viral ORF2 protein fragment fused to E.coli β-galactosidase. Recombinant protein ORF2 had been isolated from the bacterial inclusion bodies and purified by size exclusion chromatography. Antigenic specificity of the recombinant polypeptide was confirmed by ELISA and Western blotting with sera of hepatitis E patients and reference groups (healthy donors, patients with hepatitis A, B, C, infectious mononucleosis, cytomegalovirus infection and HIV-infected patients). Conclusion. HEV genotype 3 ORF2 recombinant antigen had been developed, and the possibility to use it in diagnostic tests had been experimentally shown.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Yu. I. Ammur
- Mechnikov Research Institute of Vaccines and Sera
| | - M. I. Mikhailov
- Mechnikov Research Institute of Vaccines and Sera, Russian Medical Academy of Postgraduate Education
| | - K. K. Kyuregyan
- Mechnikov Research Institute of Vaccines and Sera, Russian Medical Academy of Postgraduate Education
| | - E. Yu. Malinnikova
- Mechnikov Research Institute of Vaccines and Sera, Russian Medical Academy of Postgraduate Education
| | | | - V. M. Blinov
- Mechnikov Research Institute of Vaccines and Sera
| | - V. V. Zverev
- Mechnikov Research Institute of Vaccines and Sera, Sechenov First Moscow State Medical University
| |
Collapse
|
12
|
Sun P, Lin S, He S, Zhou EM, Zhao Q. Avian Hepatitis E Virus: With the Trend of Genotypes and Host Expansion. Front Microbiol 2019; 10:1696. [PMID: 31396195 PMCID: PMC6668596 DOI: 10.3389/fmicb.2019.01696] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 07/09/2019] [Indexed: 12/25/2022] Open
Abstract
Avian hepatitis E virus (HEV) is a single-stranded, positive-sense RNA virus with a complete genome of approximately 6.6 kb in size. To date, four major genotypes of avian HEV have been identified and classified into the Orthohepevirus B genus of the family Hepeviridae. The avian HEV associated with hepatitis-splenomegaly syndrome, big liver and spleen disease or hepatic rupture hemorrhage syndrome in chickens is genetically and antigenically related to mammalian HEV. With the increased genotypes of avian HEV identified, a broader host tropism is also notable in the epidemiological studies. Due to the lack of an efficient cell culture system, the mechanisms of avian HEV replication and pathogenesis are still poorly understood. The recent identification and characterization of animal strains of avian HEV has demonstrated the virus' ability of cross-species infection. Although it has not yet been detected in humans, the potential threat of a zoonotic HEV capable of transmission to humans needs to be taken into consideration. This review article focuses on the current knowledge regarding avian HEV in virology, epidemiology, pathogenesis, clinical presentation, transmission, diagnosis and prevention. HIGHLIGHTS - The mechanisms of avian HEV replication and pathogenesis are still poorly understood due to the lack of an efficient cell culture system.- A broader host tropism is also notable in the epidemiological studies with the increased genotypes of avian HEV identified.- The recent identification and characterization of animal strains of avian HEV has demonstrated the virus' ability of cross-species infection.- The potential threat of a zoonotic HEV capable of transmission to humans needs to be taken into consideration.
Collapse
Affiliation(s)
- Peng Sun
- School of Agriculture, Ningxia University, Yinchuan, China.,Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China.,Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, China
| | - Shaoli Lin
- Division of Immunology, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, College Park, MD, United States
| | - Shenghu He
- School of Agriculture, Ningxia University, Yinchuan, China
| | - En-Min Zhou
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China.,Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, China
| | - Qin Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China.,Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, China
| |
Collapse
|
13
|
Wang D, Zhang Y, Ma C, Ma D, Zhao Q, Wang F, Huang Y, Li J, Zhang L, Zhou EM. Live recombinant Lactococcuslactis expressing avian hepatitis virus ORF2 protein: Immunoprotection against homologous virus challenge in chickens. Vaccine 2018; 36:1108-1115. [PMID: 29406242 DOI: 10.1016/j.vaccine.2018.01.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 12/22/2017] [Accepted: 01/04/2018] [Indexed: 12/26/2022]
Abstract
Avian hepatitis E virus (aHEV) is a pathogen associated with hepatitis-splenomegaly syndrome in chickens. To date, no commercial vaccine is available for preventing aHEV infection. In this study, three recombinant LactococcuslactisNZ9000experimental live vaccines expressing cytoplasmic, secreted, and cell wall-anchored forms of aHEV truncated ORF2 protein spanning amino acids 249-606 (ΔORF2) were constructed using pTX8048 vector and characterized. Each chicken was immunized three times at two-week intervals with one of the three live aHEV ORF2 vaccines (experimental group) or with live vaccine containing empty vector only (control group). Both groups were then challenged with aHEV and evaluated to compare immune responses and immunogenic effects. Serum IgG levels, secretory IgA (sIgA) levels in bile and jejunal lavage fluid, and mRNA expression levels ofIL-2 and IFN-γ in liver and spleen were significantly higher in experimental chickens than in controls. Meanwhile, post-challenge serum and fecal virus loads were significantly lower in experimental chickens versus controls. Moreover, on day 7 post infection (PI), serum lactose dehydrogenase (LDH) levels were significantly higher in controls than experimental chickens. Furthermore, at day 28 PI, obvious gross pathological lesions and histopathological changes typical for aHEV infection were observed in control livers and spleens, with only moderate pathological changes observed in the experimental group. The results of this study collectively demonstrate that an oral vaccineusing L.lactisNZ9000 as a delivery vector for aHEV immunogenic antigen could effectively control aHEV infection of chickens.
Collapse
Affiliation(s)
- Dian Wang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, Heilongjiang, PR China
| | - Yue Zhang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, Heilongjiang, PR China
| | - Chunli Ma
- Food College, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China
| | - Dexing Ma
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, Heilongjiang, PR China.
| | - Qin Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shanxi, PR China
| | - Fen Wang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, Heilongjiang, PR China
| | - Yuchen Huang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, Heilongjiang, PR China
| | - Jian Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, Heilongjiang, PR China
| | - Lili Zhang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, Heilongjiang, PR China; Heilongjiang Key Laboratory for Laboratory Animals and Comparative Medicine, Harbin 150030, Heilongjiang, PR China
| | - En-Min Zhou
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shanxi, PR China.
| |
Collapse
|
14
|
Characterization of Three Novel Linear Neutralizing B-Cell Epitopes in the Capsid Protein of Swine Hepatitis E Virus. J Virol 2018; 92:JVI.00251-18. [PMID: 29669835 DOI: 10.1128/jvi.00251-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 04/10/2018] [Indexed: 01/13/2023] Open
Abstract
Hepatitis E virus (HEV) causes liver disease in humans and is thought to be a zoonotic infection, with domestic animals, including swine and rabbits, being a reservoir. One of the proteins encoded by the virus is the capsid protein. This is likely the major immune-dominant protein and a target for vaccination. Four monoclonal antibodies (MAbs), three novel, 1E4, 2C7, and 2G9, and one previously characterized, 1B5, were evaluated for binding to the capsid protein from genotype 4 swine HEV. The results indicated that 625DFCP628, 458PSRPF462, and 407EPTV410 peptides on the capsid protein comprised minimal amino acid sequence motifs recognized by 1E4, 2C7, and 2G9, respectively. The data suggested that 2C7 and 2G9 epitopes were partially exposed on the surface of the capsid protein. Truncated genotype 4 swine HEV capsid protein (sp239, amino acids 368 to 606) can exist in multimeric forms. Preincubation of swine HEV with 2C7, 2G9, or 1B5 before addition to HepG2 cells partially blocked sp239 cell binding and inhibited swine HEV infection. The study indicated that 2C7, 2G9, and 1B5 partially blocked swine HEV infection of rabbits better than 1E4 or normal mouse IgG. The cross-reactivity of antibodies suggested that capsid epitopes recognized by 2C7 and 2G9 are common to HEV strains infecting most host species. Collectively, MAbs 2C7, 2G9, and 1B5 were shown to recognize three novel linear neutralizing B-cell epitopes of genotype 4 HEV capsid protein. These results enhance understanding of HEV capsid protein structure to guide vaccine and antiviral design.IMPORTANCE Genotype 3 and 4 HEVs are zoonotic viruses. Here, genotype 4 HEV was studied due to its prevalence in human populations and pig herds in China. To improve HEV disease diagnosis and prevention, a better understanding of the antigenic structure and neutralizing epitopes of HEV capsid protein are needed. In this study, the locations of three novel linear B-cell recognition epitopes within genotype 4 swine HEV capsid protein were characterized. Moreover, the neutralizing abilities of three MAbs specific for this protein, 2C7, 2G9, and 1B5, were studied in vitro and in vivo Collectively, these findings reveal structural details of genotype 4 HEV capsid protein and should facilitate development of applications for the design of vaccines and antiviral drugs for broader prevention, detection, and treatment of HEV infection of diverse human and animal hosts.
Collapse
|
15
|
Nan Y, Wu C, Zhao Q, Sun Y, Zhang YJ, Zhou EM. Vaccine Development against Zoonotic Hepatitis E Virus: Open Questions and Remaining Challenges. Front Microbiol 2018; 9:266. [PMID: 29520257 PMCID: PMC5827553 DOI: 10.3389/fmicb.2018.00266] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 02/05/2018] [Indexed: 12/18/2022] Open
Abstract
Hepatitis E virus (HEV) is a fecal-orally transmitted foodborne viral pathogen that causes acute hepatitis in humans and is responsible for hepatitis E outbreaks worldwide. Since the discovery of HEV as a zoonotic agent, this virus has been isolated from a variety of hosts with an ever-expanding host range. Recently, a subunit HEV vaccine developed for the prevention of human disease was approved in China, but is not yet available to the rest of the world. Meanwhile, notable progress and knowledge has been made and revealed in recent years to better understand HEV biology and infection, including discoveries of quasi-enveloped HEV virions and of a new function of the HEV-ORF3 product. However, the impact of these new findings on the development of a protective vaccine against zoonotic HEV infection requires further discussion. In this review, hallmark characteristics of HEV zoonosis, the history of HEV vaccine development, and recent discoveries in HEV virology are described. Moreover, special attention is focused on quasi-enveloped HEV virions and the potential role of the HEV-ORF3 product as antibody-neutralization target on the surface of quasi-enveloped HEV virions to provide new insights for the future development of improved vaccines against zoonotic HEV infection.
Collapse
Affiliation(s)
- Yuchen Nan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, China
| | - Chunyan Wu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, China
| | - Qin Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, China
| | - Yani Sun
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, China
| | - Yan-Jin Zhang
- Molecular Virology Laboratory, VA-MD College of Veterinary Medicine and Maryland Pathogen Research Institute, University of Maryland, College Park, MD, United States
| | - En-Min Zhou
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Yangling, China
| |
Collapse
|
16
|
Nan Y, Wu C, Zhao Q, Zhou EM. Zoonotic Hepatitis E Virus: An Ignored Risk for Public Health. Front Microbiol 2017; 8:2396. [PMID: 29255453 PMCID: PMC5723051 DOI: 10.3389/fmicb.2017.02396] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 11/20/2017] [Indexed: 12/27/2022] Open
Abstract
Hepatitis E virus (HEV) is a quasi-enveloped, single-stranded positive-sense RNA virus. HEV belongs to the family Hepeviridae, a family comprised of highly diverse viruses originating from various species. Since confirmation of HEV's zoonosis, HEV-induced hepatitis has been a public health concern both for developing and developed countries. Meanwhile, the demonstration of a broad host range for zoonotic HEV suggests the existence of a variety of transmission routes that could lead to human infection. Moreover, anti-HEV antibody serosurveillance worldwide demonstrates a higher than expected HEV prevalence rate that conflicts with the rarity and sporadic nature of reported acute hepatitis E cases. In recent years, chronic HEV infection, HEV-related acute hepatic failure, and extrahepatic manifestations caused by HEV infection have been frequently reported. These observations suggest a significant underestimation of the number and complexity of transmission routes previously predicted to cause HEV-related disease, with special emphasis on zoonotic HEV as a public health concern. Significant research has revealed details regarding the virology and infectivity of zoonotic HEV in both humans and animals. In this review, the discovery of HEV zoonosis, recent progress in our understanding of the zoonotic HEV host range, and classification of diverse HEV or HEV-like isolates from various hosts are reviewed in a historic context. Ultimately, this review focuses on current understanding of viral pathogenesis and cross-species transmission of zoonotic HEV. Moreover, host factors and viral determinants influencing HEV host tropism are discussed to provide new insights into HEV transmission and prevalence mechanisms.
Collapse
Affiliation(s)
- Yuchen Nan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Xianyang, China
| | - Chunyan Wu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Xianyang, China
| | - Qin Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Xianyang, China
| | - En-Min Zhou
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnostic Technology, Ministry of Agriculture, Xianyang, China
| |
Collapse
|
17
|
Miles S, Navatta M, Dematteis S, Mourglia-Ettlin G. Identification of universal diagnostic peptide candidates for neglected tropical diseases caused by cestodes through the integration of multi-genome-wide analyses and immunoinformatic predictions. INFECTION GENETICS AND EVOLUTION 2017; 54:338-346. [DOI: 10.1016/j.meegid.2017.07.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/16/2017] [Accepted: 07/15/2017] [Indexed: 12/31/2022]
|
18
|
Wang H, Zhang W, Gu H, Chen W, Zeng M, Ji C, Song R, Zhang G. Identification and characterization of two linear epitope motifs in hepatitis E virus ORF2 protein. PLoS One 2017; 12:e0184947. [PMID: 28957334 PMCID: PMC5619941 DOI: 10.1371/journal.pone.0184947] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Accepted: 09/02/2017] [Indexed: 12/23/2022] Open
Abstract
Hepatitis E virus (HEV) is responsible for hepatitis E, which represents a global public health problem. HEV genotypes 3 and 4 are reported to be zoonotic, and animals are monitored for HEV infection in the interests of public hygiene and food safety. The development of novel diagnostic methods and vaccines for HEV in humans is thus important topics of research. Opening reading frame (ORF) 2 of HEV includes both linear and conformational epitopes and is regarded as the primary candidate for vaccines and diagnostic tests. We investigated the precise location of the HEV epitopes in the ORF2 protein. We prepared four monoclonal antibodies (mAbs) against genotype 4 ORF2 protein and identified two linear epitopes, G438IVIPHD444 and Y457DNQH461, corresponding to two of these mAbs using phage display biopanning technology. Both these epitopes were speculated to be universal to genotypes 1, 2, 3, 4, and avian HEVs. We also used two 12-mer fragments of ORF2 protein including these two epitopes to develop a peptide-based enzyme-linked immunosorbent assay (ELISA) to detect HEV in serum. This assay demonstrated good specificity but low sensitivity compared with the commercial method, indicating that these two epitopes could serve as potential candidate targets for diagnosis. Overall, these results further our understanding of the epitope distribution of HEV ORF2, and provide important information for the development of peptide-based immunodiagnostic tests to detect HEV in serum.
Collapse
Affiliation(s)
- Heng Wang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province, People’s Republic of China
- Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, Guangdong Province, People’s Republic of China
- * E-mail: (GZ); (HW)
| | - Weidong Zhang
- Hospital of South China Agricultural University, Guangzhou, Guangdong Province, People’s Republic of China
| | - Honglang Gu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province, People’s Republic of China
- MOA Key Laboratory of Animal Vaccine Development, Guangzhou, Guangdong Province, People’s Republic of China
| | - Wanli Chen
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province, People’s Republic of China
- Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, Guangdong Province, People’s Republic of China
| | - Meng Zeng
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province, People’s Republic of China
- Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, Guangdong Province, People’s Republic of China
| | - Chihai Ji
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province, People’s Republic of China
- MOA Key Laboratory of Animal Vaccine Development, Guangzhou, Guangdong Province, People’s Republic of China
| | - Ruyue Song
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province, People’s Republic of China
- Guangdong Provincial Key Laboratory of Prevention and Control for Severe Clinical Animal Diseases, Guangzhou, Guangdong Province, People’s Republic of China
| | - Guihong Zhang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province, People’s Republic of China
- MOA Key Laboratory of Animal Vaccine Development, Guangzhou, Guangdong Province, People’s Republic of China
- * E-mail: (GZ); (HW)
| |
Collapse
|
19
|
Syed SF, Sun Y, Du T, Chen Y, Liu B, Wang X, Li H, Nan Y, Zhou EM, Zhao Q. Evaluation of recombinant Chinese avian hepatitis E virus (CaHEV) ORF2 and ORF3 proteins for protection of chickens against CaHEV infection. Vaccine 2017; 35:3482-3489. [PMID: 28528763 DOI: 10.1016/j.vaccine.2017.05.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Revised: 05/02/2017] [Accepted: 05/06/2017] [Indexed: 01/01/2023]
Abstract
Avian hepatitis E virus (HEV) is the etiologic agent of big liver and spleen disease in chickens. In 2010, the Chinese avian HEV (CaHEV) strain was isolated from chickens and demonstrated to cause the decreased egg production in layer hens. No avian HEV commercial vaccine has yet been developed to prevent virus infection in China. In this study, recombinant CaHEV truncated ORF2 and complete ORF3 proteins were evaluated separately for immunoprotection of chickens against CaHEV infection. First, truncated ORF2 and complete ORF3 proteins were expressed in Escherichia coli. Next, 48 specific-pathogen-free chickens were randomly divided into three groups. One group was immunized with truncated ORF2 protein, the second group was immunized with recombinant ORF3 protein, while the third group (control) was mock-immunized with PBS. After booster immunization, chickens in all three groups were challenged intravenously with CaHEV infectious stock and assessed for viremia, fecal virus shedding, seroconversion, and gross hepatic lesions. In the ORF2 protein-immunized group, no chickens showed evidence of avian HEV infection. In the ORF3 protein-immunized group, nine chickens exhibited viremia and seven had fecal virus shedding. In the control group, all 16 chickens showed viremia and fecal virus shedding. However, the durations in chickens from the ORF3 protein group (2-4weeks) were shorter than the ones from the control group (4-8weeks). Moreover, no gross liver lesions emerged in the ORF2 protein group, while lesions observed in the ORF3 protein group were milder than in controls. Therefore, the ORF2 protein can confer complete immunoprotection against chicken CaHEV infection, while the ORF3 protein only confers partial immunoprotection.
Collapse
Affiliation(s)
- Shahid Faraz Syed
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnosis, China Ministry of Agriculture, Yangling 712100, Shaanxi, PR China; Faculty of Veterinary and Animal Sciences, Lasbella University of Agriculture, Water and Marine Sciences, Uthal, Baluchistan, Pakistan
| | - Yani Sun
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnosis, China Ministry of Agriculture, Yangling 712100, Shaanxi, PR China
| | - Taofeng Du
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnosis, China Ministry of Agriculture, Yangling 712100, Shaanxi, PR China
| | - Yiyang Chen
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnosis, China Ministry of Agriculture, Yangling 712100, Shaanxi, PR China
| | - Baoyuan Liu
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnosis, China Ministry of Agriculture, Yangling 712100, Shaanxi, PR China
| | - Xinjie Wang
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnosis, China Ministry of Agriculture, Yangling 712100, Shaanxi, PR China
| | - Huixia Li
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnosis, China Ministry of Agriculture, Yangling 712100, Shaanxi, PR China
| | - Yuchen Nan
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnosis, China Ministry of Agriculture, Yangling 712100, Shaanxi, PR China
| | - En-Min Zhou
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnosis, China Ministry of Agriculture, Yangling 712100, Shaanxi, PR China.
| | - Qin Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, PR China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Diagnosis, China Ministry of Agriculture, Yangling 712100, Shaanxi, PR China.
| |
Collapse
|
20
|
Zhao Q, Liu B, Sun Y, Du T, Chen Y, Wang X, Li H, Nan Y, Zhang G, Zhou EM. Decreased egg production in laying hens associated with infection with genotype 3 avian hepatitis E virus strain from China. Vet Microbiol 2017; 203:174-180. [DOI: 10.1016/j.vetmic.2017.03.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/01/2017] [Accepted: 03/03/2017] [Indexed: 12/11/2022]
|
21
|
Chingwaru W, Vidmar J. A novel porcine cell culture based protocol for the propagation of hepatitis E virus. ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2016. [DOI: 10.1016/s2222-1808(16)61092-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
22
|
Wu CH, Liu IJ, Lu RM, Wu HC. Advancement and applications of peptide phage display technology in biomedical science. J Biomed Sci 2016; 23:8. [PMID: 26786672 PMCID: PMC4717660 DOI: 10.1186/s12929-016-0223-x] [Citation(s) in RCA: 207] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Accepted: 01/11/2016] [Indexed: 12/25/2022] Open
Abstract
Combinatorial phage library is a powerful research tool for high-throughput screening of protein interactions. Of all available molecular display techniques, phage display has proven to be the most popular approach. Screening phage-displayed random peptide libraries is an effective means of identifying peptides that can bind target molecules and regulate their function. Phage-displayed peptide libraries can be used for (i) B-cell and T-cell epitope mapping, (ii) selection of bioactive peptides bound to receptors or proteins, disease-specific antigen mimics, peptides bound to non-protein targets, cell-specific peptides, or organ-specific peptides, and (iii) development of peptide-mediated drug delivery systems and other applications. Targeting peptides identified using phage display technology may be useful for basic research and translational medicine. In this review article, we summarize the latest technological advancements in the application of phage-displayed peptide libraries to applied biomedical sciences.
Collapse
Affiliation(s)
- Chien-Hsun Wu
- Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 11529, Taiwan
| | - I-Ju Liu
- Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 11529, Taiwan
| | - Ruei-Min Lu
- Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 11529, Taiwan
| | - Han-Chung Wu
- Institute of Cellular and Organismic Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 11529, Taiwan.
| |
Collapse
|
23
|
Zhao Q, Syed SF, Zhou EM. Antigenic properties of avian hepatitis E virus capsid protein. Vet Microbiol 2015; 180:10-4. [PMID: 26340899 DOI: 10.1016/j.vetmic.2015.08.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 08/23/2015] [Accepted: 08/24/2015] [Indexed: 12/23/2022]
Abstract
Avian hepatitis E virus (HEV) is the main causative agent of big liver and spleen disease and hepatitis-splenomegaly syndrome in chickens, and is genetically and antigenically related to mammalian HEVs. HEV capsid protein contains immunodominant epitopes and induces a protective humoral immune response. A better understanding of the antigenic composition of this protein is critically important for the development of effective vaccine and sensitive and specific serological assays. To date, six linear antigenic domains (I-VI) have been characterized in avian HEV capsid protein and analyzed for their applications in the serological diagnosis and vaccine design. Domains I and V induce strong immune response in chickens and are common to avian, human, and swine HEVs, indicating that the shared epitopes hampering differential diagnosis of avian HEV infection. Domains III and IV are not immunodominant and elicit a weak immune response. Domain VI, located in the N-terminal region of the capsid protein, can also trigger an intense immune response, but the anti-domain VI antibodies are transient. The protection analysis showed that the truncated capsid protein containing the C-terminal 268 amino acid residues expressed by the bacterial system can provide protective immunity against avian HEV infection in chickens. However, the synthetic peptides incorporating the different linear antigenic domains (I-VI) and epitopes are non-protective. The antigenic composition of avian HEV capsid protein is altogether complex. To develop an effective vaccine and accurate serological diagnostic methods, more conformational antigenic domains or epitopes are to be characterized in detail.
Collapse
Affiliation(s)
- Qin Zhao
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture, Yangling 712100, Shaanxi, China
| | - Shahid Faraz Syed
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture, Yangling 712100, Shaanxi, China
| | - En-Min Zhou
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China; Scientific Observing and Experimental Station of Veterinary Pharmacology and Veterinary Biotechnology, Ministry of Agriculture, Yangling 712100, Shaanxi, China.
| |
Collapse
|
24
|
Li Q, Wang X, Wang C, Yu Y, Wang G, Gao J, Liu H, Xie H, Huang B, Li Z, Kong N, Zhang G, Hsu WH, Zhou EM. Intracellular expression of an anti-idiotypic antibody single-chain variable fragment reduces porcine reproductive and respiratory syndrome virus infection in MARC-145 cells. Antivir Ther 2015. [PMID: 26214224 DOI: 10.3851/imp2980] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND Porcine reproductive and respiratory syndrome virus (PRRSV) is the causative agent of porcine reproductive and respiratory syndrome; it is one of the most economically important viral diseases affecting the swine industry worldwide. At present, neither live-attenuated nor inactivated PRRSV vaccines can provide sustainable disease control. Our previous studies have demonstrated that PRRSV infection can produce the auto-anti-idiotypic antibodies (aAb2s) specific to the idiotypic antibodies against PRRSV GP5, which plays an important role in the host immune responses to PRRSV infection. In the present study, a single-chain variable antibody fragment (scFv) from the monoclonal anti-idiotypic antibody specific for the idiotypic antibody against GP5 was expressed in MARC-145 cells and its effect on virus infection in vitro was evaluated. METHODS An scFv was constructed from the anti-idiotypic antibody (Mab2-5G2) and was named 5G2scFv. The lentiviral vector system was used as a vehicle to deliver 5G2scFv into MARC-145 cells. The effect of 5G2scFv expression in MARC-145 was analysed by determining the PRRSV N protein level and the virus titre in the supernatant. Virus attachment and the level of type I interferon (IFN) were determined to elucidate the mechanism of the scFv effect. RESULTS 5G2scFv was delivered in MARC-145 cells using the lentiviral vector system as confirmed by the western blot and indirect immunofluorescence assays. The PRRSV challenge experiments demonstrated that expressed 5G2scFv in MARC-145 strongly reduced PRRSV infection and replication by inhibiting protein synthesis and progeny virus production. This effect was not due to the change of viability or virus binding, but increased IFN-α at messenger RNA and protein levels. CONCLUSIONS The expression of the anti-idiotypic antibody 5G2scFv in MARC-145 cells has the interferential effect on PRRSV infection in the cells by induction of IFN-α, which provides a novel therapeutic approach for PRRSV infection.
Collapse
Affiliation(s)
- Qiongyi Li
- Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|