1
|
Zhao Y, Zhu X, Zhang Z, Chen J, Chen Y, Hu C, Chen X, Robertson ID, Guo A. The Prevalence and Molecular Characterization of Bovine Leukemia Virus among Dairy Cattle in Henan Province, China. Viruses 2024; 16:1399. [PMID: 39339874 PMCID: PMC11437460 DOI: 10.3390/v16091399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2024] [Revised: 08/26/2024] [Accepted: 08/27/2024] [Indexed: 09/30/2024] Open
Abstract
Enzootic bovine leukosis, a neoplastic disease caused by the bovine leukemia virus (BLV), was the primary cancer affecting cattle in China before 1985. Although its prevalence decreased significantly between 1986 and 2000, enzootic bovine leukosis has been re-emerging since 2000. This re-emergence has been largely overlooked, possibly due to the latent nature of BLV infection or the perceived lack of sufficient evidence. This study investigated the molecular epidemiology of BLV infections in dairy cattle in Henan province, Central China. Blood samples from 668 dairy cattle across nine farms were tested using nested polymerase chain reaction assays targeting the partial envelope (env) gene (gp51 fragment). Twenty-three samples tested positive (animal-level prevalence of 3.4%; 95% confidence interval: 2.2, 5.1). The full-length env gene sequences from these positive samples were obtained and phylogenetically analyzed, along with previously reported sequences from the GenBank database. The sequences from positive samples were clustered into four genotypes (1, 4, 6, and 7). The geographical annotation of the maximum clade credibility trees suggested that the two genotype 1 strains in Henan might have originated from Japan, while the genotype 7 strain is likely to have originated from Moldova. Subsequent Bayesian stochastic search variable selection analysis further indicated a strong geographical association between the Henan strains and Japan, as well as Moldova. The estimated substitution rate for the env gene ranged from 4.39 × 10-4 to 2.38 × 10-3 substitutions per site per year. Additionally, codons 291, 326, 385, and 480 were identified as positively selected sites, potentially associated with membrane fusion, epitope peptide vaccine design, and transmembrane signal transduction. These findings contribute to the broader understanding of BLV epidemiology in Chinese dairy cattle and highlight the need for measures to mitigate further BLV transmission within and between cattle herds in China.
Collapse
Affiliation(s)
- Yuxi Zhao
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (Y.Z.); (X.Z.); (J.C.); (Y.C.); (C.H.); (X.C.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Centre for Sustainable Pig Production, Wuhan 430070, China;
| | - Xiaojie Zhu
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (Y.Z.); (X.Z.); (J.C.); (Y.C.); (C.H.); (X.C.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Centre for Sustainable Pig Production, Wuhan 430070, China;
- School of Veterinary Medicine, Murdoch University, Perth, WA 6150, Australia
| | - Zhen Zhang
- Henan Province Seed Industry Development Center, Department of Agriculture and Rural Affairs of Henan Province, Zhengzhou 450045, China
| | - Jianguo Chen
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (Y.Z.); (X.Z.); (J.C.); (Y.C.); (C.H.); (X.C.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Centre for Sustainable Pig Production, Wuhan 430070, China;
| | - Yingyu Chen
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (Y.Z.); (X.Z.); (J.C.); (Y.C.); (C.H.); (X.C.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Centre for Sustainable Pig Production, Wuhan 430070, China;
| | - Changmin Hu
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (Y.Z.); (X.Z.); (J.C.); (Y.C.); (C.H.); (X.C.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Centre for Sustainable Pig Production, Wuhan 430070, China;
| | - Xi Chen
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (Y.Z.); (X.Z.); (J.C.); (Y.C.); (C.H.); (X.C.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Centre for Sustainable Pig Production, Wuhan 430070, China;
| | - Ian D. Robertson
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Centre for Sustainable Pig Production, Wuhan 430070, China;
- School of Veterinary Medicine, Murdoch University, Perth, WA 6150, Australia
| | - Aizhen Guo
- National Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; (Y.Z.); (X.Z.); (J.C.); (Y.C.); (C.H.); (X.C.)
- Hubei International Scientific and Technological Cooperation Base of Veterinary Epidemiology, The Cooperative Innovation Centre for Sustainable Pig Production, Wuhan 430070, China;
| |
Collapse
|
2
|
Tomé-Poderti L, Olivero-Deibe N, Carrión F, Portela MM, Obal G, Cabrera G, Bianchi S, Lima A, Addiego A, Durán R, Moratorio G, Pritsch O. Characterization and application of recombinant Bovine Leukemia Virus Env protein. Sci Rep 2024; 14:12190. [PMID: 38806566 PMCID: PMC11133380 DOI: 10.1038/s41598-024-62811-8] [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: 02/20/2024] [Accepted: 05/21/2024] [Indexed: 05/30/2024] Open
Abstract
The Bovine Leukemia Virus (BLV) Envelope (Env) glycoprotein complex is instrumental in viral infectivity and shapes the host's immune response. This study presents the production and characterization of a soluble furin-mutated BLV Env ectodomain (sBLV-EnvFm) expressed in a stable S2 insect cell line. We purified a 63 kDa soluble protein, corresponding to the monomeric sBLV-EnvFm, which predominantly presented oligomannose and paucimannose N-glycans, with a high content of core fucose structures. Our results demonstrate that our recombinant protein can be recognized from specific antibodies in BLV infected cattle, suggesting its potential as a powerful diagnostic tool. Moreover, the robust humoral immune response it elicited in mice shows its potential contribution to the development of subunit-based vaccines against BLV.
Collapse
Affiliation(s)
- Lorena Tomé-Poderti
- Immunovirology Lab, Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay.
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses (MAVIVH), INSERM Unit 1259, Université de Tours and CHRU de Tours, Tours, France.
| | | | - Federico Carrión
- Immunovirology Lab, Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
| | - María Magdalena Portela
- Analytical Biochemistry and Proteomics Unit, Instituto de Investigaciones Biológicas Clemente Estable/Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
- Facultad de Ciencias, Universidad de la República, 11400, Montevideo, Uruguay
| | - Gonzalo Obal
- Immunovirology Lab, Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
| | - Gleysin Cabrera
- Analytical Biochemistry and Proteomics Unit, Instituto de Investigaciones Biológicas Clemente Estable/Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
| | - Sergio Bianchi
- Laboratory of Molecular Biomarkers, Department of Physiopathology, University Hospital, Universidad de la República, 11600, Montevideo, Uruguay
- Functional Genomics Unit, Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
| | - Analia Lima
- Analytical Biochemistry and Proteomics Unit, Instituto de Investigaciones Biológicas Clemente Estable/Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
| | - Andrés Addiego
- Immunovirology Lab, Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
| | - Rosario Durán
- Analytical Biochemistry and Proteomics Unit, Instituto de Investigaciones Biológicas Clemente Estable/Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
| | - Gonzalo Moratorio
- Experimental Evolution of Viruses, Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
- Laboratorio de Virología Molecular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Otto Pritsch
- Immunovirology Lab, Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
- Immunobiology Department School of Medicine, Universidad de la República, 11800, Montevideo, Uruguay
| |
Collapse
|
3
|
Santana CS, Andrade FDO, da Silva GCS, Nascimento JODS, Campos RF, Giovanetti M, Santos LA, Gois LL, Alcantara LCJ, Barreto FK. Advances in preventive vaccine development against HTLV-1 infection: A systematic review of the last 35 years. Front Immunol 2023; 14:1073779. [PMID: 36860854 PMCID: PMC9968880 DOI: 10.3389/fimmu.2023.1073779] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 01/25/2023] [Indexed: 02/15/2023] Open
Abstract
Introduction The Human T-lymphotropic virus type 1 (HTLV-1) was the first described human retrovirus. It is currently estimated that around 5 to 10 million people worldwide are infected with this virus. Despite its high prevalence, there is still no preventive vaccine against the HTLV-1 infection. It is known that vaccine development and large-scale immunization play an important role in global public health. To understand the advances in this field we performed a systematic review regarding the current progress in the development of a preventive vaccine against the HTLV-1 infection. Methods This review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA®) guidelines and was registered at the International Prospective Register of Systematic Reviews (PROSPERO). The search for articles was performed in PubMed, Lilacs, Embase and SciELO databases. From the 2,485 articles identified, 25 were selected according to the inclusion and exclusion criteria. Results The analysis of these articles indicated that potential vaccine designs in development are available, although there is still a paucity of studies in the human clinical trial phase. Discussion Although HTLV-1 was discovered almost 40 years ago, it remains a great challenge and a worldwide neglected threat. The scarcity of funding contributes decisively to the inconclusiveness of the vaccine development. The data summarized here intends to highlight the necessity to improve the current knowledge of this neglected retrovirus, encouraging for more studies on vaccine development aiming the to eliminate this human threat. Systematic review registration https://www.crd.york.ac.uk/prospero, identifier (CRD42021270412).
Collapse
Affiliation(s)
- Carolina Souza Santana
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista, Brazil
| | | | | | | | - Raissa Frazão Campos
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista, Brazil
| | - Marta Giovanetti
- Laboratório de Mosquitos Vetores: Endossimbiontes e Interação Patógeno-Vetor, Instituto René Rachou - Fiocruz, Belo Horizonte, Minas Gerais, Brazil.,Department of Science and Technology for Humans and the Environment, University of Campus Bio-Medico di Roma, Rome, Italy
| | - Luciane Amorim Santos
- Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.,Escola Bahiana de Medicina e Saúde Pública, Salvador, Brazil
| | - Luana Leandro Gois
- Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil.,Departamento de Ciências da Biointeração, Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, Brazil
| | - Luiz Carlos Júnior Alcantara
- Laboratório de Mosquitos Vetores: Endossimbiontes e Interação Patógeno-Vetor, Instituto René Rachou - Fiocruz, Belo Horizonte, Minas Gerais, Brazil
| | - Fernanda Khouri Barreto
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista, Brazil
| |
Collapse
|
4
|
Bai L, Takeshima SN, Sato M, Davis WC, Wada S, Kohara J, Aida Y. Mapping of CD4 + T-cell epitopes in bovine leukemia virus from five cattle with differential susceptibilities to bovine leukemia virus disease progression. Virol J 2019; 16:157. [PMID: 31842930 PMCID: PMC6916044 DOI: 10.1186/s12985-019-1259-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 11/22/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bovine leukemia virus (BLV), which is closely related to human T-cell leukemia virus, is the etiological agent of enzootic bovine leukosis, a disease characterized by a highly prolonged course involving persistent lymphocytosis and B-cell lymphoma. The bovine major histocompatibility complex class II region plays a key role in the subclinical progression of BLV infection. In this study, we aimed to evaluate the roles of CD4+ T-cell epitopes in disease progression in cattle. METHODS We examined five Japanese Black cattle, including three disease-susceptible animals, one disease-resistant animal, and one normal animal, classified according to genotyping of bovine leukocyte antigen (BoLA)-DRB3 and BoLA-DQA1 alleles using polymerase chain reaction sequence-based typing methods. All cattle were inoculated with BLV-infected blood collected from BLV experimentally infected cattle and then subjected to CD4+ T-cell epitope mapping by cell proliferation assays. RESULTS Five Japanese Black cattle were successfully infected with BLV, and CD4+ T-cell epitope mapping was then conducted. Disease-resistant and normal cattle showed low and moderate proviral loads and harbored six or five types of CD4+ T-cell epitopes, respectively. In contrast, the one of three disease-susceptible cattle with the highest proviral load did not harbor CD4+ T-cell epitopes, and two of three other cattle with high proviral loads each had only one epitope. Thus, the CD4+ T-cell epitope repertoire was less frequent in disease-susceptible cattle than in other cattle. CONCLUSION Although only a few cattle were included in this study, our results showed that CD4+ T-cell epitopes may be associated with BoLA-DRB3-DQA1 haplotypes, which conferred differential susceptibilities to BLV proviral loads. These CD4+ T-cell epitopes could be useful for the design of anti-BLV vaccines targeting disease-susceptible Japanese Black cattle. Further studies of CD4+ T-cell epitopes in other breeds and using larger numbers of cattle with differential susceptibilities are required to confirm these findings.
Collapse
Affiliation(s)
- Lanlan Bai
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.,Photonics Control Technology Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Shin-Nosuke Takeshima
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan. .,Faculty of Human Life, Department of Food and Nutrition, Jumonji University, 2-1-28 Sugasawa, Niiza, Saitama, 352-0017, Japan.
| | - Masaaki Sato
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - William C Davis
- Monoclonal antibody center, Department of Veterinary Microbiology & Pathology, Washington State University, Pullman, WA, 99164-7040, USA
| | - Satoshi Wada
- Photonics Control Technology Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Junko Kohara
- Animal Research Center, Hokkaido Research Organization, 5-39-1 Shintoku, Hokkaido, 081-0038, Japan
| | - Yoko Aida
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan. .,Nakamura Laboratory, Baton Zone Program, RIKEN Cluster for Science, Technology and Innovation Hub, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
| |
Collapse
|
5
|
Matsuura R, Inabe K, Otsuki H, Kurokawa K, Dohmae N, Aida Y. Three YXXL Sequences of a Bovine Leukemia Virus Transmembrane Protein are Independently Required for Fusion Activity by Controlling Expression on the Cell Membrane. Viruses 2019; 11:E1140. [PMID: 31835517 PMCID: PMC6950344 DOI: 10.3390/v11121140] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/05/2019] [Accepted: 12/08/2019] [Indexed: 01/27/2023] Open
Abstract
Bovine leukemia virus (BLV), which is closely related to human T-cell leukemia viruses, is the causative agent of enzootic bovine leukosis, the most common neoplastic disease of cattle. The transmembrane subunit of the BLV envelope glycoprotein, gp30, contains three completely conserved YXXL sequences that fit an endocytic sorting motif. The two N-terminal YXXL sequences are reportedly critical for viral infection. However, their actual function in the viral life cycle remains undetermined. Here, we identified the novel roles of each YXXL sequence. Syncytia formation ability was upregulated by a single mutation of the tyrosine (Tyr) residue in any of the three YXXL sequences, indicating that each YXXL sequence is independently able to regulate the fusion event. The alteration resulted from significantly high expression of gp51 on the cell surface, thereby decreasing the amount of gp51 in early endosomes and further revealing that the three YXXL sequences are independently required for internalization of the envelope (Env) protein, following transport to the cell surface. Moreover, the 2nd and 3rd YXXL sequences contributed to Env protein incorporation into the virion by functionally distinct mechanisms. Our findings provide new insights regarding the three YXXL sequences toward the BLV viral life cycle and for developing new anti-BLV drugs.
Collapse
Affiliation(s)
- Ryosuke Matsuura
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Laboratory of Viral Infectious Diseases, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kazunori Inabe
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hiroyuki Otsuki
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kazuo Kurokawa
- Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Naoshi Dohmae
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yoko Aida
- Viral Infectious Diseases Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Laboratory of Viral Infectious Diseases, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Nakamura Laboratory, Baton Zone program, Riken Cluster for Science, Technology and Innovation Hub, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| |
Collapse
|
6
|
Sajiki Y, Konnai S, Okagawa T, Nishimori A, Maekawa N, Goto S, Watari K, Minato E, Kobayashi A, Kohara J, Yamada S, Kaneko MK, Kato Y, Takahashi H, Terasaki N, Takeda A, Yamamoto K, Toda M, Suzuki Y, Murata S, Ohashi K. Prostaglandin E 2-Induced Immune Exhaustion and Enhancement of Antiviral Effects by Anti-PD-L1 Antibody Combined with COX-2 Inhibitor in Bovine Leukemia Virus Infection. THE JOURNAL OF IMMUNOLOGY 2019; 203:1313-1324. [PMID: 31366713 DOI: 10.4049/jimmunol.1900342] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 06/28/2019] [Indexed: 01/09/2023]
Abstract
Bovine leukemia virus (BLV) infection is a chronic viral infection of cattle and endemic in many countries, including Japan. Our previous study demonstrated that PGE2, a product of cyclooxygenase (COX) 2, suppresses Th1 responses in cattle and contributes to the progression of Johne disease, a chronic bacterial infection in cattle. However, little information is available on the association of PGE2 with chronic viral infection. Thus, we analyzed the changes in plasma PGE2 concentration during BLV infection and its effects on proviral load, viral gene transcription, Th1 responses, and disease progression. Both COX2 expression by PBMCs and plasma PGE2 concentration were higher in the infected cattle compared with uninfected cattle, and plasma PGE2 concentration was positively correlated with the proviral load. BLV Ag exposure also directly enhanced PGE2 production by PBMCs. Transcription of BLV genes was activated via PGE2 receptors EP2 and EP4, further suggesting that PGE2 contributes to disease progression. In contrast, inhibition of PGE2 production using a COX-2 inhibitor activated BLV-specific Th1 responses in vitro, as evidenced by enhanced T cell proliferation and Th1 cytokine production, and reduced BLV proviral load in vivo. Combined treatment with the COX-2 inhibitor meloxicam and anti-programmed death-ligand 1 Ab significantly reduced the BLV proviral load, suggesting a potential as a novel control method against BLV infection. Further studies using a larger number of animals are required to support the efficacy of this treatment for clinical application.
Collapse
Affiliation(s)
- Yamato Sajiki
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Satoru Konnai
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan; .,Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Tomohiro Okagawa
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Asami Nishimori
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Naoya Maekawa
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Shinya Goto
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Kei Watari
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Erina Minato
- Department of Veterinary Clinical Medicine, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Atsushi Kobayashi
- Department of Veterinary Clinical Medicine, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Junko Kohara
- Animal Research Center, Agriculture Research Department, Hokkaido Research Organization, Shintoku 081-0038, Japan
| | - Shinji Yamada
- Department of Antibody Drug Development, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Mika K Kaneko
- Department of Antibody Drug Development, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Yukinari Kato
- Department of Antibody Drug Development, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan
| | - Hirofumi Takahashi
- Shibecha Branch, Kushiro Central Office, Hokkaido Higashi Agricultural Mutual Aid Association, Shibecha 088-2311, Japan
| | - Nobuhiro Terasaki
- Shibecha Branch, Kushiro Central Office, Hokkaido Higashi Agricultural Mutual Aid Association, Shibecha 088-2311, Japan
| | - Akira Takeda
- Shibecha Branch, Kushiro Central Office, Hokkaido Higashi Agricultural Mutual Aid Association, Shibecha 088-2311, Japan
| | - Keiichi Yamamoto
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.,Research and Development Center, Fuso Pharmaceutical Industries, Ltd., Osaka 536-8523, Japan
| | - Mikihiro Toda
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.,New Business and International Business Development, Fuso Pharmaceutical Industries, Ltd., Osaka 536-8523, Japan
| | - Yasuhiko Suzuki
- Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.,Division of Bioresources, Research Center for Zoonosis Control, Hokkaido University, Sapporo 001-0019, Japan; and.,Global Station for Zoonosis Control, Global Institution for Collaborative Research and Education, Hokkaido University, Sapporo 001-0019, Japan
| | - Shiro Murata
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.,Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Kazuhiko Ohashi
- Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.,Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| |
Collapse
|
7
|
de Brogniez A, Mast J, Willems L. Determinants of the Bovine Leukemia Virus Envelope Glycoproteins Involved in Infectivity, Replication and Pathogenesis. Viruses 2016; 8:88. [PMID: 27023592 PMCID: PMC4848583 DOI: 10.3390/v8040088] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/04/2016] [Accepted: 03/09/2016] [Indexed: 11/16/2022] Open
Abstract
Interaction of viral envelope proteins with host cell membranes has been extensively investigated in a number of systems. However, the biological relevance of these interactions in vivo has been hampered by the absence of adequate animal models. Reverse genetics using the bovine leukemia virus (BLV) genome highlighted important functional domains of the envelope protein involved in the viral life cycle. For example, immunoreceptor tyrosine-based activation motifs (ITAM) of the envelope transmembrane protein (TM) are essential determinants of infection. Although cell fusion directed by the aminoterminal end of TM is postulated to be essential, some proviruses expressing fusion-deficient envelope proteins unexpectedly replicate at wild-type levels. Surprisingly also, a conserved N-linked glycosylation site of the extracellular envelope protein (SU) inhibits cell-to-cell transmission suggesting that infectious potential has been limited during evolution. In this review, we summarize the knowledge pertaining to the BLV envelope protein in the context of viral infection, replication and pathogenesis.
Collapse
Affiliation(s)
- Alix de Brogniez
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (Gembloux Agro-Bio Tech), University of Liège (ULg), 4000 Liège, Belgium.
| | - Jan Mast
- Veterinary and Agrochemical Research Center CODA-CERVA, 1180 Brussels, Belgium.
| | - Luc Willems
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (Gembloux Agro-Bio Tech), University of Liège (ULg), 4000 Liège, Belgium.
| |
Collapse
|
8
|
Abstract
Different animal models have been proposed to investigate the mechanisms of Human T-lymphotropic Virus (HTLV)-induced pathogenesis: rats, transgenic and NOD-SCID/γcnull (NOG) mice, rabbits, squirrel monkeys, baboons and macaques. These systems indeed provide useful information but have intrinsic limitations such as lack of disease relevance, species specificity or inadequate immune response. Another strategy based on a comparative virology approach is to characterize a related pathogen and to speculate on possible shared mechanisms. In this perspective, bovine leukemia virus (BLV), another member of the deltaretrovirus genus, is evolutionary related to HTLV-1. BLV induces lymphoproliferative disorders in ruminants providing useful information on the mechanisms of viral persistence, genetic determinants of pathogenesis and potential novel therapies.
Collapse
|
9
|
Mutation of a Single Envelope N-Linked Glycosylation Site Enhances the Pathogenicity of Bovine Leukemia Virus. J Virol 2015; 89:8945-56. [PMID: 26085161 DOI: 10.1128/jvi.00261-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 06/09/2015] [Indexed: 12/29/2022] Open
Abstract
UNLABELLED Viruses have coevolved with their host to ensure efficient replication and transmission without inducing excessive pathogenicity that would indirectly impair their persistence. This is exemplified by the bovine leukemia virus (BLV) system in which lymphoproliferative disorders develop in ruminants after latency periods of several years. In principle, the equilibrium reached between the virus and its host could be disrupted by emergence of more pathogenic strains. Intriguingly but fortunately, such a hyperpathogenic BLV strain was never observed in the field or designed in vitro. In this study, we sought to understand the role of envelope N-linked glycosylation with the hypothesis that this posttranslational modification could either favor BLV infection by allowing viral entry or allow immune escape by using glycans as a shield. Using reverse genetics of an infectious molecular provirus, we identified a N-linked envelope glycosylation site (N230) that limits viral replication and pathogenicity. Indeed, mutation N230E unexpectedly leads to enhanced fusogenicity and protein stability. IMPORTANCE Infection by retroviruses requires the interaction of the viral envelope protein (SU) with a membrane-associated receptor allowing fusion and release of the viral genomic RNA into the cell. We show that N-linked glycosylation of the bovine leukemia virus (BLV) SU protein is, as expected, essential for cell infection in vitro. Consistently, mutation of all glycosylation sites of a BLV provirus destroys infectivity in vivo. However, single mutations do not significantly modify replication in vivo. Instead, a particular mutation at SU codon 230 increases replication and accelerates pathogenesis. This unexpected observation has important consequences in terms of disease control and managing.
Collapse
|
10
|
Ikebuchi R, Konnai S, Okagawa T, Nishimori A, Nakahara A, Murata S, Ohashi K. Differences in cellular function and viral protein expression between IgMhigh and IgMlow B-cells in bovine leukemia virus-infected cattle. J Gen Virol 2014; 95:1832-1842. [PMID: 24814926 DOI: 10.1099/vir.0.065011-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Bovine leukemia virus (BLV) induces abnormal B-cell proliferation and B-cell lymphoma in cattle, where the BLV provirus is integrated into the host genome. BLV-infected B-cells rarely express viral proteins in vivo, but short-term cultivation augments BLV expression in some, but not all, BLV-infected B-cells. This observation suggests that two subsets, i.e. BLV-silencing cells and BLV-expressing cells, are present among BLV-infected B-cells, although the mechanisms of viral expression have not been determined. In this study, we examined B-cell markers and viral antigen expression in B-cells from BLV-infected cattle to identify markers that may discriminate BLV-expressing cells from BLV-silencing cells. The proportions of IgM(high) B-cells were increased in blood lymphocytes from BLV-infected cattle. IgM(high) B-cells mainly expressed BLV antigens, whereas IgM(low) B-cells did not, although the provirus load was equivalent in both subsets. Several parameters were investigated in these two subsets to characterize their cellular behaviour. Real-time PCR and microarray analyses detected higher expression levels of some proto-oncogenes (e.g. Maf, Jun and Fos) in IgM(low) B-cells than those in IgM(high) B-cells. Moreover, lymphoma cells obtained from the lymph nodes of 14 BLV-infected cattle contained IgM(low) or IgM(-) B-cells but no IgM(high) B-cells. To our knowledge, this is the first study to demonstrate that IgM(high) B-cells mainly comprise BLV-expressing cells, whereas IgM(low) B-cells comprise a high proportion of BLV-silencing B-cells in BLV-infected cattle.
Collapse
Affiliation(s)
- Ryoyo Ikebuchi
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Satoru Konnai
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Tomohiro Okagawa
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Asami Nishimori
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Ayako Nakahara
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Shiro Murata
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Kazuhiko Ohashi
- Department of Disease Control, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| |
Collapse
|
11
|
Zhao X, Buehring GC. Natural genetic variations in bovine leukemia virus envelope gene: Possible effects of selection and escape. Virology 2007; 366:150-65. [PMID: 17498765 DOI: 10.1016/j.virol.2007.03.058] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Revised: 03/05/2007] [Accepted: 03/29/2007] [Indexed: 12/01/2022]
Abstract
Bovine leukemia virus (BLV) is an oncogenic virus widespread in cattle. It belongs to the genus Deltaretrovirus of the family Retroviridae along with human and simian T-lymphotropic viruses. Here we report the addition of 28 new sequences to the current literature of 16 full-length BLV envelope gene sequences. The phylogenetic clustering, genotyping, and geographic distribution of BLV env variations corresponded in most cases. Most natural variations are mapped to the surface of the proposed conformational models of BLV gp51 N-terminus and gp30 external domain, overlapping with or adjacent to immunogenic epitopes. Analyses for evidence of possible selection pressures suggest the BLV env is under stringent negative selection overall, while strong positive selection is indicated for immunogenic epitope G. Natural env deletions bounded by similar flanking sequences were observed in multiple isolates and would result in truncated signal peptides, missing gp51, and aberrant coding frames for other proteins.
Collapse
Affiliation(s)
- Xiangrong Zhao
- Graduate Program in Endocrinology, 3060 Valley Life Science Building, University of California, Berkeley, CA 94720-3140, USA.
| | | |
Collapse
|
12
|
Florins A, Gillet N, Boxus M, Kerkhofs P, Kettmann R, Willems L. Even attenuated bovine leukemia virus proviruses can be pathogenic in sheep. J Virol 2007; 81:10195-200. [PMID: 17626096 PMCID: PMC2045414 DOI: 10.1128/jvi.01058-07] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Based on a reverse genetics approach, we previously reported that bovine leukemia virus (BLV) mutants harboring deletions in the accessory R3 and G4 genes persist at very low proviral loads and are unable to induce leukemia or lymphoma in sheep, indicating that these R3 and G4 gene sequences are required for pathogenesis. We now show that lymphoma can occur, albeit infrequently (1 case of 20) and after extended periods of latency (7 years). Direct sequencing and reinfection experiments demonstrated that lymphomagenesis was not due to the reversion of the mutant to the wild type. Similar observations with another type of attenuated mutant impaired in the transmembrane protein (TM) YXXL signaling motifs were made. We conclude that the R3 and G4 genes and the TM YXXL motifs are not strictly required for pathogenesis but that their integrity contributes to disease frequency and latency.
Collapse
Affiliation(s)
- Arnaud Florins
- Molecular and Cellular Biology Laboratory, National Fund for Scientific Research-FUSAGx, 13 avenue Maréchal Juin, 5030 Gembloux, Belgium
| | | | | | | | | | | |
Collapse
|
13
|
Camargos MF, Pereda A, Stancek D, Rocha MA, dos Reis JKP, Greiser-Wilke I, Leite RC. Molecular characterization of the env gene from Brazilian field isolates of Bovine Leukemia Virus. Virus Genes 2007; 34:343-50. [PMID: 16917740 DOI: 10.1007/s11262-006-0011-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2006] [Accepted: 04/27/2006] [Indexed: 11/24/2022]
Abstract
Molecular characterization of Bovine leukemia virus (BLV) isolates from Brazil using the env gene sequences revealed a high conservation of this gene. In most cases the substitutions corresponded to silent transitions. In addition, cystein residues, potential glycosylation sites, neutralization domains and other critical residues involved with the envelope structural domains and viral infectivity were conserved. Most of the substitutions found in the aminoacid sequences of the gp51 protein were localized in the G and H epitopes. Using the SIFT software, it was predicted that they should not alter the protein functions. Phylogenetic analyses showed that partial or complete env gene sequences grouped in three or four phylogenetic clusters, respectively. The sequences from the Brazilian isolates had similar mutation rates as compared to samples from other countries, and belonged to at least two phylogenetic clusters.
Collapse
Affiliation(s)
- Marcelo Fernandes Camargos
- Setor de Virologia do Laboratório Nacional Agropecuário de Minas Gerais, Av. Rômulo Joviano s/n Caixa Postal 50, Pedro Leopoldo, MG, Brasil CEP. 33.600-000.
| | | | | | | | | | | | | |
Collapse
|
14
|
Gillet N, Florins A, Boxus M, Burteau C, Nigro A, Vandermeers F, Balon H, Bouzar AB, Defoiche J, Burny A, Reichert M, Kettmann R, Willems L. Mechanisms of leukemogenesis induced by bovine leukemia virus: prospects for novel anti-retroviral therapies in human. Retrovirology 2007; 4:18. [PMID: 17362524 PMCID: PMC1839114 DOI: 10.1186/1742-4690-4-18] [Citation(s) in RCA: 242] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2007] [Accepted: 03/16/2007] [Indexed: 12/15/2022] Open
Abstract
In 1871, the observation of yellowish nodules in the enlarged spleen of a cow was considered to be the first reported case of bovine leukemia. The etiological agent of this lymphoproliferative disease, bovine leukemia virus (BLV), belongs to the deltaretrovirus genus which also includes the related human T-lymphotropic virus type 1 (HTLV-1). This review summarizes current knowledge of this viral system, which is important as a model for leukemogenesis. Recently, the BLV model has also cast light onto novel prospects for therapies of HTLV induced diseases, for which no satisfactory treatment exists so far.
Collapse
Affiliation(s)
- Nicolas Gillet
- Molecular and Cellular Biology, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium
| | - Arnaud Florins
- Molecular and Cellular Biology, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium
| | - Mathieu Boxus
- Molecular and Cellular Biology, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium
| | - Catherine Burteau
- Molecular and Cellular Biology, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium
| | - Annamaria Nigro
- Molecular and Cellular Biology, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium
| | - Fabian Vandermeers
- Molecular and Cellular Biology, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium
| | - Hervé Balon
- Molecular and Cellular Biology, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium
| | - Amel-Baya Bouzar
- Molecular and Cellular Biology, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium
| | - Julien Defoiche
- Molecular and Cellular Biology, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium
| | - Arsène Burny
- Molecular and Cellular Biology, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium
| | | | - Richard Kettmann
- Molecular and Cellular Biology, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium
| | - Luc Willems
- Molecular and Cellular Biology, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium
- Luc Willems, National fund for Scientific Research, Molecular and Cellular Biology laboratory, 13 avenue Maréchal Juin, 5030 Gembloux, Belgium
| |
Collapse
|
15
|
Okada K, Nakae N, Kuramochi K, Yin SA, Ikeda M, Takami S, Hirata TI, Goryo M, Numakunai S, Takeshima SN, Takahashi M, Tajima S, Konnai S, Onuma M, Aida Y. Bovine leukemia virus high tax molecular clone experimentally induces leukemia/lymphoma in sheep. J Vet Med Sci 2006; 67:1231-5. [PMID: 16397381 DOI: 10.1292/jvms.67.1231] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Sheep were inoculated with high tax coded pBLV-IF (H group, Nos.1-5) of bovine leukemia virus (BLV), wild tax coded pBLV-IF (W group, Nos. 6-11), or control plasmid (C group, Nos. 12-14). During the observation period (4 to 46 months), 5 of 5 cases in H group and 3 of 6 cases (Nos. 6, 7, 9) in W group became positive for gp 51. Only 1 case in H group became leukemic, and one case each of H and W groups developed lymphoma. In No. 3, lesions were found in multiple organs including the lymph nodes, gastrointestinal tract following abomasum, and heart. In No. 6, lesions of lymphoma were found only in the jejunum and heart. Morphologically, small to middle-sized lymphocytic neoplastic (NP) cells were found in both cases, but lymphoblastic NP cells were found only in No. 3. By immunohistochemical examination, the phenotypes of NP cells were determined as CD1-, CD4-, CD5- -, CD8alpha-, sIgM+, lambda light chain+, B-B4+, MHC class II+ in both case. The results of this study indicate that inoculation of pBLV-IF can induce lymphocytic and lymphoblastic leukemia/lymphoma in sheep. Additionally, it is suggested that the expression rate of tax gene is not associated with the development of leukemia/lymphoma in sheep experimentally inoculated with pBLV-IF.
Collapse
Affiliation(s)
- Kosuke Okada
- Department of Veterinary Pathology, Faculty of Agriculture, Iwate University, Iwate, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Debacq C, Sanchez Alcaraz MT, Mortreux F, Kerkhofs P, Kettmann R, Willems L. Reduced proviral loads during primo-infection of sheep by Bovine Leukemia virus attenuated mutants. Retrovirology 2004; 1:31. [PMID: 15462678 PMCID: PMC526217 DOI: 10.1186/1742-4690-1-31] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2004] [Accepted: 10/05/2004] [Indexed: 11/23/2022] Open
Abstract
Background The early stages consecutive to infection of sheep (e.g. primo-infection) by Bovine leukemia virus mutants are largely unknown. In order to better understand the mechanisms associated with this period, we aimed at analyzing simultaneously three parameters: B-lymphocytosis, cell proliferation and viral replication. Results Sheep were experimentally infected either with a wild type BLV provirus or with selected mutants among which: a virus harboring an optimalized LTR promoter with consensus cyclic AMP-responsive elements, two deletants of the R3 or the G4 accessory genes and a fusion-deficient transmembrane recombinant. Seroconversion, as revealed by the onset of an anti-viral antibody response, was detected at 3 to 11 weeks after inoculation. At seroconversion, all sheep exhibited a marked increase in the numbers of circulating B lymphocytes expressing the CD5 and CD11b cluster of differentiation markers and, interestingly, this phenomenon occurred independently of the type of virus. The net increase of the absolute number of B cells was at least partially due to accelerated proliferation as revealed, after intravenous injection of bromodeoxyuridine, by the higher proportion of circulating BrdU+ B lymphocytes. BLV proviral DNA was detected by polymerase chain reaction in the leucocytes of all sheep, as expected. However, at seroconversion, the proviral loads were lower in sheep infected by the attenuated proviruses despite similar levels of B cell lymphocytosis. Conclusions We conclude that the proviral loads are not directly linked to the extent of B cell proliferation observed during primo-infection of BLV-infected sheep. We propose a model of opportunistic replication of the virus supported by a general activation process of B lymphocytes.
Collapse
Affiliation(s)
| | | | - Franck Mortreux
- Unité d'Oncogenèse Virale, CNRS UMR5537, Centre Léon Bérard, Lyon, France
| | - Pierre Kerkhofs
- Department of Virology, Veterinary and Agrochemical Research Centre, Uccle, Belgium
| | | | - Luc Willems
- Molecular and cellular biology, FUSAGx, Gembloux, Belgium
| |
Collapse
|
17
|
Novakovic S, Sawai ET, Radke K. Dileucine and YXXL motifs in the cytoplasmic tail of the bovine leukemia virus transmembrane envelope protein affect protein expression on the cell surface. J Virol 2004; 78:8301-11. [PMID: 15254202 PMCID: PMC446140 DOI: 10.1128/jvi.78.15.8301-8311.2004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2003] [Accepted: 03/12/2004] [Indexed: 12/17/2022] Open
Abstract
Several retroviruses downmodulate the cell surface expression of envelope (Env) proteins through peptide sequences located in the cytoplasmic tail of the transmembrane (TM) subunit. We investigated whether cell surface expression of a chimeric protein containing the cytoplasmic domain of the TM protein (CTM) of bovine leukemia virus (BLV) was regulated by two membrane-proximal dileucine motifs or by tyrosine Y487 or Y498 in YXXL motifs. A chimeric protein composed of the extracellular and membrane-spanning portions of human CD8-alpha plus a wild-type (wt) BLV CTM was detectable on the surface of only 40% of the cells in which it was transiently expressed. Replacement of either dileucine pair with alanines increased the level of surface display of chimeric proteins. Nearly all cells became surface positive when both dileucine motifs were altered simultaneously and when either an N-terminal segment containing both dileucine motifs or a C-terminal segment containing all YXXL motifs was deleted. In contrast, replacement of Y487 or Y498 with alanine or phenylalanine enabled only small increases in surface display compared with wt levels. Chimeric proteins had similar stabilities but were downmodulated from the cell surface at three different rates. Point mutants segregated into each of the three groups of proteins categorized according to these different rates. Interestingly, Y487 mutants were downmodulated less efficiently than Y498 mutants, which behaved like wt. CD8-CTM chimeric proteins were phosphorylated on serine residues, but the native BLV Env protein was not phosphorylated either in transfected cells or in a lymphoid cell line constitutively producing BLV. Thus, both dileucine and YXXL motifs within the BLV CTM contribute to downmodulation of a protein containing this domain. Interactions with other proteins may influence surface exposure of Env protein complexes in virus-infected cells, assisting in viral evasion of adaptive immunity.
Collapse
Affiliation(s)
- Sinisa Novakovic
- Department of Animal Science, University of California, Davis, Davis, CA 95616-8521, USA
| | | | | |
Collapse
|
18
|
Sundaram R, Lynch MP, Rawale SV, Sun Y, Kazanji M, Kaumaya PTP. De Novo Design of Peptide Immunogens That Mimic the Coiled Coil Region of Human T-cell Leukemia Virus Type-1 Glycoprotein 21 Transmembrane Subunit for Induction of Native Protein Reactive Neutralizing Antibodies. J Biol Chem 2004; 279:24141-51. [PMID: 15060075 DOI: 10.1074/jbc.m313210200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Peptide vaccines able to induce high affinity and protective neutralizing antibodies must rely in part on the design of antigenic epitopes that mimic the three-dimensional structure of the corresponding region in the native protein. We describe the design, structural characterization, immunogenicity, and neutralizing potential of antibodies elicited by conformational peptides derived from the human T-cell leukemia virus type 1 (HTLV-1) gp21 envelope glycoprotein spanning residues 347-374. We used a novel template design and a unique synthetic approach to construct two peptides (WCCR2T and CCR2T) that would each assemble into a triple helical coiled coil conformation mimicking the gp21 crystal structure. The peptide B-cell epitopes were grafted onto the epsilon side chains of three lysyl residues on a template backbone construct consisting of the sequence acetyl-XGKGKGKGCONH2 (where X represents the tetanus toxoid promiscuous T cell epitope (TT) sequence 580-599). Leucine substitutions were introduced at the a and d positions of the CCR2T sequence to maximize helical character and stability as shown by circular dichroism and guanidinium hydrochloride studies. Serum from an HTLV-1-infected patient was able to recognize the selected epitopes by enzyme-linked immunosorbent assay (ELISA). Mice immunized with the wild-type sequence (WCCR2T) and the mutant sequence (CCR2T) elicited high antibody titers that were capable of recognizing the native protein as shown by flow cytometry and whole virus ELISA. Sera and purified antibodies from immunized mice were able to reduce the formation of syncytia induced by the envelope glycoprotein of HTLV-1, suggesting that antibodies directed against the coiled coil region of gp21 are capable of disrupting cell-cell fusion. Our results indicate that these peptides represent potential candidates for use in a peptide vaccine against HTLV-1.
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- Binding, Competitive
- COS Cells
- Cell Line
- Cells, Cultured
- Circular Dichroism
- Crystallography, X-Ray
- Dose-Response Relationship, Drug
- Dose-Response Relationship, Immunologic
- Enzyme-Linked Immunosorbent Assay
- Epitopes/chemistry
- Female
- Flow Cytometry
- Gene Products, env/chemistry
- Gene Products, env/immunology
- Guanidine/chemistry
- Guanidine/pharmacology
- HTLV-I Antibodies/chemistry
- HTLV-I Antibodies/immunology
- HeLa Cells
- Human T-lymphotropic virus 1/metabolism
- Humans
- Leucine/chemistry
- Mice
- Mice, Inbred ICR
- Molecular Sequence Data
- Peptides/chemistry
- Protein Conformation
- Protein Structure, Tertiary
- Recombinant Proteins/chemistry
- Retroviridae Proteins, Oncogenic/chemistry
- Retroviridae Proteins, Oncogenic/immunology
- Temperature
- Vaccines, Subunit/chemistry
- beta-Galactosidase/metabolism
- env Gene Products, Human Immunodeficiency Virus
Collapse
Affiliation(s)
- Roshni Sundaram
- Peptide and Protein Engineering Laboratory, Department of Obstetrics and Gynecology, Division of Vaccine Research, The Ohio State University, Columbus, Ohio 43210, USA
| | | | | | | | | | | |
Collapse
|
19
|
Johnston ER, Albritton LM, Radke K. Envelope proteins containing single amino acid substitutions support a structural model of the receptor-binding domain of bovine leukemia virus surface protein. J Virol 2002; 76:10861-72. [PMID: 12368329 PMCID: PMC136609 DOI: 10.1128/jvi.76.21.10861-10872.2002] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Functional domains of the strikingly conserved envelope (Env) glycoproteins of bovine leukemia virus (BLV) and its close relative, human T-cell leukemia virus type 1 (HTLV-1), are still being defined. We have used BLV Env protein variants to gain insights into the structure and function of this important determinant of viral infectivity. Each of 23 different single amino acid variants found in cDNA clones of env transcripts present after short-term culture of peripheral blood mononuclear cells from BLV-infected sheep was expressed in COS-1 cells and tested for the ability to mediate cell fusion and to be cleaved to surface (SU) and transmembrane (TM) protein subunits. Of 11 Env variants that failed to induce syncytia or did so poorly, 7 contained changes in amino acids identical or chemically conserved in the HTLV-1 Env protein. These seven included the four variants that showed aberrant proteolytic cleavage and poor cell surface expression, underscoring their importance for Env structure. Ten of 12 variants that retained wild-type syncytium-inducing ability clustered in the N-terminal half of BLV SU, which forms the putative receptor-binding domain (RBD). Several variants in the RBD showed evidence of subtle misfolding, as judged by reduced binding to monoclonal antibodies recognizing conformational epitopes F, G, and H formed by the N terminus of SU. We modeled the BLV RBD by aligning putative structural elements with known elements of the ecotropic Friend murine leukemia virus RBD monomer. All the variant RBD residues but one are exposed on the surface of this BLV model. These variants as well as function-altering, antibody-reactive residues defined by other investigators group on one face of the molecular model. They are strikingly absent from the opposite face, implying that it is likely to face inward in Env complexes. This surface might interact with the C-terminal domain of SU or with an adjacent monomer in the Env oligomer. This location suggests an orientation for the monomer of ecotropic Friend murine leukemia virus RBD.
Collapse
Affiliation(s)
- Elizabeth R Johnston
- Department of Animal Science and Graduate Group in Biochemistry and Molecular Biology, University of California, Davis, California 95616, USA
| | | | | |
Collapse
|
20
|
Gatot JS, Callebaut I, Van Lint C, Demonté D, Kerkhofs P, Portetelle D, Burny A, Willems L, Kettmann R. Bovine leukemia virus SU protein interacts with zinc, and mutations within two interacting regions differently affect viral fusion and infectivity in vivo. J Virol 2002; 76:7956-67. [PMID: 12134000 PMCID: PMC155115 DOI: 10.1128/jvi.76.16.7956-7967.2002] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2002] [Accepted: 05/10/2002] [Indexed: 11/20/2022] Open
Abstract
Bovine leukemia virus (BLV) and human T-cell lymphotropic virus type 1 (HTLV-1) belong to the genus of deltaretroviruses. Their entry into the host cell is supposed to be mediated by interactions of the extracellular (SU) envelope glycoproteins with cellular receptors. To gain insight into the mechanisms governing this process, we investigated the ability of SU proteins to interact with specific ligands. In particular, by affinity chromatography, we have shown that BLV SU protein specifically interacted with zinc ions. To identify the protein domains involved in binding, 16 peptides distributed along the sequence were tested. Two of them appeared to be able to interact with zinc. To unravel the role of these SU regions in the biology of the virus, mutations were introduced into the env gene of a BLV molecular clone in order to modify residues potentially interacting with zinc. The fusogenic capacity of envelope mutated within the first zinc-binding region (104 to 123) was completely abolished. Furthermore, the integrity of this domain was also required for in vivo infectivity. In contrast, mutations within the second zinc-binding region (218 to 237) did not hamper the fusogenic capacity; indeed, the syncytia were even larger. In sheep, mutations in region 218 to 237 did not alter infectivity or viral spread. Finally, we demonstrated that the envelope of the related HTLV-1 was also able to bind zinc. Interestingly, zinc ions were found to be associated with the receptor-binding domain (RBD) of Friend murine leukemia virus (Fr-MLV) SU glycoprotein, further supporting their relevance in SU structure. Based on the sequence similarities shared with the Fr-MLV RBD, whose three-dimensional structure has been experimentally determined, we located the BLV zinc-binding peptide 104-123 on the opposite side of the potential receptor-binding surface. This observation supports the hypothesis that zinc ions could mediate interactions of the SU RBD either with the C-terminal part of SU, thereby contributing to the SU structural integrity, or with a partner(s) different from the receptor.
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Binding Sites/genetics
- Cattle
- Cells, Cultured
- Cricetinae
- Cysteine/chemistry
- DNA, Viral/genetics
- Enzootic Bovine Leukosis/etiology
- Gene Products, env/genetics
- Gene Products, env/physiology
- Human T-lymphotropic virus 1/physiology
- Humans
- Leukemia Virus, Bovine/genetics
- Leukemia Virus, Bovine/pathogenicity
- Leukemia Virus, Bovine/physiology
- Membrane Fusion
- Models, Molecular
- Molecular Sequence Data
- Mutation
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- Retroviridae Proteins, Oncogenic/genetics
- Retroviridae Proteins, Oncogenic/physiology
- Transfection
- Viral Envelope Proteins/chemistry
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/physiology
- Virulence
- Zinc/metabolism
Collapse
Affiliation(s)
- Jean-Stéphane Gatot
- Unité de Biologie Cellulaire et Moléculaire, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Willems L, Burny A, Collete D, Dangoisse O, Dequiedt F, Gatot JS, Kerkhofs P, Lefèbvre L, Merezak C, Peremans T, Portetelle D, Twizere JC, Kettmann R. Genetic determinants of bovine leukemia virus pathogenesis. AIDS Res Hum Retroviruses 2000; 16:1787-95. [PMID: 11080828 DOI: 10.1089/08892220050193326] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The understanding of HTLV-induced disease is hampered by the lack of a suitable animal model allowing the study of both viral replication and leukemogenesis in vivo. Although valuable information has been obtained in different species, such as rabbits, mice, rats, and monkeys, none of these systems was able to conciliate topics as different as viral infectivity, propagation within the host, and generation of leukemic cells. An alternate strategy is based on the understanding of diseases induced by viruses closely related to HTLV-1, like bovine leukemia virus (BLV). Both viruses indeed belong to the same subfamily of retroviruses, harbor a similar genomic organization, and infect and transform cells of the hematopoietic system. The main advantage of the BLV system is that it allows direct experimentation in two different species, cattle and sheep.
Collapse
Affiliation(s)
- L Willems
- Department of Applied Biochemistry and Biology, Faculty of Agronomy, B5030 Gembloux, Belgium.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Johnston ER, Radke K. The SU and TM envelope protein subunits of bovine leukemia virus are linked by disulfide bonds, both in cells and in virions. J Virol 2000; 74:2930-5. [PMID: 10684314 PMCID: PMC111788 DOI: 10.1128/jvi.74.6.2930-2935.2000] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
After the polyprotein precursor of retroviral envelope proteins is proteolytically cleaved, the surface (SU) and transmembrane (TM) subunits remain associated with each other by noncovalent interactions or by disulfide bonds. Disulfide linkages confer a relatively stable association between the SU and TM envelope protein subunits of Rous sarcoma virus and murine leukemia virus. In contrast, the noncovalent association between SU and TM of human immunodeficiency virus leads to significant shedding of SU from the surface of infected cells. The SU and TM proteins of bovine leukemia virus (BLV) initially were reported to be disulfide linked but later were concluded not to be, since TM is often lost during purification of SU protein. Here, we show that SU and TM of BLV do, indeed, associate through disulfide bonds, whether the envelope proteins are overexpressed in transfected cells, are produced in virus-infected cells, or are present in newly produced virions.
Collapse
Affiliation(s)
- E R Johnston
- Department of Animal Science and Graduate Group in Biochemistry and Molecular Biology, University of California, Davis, California 95616-8521, USA
| | | |
Collapse
|