1
|
Analysis of Nucleotide Sequence of Tax, miRNA and LTR of Bovine Leukemia Virus in Cattle with Different Levels of Persistent Lymphocytosis in Russia. Pathogens 2021; 10:pathogens10020246. [PMID: 33672613 PMCID: PMC7924208 DOI: 10.3390/pathogens10020246] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/10/2021] [Accepted: 02/18/2021] [Indexed: 11/17/2022] Open
Abstract
Bovine Leukemia Virus (BLV) is the etiological agent of enzootic bovine leucosis (EBL), a lymphoproliferative disease of the bovine species. In BLV-infected cells, the long terminal repeat (LTR), the viral Tax protein and viral miRNAs promote viral and cell proliferation as well as tumorigenesis. Although their respective roles are decisive in BLV biology, little is known about the genetic sequence variation of these parts of the BLV genome and their impact on disease outcome. Therefore, the objective of this study was to assess the relationship between disease progression and sequence variation of the BLV Tax, miRNA and LTR regions in infected animals displaying either low or high levels of persistent lymphocytosis (PL). A statistically significant association was observed between the A(+187)C polymorphism in the downstream activator sequence (DAS) region in LTR (p-value = 0.00737) and high lymphocytosis. Our study also showed that the mutation A(−4)G in the CAP site occurred in 70% of isolates with low PL and was not found in the high PL group. Conversely, the mutations G(−133)A/C in CRE2 (46.7%), C(+160)T in DAS (30%) and A(310)del in BLV-mir-B4-5p, A(357)G in BLV-mir-B4-3p, A(462)G in BLV-mir-B5-5p, and GA(497–498)AG in BLV-mir-B5-3p (26.5%) were often seen in isolates with high PL and did not occur in the low PL group. In conclusion, we found several significant polymorphisms among BLV genomic sequences in Russia that would explain a progression towards higher or lower lymphoproliferation. The data presented in this article enabled the classification between two different genotypes; however, clear association between genotypes and the PL development was not found.
Collapse
|
2
|
Abdala A, Alvarez I, Brossel H, Calvinho L, Carignano H, Franco L, Gazon H, Gillissen C, Hamaidia M, Hoyos C, Jacques JR, Joris T, Laval F, Petersen M, Porquet F, Porta N, Ruiz V, Safari R, Suárez Archilla G, Trono K, Willems L. BLV: lessons on vaccine development. Retrovirology 2019; 16:26. [PMID: 31590667 PMCID: PMC6781361 DOI: 10.1186/s12977-019-0488-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 09/10/2019] [Indexed: 01/12/2023] Open
Abstract
Vaccination against retroviruses is a challenge because of their ability to stably integrate into the host genome, undergo long-term latency in a proportion of infected cells and thereby escape immune response. Since clearance of the virus is almost impossible once infection is established, the primary goal is to achieve sterilizing immunity. Besides efficacy, safety is the major issue since vaccination has been associated with increased infection or reversion to pathogenicity. In this review, we discuss the different issues that we faced during the development of an efficient vaccine against bovine leukemia virus (BLV). We summarize the historical failures of inactivated vaccines, the efficacy and safety of a live-attenuated vaccine and the economical constraints of further industrial development.
Collapse
Affiliation(s)
- Alejandro Abdala
- Estacion Experimental Agropecuaria Rafaela, INTA, 2300, Rafaela, Argentina
| | - Irene Alvarez
- Instituto de Virología e Innovaciones tecnológicas, Centro de Investigaciones en Ciencias Veterinarias y Agronómicas, INTA-CONICET, C.C. 1712, Castelar, Argentina
| | - Hélène Brossel
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (TERRA), University of Liège (ULiège), 4000, Liege, Belgium
| | - Luis Calvinho
- Estacion Experimental Agropecuaria Rafaela, INTA, 2300, Rafaela, Argentina
| | - Hugo Carignano
- Instituto de Virología e Innovaciones tecnológicas, Centro de Investigaciones en Ciencias Veterinarias y Agronómicas, INTA-CONICET, C.C. 1712, Castelar, Argentina
| | - Lautaro Franco
- Instituto de Virología e Innovaciones tecnológicas, Centro de Investigaciones en Ciencias Veterinarias y Agronómicas, INTA-CONICET, C.C. 1712, Castelar, Argentina
| | - Hélène Gazon
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (TERRA), University of Liège (ULiège), 4000, Liege, Belgium
| | - Christelle Gillissen
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (TERRA), University of Liège (ULiège), 4000, Liege, Belgium
| | - Malik Hamaidia
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (TERRA), University of Liège (ULiège), 4000, Liege, Belgium
| | - Clotilde Hoyos
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (TERRA), University of Liège (ULiège), 4000, Liege, Belgium
| | - Jean-Rock Jacques
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (TERRA), University of Liège (ULiège), 4000, Liege, Belgium
| | - Thomas Joris
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (TERRA), University of Liège (ULiège), 4000, Liege, Belgium
| | - Florent Laval
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (TERRA), University of Liège (ULiège), 4000, Liege, Belgium
| | - Marcos Petersen
- Instituto de Virología e Innovaciones tecnológicas, Centro de Investigaciones en Ciencias Veterinarias y Agronómicas, INTA-CONICET, C.C. 1712, Castelar, Argentina
| | - Florent Porquet
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (TERRA), University of Liège (ULiège), 4000, Liege, Belgium
| | - Natalia Porta
- Instituto de Virología e Innovaciones tecnológicas, Centro de Investigaciones en Ciencias Veterinarias y Agronómicas, INTA-CONICET, C.C. 1712, Castelar, Argentina
| | - Vanesa Ruiz
- Instituto de Virología e Innovaciones tecnológicas, Centro de Investigaciones en Ciencias Veterinarias y Agronómicas, INTA-CONICET, C.C. 1712, Castelar, Argentina
| | - Roghaiyeh Safari
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (TERRA), University of Liège (ULiège), 4000, Liege, Belgium
| | | | - Karina Trono
- Instituto de Virología e Innovaciones tecnológicas, Centro de Investigaciones en Ciencias Veterinarias y Agronómicas, INTA-CONICET, C.C. 1712, Castelar, Argentina
| | - Luc Willems
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (TERRA), University of Liège (ULiège), 4000, Liege, Belgium. .,Molecular and Cellular Epigenetics, Interdisciplinary Cluster for Applied Genoproteomics (GIGA) of University of Liège (ULiège), B34, 1 avenue de l'Hôpital, Sart-Tilman, 4000, Liege, Belgium.
| |
Collapse
|
3
|
Inoue E, Matsumura K, Soma N, Hirasawa S, Wakimoto M, Arakaki Y, Yoshida T, Osawa Y, Okazaki K. L233P mutation of the Tax protein strongly correlated with leukemogenicity of bovine leukemia virus. Vet Microbiol 2013; 167:364-71. [PMID: 24139177 DOI: 10.1016/j.vetmic.2013.09.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 09/11/2013] [Accepted: 09/17/2013] [Indexed: 10/26/2022]
Abstract
The bovine leukemia virus (BLV) Tax protein is believed to play a crucial role in leukemogenesis by the virus. BLV usually causes asymptomatic infections in cattle, but only one-third develop persistent lymphocytosis that rarely progress after a long incubation period to lymphoid tumors, namely enzootic bovine leucosis (EBL). In the present study, we demonstrated that the BLV tax genes could be divided into two alleles and developed multiplex PCR detecting an L233P mutation of the Tax protein. Then, in order to define the relationship between the Tax protein and leukemogenicity, we examined 360 tumor samples randomly collected from dairy or breeding cattle in Japan, of which Tax proteins were categorized, for age at the time of diagnosis of EBL. The ages of 288 animals (80.0%) associated with L233-Tax and those of 70 animals (19.4%) with P233-Tax individually followed log-normal distributions. Only the two earliest cases (0.6%) with L233-Tax disobeyed the log-normal distribution. These findings suggest that the animals affected by EBL were infected with the virus at a particular point in life, probably less than a few months after birth. Median age of those with P233-Tax was 22 months older than that with L233-Tax and geometric means exhibited a significant difference (P<0.01). It is also quite unlikely that viruses carrying the particular Tax protein infect older cattle. Here, we conclude that BLV could be divided into two categories on the basis of amino acid at position 233 of the Tax protein, which strongly correlated with leukemogenicity.
Collapse
Affiliation(s)
- Emi Inoue
- Laboratory of Microbiology and Immunology, Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061-0293, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Panei CJ, Serena MS, Metz GE, Bravi ME, González ET, Echeverría MG. Analysis of the pX region of bovine leukemia virus in different clinical stages of Enzootic Bovine Leukemia in Argentine Holstein cattle. Virus Res 2013; 171:97-102. [DOI: 10.1016/j.virusres.2012.08.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 07/31/2012] [Accepted: 08/06/2012] [Indexed: 11/15/2022]
|
5
|
Pomier C, Alcaraz MTS, Debacq C, Lançon A, Kerkhofs P, Willems L, Wattel E, Mortreux F. A dose-effect relationship for deltaretrovirus-dependent leukemogenesis in sheep. Retrovirology 2009; 6:30. [PMID: 19344505 PMCID: PMC2670259 DOI: 10.1186/1742-4690-6-30] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Accepted: 04/03/2009] [Indexed: 01/07/2023] Open
Abstract
Background Retrovirus-induced tumors develop in a broad range of frequencies and after extremely variable periods of time, from only a few days to several decades, depending mainly on virus type. For hitherto unexplained reasons, deltaretroviruses cause hematological malignancies only in a minority of naturally infected organisms and after a very prolonged period of clinical latency. Results Here we demonstrate that the development of malignancies in sheep experimentally infected with the deltaretrovirus bovine leukemia virus (BLV) depends only on the level of BLV replication. Animals were experimentally infected with leukemogenic or attenuated, but infectious, BLV molecular clones and monitored prospectively through 8 months for viral replication. As early as 2 weeks after infection and subsequently at any time during follow-up, leukemogenic viruses produced significantly higher absolute levels of reverse transcription (RT), clonal expansion of infected cells, and circulating proviruses with RT- and somatic-dependent mutations than attenuated viruses. These differences were only quantitative, and both kinds of viruses triggered parallel temporal fluctuations of host lymphoid cells, viral loads, infected cell clonality and proliferation. Conclusion Deltaretrovirus-associated leukemogenesis in sheep appears to be a two-hit process over time depending on the amounts of first horizontally and then vertically expanded viruses.
Collapse
Affiliation(s)
- Carole Pomier
- CNRS FRE-3011-Université Lyon I, Oncovirologie et Biothérapies, Centre Léon Bérard, Lyon, France.
| | | | | | | | | | | | | | | |
Collapse
|
6
|
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: 1.6] [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
|
7
|
Nguyên TLA, de Walque S, Veithen E, Dekoninck A, Martinelli V, de Launoit Y, Burny A, Harrod R, Van Lint C. Transcriptional regulation of the bovine leukemia virus promoter by the cyclic AMP-response element modulator tau isoform. J Biol Chem 2007; 282:20854-67. [PMID: 17526487 DOI: 10.1074/jbc.m703060200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bovine leukemia virus (BLV) expression is controlled at the transcriptional level through three Tax(BLV)-responsive elements (TxREs) responsive to the viral transactivator Tax(BLV). The cAMP-responsive element (CRE)-binding protein (CREB) has been shown to interact with CRE-like sequences present in the middle of each of these TxREs and to play critical transcriptional roles in both basal and Tax(BLV)-transactivated BLV promoter activity. In this study, we have investigated the potential involvement of the cAMP-response element modulator (CREM) in BLV transcriptional regulation, and we have demonstrated that CREM proteins were expressed in BLV-infected cells and bound to the three BLV TxREs in vitro. Chromatin immunoprecipitation assays using BLV-infected cell lines demonstrated in the context of chromatin that CREM proteins were recruited to the BLV promoter TxRE region in vivo. Functional studies, in the absence of Tax(BLV), indicated that ectopic CREMtau protein had a CRE-dependent stimulatory effect on BLV promoter transcriptional activity. Cross-link of the B-cell receptor potentiated CREMtau transactivation of the viral promoter. Further experiments supported the notion that this potentiation involved CREMtau Ser-117 phosphorylation and recruitment of CBP/p300 to the BLV promoter. Although CREB and Tax(BLV) synergistically transactivated the BLV promoter, CREMtau repressed this Tax(BLV)/CREB synergism, suggesting that a modulation of the level of Tax(BLV) transactivation through opposite actions of CREB and CREMtau could facilitate immune escape and allow tumor development.
Collapse
Affiliation(s)
- Thi Lien-Anh Nguyên
- Institut de Biologie et de Médecine Moléculaires, Laboratoire de Virologie Moléculaire, Université Libre de Bruxelles, Rue des Profs Jeener et Brachet 12, 6041 Gosselies, Belgium
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
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: 13.4] [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
|
9
|
Twizere JC, Lefèbvre L, Collete D, Debacq C, Urbain P, Heremans H, Jauniaux JC, Burny A, Willems L, Kettmann R. The homeobox protein MSX2 interacts with tax oncoproteins and represses their transactivation activity. J Biol Chem 2005; 280:29804-11. [PMID: 15970589 DOI: 10.1074/jbc.m503674200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bovine leukemia virus (BLV) tax is an essential gene involved in the transcriptional activation of viral expression. Tax is also believed to be implicated in leukemogenesis because of its ability to immortalize primary cells in vitro. To gain insight into the molecular pathways mediating the activities of this important gene, we identified cellular proteins interacting with Tax. By means of a two-hybrid approach, we show that Tax specifically interacts with MSX2, a general repressor of gene expression. GST pull-down experiments and co-immunoprecipitation assays further confirmed binding specificity. Furthermore, the N-terminal residues 1-79 of MSX2 are required for binding, whereas the C-terminal residues 201-267 of MSX2 do not play a critical role. Whereas the oncogenic potential of Tax in primary cells was only slightly affected by overexpression of MSX2, the other function of Tax, namely LTR-dependent transcriptional activation, was inhibited by MSX2 in human HeLa and bovine B-lymphoblastoid (BL3) cell lines. This MSX2 repression function can be counteracted by overexpression of transcription factors CREB2 and RAP74. The Tax/MSX2 interplay thus results in repression of viral transcriptional activation possibly acting as a regulatory feedback loop. Importantly, this viral gene silencing is not strictly associated with a concomitant loss of Tax oncogenicity as measured by its ability to immortalize primary cells. And interestingly, MSX2 also interacts with and inhibits the transactivation function of the related Tax1 protein encoded by the Human T-cell leukemia virus type 1 (HTLV-1).
Collapse
|
10
|
Takahashi M, Tajima S, Takeshima SN, Konnai S, Yin SA, Okada K, Davis WC, Aida Y. Ex vivo survival of peripheral blood mononuclear cells in sheep induced by bovine leukemia virus (BLV) mainly occurs in CD5- B cells that express BLV. Microbes Infect 2005; 6:584-95. [PMID: 15158193 DOI: 10.1016/j.micinf.2004.02.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2003] [Accepted: 02/09/2004] [Indexed: 10/26/2022]
Abstract
Bovine leukemia virus (BLV) is the etiologic agent of enzootic bovine leukosis (EBL). In a previous report, we found that in a sheep model, only CD5(-) B cells proliferated clonally, while CD5(+) B cells rapidly decreased when the disease progressed to the lymphoma stage. We demonstrate here that, although both CD5(+) and CD5(-) B cells, but not CD4(+) T, CD8(+) T and gammadeltaTCR(+)T cells, are protected from spontaneous ex vivo apoptosis in sheep infected with wild-type and a mutant BLV that encodes a mutant Tax D247G protein with elevated trans-activation activity, only CD5(-) B cells become the main target for ex vivo survival when the disease proceeds to the persistent lymphocytotic stage, which showed an increased expansion of the CD5(-) B cells. In addition, we identified, by four-color flow cytometric analysis, that in CD5(-) B cells, the apoptotic rates of cells that expressed wild-type and mutant BLV were greatly decreased compared with those of BLV-negative cells. There was only a slight reduction in the apoptotic rates in BLV-positive cells from CD5(+) B cells. In addition, supernatants from peripheral blood mononuclear cell (PBMC) cultures from wild-type- and mutant BLV-infected sheep mainly protected CD5(-) B cells from spontaneous apoptosis. Our results suggest that, although BLV can protect both CD5(+) and CD5(-) B cells from ex vivo apoptosis, the mechanisms accounting for the ex vivo survival between these two B-cell subsets differ. Therefore, it appears that the phenotypic changes in cells that express CD5 at the lymphoma stage could result from a difference in susceptibility to apoptosis in CD5(+) and CD5(-) B cells in BLV-infected sheep.
Collapse
MESH Headings
- Animals
- Apoptosis
- B-Lymphocyte Subsets/physiology
- B-Lymphocyte Subsets/virology
- CD4 Antigens/analysis
- CD5 Antigens/analysis
- CD8 Antigens/analysis
- Cattle
- Cells, Cultured
- Deltaretrovirus Infections/physiopathology
- Deltaretrovirus Infections/virology
- Disease Progression
- Enzootic Bovine Leukosis/virology
- Flow Cytometry
- Genes, pX
- Leukemia Virus, Bovine/genetics
- Leukemia Virus, Bovine/physiology
- Leukocytes, Mononuclear/physiology
- Leukocytes, Mononuclear/virology
- Mutation, Missense
- Receptors, Antigen, T-Cell, gamma-delta/analysis
- Sheep
Collapse
Affiliation(s)
- Masahiko Takahashi
- Retrovirus Research Unit, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Harms JS, Eakle KA, Kuo LS, Bremel RD, Splitter GA. Comparison of bovine leukemia virus (BLV) and CMV promoter-driven reporter gene expression in BLV-infected and non-infected cells. GENETIC VACCINES AND THERAPY 2004; 2:11. [PMID: 15327692 PMCID: PMC516020 DOI: 10.1186/1479-0556-2-11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2004] [Accepted: 08/24/2004] [Indexed: 11/25/2022]
Abstract
Background Viral promoters are used in mammalian expression vectors because they generally have strong activity in a wide variety of cells of differing tissues and species. Methods The utility of the BLV LTR/promoter (BLVp) for use in mammalian expression vectors was investigated through direct comparison to the CMV promoter (CMVp). Promoter activity was measured using luciferase assays of cell lines from different tissues and species stably transduced with BLVp or CMVp driven luciferase vectors including D17, FLK, BL3.1 and primary bovine B cells. Cells were also modified through the addition of BLV Tax expression vectors and/or BLV infection as well as treatment with trichostatin A (TSA). Results Results indicate the BLV promoter, while having low basal activity compared to the CMV promoter, can be induced to high-levels of activity similar to the CMV promoter in all cells tested. Tax or BLV infection specifically enhanced BLVp activity with no effect on CMVp activity. In contrast, the non-specific activator, TSA, enhanced both BLVp and CMVp activity. Conclusion Based on these data, we conclude the BLV promoter could be very useful for transgene expression in mammalian expression vectors.
Collapse
Affiliation(s)
- Jerome S Harms
- Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison, Madison, WI 53706-1581, USA
| | - Kurt A Eakle
- GALA Biotech, 8137 Forsythia Street, Middleton, WI 53562, USA
| | - Lillian S Kuo
- Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison, Madison, WI 53706-1581, USA
| | - Robert D Bremel
- IoGenetics LLC, 3591 Anderson St., Suite 218, Madison, WI 53704, USA
| | - Gary A Splitter
- Department of Animal Health and Biomedical Sciences, University of Wisconsin-Madison, Madison, WI 53706-1581, USA
| |
Collapse
|
12
|
Alcaraz TS, Kerkhofs P, Reichert M, Kettmann R, Willems L. Involvement of glutathione as a mechanism of indirect protection against spontaneous ex vivo apoptosis associated with bovine leukemia virus. J Virol 2004; 78:6180-9. [PMID: 15163711 PMCID: PMC416522 DOI: 10.1128/jvi.78.12.6180-6189.2004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Viruses have developed strategies to counteract the apoptotic response of the infected host cells. Modulation of apoptosis is also thought to be a major component of viral persistence and progression to leukemia induced by retroviruses like human T-lymphotropic virus type 1 (HTLV-1) and bovine leukemia virus (BLV). Here, we analyzed the mechanism of ex vivo apoptosis occurring after isolation of peripheral blood mononuclear cells from BLV-infected sheep. We show that spontaneous apoptosis of ovine B lymphocytes requires at least in part a caspase 8-dependent pathway regardless of viral infection. Cell death is independent of cytotoxic response and does not involve the tumor necrosis factor alpha/NF-kappaB/nitric oxide synthase/cyclooxygenase pathway. In contrast, pharmaceutical depletion of reduced glutathione (namely, gamma-glutamyl-l-cysteinyl-glycine [GSH]) by using ethacrynic acid or 1-pyrrolidinecarbodithioic acid specifically reverts inhibition of spontaneous apoptosis conferred indirectly by protective BLV-conditioned media; inversely, exogenously provided membrane-permeable GSH-monoethyl ester restores cell viability in B lymphocytes of BLV-infected sheep. Most importantly, intracellular GSH levels correlate with virus-associated protection against apoptosis but not with general inhibition of cell death induced by polyclonal activators, such as phorbol esters and ionomycin. Finally, inhibition of apoptosis does not correlate with the activities of GSH peroxidase and GSH reductase. In summary, our data fit into a model in which modulation of the glutathione system is a key event involved in indirect inhibition of apoptosis associated with BLV. These observations could have decisive effects during therapeutic treatment of delta-retroviral pathogenesis.
Collapse
Affiliation(s)
- Teresa Sanchez Alcaraz
- Molecular and Cellular Biology, Faculty of Agronomy, Gembloux, Department of Virology, Veterinary and Agrochemical Research Centre, Uccle, Belgium, Department of Pathology, National Veterinary Research Institute, Pulawy, Poland
| | - Pierre Kerkhofs
- Molecular and Cellular Biology, Faculty of Agronomy, Gembloux, Department of Virology, Veterinary and Agrochemical Research Centre, Uccle, Belgium, Department of Pathology, National Veterinary Research Institute, Pulawy, Poland
| | - Michal Reichert
- Molecular and Cellular Biology, Faculty of Agronomy, Gembloux, Department of Virology, Veterinary and Agrochemical Research Centre, Uccle, Belgium, Department of Pathology, National Veterinary Research Institute, Pulawy, Poland
| | - Richard Kettmann
- Molecular and Cellular Biology, Faculty of Agronomy, Gembloux, Department of Virology, Veterinary and Agrochemical Research Centre, Uccle, Belgium, Department of Pathology, National Veterinary Research Institute, Pulawy, Poland
| | - Luc Willems
- Molecular and Cellular Biology, Faculty of Agronomy, Gembloux, Department of Virology, Veterinary and Agrochemical Research Centre, Uccle, Belgium, Department of Pathology, National Veterinary Research Institute, Pulawy, Poland
- Corresponding author. Mailing address: Molecular and Cellular biology, Faculty of Agronomy (Faculté Universitaire des Sciences Agronomiques, FUSAGx), 13 avenue Maréchal Juin, 5030 Gembloux, Belgium. Phone: 32-81-622157. Fax: 32-81-6133888. E-mail:
| |
Collapse
|
13
|
Affiliation(s)
- N. F. Starodub
- Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine
| | - V. M. Starodub
- Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine
| |
Collapse
|
14
|
Szynal M, Cleuter Y, Beskorwayne T, Bagnis C, Van Lint C, Kerkhofs P, Burny A, Martiat P, Griebel P, Van den Broeke A. Disruption of B-cell homeostatic control mediated by the BLV-Tax oncoprotein: association with the upregulation of Bcl-2 and signaling through NF-kappaB. Oncogene 2003; 22:4531-42. [PMID: 12881710 DOI: 10.1038/sj.onc.1206546] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Transactivating proteins associated with complex onco-retroviruses including human T-cell leukemia virus-1 (HTLV-1) and bovine leukemia virus (BLV) mediate transformation using poorly understood mechanisms. To gain insight into the processes that govern tumor onset and progression, we have examined the impact of BLV-Tax expression on ovine B-cells, the targets of BLV in experimentally infected sheep, using B-cell clones that are dependent on CD154 and gammac-common cytokines. Tax was capable of mediating progression of B-cells from cytokine dependence to cytokine independence, indicating that the transactivator can over-ride signaling pathways typically controlled by cytokine receptor activation in B-cells. When examined in the presence of both CD154 and interleukin-4, Tax had a clear supportive role on B-cell growth, with an impact on B-cell proliferation, cell cycle phase distribution, and survival. Apoptotic B-cell death mediated by growth factor withdrawal, physical insult, and NF-kappaB inhibition was dramatically reduced in the presence of Tax. Furthermore, the expression of Tax was associated with higher Bcl-2 protein levels, providing rationale for the rescue signals mediated by the transactivator. Finally, Tax expression in B-cells led to a dramatic increase of nuclear RelB/p50 and p50/p50 NF-kappaB dimers, indicating that cellular signaling through NF-kappaB is a major contributory mechanism in the disruption of B-cell homeostasis. Although Tax is involved in aspects of pathogenesis that are unique to complex retroviruses, the viral strategies associated with this transactivating oncoprotein may have wide-ranging effects that are relevant to other B-cell malignancies.
Collapse
Affiliation(s)
- Maud Szynal
- Laboratory of Experimental Hematology, Bordet Institute, 1000 Brussels, Belgium
| | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Tajima S, Takahashi M, Takeshima SN, Konnai S, Yin SA, Watarai S, Tanaka Y, Onuma M, Okada K, Aida Y. A mutant form of the tax protein of bovine leukemia virus (BLV), with enhanced transactivation activity, increases expression and propagation of BLV in vitro but not in vivo. J Virol 2003; 77:1894-903. [PMID: 12525624 PMCID: PMC140974 DOI: 10.1128/jvi.77.3.1894-1903.2003] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In a previous study, we identified an interesting mutant form of the Tax protein of bovine leukemia virus (BLV), designated D247G. This mutant protein strongly transactivated the long terminal repeat of BLV and was also able to transactivate the cellular proto-oncogene c-fos. This finding suggested that BLV that encode the mutant protein might propagate and induce lymphoma more efficiently than wild-type BLV. To characterize the effects of the strong transactivation activity of the mutant Tax protein, we constructed an infectious molecular clone of BLV that encoded D247G and examined the replication and propagation of the virus in vitro and in vivo. Cultured cells were transfected with the wild-type and mutant BLV, and then levels of viral proteins and particles and the propagation of viruses were compared. As expected, in vitro, mutant BLV produced more viral proteins and particles and was transmitted very effectively. We injected the wild-type and mutant BLV into sheep, which are easily infected with BLV, and monitored the proportion of BLV-positive cells in the blood and the expression of BLV RNA for 28 weeks. By contrast to the results of our analyses in vitro, we found no significant difference in the viral load or the expression of viral RNA between sheep inoculated with wild-type or mutant BLV. Our observations indicate that the mutant D247G Tax protein does not enhance the expansion of BLV and that there might be a dominant mechanism for regulation of the expression of BLV in vivo.
Collapse
Affiliation(s)
- Shigeru Tajima
- Retrovirus Research Unit, RIKEN, Wako, Saitama 351-0198, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Debacq C, Asquith B, Kerkhofs P, Portetelle D, Burny A, Kettmann R, Willems L. Increased cell proliferation, but not reduced cell death, induces lymphocytosis in bovine leukemia virus-infected sheep. Proc Natl Acad Sci U S A 2002; 99:10048-53. [PMID: 12119390 PMCID: PMC126622 DOI: 10.1073/pnas.142100999] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Lymphocyte homeostasis is the result of a critical balance between cell proliferation and death. Disruption of this subtle equilibrium can lead to the onset of leukemia, an increase in the number of lymphocytes being potentially due to both of these parameters. The relative importance of cell proliferation vs. apoptosis during pathogenesis induced by the primate T cell lymphotropic viruses and bovine leukemia virus (BLV) has been difficult to assess because of conflicting data from a range of in vitro and ex vivo experimental systems. Here, we aim to resolve this issue by measuring the rates of cell proliferation and death in the BLV-ovine system, an animal model of human T lymphotropic virus (HTLV-1). We use a method based on the i.v. injection of 5-bromodeoxyuridine into BLV-infected sheep. We show that B lymphocytes in BLV(+) asymptomatic sheep proliferate significantly faster than in uninfected controls (average proliferation rate: 0.020 per day vs. 0.011 per day). In contrast, the rates of cell death were not significantly different between aleukemic BLV-infected and control sheep (average death rate 0.089 per day vs. 0.094 per day, respectively). We conclude that the increase in the number of B cells during BLV-induced lymphocytosis results from higher proliferation rates but is not due to a significant decrease in apoptosis, in contrast to data from in vitro (ex vivo) experiments. The imbalance created by the net increase in proliferation in the absence of compensating cell death reveals a complex mechanism of feedback regulation controlling homeostasis in the blood compartment.
Collapse
Affiliation(s)
- Christophe Debacq
- Department of Applied Biochemistry and Biology, Faculty of Agronomy, 5030 Gembloux, Belgium
| | | | | | | | | | | | | |
Collapse
|