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Ledesma-Feliciano C, Hagen S, Troyer R, Zheng X, Musselman E, Slavkovic Lukic D, Franke AM, Maeda D, Zielonka J, Münk C, Wei G, VandeWoude S, Löchelt M. Replacement of feline foamy virus bet by feline immunodeficiency virus vif yields replicative virus with novel vaccine candidate potential. Retrovirology 2018; 15:38. [PMID: 29769087 PMCID: PMC5956581 DOI: 10.1186/s12977-018-0419-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 05/03/2018] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Hosts are able to restrict viral replication to contain virus spread before adaptive immunity is fully initiated. Many viruses have acquired genes directly counteracting intrinsic restriction mechanisms. This phenomenon has led to a co-evolutionary signature for both the virus and host which often provides a barrier against interspecies transmission events. Through different mechanisms of action, but with similar consequences, spumaviral feline foamy virus (FFV) Bet and lentiviral feline immunodeficiency virus (FIV) Vif counteract feline APOBEC3 (feA3) restriction factors that lead to hypermutation and degradation of retroviral DNA genomes. Here we examine the capacity of vif to substitute for bet function in a chimeric FFV to assess the transferability of anti-feA3 factors to allow viral replication. RESULTS We show that vif can replace bet to yield replication-competent chimeric foamy viruses. An in vitro selection screen revealed that an engineered Bet-Vif fusion protein yields suboptimal protection against feA3. After multiple passages through feA3-expressing cells, however, variants with optimized replication competence emerged. In these variants, Vif was expressed independently from an N-terminal Bet moiety and was stably maintained. Experimental infection of immunocompetent domestic cats with one of the functional chimeras resulted in seroconversion against the FFV backbone and the heterologous FIV Vif protein, but virus could not be detected unambiguously by PCR. Inoculation with chimeric virus followed by wild-type FFV revealed that repeated administration of FVs allowed superinfections with enhanced antiviral antibody production and detection of low level viral genomes, indicating that chimeric virus did not induce protective immunity against wild-type FFV. CONCLUSIONS Unrelated viral antagonists of feA3 cellular restriction factors can be exchanged in FFV, resulting in replication competence in vitro that was attenuated in vivo. Bet therefore may have additional functions other than A3 antagonism that are essential for successful in vivo replication. Immune reactivity was mounted against the heterologous Vif protein. We conclude that Vif-expressing FV vaccine vectors may be an attractive tool to prevent or modulate lentivirus infections with the potential option to induce immunity against additional lentivirus antigens.
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Affiliation(s)
- Carmen Ledesma-Feliciano
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Sarah Hagen
- Department of Molecular Diagnostics of Oncogenic Infections, Research Program Infection, Inflammation and Cancer, German Cancer Research Center, (Deutsches Krebsforschungszentrum Heidelberg, DKFZ), Im Neuenheimer Feld 242, 69120, Heidelberg, Germany
| | - Ryan Troyer
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.,Department of Microbiology and Immunology, Western University, London, ON, Canada
| | - Xin Zheng
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Esther Musselman
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Dragana Slavkovic Lukic
- Department of Molecular Diagnostics of Oncogenic Infections, Research Program Infection, Inflammation and Cancer, German Cancer Research Center, (Deutsches Krebsforschungszentrum Heidelberg, DKFZ), Im Neuenheimer Feld 242, 69120, Heidelberg, Germany.,Department of Internal Medicine II, Division of Hematology, University Hospital of Würzburg, Würzburg, Germany
| | - Ann-Mareen Franke
- Department of Molecular Diagnostics of Oncogenic Infections, Research Program Infection, Inflammation and Cancer, German Cancer Research Center, (Deutsches Krebsforschungszentrum Heidelberg, DKFZ), Im Neuenheimer Feld 242, 69120, Heidelberg, Germany.,Roche Pharma AG, Grenzach-Wyhlen, Germany
| | - Daniel Maeda
- Department of Molecular Diagnostics of Oncogenic Infections, Research Program Infection, Inflammation and Cancer, German Cancer Research Center, (Deutsches Krebsforschungszentrum Heidelberg, DKFZ), Im Neuenheimer Feld 242, 69120, Heidelberg, Germany.,University of Dar es Salaam, Dar es Salaam, Tanzania
| | - Jörg Zielonka
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.,Roche Glycart AG, Schlieren, 8952, Switzerland
| | - Carsten Münk
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Guochao Wei
- Department of Molecular Diagnostics of Oncogenic Infections, Research Program Infection, Inflammation and Cancer, German Cancer Research Center, (Deutsches Krebsforschungszentrum Heidelberg, DKFZ), Im Neuenheimer Feld 242, 69120, Heidelberg, Germany.,Division of Infectious Disease, University of Colorado, Anschutz Medical Campus, Aurora, USA
| | - Sue VandeWoude
- Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Martin Löchelt
- Department of Molecular Diagnostics of Oncogenic Infections, Research Program Infection, Inflammation and Cancer, German Cancer Research Center, (Deutsches Krebsforschungszentrum Heidelberg, DKFZ), Im Neuenheimer Feld 242, 69120, Heidelberg, Germany.
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James L, Sargueil B. RNA secondary structure of the feline immunodeficiency virus 5'UTR and Gag coding region. Nucleic Acids Res 2008; 36:4653-66. [PMID: 18625613 PMCID: PMC2504303 DOI: 10.1093/nar/gkn447] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The 5′ untranslated region (5′UTR) of lentiviral genomic RNA is highly structured, and is the site of multiple RNA–RNA and RNA–protein interactions throughout the viral life cycle. The 5′UTR plays a critical role during transcription, translational regulation, genome dimerization, reverse transcription priming and encapsidation. The 5′UTR structures of human lentiviruses have been extensively studied, yet the respective role and conformation of each domain is still controversial. To gain insight into the structure-function relationship of lentiviral 5′UTRs, we modelled the RNA structure of the feline immunodeficiency virus (FIV), a virus that is evolutionarily distant from the primate viruses. Through combined chemical and enzymatic structure probing and a thorough phylogenetic study, we establish a model for the secondary structure of the 5′UTR and Gag coding region. This work highlights properties common to all lentiviruses, like the primer binding site structure and the presence of a stable stem-loop at the 5′ extremity. We find that FIV has also evolved specific features, including a long stem loop overlapping the end of the 5′UTR and the beginning of the coding region. In addition, we observed footprints of Gag protein on each side of the initiation codon, this sheds light on the role of the sequences required for encapsidation.
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Affiliation(s)
- Laurie James
- CNRS UPR2167 - Centre de Génétique Moléculaire, Avenue de la Terrasse, 91190 Gif sur yvette, France
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