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Luperchio AM, Jónsson SR, Salamango DJ. Evolutionary Conservation of PP2A Antagonism and G2/M Cell Cycle Arrest in Maedi-Visna Virus Vif. Viruses 2022; 14:v14081701. [PMID: 36016323 PMCID: PMC9413702 DOI: 10.3390/v14081701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/29/2022] [Accepted: 07/29/2022] [Indexed: 11/18/2022] Open
Abstract
The canonical function of lentiviral Vif proteins is to counteract the mutagenic potential of APOBEC3 antiviral restriction factors. However, recent studies have discovered that Vif proteins from diverse HIV-1 and simian immunodeficiency virus (SIV) isolates degrade cellular B56 phosphoregulators to remodel the host phosphoproteome and induce G2/M cell cycle arrest. Here, we evaluate the conservation of this activity among non-primate lentiviral Vif proteins using fluorescence-based degradation assays and demonstrate that maedi-visna virus (MVV) Vif efficiently degrades all five B56 family members. Testing an extensive panel of single amino acid substitution mutants revealed that MVV Vif recognizes B56 proteins through a conserved network of electrostatic interactions. Furthermore, experiments using genetic and pharmacologic approaches demonstrate that degradation of B56 proteins requires the cellular cofactor cyclophilin A. Lastly, MVV Vif-mediated depletion of B56 proteins induces a potent G2/M cell cycle arrest phenotype. Therefore, remodeling of the cellular phosphoproteome and induction of G2/M cell cycle arrest are ancient and conserved functions of lentiviral Vif proteins, which suggests that they are advantageous for lentiviral pathogenesis.
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Affiliation(s)
- Adeline M. Luperchio
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, NY 11794, USA;
| | - Stefán R. Jónsson
- Institute for Experimental Pathology, University of Iceland, Keldur, 112 Reykjavik, Iceland;
| | - Daniel J. Salamango
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, NY 11794, USA;
- Correspondence: ; Tel.: +1-631-632-8472; Fax: +1-631-632-9797
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Nakano Y, Yamamoto K, Ueda MT, Soper A, Konno Y, Kimura I, Uriu K, Kumata R, Aso H, Misawa N, Nagaoka S, Shimizu S, Mitsumune K, Kosugi Y, Juarez-Fernandez G, Ito J, Nakagawa S, Ikeda T, Koyanagi Y, Harris RS, Sato K. A role for gorilla APOBEC3G in shaping lentivirus evolution including transmission to humans. PLoS Pathog 2020; 16:e1008812. [PMID: 32913367 PMCID: PMC7482973 DOI: 10.1371/journal.ppat.1008812] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/15/2020] [Indexed: 12/12/2022] Open
Abstract
The APOBEC3 deaminases are potent inhibitors of virus replication and barriers to cross-species transmission. For simian immunodeficiency virus (SIV) to transmit to a new primate host, as happened multiple times to seed the ongoing HIV-1 epidemic, the viral infectivity factor (Vif) must be capable of neutralizing the APOBEC3 enzymes of the new host. Although much is known about current interactions of HIV-1 Vif and human APOBEC3s, the evolutionary changes in SIV Vif required for transmission from chimpanzees to gorillas and ultimately to humans are poorly understood. Here, we demonstrate that gorilla APOBEC3G is a factor with the potential to hamper SIV transmission from chimpanzees to gorillas. Gain-of-function experiments using SIVcpzPtt Vif revealed that this barrier could be overcome by a single Vif acidic amino acid substitution (M16E). Moreover, degradation of gorilla APOBEC3F is induced by Vif through a mechanism that is distinct from that of human APOBEC3F. Thus, our findings identify virus adaptations in gorillas that preceded and may have facilitated transmission to humans. Humans are exposed continuously to a menace of viral diseases such as Ebola virus and coronaviruses. Such emerging/re-emerging viral outbreaks can be triggered by cross-species viral transmission from wild animals to humans. HIV-1, the causative agent of AIDS, most likely originated from related precursors found in chimpanzees and gorillas (SIVcpzPtt or SIVgor), approximately 100 years ago. Additionally, SIVgor most likely emerged through the cross-species jump of SIVcpzPtt from chimpanzees to gorillas. However, it remains unclear how primate lentiviruses successfully transmitted among different species. To limit cross-species lentiviral transmission, cellular "restriction factors", including tetherin, SAMHD1, and APOBEC3 proteins potentially inhibit lentiviral replication. In contrast, primate lentiviruses have evolutionary acquired their own "arms" to antagonize the antiviral effect of restriction factors. Here we show that gorilla APOBEC3G potentially plays a role in inhibiting SIVcpzPtt replication. To our knowledge, this is the first report suggesting that a great ape APOBEC3 protein can potentially restrict the cross-species transmission of great ape lentiviruses and how lentiviruses overcame this species barrier.
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Affiliation(s)
- Yusuke Nakano
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Keisuke Yamamoto
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Mahoko Takahashi Ueda
- Department of Molecular Life Science, Tokai University School of Medicine, Kanagawa, Japan
| | - Andrew Soper
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Yoriyuki Konno
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Division of Systems Virology, Department of Infectious Disease Control, International Research Center for Infectious Diseases, Institute of Medical Science, the University of Tokyo, Tokyo, Japan
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Izumi Kimura
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Division of Systems Virology, Department of Infectious Disease Control, International Research Center for Infectious Diseases, Institute of Medical Science, the University of Tokyo, Tokyo, Japan
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Keiya Uriu
- Division of Systems Virology, Department of Infectious Disease Control, International Research Center for Infectious Diseases, Institute of Medical Science, the University of Tokyo, Tokyo, Japan
- Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
| | - Ryuichi Kumata
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Division of Systems Virology, Department of Infectious Disease Control, International Research Center for Infectious Diseases, Institute of Medical Science, the University of Tokyo, Tokyo, Japan
- Faculty of Science, Kyoto University, Kyoto, Japan
| | - Hirofumi Aso
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Division of Systems Virology, Department of Infectious Disease Control, International Research Center for Infectious Diseases, Institute of Medical Science, the University of Tokyo, Tokyo, Japan
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Naoko Misawa
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Shumpei Nagaoka
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Division of Systems Virology, Department of Infectious Disease Control, International Research Center for Infectious Diseases, Institute of Medical Science, the University of Tokyo, Tokyo, Japan
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Soma Shimizu
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Keito Mitsumune
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Yusuke Kosugi
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Guillermo Juarez-Fernandez
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Jumpei Ito
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Division of Systems Virology, Department of Infectious Disease Control, International Research Center for Infectious Diseases, Institute of Medical Science, the University of Tokyo, Tokyo, Japan
| | - So Nakagawa
- Department of Molecular Life Science, Tokai University School of Medicine, Kanagawa, Japan
| | - Terumasa Ikeda
- Department of Biochemistry, Molecular Biology and Biophysics, Masonic Cancer Center, Institute for Molecular Virology, Center for Genome Engineering, University of Minnesota, Minneapolis, Minnesota, United States of America
- Howard Hughes Medical Institute, University of Minnesota, Minneapolis, Minnesota, United States of America
- Division of Molecular Virology and Genetics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
| | - Yoshio Koyanagi
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Reuben S. Harris
- Department of Biochemistry, Molecular Biology and Biophysics, Masonic Cancer Center, Institute for Molecular Virology, Center for Genome Engineering, University of Minnesota, Minneapolis, Minnesota, United States of America
- Howard Hughes Medical Institute, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Kei Sato
- Laboratory of Systems Virology, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- Division of Systems Virology, Department of Infectious Disease Control, International Research Center for Infectious Diseases, Institute of Medical Science, the University of Tokyo, Tokyo, Japan
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
- Graduate School of Medicine, the University of Tokyo, Tokyo, Japan
- CREST, Japan Science and Technology Agency, Saitama, Japan
- * E-mail:
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3
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Fu Y, Lu D, Su Y, Chi H, Wang J, Huang J. The Vif protein of caprine arthritis encephalitis virus inhibits interferon production. Arch Virol 2020; 165:1557-1567. [PMID: 32356187 DOI: 10.1007/s00705-020-04637-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 04/01/2020] [Indexed: 11/24/2022]
Abstract
Caprine arthritis-encephalitis (CAE) is a chronic progressive infectious disease caused by caprine arthritis-encephalitis virus (CAEV) that seriously threatens the goat industry. Chronic infection and life-long multi-tissue inflammation are the typical features of the disease. Innate antiviral immunity is essential for the host defense system that rapidly recognizes and eliminates invading viruses. Interferon β (IFN-β) is important for innate immunity and regulates immunity against a broad spectrum of viruses. To investigate the details of the IFN-β response to CAEV infection, the effects of six viral proteins and the molecular mechanisms by which they affect IFN-β production were analyzed. Overexpression of DU and Vif promote virus proliferation and inhibit the production of IFN-β. qRT-PCR and luciferase reporter assays showed that overexpression of Vif inhibits the expression of luciferase under the control of the ISRE, NF-κB or IFN-β promoter but does not affect the expression of IFN-β activated by IRF3, indicating that Vif negatively regulates IFN-β production by affecting upstream signal transduction of IRF3. Amino acids 149-164 of Vif were found to be necessary for the inhibitory effect of IFN-β production. Our results indicate that CAEV evades surveillance and clearance by intracellular innate immunity by downregulating IFN-β production.
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Affiliation(s)
- Yali Fu
- School of Life Sciences, Tianjin University, No. 92, Weijin road, Nankai District, Tianjin, 300072, China
| | - Dong Lu
- School of Life Sciences, Tianjin University, No. 92, Weijin road, Nankai District, Tianjin, 300072, China
| | - Yanxin Su
- School of Life Sciences, Tianjin University, No. 92, Weijin road, Nankai District, Tianjin, 300072, China
| | - Heng Chi
- School of Life Sciences, Tianjin University, No. 92, Weijin road, Nankai District, Tianjin, 300072, China
| | - Jiashun Wang
- School of Life Sciences, Tianjin University, No. 92, Weijin road, Nankai District, Tianjin, 300072, China
| | - Jinhai Huang
- School of Life Sciences, Tianjin University, No. 92, Weijin road, Nankai District, Tianjin, 300072, China.
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4
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Binning JM, Chesarino NM, Emerman M, Gross JD. Structural Basis for a Species-Specific Determinant of an SIV Vif Protein toward Hominid APOBEC3G Antagonism. Cell Host Microbe 2020; 26:739-747.e4. [PMID: 31830442 DOI: 10.1016/j.chom.2019.10.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 09/05/2019] [Accepted: 10/22/2019] [Indexed: 12/31/2022]
Abstract
Primate lentiviruses encode a Vif protein that counteracts the host antiviral APOBEC3 (A3) family members. The adaptation of Vif to species-specific A3 determinants is a critical event that allowed the spillover of a lentivirus from monkey reservoirs to chimpanzees and subsequently to humans, which gave rise to HIV-1 and the acquired immune deficiency syndrome (AIDS) pandemic. How Vif-A3 protein interactions are remodeled during evolution is unclear. Here, we report a 2.94 Å crystal structure of the Vif substrate receptor complex from simian immunodeficiency virus isolated from red-capped mangabey (SIVrcm). The structure of the SIVrcm Vif complex illuminates the stage of lentiviral Vif evolution that is immediately prior to entering hominid primates. Structure-function studies reveal the adaptations that allowed SIVrcm Vif to antagonize hominid A3G. These studies show a partitioning between an evolutionarily dynamic specificity determinant and a conserved protein interacting surface on Vif that enables adaptation while maintaining protein interactions required for potent A3 antagonism.
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Affiliation(s)
- Jennifer M Binning
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Nicholas M Chesarino
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Michael Emerman
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
| | - John D Gross
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA.
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5
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Cano-Ortiz L, Maletich Junqueira D, Comerlato J, Zani A, Santos Costa C, Michel Roehe P, Franco AC. Absence of A3Z3-Related Hypermutations in the env and vif Proviral Genes in FIV Naturally Infected Cats. Viruses 2018; 10:v10060296. [PMID: 29857485 PMCID: PMC6024795 DOI: 10.3390/v10060296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 05/24/2018] [Accepted: 05/27/2018] [Indexed: 11/16/2022] Open
Abstract
Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3 (APOBEC3; A3) proteins comprise an important family of restriction factors that produce hypermutations on proviral DNA and are able to limit virus replication. Vif, an accessory protein present in almost all lentiviruses, counteracts the antiviral A3 activity. Seven haplotypes of APOBEC3Z3 (A3Z3) were described in domestic cats (hap I–VII), and in-vitro studies have demonstrated that these proteins reduce infectivity of vif-defective feline immunodeficiency virus (FIV). Moreover, hap V is resistant to vif-mediated degradation. However, studies on the effect of A3Z3 in FIV-infected cats have not been developed. Here, the correlation between APOBEC A3Z3 haplotypes in domestic cats and the frequency of hypermutations in the FIV vif and env genes were assessed in a retrospective cohort study with 30 blood samples collected between 2012 and 2016 from naturally FIV-infected cats in Brazil. The vif and env sequences were analyzed and displayed low or undetectable levels of hypermutations, and could not be associated with any specific A3Z3 haplotype.
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Affiliation(s)
- Lucía Cano-Ortiz
- Virology Laboratory, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, RS CEP 90150-070, Brazil.
| | - Dennis Maletich Junqueira
- Health Science Department, UniRitter Laureate International Universities, Rua Orfanotrófio, 555, Alto Teresópolis, Porto Alegre, RS CEP 90840-440C, Brazil.
| | - Juliana Comerlato
- Virology Laboratory, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, RS CEP 90150-070, Brazil.
| | - André Zani
- Virology Laboratory, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, RS CEP 90150-070, Brazil.
| | - Cristina Santos Costa
- Virology Laboratory, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, RS CEP 90150-070, Brazil.
| | - Paulo Michel Roehe
- Virology Laboratory, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, RS CEP 90150-070, Brazil.
| | - Ana Cláudia Franco
- Virology Laboratory, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite 500, Porto Alegre, RS CEP 90150-070, Brazil.
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6
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Yoshikawa R, Nakano Y, Yamada E, Izumi T, Misawa N, Koyanagi Y, Sato K. Species-specific differences in the ability of feline lentiviral Vif to degrade feline APOBEC3 proteins. Microbiol Immunol 2016; 60:272-9. [PMID: 26935128 PMCID: PMC5074269 DOI: 10.1111/1348-0421.12371] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 02/21/2016] [Accepted: 02/29/2016] [Indexed: 01/24/2023]
Abstract
How host-virus co-evolutionary relationships manifest is one of the most intriguing issues in virology. To address this topic, the mammal-lentivirus relationship can be considered as an interplay of cellular and viral proteins, particularly apolipoprotein B mRNA editing enzyme catalytic polypeptide-like 3 (APOBEC3) and viral infectivity factor (Vif). APOBEC3s enzymatically restrict lentivirus replication, whereas Vif antagonizes the host anti-viral action mediated by APOBEC3. In this study, the focus was on the interplay between feline APOBEC3 proteins and two feline immunodeficiency viruses in cats and pumas. To our knowledge, this study provides the first evidence of non-primate lentiviral Vif being incapable of counteracting a natural host's anti-viral activity mediated via APOBEC3 protein.
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Affiliation(s)
- Rokusuke Yoshikawa
- Laboratory of Viral PathogenesisInstitute for Virus ResearchKyoto UniversityKyoto6068507
| | - Yusuke Nakano
- Laboratory of Viral PathogenesisInstitute for Virus ResearchKyoto UniversityKyoto6068507
| | - Eri Yamada
- Laboratory of Viral PathogenesisInstitute for Virus ResearchKyoto UniversityKyoto6068507
| | - Taisuke Izumi
- Laboratory of Viral PathogenesisInstitute for Virus ResearchKyoto UniversityKyoto6068507
- CRESTJapan Science and Technology AgencySaitama3220012Japan
| | - Naoko Misawa
- Laboratory of Viral PathogenesisInstitute for Virus ResearchKyoto UniversityKyoto6068507
| | - Yoshio Koyanagi
- Laboratory of Viral PathogenesisInstitute for Virus ResearchKyoto UniversityKyoto6068507
| | - Kei Sato
- Laboratory of Viral PathogenesisInstitute for Virus ResearchKyoto UniversityKyoto6068507
- CRESTJapan Science and Technology AgencySaitama3220012Japan
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Etienne L, Hahn BH, Sharp PM, Matsen FA, Emerman M. Gene loss and adaptation to hominids underlie the ancient origin of HIV-1. Cell Host Microbe 2014; 14:85-92. [PMID: 23870316 DOI: 10.1016/j.chom.2013.06.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 04/26/2013] [Accepted: 05/20/2013] [Indexed: 11/19/2022]
Abstract
HIV-1 resulted from cross-species transmission of SIVcpz, a simian immunodeficiency virus that naturally infects chimpanzees. SIVcpz, in turn, is a recombinant between two SIV lineages from Old World monkeys. Lentiviral interspecies transmissions are partly driven by the evolution and capacity of viral accessory genes, such as vpx, vpr, and vif, to antagonize host antiviral factors, such as SAMHD1 and the APOBEC3 proteins. We show that vpx, which in other lentiviruses antagonizes SAMHD1, was deleted during the creation of SIVcpz. This genomic deletion resulted in the reconstruction of the overlapping vif gene by "overprinting," creating a unique vif that overlaps in its 3' end with the vpr gene and can antagonize hominid APOBEC3s. Moreover, passage of SIVs through chimpanzees facilitated the subsequent adaptation of HIV-1 to humans. Thus, HIV-1 originated through a series of gene loss and adaptation events that generated its chimpanzee precursor and lowered the species barrier to human infection.
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Affiliation(s)
- Lucie Etienne
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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8
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Martins MA, Bonaldo MC, Rudersdorf RA, Piaskowski SM, Rakasz EG, Weisgrau KL, Furlott JR, Eernisse CM, Veloso de Santana MG, Hidalgo B, Friedrich TC, Chiuchiolo MJ, Parks CL, Wilson NA, Allison DB, Galler R, Watkins DI. Immunogenicity of seven new recombinant yellow fever viruses 17D expressing fragments of SIVmac239 Gag, Nef, and Vif in Indian rhesus macaques. PLoS One 2013; 8:e54434. [PMID: 23336000 PMCID: PMC3545953 DOI: 10.1371/journal.pone.0054434] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 12/11/2012] [Indexed: 12/31/2022] Open
Abstract
An effective vaccine remains the best solution to stop the spread of human immunodeficiency virus (HIV). Cellular immune responses have been repeatedly associated with control of viral replication and thus may be an important element of the immune response that must be evoked by an efficacious vaccine. Recombinant viral vectors can induce potent T-cell responses. Although several viral vectors have been developed to deliver HIV genes, only a few have been advanced for clinical trials. The live-attenuated yellow fever vaccine virus 17D (YF17D) has many properties that make it an attractive vector for AIDS vaccine regimens. YF17D is well tolerated in humans and vaccination induces robust T-cell responses that persist for years. Additionally, methods to manipulate the YF17D genome have been established, enabling the generation of recombinant (r)YF17D vectors carrying genes from unrelated pathogens. Here, we report the generation of seven new rYF17D viruses expressing fragments of simian immunodeficiency virus (SIV)mac239 Gag, Nef, and Vif. Studies in Indian rhesus macaques demonstrated that these live-attenuated vectors replicated in vivo, but only elicited low levels of SIV-specific cellular responses. Boosting with recombinant Adenovirus type-5 (rAd5) vectors resulted in robust expansion of SIV-specific CD8+ T-cell responses, particularly those targeting Vif. Priming with rYF17D also increased the frequency of CD4+ cellular responses in rYF17D/rAd5-immunized macaques compared to animals that received rAd5 only. The effect of the rYF17D prime on the breadth of SIV-specific T-cell responses was limited and we also found evidence that some rYF17D vectors were more effective than others at priming SIV-specific T-cell responses. Together, our data suggest that YF17D – a clinically relevant vaccine vector – can be used to prime AIDS virus-specific T-cell responses in heterologous prime boost regimens. However, it will be important to optimize rYF17D-based vaccine regimens to ensure maximum delivery of all immunogens in a multivalent vaccine.
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MESH Headings
- AIDS Vaccines/genetics
- AIDS Vaccines/immunology
- Animals
- CD8-Positive T-Lymphocytes/immunology
- Epitopes, T-Lymphocyte/immunology
- Female
- Gene Order
- Gene Products, gag/genetics
- Gene Products, gag/immunology
- Gene Products, nef/genetics
- Gene Products, nef/immunology
- Gene Products, vif/genetics
- Gene Products, vif/immunology
- Genetic Vectors/genetics
- Humans
- Immunization
- Immunization, Secondary
- Kinetics
- Macaca mulatta
- Male
- Simian Immunodeficiency Virus/genetics
- Simian Immunodeficiency Virus/immunology
- T-Lymphocytes/immunology
- Vaccines, Synthetic/genetics
- Vaccines, Synthetic/immunology
- Virus Replication
- Yellow fever virus/genetics
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Affiliation(s)
- Mauricio A. Martins
- Department of Pathology, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Myrna C. Bonaldo
- Laboratório de Biologia Molecular de Flavivírus, Instituto Oswaldo Cruz – FIOCRUZ, Rio de Janeiro, Brazil
| | - Richard A. Rudersdorf
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Shari M. Piaskowski
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Eva G. Rakasz
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Kim L. Weisgrau
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Jessica R. Furlott
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Christopher M. Eernisse
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | | | - Bertha Hidalgo
- Section on Statistical Genetics, Department of Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Thomas C. Friedrich
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Maria J. Chiuchiolo
- International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn Army Terminal, Brooklyn, New York, United States of America
| | - Christopher L. Parks
- International AIDS Vaccine Initiative, AIDS Vaccine Design and Development Laboratory, Brooklyn Army Terminal, Brooklyn, New York, United States of America
| | - Nancy A. Wilson
- Wisconsin National Primate Research Center, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - David B. Allison
- Section on Statistical Genetics, Department of Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Ricardo Galler
- Laboratório de Biologia Molecular de Flavivírus, Instituto Oswaldo Cruz – FIOCRUZ, Rio de Janeiro, Brazil
| | - David I. Watkins
- Department of Pathology, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- * E-mail:
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9
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Wang J, Zhang W, Lv M, Zuo T, Kong W, Yu X. Identification of a Cullin5-ElonginB-ElonginC E3 complex in degradation of feline immunodeficiency virus Vif-mediated feline APOBEC3 proteins. J Virol 2011; 85:12482-91. [PMID: 21957297 PMCID: PMC3209414 DOI: 10.1128/jvi.05218-11] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Accepted: 09/15/2011] [Indexed: 01/14/2023] Open
Abstract
Various feline APOBEC3 (fA3) proteins exhibit broad antiviral activities against a wide range of viruses, such as feline immunodeficiency virus (FIV), feline foamy virus (FFV), and feline leukemia virus (FeLV), as well as those of other species. This activity can be counteracted by the FIV Vif protein, but the mechanism by which FIV Vif suppresses fA3s is unknown. In the present study, we demonstrated that FIV Vif could act via a proteasome-dependent pathway to overcome fA3s. FIV Vif interacted with feline cellular proteins Cullin5 (Cul5), ElonginB, and ElonginC to form an E3 complex to induce degradation of fA3s. Both the dominant-negative Cul5 mutant and a C-terminal hydrophilic replacement ElonginC mutant potently disrupted the FIV Vif activity against fA3s. Furthermore, we identified a BC-box motif in FIV Vif that was essential for the recruitment of E3 ubiquitin ligase and also required for FIV Vif-mediated degradation of fA3s. Moreover, despite the lack of either a Cul5-box or a HCCH zinc-binding motif, FIV Vif specifically selected Cul5. Therefore, FIV Vif may interact with Cul5 via a novel mechanism. These finding imply that SOCS proteins may possess distinct mechanisms to bind Cul5 during formation of the Elongin-Cullin-SOCS box complex.
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Affiliation(s)
- Jiawen Wang
- National Engineering Laboratory for AIDS Vaccine, College of Life Science, Jilin University, Changchun, Jilin Province, People's Republic of China
| | - Wenyan Zhang
- First Affiliated Hospital, Institute of Virology and AIDS Research, Jilin University, Changchun, Jilin Province, People's Republic of China
| | - Mingyu Lv
- National Engineering Laboratory for AIDS Vaccine, College of Life Science, Jilin University, Changchun, Jilin Province, People's Republic of China
| | - Tao Zuo
- National Engineering Laboratory for AIDS Vaccine, College of Life Science, Jilin University, Changchun, Jilin Province, People's Republic of China
| | - Wei Kong
- National Engineering Laboratory for AIDS Vaccine, College of Life Science, Jilin University, Changchun, Jilin Province, People's Republic of China
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Science, Jilin University, Changchun, Jilin Province, People's Republic of China
| | - Xianghui Yu
- National Engineering Laboratory for AIDS Vaccine, College of Life Science, Jilin University, Changchun, Jilin Province, People's Republic of China
- Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Science, Jilin University, Changchun, Jilin Province, People's Republic of China
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10
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Schmitt K, Hill MS, Liu Z, Ruiz A, Culley N, Pinson DM, Stephens EB. Comparison of the replication and persistence of simian-human immunodeficiency viruses expressing Vif proteins with mutation of the SLQYLA or HCCH domains in macaques. Virology 2010; 404:187-203. [PMID: 20627348 PMCID: PMC2974619 DOI: 10.1016/j.virol.2010.04.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Revised: 02/17/2010] [Accepted: 04/18/2010] [Indexed: 01/30/2023]
Abstract
The Vif protein of primate lentiviruses interacts with APOBEC3 proteins, which results in shunting of the APOBEC3-Vif complex to the proteosome for degradation. Using the simian-human immunodeficiency virus (SHIV)/macaque model, we compared the replication and pathogenicity of SHIVs that express a Vif protein in which the entire SLQYLA (SHIV(Vif5A)) or HCCH (SHIV(VifHCCH(-))) domains were substituted with alanine residues. Each virus was inoculated into three macaques and various viral and immunological parameters followed for 6 months. All macaques maintained stable circulating CD4+ T cells, developed low viral loads, maintained the engineered mutations, yielded no histological lesions, and developed immunoprecipitating antibodies early post-inoculation. Sequence analysis of nef and vpu from three lymphoid tissues revealed a high percentage of G-to-A-substitutions. Our results show that while the presence of HCCH and SLQYLA domains are critical in vivo, there may exist APOBEC3 negative reservoirs that allow for low levels of viral replication and persistence but not disease.
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Affiliation(s)
- Kimberly Schmitt
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - M. Sarah Hill
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Zhenqian Liu
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Autumn Ruiz
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Nathan Culley
- Laboratory Animal Resources, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - David M. Pinson
- Laboratory Medicine and Pathology, University of Kansas Medical Center, Kansas City, Kansas 66160
| | - Edward B. Stephens
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas 66160
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, Kansas 66160
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11
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Maksaereekul S, Dubie RA, Shen X, Kieu H, Dean GA, Sparger EE. Vaccination with vif-deleted feline immunodeficiency virus provirus, GM-CSF, and TNF-alpha plasmids preserves global CD4 T lymphocyte function after challenge with FIV. Vaccine 2009; 27:3754-65. [PMID: 19464559 PMCID: PMC2802579 DOI: 10.1016/j.vaccine.2009.03.081] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Revised: 03/24/2009] [Accepted: 03/26/2009] [Indexed: 12/17/2022]
Abstract
Feline immunodeficiency virus (FIV) DNA vaccine approaches that included a vif-deleted FIV provirus (FIV-pPPRDeltavif) and feline cytokine expression plasmids were tested for immunogenicity and efficacy by immunization of specific pathogen free cats. Vaccine protocols included FIV-pPPRDeltavif plasmid alone; a combination of FIV-pPPRDeltavif DNA and feline granulocyte macrophage-colony stimulating factor (GM-CSF) and tumor necrosis factor (TNF)-alpha expression plasmids; or a combination of FIV-pPPRDeltavif and feline interleukin (IL)-15 plasmids. Cats immunized with FIV-pPPRDeltavif, GM-CSF and TNF-alpha plasmids demonstrated an increased frequency of FIV-specific T cell proliferation responses compared to other vaccine groups. Immunization with FIV-pPPRDeltavif and IL-15 plasmids was distinguished from other vaccine protocols by the induction of antiviral antibodies. Suppression of virus loads was not observed for any of the FIV-pPPRDeltavif DNA vaccine protocols after challenge with the FIV-PPR isolate. However, prior immunization with FIV-pPPRDeltavif, GM-CSF, and TNF-alpha plasmids resulted in preservation of CD4 T cell functions, including mitogen-induced cytokine expression and antigen-specific proliferation upon infection with FIV. These findings justify further examination of cytokine combinations as adjuvants for lentiviral DNA vaccines.
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Affiliation(s)
- Saipiroon Maksaereekul
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California 95616
| | - Robert A. Dubie
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California 95616
| | - Xiaoying Shen
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California 95616
| | - Hung Kieu
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California 95616
| | - Gregg A. Dean
- Center for Comparative Medicine and Translational Research, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina 27606
| | - Ellen E. Sparger
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California 95616
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12
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Dubie RA, Maksaereekul S, Shacklett BL, Lemongello D, Cole KS, Villinger F, Blozis SA, Luciw PA, Sparger EE. Co-immunization with IL-15 enhances cellular immune responses induced by a vif-deleted simian immunodeficiency virus proviral DNA vaccine and confers partial protection against vaginal challenge with SIVmac251. Virology 2009; 386:109-21. [PMID: 19193388 PMCID: PMC3640844 DOI: 10.1016/j.virol.2009.01.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2008] [Revised: 10/30/2008] [Accepted: 01/08/2009] [Indexed: 11/18/2022]
Abstract
Simian immunodeficiency virus (SIV) infection of rhesus macaques is a valuable animal model for human immunodeficiency virus (HIV)-1 vaccine development. Our laboratory recently described the immunogenicity and limited efficacy of a vif-deleted SIVmac239 proviral DNA (SIV/CMVDelta vif) vaccine. The current report characterizes immunogenicity and efficacy for the SIV/CMVDelta vif proviral DNA vaccine when co-inoculated with an optimized rhesus interleukin (rIL)-15 expression plasmid. Macaques co-inoculated with rIL-15 and SIV/CMVDelta vif proviral plasmids showed significantly improved SIV-specific CD8 T cell immunity characterized by increased IFN-gamma ELISPOT and polyfunctional CD8 T cell responses. Furthermore, these animals demonstrated a sustained suppression of plasma virus loads after multiple low dose vaginal challenges with pathogenic SIVmac251. Importantly, SIV-specific cellular responses were greater in immunized animals compared to unvaccinated controls during the initial 12 weeks after challenge. Taken together, these findings support the use of IL-15 as an adjuvant in prophylactic anti-HIV vaccine strategies.
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Affiliation(s)
- Robert A Dubie
- Department of Medicine and Epidemiology, 2108 Tupper Hall, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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13
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Zhang W, Huang M, Wang T, Tan L, Tian C, Yu X, Kong W, Yu XF. Conserved and non-conserved features of HIV-1 and SIVagm Vif mediated suppression of APOBEC3 cytidine deaminases. Cell Microbiol 2008; 10:1662-75. [PMID: 18419775 PMCID: PMC3086741 DOI: 10.1111/j.1462-5822.2008.01157.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Human cytidine deaminase APOBEC3C (A3C) acts as a potent inhibitor of SIVagm and can be regulated by both HIV-1 and SIVagm Vif. The mechanism by which Vif suppresses A3C is unknown. In the present study, we demonstrate that both HIV-1 and SIVagm Vif can act in a proteasome-dependent manner to overcome A3C. SIVagm Vif requires the Cullin5-ElonginB-ElonginC E3 ubiquitin ligase for the degradation of A3C as well as the suppression of its antiviral activity. Mutation of a residue critical for the species-specific recognition of human or monkey A3G by HIV-1 Vif or SIVagm Vif in A3C had little effect on HIV-1 or SIVagm Vif-mediated degradation of A3C. Although the amino-terminal region of A3G was not important for Vif-mediated degradation, the corresponding region in A3C was critical. A3C mutants that were competent for Vif binding but resistant to Vif-mediated degradation were identified. These data suggest that primate lentiviral Vif molecules have evolved to recognize multiple host APOBEC3 proteins through distinct mechanisms. However, Cul5-E3 ubiquitin ligase appears to be a common pathway hijacked by HIV-1 and SIV Vif to defeat APOBEC3 proteins. Furthermore, Vif and APOBEC3 binding is not sufficient for target protein degradation indicating an important but uncharacterized Vif function.
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Affiliation(s)
- Wenyan Zhang
- College of Life Science, Jilin University, Changchun 130021, China
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14
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Abstract
The HIV-1 Vif protein is essential for overcoming the antiviral activity of DNA-editing apolipoprotein B mRNA editing enzyme, catalytic polypeptide 3 (APOBEC3) cytidine deaminases. We show that naturally occurring HIV-1 Vif point mutants with suboptimal anti-APOBEC3G activity induce the appearance of proviruses with lamivudine (3TC) drug resistance-associated mutations before any drug exposure. These mutations, ensuing from cytidine deamination events, were detected in >40% of proviruses with partially defective Vif mutants. Transfer of drug resistance from hypermutated proviruses via recombination allowed for 3TC escape under culture conditions prohibitive for any WT viral growth. These results demonstrate that defective hypermutated genomes can shape the phenotype of the circulating viral population. Partially active Vif alleles resulting in incomplete neutralization of cytoplasmic APOBEC3 molecules are directly responsible for the generation of a highly diverse, yet G-to-A biased, proviral reservoir, which can be exploited by HIV-1 to generate viable and drug-resistant progenies.
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Affiliation(s)
| | - Ariana Harari
- *Department of Medicine, Division of Infectious Diseases, and
| | - Viviana Simon
- *Department of Medicine, Division of Infectious Diseases, and
- Department of Microbiology, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1090, New York, NY 10029
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15
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Shen X, Leutenegger CM, Stefano Cole K, Pedersen NC, Sparger EE. A feline immunodeficiency virus vif-deletion mutant remains attenuated upon infection of newborn kittens. J Gen Virol 2007; 88:2793-2799. [PMID: 17872533 DOI: 10.1099/vir.0.83268-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
This report characterizes lentivirus attenuation associated with a vif mutation by inoculation of newborn kittens with a vif-deleted feline immunodeficiency virus provirus plasmid (FIV-pPPRDeltavif). Virus in peripheral blood, antiviral antibody or CD4 T-cell count alterations were not detected in kittens inoculated with FIV-pPPRDeltavif plasmid, with the exception of one kitten that demonstrated FIV Gag antibody production at 42 weeks after inoculation. In contrast, wild-type FIV-pPPR-infected kittens were viraemic, seropositive and exhibited a decrease in the CD4 T-cell subset in peripheral blood. Interestingly, FIV-specific T-cell proliferative responses detected at 32 and 36 weeks after infection were comparable for both FIV-pPPRDeltavif- and wild-type FIV-pPPR-inoculated kittens and suggested the possibility of a discreet tissue reservoir supporting sustained FIV-pPPRDeltavif expression or replication. Overall, these findings confirmed that the severe virus attenuation for both replication and pathogenicity exhibited by a vif-deleted FIV mutant is similar for both neonatal and adult hosts.
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Affiliation(s)
- Xiaoying Shen
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Christian M Leutenegger
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Kelly Stefano Cole
- Department of Medicine, Infectious Diseases Division, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Niels C Pedersen
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | - Ellen E Sparger
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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16
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Goila-Gaur R, Khan MA, Miyagi E, Kao S, Strebel K. Targeting APOBEC3A to the viral nucleoprotein complex confers antiviral activity. Retrovirology 2007; 4:61. [PMID: 17727729 PMCID: PMC2018723 DOI: 10.1186/1742-4690-4-61] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Accepted: 08/29/2007] [Indexed: 11/17/2022] Open
Abstract
Background APOBEC3 (A3) proteins constitute a family of cytidine deaminases that provide intracellular resistance to retrovirus replication and to transposition of endogenous retroelements. A3A has significant homology to the C-terminus of A3G but has only a single cytidine deaminase active site (CDA), unlike A3G, which has a second N-terminal CDA previously found to be important for Vif sensitivity and virus encapsidation. A3A is packaged into HIV-1 virions but, unlike A3G, does not have antiviral properties. Here, we investigated the reason for the lack of A3A antiviral activity. Results Sequence alignment of A3G and A3A revealed significant homology of A3A to the C-terminal region of A3G. However, while A3G co-purified with detergent-resistant viral nucleoprotein complexes (NPC), virus-associated A3A was highly detergent-sensitive leading us to speculate that the ability to assemble into NPC may be a property conveyed by the A3G N-terminus. To test this model, we constructed an A3G-3A chimeric protein, in which the N-terminal half of A3G was fused to A3A. Interestingly, the A3G-3A chimera was packaged into HIV-1 particles and, unlike A3A, associated with the viral NPC. Furthermore, the A3G-3A chimera displayed strong antiviral activity against HIV-1 and was sensitive to inhibition by HIV-1 Vif. Conclusion Our results suggest that the A3G N-terminal domain carries determinants important for targeting the protein to viral NPCs. Transfer of this domain to A3A results in A3A targeting to viral NPCs and confers antiviral activity.
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Affiliation(s)
- Ritu Goila-Gaur
- Laboratory of Molecular Microbiology, Viral Biochemistry Section, National Institute of Allergy and Infectious Diseases, NIH, Building 4, Room 310, 4 Center Drive, MSC 0460; Bethesda, MD 20892-0460, USA
| | - Mohammad A Khan
- Laboratory of Molecular Microbiology, Viral Biochemistry Section, National Institute of Allergy and Infectious Diseases, NIH, Building 4, Room 310, 4 Center Drive, MSC 0460; Bethesda, MD 20892-0460, USA
| | - Eri Miyagi
- Laboratory of Molecular Microbiology, Viral Biochemistry Section, National Institute of Allergy and Infectious Diseases, NIH, Building 4, Room 310, 4 Center Drive, MSC 0460; Bethesda, MD 20892-0460, USA
| | - Sandra Kao
- Laboratory of Molecular Microbiology, Viral Biochemistry Section, National Institute of Allergy and Infectious Diseases, NIH, Building 4, Room 310, 4 Center Drive, MSC 0460; Bethesda, MD 20892-0460, USA
| | - Klaus Strebel
- Laboratory of Molecular Microbiology, Viral Biochemistry Section, National Institute of Allergy and Infectious Diseases, NIH, Building 4, Room 310, 4 Center Drive, MSC 0460; Bethesda, MD 20892-0460, USA
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17
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Takeuchi H, Buckler-White A, Goila-Gaur R, Miyagi E, Khan MA, Opi S, Kao S, Sokolskaja E, Pertel T, Luban J, Strebel K. Vif counteracts a cyclophilin A-imposed inhibition of simian immunodeficiency viruses in human cells. J Virol 2007; 81:8080-90. [PMID: 17522232 PMCID: PMC1951326 DOI: 10.1128/jvi.02727-06] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Accepted: 05/05/2007] [Indexed: 11/20/2022] Open
Abstract
Vif is a primate lentiviral accessory protein that is crucial for viral infectivity. Vif counteracts the antiviral activity of host deaminases such as APOBEC3G and APOBEC3F. We now report a novel function of African green monkey simian immunodeficiency virus (SIVagm) Vif that promotes replication of SIVagm in human cells lacking detectable deaminase activity. We found that cyclophilin A (CypA) was excluded from wild-type SIV particles but was efficiently packaged into vif-deficient SIVagm virions. The presence of CypA in vif-defective SIVagm was correlated with reduced viral replication. Infection of CypA knockout Jurkat cells or treatment of Jurkat cells with cyclosporine A eliminated the Vif-sensitive inhibition and resulted in replication profiles that were similar for wild-type and vif-deficient SIVagm. Importantly, the inhibitory effect of CypA was restricted to virus-producing cells and was TRIM5alpha independent. The abilities of SIVagm Vif to inhibit encapsidation of CypA and to increase viral infectivity were shared by rhesus macaque SIV Vif and thus seem to be general properties of SIV Vif proteins. Exclusion of CypA from SIVagm particles was not associated with intracellular degradation, suggesting a mode of Vif action distinct from that proposed for APOBEC3G. This is the first report of a novel vif-sensitive antiviral activity of human CypA that may limit zoonotic transmission of SIV and the first demonstration of CypA encapsidation into a virus other than human immunodeficiency virus type 1.
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Affiliation(s)
- Hiroaki Takeuchi
- Laboratory of Molecular Microbiology, Viral Biochemistry Section, National Institute of Allergy and Infectious Diseases, NIH, Building 4, Room 310, 4 Center Drive, MSC 0460, Bethesda, Maryland 20892-0460, USA
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18
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Abstract
The HIV-1 viral infectivity factor (Vif) is a small basic protein essential for viral fitness and pathogenicity. Some "non-permissive" cell lines cannot sustain replication of Vif(-) HIV-1 virions. In these cells, Vif counteracts the natural antiretroviral activity of the DNA-editing enzymes APOBEC3G/3F. Moreover, Vif is packaged into viral particles through a strong interaction with genomic RNA in viral nucleoprotein complexes. To gain insights into determinants of this binding process, we performed the first characterization of Vif/nucleic acid interactions using Vif intrinsic fluorescence. We determined the affinity of Vif for RNA fragments corresponding to various regions of the HIV-1 genome. Our results demonstrated preferential and moderately cooperative binding for RNAs corresponding to the 5'-untranslated region of HIV-1 (5'-untranslated region) and gag (cooperativity parameter omega approximately 65-80, and K(d) = 45-55 nM). In addition, fluorescence spectroscopy allowed us to point out the TAR apical loop and a short region in gag as primary strong affinity binding sites (K(d) = 9.5-14 nM). Interestingly, beside its RNA binding properties, the Vif protein can also bind the corresponding DNA oligonucleotides and their complementary counterparts with an affinity similar to the one observed for the RNA sequences, while other DNA sequences displayed reduced affinity. Taken together, our results suggest that Vif binding to RNA and DNA offers several non-exclusive ways to counteract APOBEC3G/3F factors, in addition to the well documented Vif-induced degradation by the proteasome and to the Vif-mediated repression of translation of these antiviral factors.
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MESH Headings
- 5' Untranslated Regions/genetics
- 5' Untranslated Regions/immunology
- 5' Untranslated Regions/metabolism
- APOBEC-3G Deaminase
- Binding Sites/physiology
- Cytidine Deaminase
- Cytosine Deaminase/immunology
- Cytosine Deaminase/metabolism
- DNA, Viral/genetics
- DNA, Viral/immunology
- DNA, Viral/metabolism
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/immunology
- DNA-Binding Proteins/metabolism
- Gene Products, gag/genetics
- Gene Products, gag/immunology
- Gene Products, gag/metabolism
- Gene Products, vif/genetics
- Gene Products, vif/immunology
- Gene Products, vif/metabolism
- Genome, Viral/physiology
- HIV Long Terminal Repeat/physiology
- HIV-1/genetics
- HIV-1/immunology
- HIV-1/metabolism
- HIV-1/pathogenicity
- Humans
- Immunity, Innate/physiology
- Nucleoside Deaminases/immunology
- Nucleoside Deaminases/metabolism
- Oligonucleotides/genetics
- Oligonucleotides/immunology
- Oligonucleotides/metabolism
- Protein Binding/physiology
- Protein Biosynthesis/physiology
- RNA, Viral/genetics
- RNA, Viral/immunology
- RNA, Viral/metabolism
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/immunology
- RNA-Binding Proteins/metabolism
- Repressor Proteins/genetics
- Repressor Proteins/immunology
- Repressor Proteins/metabolism
- vif Gene Products, Human Immunodeficiency Virus
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Affiliation(s)
- Serena Bernacchi
- Architecture et Réactivité de l'ARN, Université Louis Pasteur de Strasbourg, CNRS, IBMC, 15 Rue René Descartes, 67084 Strasbourg, France
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19
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Opi S, Kao S, Goila-Gaur R, Khan MA, Miyagi E, Takeuchi H, Strebel K. Human immunodeficiency virus type 1 Vif inhibits packaging and antiviral activity of a degradation-resistant APOBEC3G variant. J Virol 2007; 81:8236-46. [PMID: 17522211 PMCID: PMC1951302 DOI: 10.1128/jvi.02694-06] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) Vif counteracts the antiviral activity of the human cytidine deaminase APOBEC3G (APO3G) by inhibiting its incorporation into virions. This has been attributed to the Vif-induced degradation of APO3G by cytoplasmic proteasomes. We recently demonstrated that although APO3G has a natural tendency to form RNA-dependent homo-multimers, multimerization was not essential for encapsidation into HIV-1 virions or antiviral activity. We now demonstrate that a multimerization-defective APO3G variant (APO3G C97A) is able to assemble into RNase-sensitive high-molecular-mass (HMM) complexes, suggesting that homo-multimerization of APO3G and assembly into HMM complexes are unrelated RNA-dependent processes. Interestingly, APO3G C97A was highly resistant to Vif-induced degradation even though the two proteins were found to interact in coimmunoprecipitation experiments and exhibited partial colocalization in transfected HeLa cells. Surprisingly, encapsidation and antiviral activity of APO3G C97A were both inhibited by Vif despite resistance to degradation. These results demonstrate that targeting of APO3G to proteasome degradation and interference with viral encapsidation are distinct functional properties of Vif.
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Affiliation(s)
- Sandrine Opi
- Laboratory of Molecular Microbiology, Viral Biochemistry Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Building 4, Room 310, 4 Center Drive, MSC 0460, Bethesda, Maryland 20892-0460, USA
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20
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Russell RA, Pathak VK. Identification of two distinct human immunodeficiency virus type 1 Vif determinants critical for interactions with human APOBEC3G and APOBEC3F. J Virol 2007; 81:8201-10. [PMID: 17522216 PMCID: PMC1951317 DOI: 10.1128/jvi.00395-07] [Citation(s) in RCA: 189] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human cytidine deaminases APOBEC3G (A3G) and APOBEC3F (A3F) inhibit replication of Vif-deficient human immunodeficiency virus type 1 (HIV-1). HIV-1 Vif overcomes these host restriction factors by binding to them and inducing their proteasomal degradation. The Vif-A3G and Vif-A3F interactions are attractive targets for antiviral drug development because inhibiting the interactions could allow the host defense mechanism to control HIV-1 replication. It was recently reported that the Vif amino acids D(14)RMR(17) are important for functional interaction and degradation of the previously identified Vif-resistant mutant of A3G (D128K-A3G). However, the Vif determinants important for functional interaction with A3G and A3F have not been fully characterized. To identify these determinants, we performed an extensive mutational analysis of HIV-1 Vif. Our analysis revealed two distinct Vif determinants, amino acids Y(40)RHHY(44) and D(14)RMR(17), which are essential for binding to A3G and A3F, respectively. Interestingly, mutation of the A3G-binding region increased Vif's ability to suppress A3F. Vif binding to D128K-A3G was also dependent on the Y(40)RHHY(44) region but not the D(14)RMR(17) region. Consistent with previous observations, subsequent neutralization of the D128K-A3G antiviral activity required substitution of Vif determinant D(14)RMR(17) with SEMQ, similar to the SERQ amino acids in simian immunodeficiency virus SIV(AGM) Vif, which is capable of neutralizing D128K-A3G. These studies are the first to clearly identify two distinct regions of Vif that are critical for independent interactions with A3G and A3F. Pharmacological interference with the Vif-A3G or Vif-A3F interactions could result in potent inhibition of HIV-1 replication by the APOBEC3 proteins.
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Affiliation(s)
- Rebecca A Russell
- HIV Drug Resistance Program, National Cancer Institute-Frederick, P.O. Box B, Bldg. 535, Rm. 334, Frederick, MD 21702-1201, USA
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21
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Paul TA, Casey JW, Avery RJ, Sutton CA. Expression of feline immunodeficiency virus Vif is associated with reduced viral mutation rates without restoration of replication of vif mutant viruses. Virology 2007; 361:112-22. [PMID: 17169394 DOI: 10.1016/j.virol.2006.11.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Revised: 09/08/2006] [Accepted: 11/08/2006] [Indexed: 10/23/2022]
Abstract
The vif gene of lentiviruses has been demonstrated to be essential for efficient viral replication in many cell types. Although the Vif protein of feline immunodeficiency virus (FIV) displays limited homology to HIV-1 Vif, the role of vif in FIV replication is not known. We have examined the requirements of vif for replication of a FIV strain isolated from a non-domestic felid, Otocolobus manul (FIV-Oma). In agreement with others, we find that replication of FIV vif mutant molecular clones in CrFK cells is highly attenuated. Initial attempts to rescue vif mutant viruses in trans were limited by lack of detectable wild-type Vif expression from DNA constructs. We demonstrate that FIV-Oma Vif expression can be increased by re-synthesis of the gene to remove splice donor and acceptor sites as well as improving codon usage to a mammalian codon optimized model. Cellular localization of resynthesized Vif (Vif-RS) is cytoplasmic. Clonal stable transfectants expressing HA-tagged Vif-RS do not restore replication levels of vif mutant virus. However, in such cell lines, G-to-A mutation rates in replicating wild-type viruses are reduced.
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Affiliation(s)
- Thomas A Paul
- Department of Microbiology and Immunology, Cornell University, C4-137 Veterinary Medical Center, Ithaca, NY 14853, USA
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22
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Park CS, Kim MS, Yi HA, Lee DH, Lee KM, Lee CH. Analysis of substitution events in HIV-1 vif gene of the Korean clade. J Microbiol 2007; 45:75-8. [PMID: 17342060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Nucleotide and amino acid substitution pattern in vif gene of the Korean clade of HIV-1 isolated from Koreans were analyzed using consensus sequences. At nucleotide level, transition/transversion substitution ratio was 1.88, and nonsynonymous/synonymous substitution ratio was 2.67, suggesting a divergent evolution in the Korean clade. At amino acid level, there were 17 substitutions and G-->E substitution at position 37 may be responsible for change in predicted secondary structure.
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Affiliation(s)
- Chan Seung Park
- School of Life Sciences, Chungbuk National University, Cheongju, Republic of Korea
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23
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Yang Y, Sun Y, Luo X, Zhang Y, Chen Y, Tian E, Lints R, Zhang H. Polycomb-like genes are necessary for specification of dopaminergic and serotonergic neurons in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2007; 104:852-7. [PMID: 17215367 PMCID: PMC1783403 DOI: 10.1073/pnas.0610261104] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The molecular mechanisms underlying the formation of neurons with defined neurotransmitters are not well understood. In this study, we demonstrate that the PcG-like genes in Caenorhabditis elegans, sop-2 and sor-3, regulate the formation of dopaminergic and serotonergic neurons and several other neuronal properties. sor-3 encodes a novel protein containing an MBT repeat, a domain that contains histone-binding activity and is present in PcG proteins SCM and Sfmbt in other organisms. We further show that mutations in sor-3 lead to ectopic expression of Hox genes and cause homeotic transformations. Specification of certain neuronal identities by these PcG-like genes appears to involve regulation of non-Hox gene targets. Our studies revealed that the PcG-like genes are crucial for coordinately regulating the expression of discrete aspects of neuronal identities in C. elegans.
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Affiliation(s)
- Yong Yang
- *National Institute of Biological Sciences, Beijing 102206, People's Republic of China
- Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, People's Republic of China; and
| | - Yinyan Sun
- *National Institute of Biological Sciences, Beijing 102206, People's Republic of China
| | - Xin Luo
- *National Institute of Biological Sciences, Beijing 102206, People's Republic of China
| | - Yuxia Zhang
- *National Institute of Biological Sciences, Beijing 102206, People's Republic of China
| | - Yaoyao Chen
- *National Institute of Biological Sciences, Beijing 102206, People's Republic of China
| | - E. Tian
- *National Institute of Biological Sciences, Beijing 102206, People's Republic of China
| | - Robyn Lints
- Department of Biology, Texas A&M University, College Station, TX 77843
| | - Hong Zhang
- *National Institute of Biological Sciences, Beijing 102206, People's Republic of China
- To whom correspondence should be addressed at:
National Institute of Biological Sciences, Zhongguancun Life Science Park, No. 7 Science Park Road, Beijing 102206, People's Republic of China. E-mail:
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24
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Affiliation(s)
- Klaus Strebel
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious, Diseases, National Institutes of Health, 4/312, Bethesda, MD 20892, USA
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25
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Fischer W, Perkins S, Theiler J, Bhattacharya T, Yusim K, Funkhouser R, Kuiken C, Haynes B, Letvin NL, Walker BD, Hahn BH, Korber BT. Polyvalent vaccines for optimal coverage of potential T-cell epitopes in global HIV-1 variants. Nat Med 2006; 13:100-6. [PMID: 17187074 DOI: 10.1038/nm1461] [Citation(s) in RCA: 335] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Accepted: 07/09/2006] [Indexed: 11/08/2022]
Abstract
HIV-1/AIDS vaccines must address the extreme diversity of HIV-1. We have designed new polyvalent vaccine antigens comprised of sets of 'mosaic' proteins, assembled from fragments of natural sequences via a computational optimization method. Mosaic proteins resemble natural proteins, and a mosaic set maximizes the coverage of potential T-cell epitopes (peptides of nine amino acids) for a viral population. We found that coverage of viral diversity using mosaics was greatly increased compared to coverage by natural-sequence vaccine candidates, for both variable and conserved proteins; for conserved HIV-1 proteins, global coverage may be feasible. For example, four mosaic proteins perfectly matched 74% of 9-amino-acid potential epitopes in global Gag sequences; 87% of potential epitopes matched at least 8 of 9 positions. In contrast, a single natural Gag protein covered only 37% (9 of 9) and 67% (8 of 9). Mosaics provide diversity coverage comparable to that afforded by thousands of separate peptides, but, because the fragments of natural proteins are compressed into a small number of native-like proteins, they are tractable for vaccines.
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MESH Headings
- AIDS Vaccines/genetics
- AIDS Vaccines/immunology
- Algorithms
- Epitopes, T-Lymphocyte/immunology
- Gene Products, env/genetics
- Gene Products, env/immunology
- Gene Products, gag/genetics
- Gene Products, gag/immunology
- Gene Products, nef/genetics
- Gene Products, nef/immunology
- Gene Products, rev/genetics
- Gene Products, rev/immunology
- Gene Products, tat/genetics
- Gene Products, tat/immunology
- Gene Products, vif/genetics
- Gene Products, vif/immunology
- Genetic Heterogeneity
- Genetic Variation
- HIV Antigens/genetics
- HIV Antigens/immunology
- HIV Infections/immunology
- HIV Infections/prevention & control
- HIV Infections/virology
- HIV-1/genetics
- HIV-1/immunology
- Humans
- nef Gene Products, Human Immunodeficiency Virus
- rev Gene Products, Human Immunodeficiency Virus
- tat Gene Products, Human Immunodeficiency Virus
- vif Gene Products, Human Immunodeficiency Virus
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Affiliation(s)
- Will Fischer
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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26
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Park CS, Kim MS, Lee SD, Kim SS, Lee KM, Lee CH. Molecular phylogenetic analysis of HIV-1 vif gene from Korean isolates. J Microbiol 2006; 44:655-9. [PMID: 17205044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Phylogenetic studies of nef, pol, and env gene sequences of HIV-1 isolated from Koreans suggested the presence of a Korean clade in which Korean sequences are clustered to the exclusion of foreign sequences. We attempted to identify and characterize the Korean clade using all vif gene sequences isolated from Koreans registered in the NCBI GenBank database (n = 233). Most (77 %) of the Korean isolates belonged to the Korean clade as a large subcluster in subtype B, designated the Korean clade subtype B (KCB). KCB sequences were relatively homogenous compared to Korean subtype B sequences that did not belong to the KCB (non-Korean clade subtype B; NKCB). Comparison of amino acid frequencies of KCB and NKCB sequences revealed several positions where the amino acid frequencies were significantly different. These amino acid residues were critical in separating KCB from NKCB or from foreign sequences, since substitution of these amino acids in KCB with the NKCB amino acids relocated the KCB sequences to NKCB, and vice versa. Further analyses of KCB will help us to understand the origin and evolutionary history of KCB.
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Affiliation(s)
- Chan Seung Park
- School of Life Sciences, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea
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27
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Ikeda M, Habu Y, Miyano-Kurosaki N, Takaku H. Suppression of HIV-1 replication by a combination of endonucleolytic ribozymes (RNase P and tRNnase ZL). Nucleosides Nucleotides Nucleic Acids 2006; 25:427-37. [PMID: 16838836 DOI: 10.1080/01457630600684120] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
We examined the combinatorial action of RNase P and tRNase ZL-mediated specific inhibition of HIV-1 in cultured cells. We designed two short extra guide sequences (sEGS) that specifically recognize the tat and vifregions of HIV-1 mRNA and mediate the subsequent cleavage of hybridized mRNA by the RNase P and tRNase ZL components. We constructed an RNase P and tRNase ZL-associated vif and tat sEGS expression vector; which used the RNA-polymerase III dependent U6 promoter, as an expression cassette for EGS. Together, the RNase P and tRNase ZL-associated sEGS molecules allow more efficient suppression of HIV-1 mRNA production when separately applied. The possibilities offered by the vector to encode sEGS will provide a powerful tool for gene therapy.
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Affiliation(s)
- Masahiro Ikeda
- Department of Life and Environmental Science, Faculty of Engineering, Chiba Institute of Technology, Narashino, Chiba, Japan
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28
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Xu H, Chertova E, Chen J, Ott DE, Roser JD, Hu WS, Pathak VK. Stoichiometry of the antiviral protein APOBEC3G in HIV-1 virions. Virology 2006; 360:247-56. [PMID: 17126871 DOI: 10.1016/j.virol.2006.10.036] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Revised: 05/01/2006] [Accepted: 10/17/2006] [Indexed: 10/23/2022]
Abstract
A host cytidine deaminase, APOBEC3G (A3G), inhibits replication of human immunodeficiency virus type 1 (HIV-1) by incorporating into virions in the absence of the virally encoded Vif protein (Deltavif virions), at least in part by causing G-to-A hypermutation. To gain insight into the antiretroviral function of A3G, we determined the quantities of A3G molecules that are incorporated in Deltavif virions. We combined three experimental approaches-reversed-phase high-pressure liquid chromatography (HPLC), scintillation proximity assay (SPA), and quantitative immunoblotting-to determine the molar ratio of A3G to HIV-1 capsid protein in Deltavif virions. Our studies revealed that the amount of the A3G incorporated into Deltavif virions was proportional to the level of its expression in the viral producing cells, and the ratio of the A3G to Gag in the Deltavif virions produced from activated human peripheral blood mononuclear cells (PBMC) was approximately 1:439. Based on previous estimates of the stoichiometry of HIV-1 Gag in virions (1400-5000), we conclude that approximately 7 (+/-4) molecules of A3G are incorporated into Deltavif virions produced from human PBMCs. These results indicate that virion incorporation of only a few molecules of A3G is sufficient to inhibit HIV-1 replication.
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Affiliation(s)
- Hongzhan Xu
- Viral Mutation Section, HIV Drug Resistance Program, Center for Cancer Research, National Cancer Institute-Frederick, P. O. Box B, Bldg. 535, Rm. 334, Frederick, MD 21702, USA
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29
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Abstract
Members of the APOBEC family of cellular polynucleotide cytidine deaminases (e.g., APOBEC3G) are potent inhibitors of HIV infection. Wild type viral infections are largely spared from APOBEC function through the action of the viral Vif protein. In Vif's absence, inhibitory APOBEC proteins are encapsidated by budding virus particles leading to excessive cytidine (C) to uridine (U) hypermutation of negative sense reverse transcripts in newly infected cells. This registers as guanosine (G) to adenosine (A) mutations in plus stranded cDNA. Because the functions of Vif and APOBEC proteins oppose each other, it is likely that fluctuations in the Vif/APOBEC balance can influence the natural history of HIV infection. Experimental support for this notion would further justify and stimulate drug discovery initiatives in this area.
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Affiliation(s)
- Michael H Malim
- Department of Infectious Diseases, King's College London, School of Medicine, 2nd Floor, New Guy's House, Guy's Hospital, London Bridge, London SE1 9RT, UK.
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30
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Wang J, Shackelford JM, Casella CR, Shivers DK, Rapaport EL, Liu B, Yu XF, Finkel TH. The Vif accessory protein alters the cell cycle of human immunodeficiency virus type 1 infected cells. Virology 2006; 359:243-52. [PMID: 17056089 PMCID: PMC1934563 DOI: 10.1016/j.virol.2006.09.026] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Revised: 03/29/2006] [Accepted: 09/12/2006] [Indexed: 10/24/2022]
Abstract
The viral infectivity factor gene (vif) of HIV-1 increases the infectivity of viral particles by inactivation of cellular anti-viral factors, and supports productive viral replication in primary human CD4 T cells and in certain non-permissive T cell lines. Here, we demonstrate that Vif also contributes to the arrest of HIV-1 infected cells in the G(2) phase of the cell cycle. Viruses deleted in Vif or Vpr induce less cell cycle arrest than wild-type virus, while cells infected with HIV-1 deleted in both Vif and Vpr have a cell cycle profile equivalent to that of uninfected cells. Furthermore, expression of Vif alone induces accumulation of cells in the G(2) phase of the cell cycle. These data demonstrate a novel role for Vif in cell cycle regulation and suggest that Vif and Vpr independently drive G(2) arrest in HIV-1 infected cells. Our results may have implications for the actions and interactions of key HIV-1 accessory proteins in AIDS pathogenesis.
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Affiliation(s)
- Jiangfang Wang
- Division of Rheumatology, Department of Pediatrics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
| | - Jason M. Shackelford
- Division of Rheumatology, Department of Pediatrics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
| | - Carolyn R. Casella
- Division of Basic Sciences, Department of Pediatrics, National Jewish Medical and Research Center, Denver, Colorado 80206
| | - Debra K. Shivers
- Division of Rheumatology, Department of Pediatrics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
| | - Eric L. Rapaport
- Department of Medicine, University of Colorado Health Sciences Center, Denver, Colorado 80262
| | - Bindong Liu
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205
| | - Xiao-Fang Yu
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205
| | - Terri H. Finkel
- Division of Rheumatology, Department of Pediatrics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
- *Corresponding author: Mailing address: The Children’s Hospital of Philadelphia, 1102 Abramson Research Center, 3516 Civic Center Boulevard, Philadelphia, PA 19104. Phone: 215-590-7180, , FAX: 215-590-1258
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31
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Pace C, Keller J, Nolan D, James I, Gaudieri S, Moore C, Mallal S. Population level analysis of human immunodeficiency virus type 1 hypermutation and its relationship with APOBEC3G and vif genetic variation. J Virol 2006; 80:9259-69. [PMID: 16940537 PMCID: PMC1563905 DOI: 10.1128/jvi.00888-06] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
APOBEC3G and APOBEC3F restrict human immunodeficiency virus type 1 (HIV-1) replication in vitro through the induction of G-->A hypermutation; however, the relevance of this host antiviral strategy to clinical HIV-1 is currently not known. Here, we describe a population level analysis of HIV-1 hypermutation in [corrected] clade B proviral DNA sequences (n = 127). G-->A hypermutation conforming to expected APOBEC3G polynucleotide sequence preferences was inferred in 9.4% (n = 12) of the HIV-1 sequences, with a further 2.4% (n = 3) conforming to APOBEC3F, and was independently associated with reduced pretreatment viremia (reduction of 0.7 log(10) copies/ml; P = 0.001). Defective vif was strongly associated with HIV-1 hypermutation, with additional evidence for a contribution of vif amino acid polymorphism at residues important for APOBEC3G-vif interactions. A concurrent analysis of APOBEC3G polymorphism revealed this gene to be highly conserved at the amino acid level, although an intronic allele (6,892 C) was marginally associated with HIV-1 hypermutation. These data indicate that APOBEC3G-induced HIV-1 hypermutation represents a potent host antiviral factor in vivo and that the APOBEC3G-vif interaction may represent a valuable therapeutic target.
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Affiliation(s)
- Craig Pace
- Centre for Clinical Immunology and Biomedical Statistics, 2nd Floor, North Block, Royal Perth Hospital, Wellington Street, Perth 6000, Western Australia
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32
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Khamsri B, Fujita M, Kamada K, Piroozmand A, Yamashita T, Uchiyama T, Adachi A. Effects of lysine to arginine mutations in HIV-1 Vif on its expression and viral infectivity. Int J Mol Med 2006; 18:679-83. [PMID: 16964423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023] Open
Abstract
We previously demonstrated that the expression in cells of human immunodeficiency virus type 1 (HIV-1) Vif is maintained at low level by proteasome-degradation. We examined the contribution of 16 lysines present in Vif (NL432 clone), which is composed of 192 amino acids (aa), to its expression within cells and to viral infectivity for non-permissive cells. To this end, various lysine-arginine mutations were introduced into wild-type (wt) Vif, and the mutational effects were monitored by transfection experiments. When all the lysines were changed to arginines, the mutant Vif was expressed in cells at much higher level than wt and was much more stable. Both N-terminal (aa nos. 34 and 36) and C-terminal (aa nos. 179 and 181) lysines were found to be almost sufficient for wt property. Different from this observation, one of the lysines at aa nos. 22 and 26 was demonstrated to be essential for the virus to grow in non-permissive cells. Our results showed that there is no clear co-relationship between the expression level of HIV-1 Vif and viral infectivity.
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Affiliation(s)
- Boonruang Khamsri
- Department of Virology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8503, Japan
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33
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Guo F, Cen S, Niu M, Saadatmand J, Kleiman L. Inhibition of tRNA₃(Lys)-primed reverse transcription by human APOBEC3G during human immunodeficiency virus type 1 replication. J Virol 2006; 80:11710-22. [PMID: 16971427 PMCID: PMC1642613 DOI: 10.1128/jvi.01038-06] [Citation(s) in RCA: 162] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Cells are categorized as being permissive or nonpermissive according to their ability to produce infectious human immunodeficiency virus type 1 (HIV-1) lacking the viral protein Vif. Nonpermissive cells express the human cytidine deaminase APOBEC3G (hA3G), and Vif has been shown to bind to APOBEC3G and facilitate its degradation. Vif-negative HIV-1 virions produced in nonpermissive cells incorporate hA3G and have a severely reduced ability to produce viral DNA in newly infected cells. While it has been proposed that the reduction in DNA production is due to hA3G-facilitated deamination of cytidine, followed by DNA degradation, we provide evidence here that a decrease in the synthesis of the DNA by reverse transcriptase may account for a significant part of this reduction. During the infection of cells with Vif-negative HIV-1 produced from 293T cells transiently expressing hA3G, much of the inhibition of early (> or =50% reduction) and late (> or =95% reduction) viral DNA production, and of viral infectivity (> or =95% reduction), can occur independently of DNA deamination. The inhibition of the production of early minus-sense strong stop DNA is also correlated with a similar inability of tRNA(3)(Lys) to prime reverse transcription. A similar reduction in tRNA(3)(Lys) priming and viral infectivity is also seen in the naturally nonpermissive cell H9, albeit at significantly lower levels of hA3G expression.
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Affiliation(s)
- Fei Guo
- Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 Cote St. Catherine Road, Montreal, Quebec, Canada H3T 1E2
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34
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Mezei M, Minarovits J. Reversal of HIV drug resistance and novel strategies to curb HIV infection: the viral infectivity factor Vif as a target and tool of therapy. Curr Drug Targets 2006; 7:881-5. [PMID: 16842218 DOI: 10.2174/138945006777709610] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Due to the high genetic variability of human immunodeficiency virus (HIV), treatment of AIDS (acquired immunodeficiency syndrome) patients with inhibitors of reverse trancriptase (RT) and drugs blocking the viral protease regularly results in the accumulation of drug resistant HIV variants and treatment failure. The sensitivity of clinically derived resistant HIV-1 strains to nucleotide RT inhibitors could be restored, however, in several laboratories by pharmacological depletion of the appropriate endogenous deoxynucleotide triphosphate (dNTP), and such a manipulation (induction of dCTP pool imbalance during reverse transcription in the presence of a non-nucleoside RT inhibitor) altered the mutation spectrum of the HIV-1 genome, resulting in a lower level of HIV resistance to certain drugs. The cytoplasmic single-stranded DNA cytidine deaminases APOBEC3G and APOBEC3F block HIV replication by introducing premature stop codons into the viral genome. We suggest that the resulting crippled, defective HIV (dHIV) variants could interfere with replication of "wild type" viruses and curbe disese progression in long term non-progressor individuals. Vif, an accessory protein encoded by HIV, counteracts APOBEC3G/F action. We speculate that small molecule inhibitors of Vif could permit lethal or sublethal mutagenesis of HIV genomes. We suggest that an artificial dHIV construct carrying a mutated vif gene (coding for a Vif protein unable to block APOBEC3G/F) could have a therapeutic effect as well in HIV infected individuals and AIDS patients.
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Affiliation(s)
- M Mezei
- Microbiological Research Group, National Center for Epidemiology, H-1529 Budapest, Piheno u. 1, Hungary
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35
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Vallanti G, Lupo R, Federico M, Mavilio F, Bovolenta C. T Lymphocytes transduced with a lentiviral vector expressing F12-Vif are protected from HIV-1 infection in an APOBEC3G-independent manner. Mol Ther 2006; 12:697-706. [PMID: 16039909 DOI: 10.1016/j.ymthe.2005.05.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2005] [Revised: 05/02/2005] [Accepted: 05/16/2005] [Indexed: 02/04/2023] Open
Abstract
The viral infectivity factor (Vif) is an essential component of the HIV-1 infectious cycle. Vif counteracts the action of the cytidine deaminase APOBEC3G (AP3G), which confers nonimmune antiviral defense against HIV-1 to T lymphocytes. Disabling or interfering with the function of Vif could represent an alternative therapeutic approach to AIDS. We have expressed a natural mutant of Vif, F12-Vif, in a VSV-G-pseudotyped lentiviral vector under the Tat-inducible control of the HIV-1 LTR. Conditional expression of F12-Vif prevents replication and spreading of both CXCR4 and CCR5 strains of HIV-1 in human primary T lymphocyte and T cell lines. T cells transduced with F12-Vif release few HIV-1 virions and with reduced infectivity. Several lines of evidence indicate that HIV-1 interference requires the presence of both wild-type and F12-Vif proteins, suggesting a dominant-negative feature of the F12-Vif mutant. Surprisingly, however, the F12-Vif-mediated inhibition does not depend on the reestablishment of the AP3G function.
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36
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Schröfelbauer B, Senger T, Manning G, Landau NR. Mutational alteration of human immunodeficiency virus type 1 Vif allows for functional interaction with nonhuman primate APOBEC3G. J Virol 2006; 80:5984-91. [PMID: 16731937 PMCID: PMC1472613 DOI: 10.1128/jvi.00388-06] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human APOBEC3F (hA3F) and APOBEC3G (hA3G) are antiretroviral cytidine deaminases that can be encapsidated during virus assembly to catalyze C-->U deamination of the viral reverse transcripts in the next round of infection. Lentiviruses such as human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) have evolved the accessory protein Vif to induce their degradation before packaging. HIV type 1 (HIV-1) Vif counteracts hA3G but not rhesus macaque APOBEC3G (rhA3G) or African green monkey (AGM) APOBEC3G (agmA3G) because of a failure to bind the nonhuman primate proteins. The species specificity of the interaction is controlled by amino acid 128, which is aspartate in hA3G and lysine in rhA3G. With the objective of overcoming this species restriction, mutations were introduced into HIV-1 Vif at amino acid positions that differed in charge between HIV-1 Vif and SIV Vif. The mutant proteins were tested for the ability to counteract hA3G, rhA3G, and agmA3G. Alteration of the conserved sequence at positions 14 to 17 from DRMR to SERQ, which is the sequence in AGM Vif, caused HIV-1 Vif to functionally interact with rhA3G and agmA3G. Mutation of three residues to the sequence SEMQ allowed interaction with rhA3G. SEMQ Vif also counteracted D128K mutant hA3G and wild-type hA3G. Introduction of the sequence into an infectious molecular HIV-1 clone allowed the virus to replicate productively in human cells that expressed rhA3G or hA3G. These findings provide insight into the interaction of Vif with A3G and are a step toward the development of a novel primate model for AIDS.
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Affiliation(s)
- Bärbel Schröfelbauer
- Infectious Disease Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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37
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Franca R, Spadari S, Maga G. APOBEC deaminases as cellular antiviral factors: a novel natural host defense mechanism. Med Sci Monit 2006; 12:RA92-8. [PMID: 16641889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2005] [Accepted: 11/25/2005] [Indexed: 05/08/2023] Open
Abstract
The APOBEC (acronym for apolipoprotein B editing catalytic polypeptide) family of cytidine deaminases are widely distributed in the biological world and play a central role in diverse enzymatic pathways. Members of this family (APOBEC3G and APOBEC3F) have been recently shown to be able to restrict HIV-1 replication in physiologically relevant target cells (macrophages, lymphocytes), presumably by triggering extensive deamination of the viral RNA/DNA replication intermediates. This natural antiretroviral host defense mechanism is counteracted by the HIV-1 protein Vif, which is able to target APOBECs to degrade. The so-called "Vif/APOBEC3G paradigm" has been confirmed by a growing literature. However, evidence arising from recent studies has expanded this view, showing that the replication of other viruses is also restricted by APOBEC family members and suggesting antiviral mechanism(s) of action unrelated to the catalytic activity of these proteins. Furthermore, evolutionary investigations on primates have shown that APOBEC3 gene expansion might be related to an ancient adaptive selection to prevent endogenous genetic instability, indicating an additional ancient protective role of APOBECs. This article is aimed at broadening the current knowledge about the antiviral activity of the APOBEC members and to highlight the notion that their role(s) might be more general than previously anticipated.
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Tian C, Yu X, Zhang W, Wang T, Xu R, Yu XF. Differential requirement for conserved tryptophans in human immunodeficiency virus type 1 Vif for the selective suppression of APOBEC3G and APOBEC3F. J Virol 2006; 80:3112-5. [PMID: 16501124 PMCID: PMC1395459 DOI: 10.1128/jvi.80.6.3112-3115.2006] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
APOBEC3G (A3G) and related cytidine deaminases, such as APOBEC3F (A3F), are potent inhibitors of retroviruses. Formation of infectious human immunodeficiency virus type 1 (HIV-1) requires suppression of multiple cytidine deaminases by Vif. Whether HIV-1 Vif recognizes various APOBEC3 proteins through a common mechanism is unclear. The domains in Vif that mediate APOBEC3 recognitions are also poorly defined. The N-terminal region of HIV-1 Vif is unusually rich in Trp residues, which are highly conserved. In the present study, we examined the role of these Trp residues in the suppression of APOBEC3 proteins by HIV-1 Vif. We found that most of the highly conserved Trp residues were required for efficient suppression of both A3G and A3F, but some of these residues were selectively required for the suppression of A3F but not A3G. Mutant Vif molecules in which Ala was substituted for Trp79 and, to a lesser extent, for Trp11 remained competent for A3G interaction and its suppression; however, they were defective for A3F interaction and therefore could not efficiently suppress the antiviral activity of A3F. Interestingly, while the HIV-1 Vif-mediated degradation of A3G was not affected by the different C-terminal tag peptides, that of A3F was significantly influenced by its C-terminal tags. These data indicate that the mechanisms by which HIV-1 Vif recognizes its target molecules, A3G and A3F, are not identical. The fact that several highly conserved residues in Vif are required for the suppression of A3F but not that of A3G suggests a critical role for A3F in the restriction of HIV-1 in vivo.
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Affiliation(s)
- Chunjuan Tian
- Second Affiliated Hospital, Cancer Institute, School of Medicine, Zhejiang University, Hangzhou, China
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39
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Santa-Marta M, Aires da Silva F, Fonseca AM, Rato S, Goncalves J. HIV-1 Vif protein blocks the cytidine deaminase activity of B-cell specific AID in E. coli by a similar mechanism of action. Mol Immunol 2006; 44:583-90. [PMID: 16580072 DOI: 10.1016/j.molimm.2006.02.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2005] [Revised: 01/24/2006] [Accepted: 02/07/2006] [Indexed: 01/27/2023]
Abstract
HIV-1 Vif protein protects viral replication in non-permissive cells by inducing degradation of APOBEC3G via ubiquitination and proteasomal pathway, although new studies indicate a putative role in Vif's direct inhibition of APOBEC3G. APOBEC3G is member of a homologous family of proteins with cytidine deaminase activity expressed with characteristic tissue specificity, that in humans consist of APOBEC1, APOBEC2, APOBEC3A-H, APOBEC4 and the activation-induced deaminase (AID), a B lymphoid protein necessary for somatic hypermutation, gene conversion and class switch recombination. In this work we show that Vif can counteract AID's activity in E. coli in absence of specific eukaryotic co-factors necessary for AID induced somatic hypermutation, gene conversion and to stimulate class switch recombination in B-cells. We show that AID inhibition is mediated by a direct protein-protein interaction via unique amino acid D118 an homologous mutant responsible for the species-specific restriction of HIV-1 Vif protein existent for APOBEC3G. These results raise the hypothesis that Vif related proteins can act as a broad inhibitor of deaminase activity. Moreover as AID and Vif evolved in different cellular environments, these results may indicate that Vif related proteins might mimic cellular factors that interact with a structural conserved domain of cytidine deaminases during evolution.
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Affiliation(s)
- Mariana Santa-Marta
- URIA-Centro de Patogénese Molecular, Faculdade de Farmácia, Universidade de Lisboa, 1649-019 Lisboa, Portugal
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40
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Barnor JS, Miyano-Kurosaki N, Takaku H, Yamaguchi K, Sakamoto A, Ishikawa K, Yamamoto N, Osei-Kwasi M, Ofori-Adjei D. The middle to 3' end of the HIV-1 vif gene sequence is important for vif biological activity and could be used for antisense oligonucleotide targets. Nucleosides Nucleotides Nucleic Acids 2006; 24:1745-61. [PMID: 16438045 DOI: 10.1080/10810730500265823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The human immunodeficiency virus type-1 (HIV-1)-encoded vif protein is essential for viral replication, virion production, and pathogenicity. HIV-1 Vif interacts with the endogenous human APOBEC3G protein (an mRNA editor) in target cells to prevent its encapsidation into virions. Some studies have established targets within the HIV-1 vif gene that are important for its biologic function; however, it is important to determine effective therapeutic targets in vif because of its critical role in HIV-1 infectivity and pathogenicity. The present study demonstrates that virions generated in transfected HeLa-CD4+ cells, especially from HIV-1 vif frame-shift mutant (3' delta vif; 5561-5849), were affected in splicing and had low infectivity in MT-4 cells. In addition, HIV-1 vif antisense RNA fragments constructed within the same region, notably the region spanning nucleic acid positions 5561-5705 (M-3'-AS), which corresponds to amino acid residues 96-144, significantly inhibited HIV-1 replication in MT-4 and reduced the HIV-1 vif mRNA transcripts and reporter gene (EGFP) expression. The generated virions showed low secondary infection in H9 cells. These data therefore suggest that the middle to the 3' end of vif is important for its biological activity in the target cells.
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Affiliation(s)
- Jacob Samson Barnor
- Department of Life and Environmental Science, Chiba Institute of Technology, Tsudanuma, Narashino, Chiba, Japan
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41
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Xiao Z, Ehrlich E, Yu Y, Luo K, Wang T, Tian C, Yu XF. Assembly of HIV-1 Vif-Cul5 E3 ubiquitin ligase through a novel zinc-binding domain-stabilized hydrophobic interface in Vif. Virology 2006; 349:290-9. [PMID: 16530799 DOI: 10.1016/j.virol.2006.02.002] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Revised: 01/02/2006] [Accepted: 02/02/2006] [Indexed: 02/08/2023]
Abstract
APOBEC3G (A3G) and related cytidine deaminases are potent inhibitors of retroviruses. HIV-1 Vif hijacks the cellular Cul5-E3 ubiquitin ligase to degrade APOBEC3 proteins and render them ineffective against these viruses. Here, we report that HIV-1 Vif is a novel zinc-binding protein containing an H-x(5)-C-x(17-18)-C-x(3-5)-H motif that is distinct from other recognized classes of zinc fingers. Zinc-binding stabilized a conserved hydrophobic interface within the HCCH motif that is critical for Vif-Cul5 E3 assembly and Vif function. An N-terminal region in the first Cullin repeat of Cul5, which is dispensable for adaptor ElonginC binding, was required for interaction with Vif. This region is the most divergent sequence between Cul2 and Cul5, a factor that may contribute to the selection of Cul5 and not Cul2 by Vif. This is the first example of a zinc-binding substrate receptor responsible for the assembly of a Cullin-RING ligase, representing a new target for antiviral development.
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Affiliation(s)
- Zuoxiang Xiao
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
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42
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Verheije MH, Würdinger T, van Beusechem VW, de Haan CAM, Gerritsen WR, Rottier PJM. Redirecting coronavirus to a nonnative receptor through a virus-encoded targeting adapter. J Virol 2006; 80:1250-60. [PMID: 16415002 PMCID: PMC1346946 DOI: 10.1128/jvi.80.3.1250-1260.2006] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Murine hepatitis coronavirus (MHV)-A59 infection depends on the interaction of its spike (S) protein with the cellular receptor mCEACAM1a present on murine cells. Human cells lack this receptor and are therefore not susceptible to MHV. Specific alleviation of the tropism barrier by redirecting MHV to a tumor-specific receptor could lead to a virus with appealing properties for tumor therapy. To demonstrate that MHV can be retargeted to a nonnative receptor on human cells, we produced bispecific adapter proteins composed of the N-terminal D1 domain of mCEACAM1a linked to a short targeting peptide, the six-amino-acid His tag. Preincubation of MHV with the adapter proteins and subsequent inoculation of human cells expressing an artificial His receptor resulted in infection of these otherwise nonsusceptible cells and led to subsequent production of progeny virus. To generate a self-targeted virus able to establish multiround infection of the target cells, we subsequently incorporated the gene encoding the bispecific adapter protein as an additional expression cassette into the MHV genome through targeted RNA recombination. When inoculated onto murine LR7 cells, the resulting recombinant virus indeed expressed the adapter protein. Furthermore, inoculation of human target cells with the virus resulted in a His receptor-specific infection that was multiround. Extensive cell-cell fusion and rapid cell killing of infected target cells was observed. Our results show that MHV can be genetically redirected via adapters composed of the S protein binding part of mCEACAM1a and a targeting peptide recognizing a nonnative receptor expressed on human cells, consequently leading to rapid cell death. The results provide interesting leads for further investigations of the use of coronaviruses as antitumor agents.
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Affiliation(s)
- M H Verheije
- Virology Division, Department of Infectious Diseases and Immunology, Utrecht University, 3584 CL Utrecht, The Netherlands
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43
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Pupecka M, Pacak A. [The innate antiretroviral defense of human cells, based on the DNA editing]. Postepy Biochem 2006; 52:247-52. [PMID: 17201059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The editing process may play an essential role in the antiviral cell defense. The human cytidine deaminase APOBEC3G, that catalyses the deoxycytidine to deoxyuridine deamination reaction in the reverse transcript of the HIV-1 genome, leads to instability of the viral DNA, if only HIV-1 virion is defective and lacks the Vif protein. This mechanism has an affect on G-A hipermutation appearing in the provirus DNA and defective HIV-1 viral RNA, yielded in infected cell. Such hipermutation has previously been discovered in the viral HIV-1 genome, produced in peripheral blood mononuclears that were long-term cultured after collection from infected patient. Probably, the deamination reaction that is inhibited in the wild type HIV-1 by the Vif protein, occurs rarely during infection and thus increases viral diversity and drug's resistance. In this review, we present the results of latest studies concerning the mechanism of viral DNA deamination, specifity of this process and APOBEC3G - HIV-1 Vif interactions, that may be useful in designing the new anti-HIV therapies.
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Affiliation(s)
- Małgorzata Pupecka
- Institute of Human Genetics Polish Academy of Sciences, 32 Strzeszyńska St., 60-479 Poznań, Poland
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44
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Barnor JS, Miyano-Kurosaki N, Yamaguchi K, Abumi Y, Ishikawa K, Yamamoto N. Lentiviral-mediated delivery of combined HIV-1 decoy TAR and Vif siRNA as a single RNA molecule that cleaves to inhibit HIV-1 in transduced cells. Nucleosides Nucleotides Nucleic Acids 2005; 24:431-4. [PMID: 16247965 DOI: 10.1081/ncn-200059981] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
RNA interference (RNAi) silences gene expression via short interfering 21-23 mer double-stranded RNA (siRNA) segments that guide cognate mRNA degradation in a sequence-specific manner. On the other hand, HIV-1 decoy TAR RNA are known to competitively interact with the HIV-1 Tat protein, to downregulate the enhanced gene expression from the long terminal repeat (LTR) promoters. Here we report that a novel expression construct, encoding both HIV-1 decoy TAR and Vif siRNA, as a single RNA substrate, was expressed under the control of the human U6 promoter, and later the TAR and siRNA were cleaved into their respective separate RNA by the endogenous RNase III-like enzyme. Each of the cleaved HIV-1 anti-genes then synergistically contributed toward enhancing the inhibition efficacy (>80%) of HIV-1 replication in transduced Jurkat cells. These results suggest that targeting HIV-1 mRNA with simultaneously expressed intracellular decoy TAR and Vif-siRNA could lead to an effective gene therapy strategy for the control and management of HIV-AIDS.
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Affiliation(s)
- Jacob Samson Barnor
- Department of Life and Environmental Science, Chiba Institute of Technology, Chiba, Japan
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45
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Abstract
We have constructed reading frames for the HIV-1 YU-2 minor proteins Vpr, Vpu, Vif and Nef that are codon-optimized for high-level expression in mammalian cells. We show that, in the absence of the Rev/Rev-response element system, these codon-optimized reading frames result in greatly increased levels of expression of the corresponding proteins in cell culture systems when compared with the native reading frame. Northern blot analysis shows that the increase in expression found with the codon-optimized reading frames is largely owing to increased steady-state mRNA levels.
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MESH Headings
- Blotting, Northern
- Blotting, Western
- Codon
- Gene Expression
- Gene Expression Regulation, Viral
- Gene Products, nef/biosynthesis
- Gene Products, nef/genetics
- Gene Products, vif/biosynthesis
- Gene Products, vif/genetics
- Gene Products, vpr/biosynthesis
- Gene Products, vpr/genetics
- Genes, nef
- Genes, vif
- Genes, vpr
- Genes, vpu
- HIV-1/genetics
- HIV-1/metabolism
- Human Immunodeficiency Virus Proteins
- RNA, Messenger/biosynthesis
- Reading Frames
- Viral Regulatory and Accessory Proteins/biosynthesis
- Viral Regulatory and Accessory Proteins/genetics
- nef Gene Products, Human Immunodeficiency Virus
- vif Gene Products, Human Immunodeficiency Virus
- vpr Gene Products, Human Immunodeficiency Virus
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Affiliation(s)
- D S Anson
- Department of Genetic Medicine, Children, Youth, and Women's Health Service, 72 King William Road, North Adelaide, Australia.
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46
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Gudmundsson B, Jónsson SR, Olafsson O, Agnarsdóttir G, Matthíasdóttir S, Georgsson G, Torsteinsdóttir S, Svansson V, Kristbjornsdóttir HB, Franzdóttir SR, Andrésson OS, Andrésdóttir V. Simultaneous mutations in CA and Vif of Maedi-Visna virus cause attenuated replication in macrophages and reduced infectivity in vivo. J Virol 2005; 79:15038-42. [PMID: 16306574 PMCID: PMC1316017 DOI: 10.1128/jvi.79.24.15038-15042.2005] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Accepted: 09/20/2005] [Indexed: 11/20/2022] Open
Abstract
Maedi-visna virus (MVV) is a lentivirus of sheep sharing several key features with the primate lentiviruses. The virus causes slowly progressive diseases, mainly in the lungs and the central nervous system of sheep. Here, we investigate the molecular basis for the differential growth phenotypes of two MVV isolates. One of the isolates, KV1772, replicates well in a number of cell lines and is highly pathogenic in sheep. The second isolate, KS1, no longer grows on macrophages or causes disease. The two virus isolates differ by 129 nucleotide substitutions and two deletions of 3 and 15 nucleotides in the env gene. To determine the molecular nature of the lesions responsible for the restrictive growth phenotype, chimeric viruses were constructed and used to map the phenotype. An L120R mutation in the CA domain, together with a P205S mutation in Vif (but neither alone), could fully convert KV1772 to the restrictive growth phenotype. These results suggest a functional interaction between CA and Vif in MVV replication, a property that may relate to the innate antiretroviral defense mechanisms in sheep.
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Affiliation(s)
- Bjarki Gudmundsson
- Institute for Experimental Pathology, University of Iceland, Keldur v/Vesturlandsveg, 112 Reykjavík, Iceland
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47
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Cao J, Isaacson J, Patick AK, Blair WS. High-throughput human immunodeficiency virus type 1 (HIV-1) full replication assay that includes HIV-1 Vif as an antiviral target. Antimicrob Agents Chemother 2005; 49:3833-41. [PMID: 16127060 PMCID: PMC1195408 DOI: 10.1128/aac.49.9.3833-3841.2005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antiviral screens have proved useful for the identification of novel human immunodeficiency virus type 1 (HIV-1) inhibitors. In this study, we describe an HIV-1 full replication (HIV-1 Rep) assay that incorporates all of the targets required for replication in T-cell lines, including the HIV-1 Vif gene. The HIV-1 Rep assay was designed to exhibit optimal sensitivity to late-stage as well as early-stage inhibitors to maximize the likelihood of identification of novel target antiviral compounds in a screen. In addition, the flexibility of the HIV-1 Rep assay allows the rapid evaluation of antiviral compounds against different virus strains in different T-cell lines without significant modification of the assay format. We demonstrate that the HIV-1 Rep assay exhibits characteristics (e.g., a favorable Z' value) compatible with high-throughput screening in a 384-well format. The utility of the HIV-1 Rep assay was demonstrated in a high-throughput screen of >10(6) compounds. To our knowledge, this study represents the first example of an HIV-1 antiviral screen that includes Vif as a functional target and was executed on an industrial scale.
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Affiliation(s)
- Joan Cao
- Department of Virology, Pfizer Global Research and Development, La Jolla Laboratories, 10777 Science Center Dr. (CB1), San Diego, CA 92121-1111, USA
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48
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Victoria JG, Robinson WE. Disruption of the putative splice acceptor site for SIV(mac239)Vif reveals tight control of SIV splicing and impaired replication in Vif non-permissive cells. Virology 2005; 338:281-91. [PMID: 15950999 DOI: 10.1016/j.virol.2005.05.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2005] [Revised: 04/25/2005] [Accepted: 05/06/2005] [Indexed: 11/24/2022]
Abstract
Vif is dispensable for simian immunodeficiency virus (SIV) replication in some cells, termed permissive (i.e., CEM-SS), but not in others, termed non-permissive (i.e., H9, CEMx174, and peripheral blood lymphocytes). Non-permissive cells express the RNA editing enzyme, APOBEC3G. To determine whether vif mRNA could be alternatively spliced, a mutation altering the putative vif splice acceptor site (SA1) was introduced into SIV(mac239) (SIV(Deltavif-SA)). Despite three consensus splice acceptor sites nearby SA1, SIV(Deltavif-SA) did not efficiently generate alternatively spliced vif mRNA. SIV(Deltavif-SA) was growth attenuated in CEMx174 and H9 cells but not in CEM-SS cells. Following SIV(Deltavif-SA), but not SIV(mac239), infection in either H9 or CEMx174 cells viral cDNA contained numerous G to A mutations; no such differences were observed in CEM-SS cells. This pattern is consistent with mutations generated by APOBEC3G in the absence of Vif. Therefore, efficient splicing of SIV vif mRNA is tightly controlled and requires the SA1 site.
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Affiliation(s)
- Joseph G Victoria
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA 92697-4800, USA
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49
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Luo K, Xiao Z, Ehrlich E, Yu Y, Liu B, Zheng S, Yu XF. Primate lentiviral virion infectivity factors are substrate receptors that assemble with cullin 5-E3 ligase through a HCCH motif to suppress APOBEC3G. Proc Natl Acad Sci U S A 2005; 102:11444-9. [PMID: 16076960 PMCID: PMC1182177 DOI: 10.1073/pnas.0502440102] [Citation(s) in RCA: 154] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Cullin-Ring E3 ubiquitin ligases target substrates for ubiquitin-dependent, proteasome-mediated degradation and regulate critical cellular processes. These cullins assemble with cellular substrate receptor proteins through specific adaptor molecules. F-box- and BC-box-containing receptors use Skp1, ElonginB, and ElonginC as adaptors to recruit Cul1/Cul7 and Cul2/Cul5, respectively. At present, the determinants of Cul2 vs. Cul5 specificity for the BC-box-containing receptors are poorly defined. Here, we demonstrate that primate lentiviral Vif (virion infectivity factor) proteins represent previously uncharacterized substrate receptor proteins that contain divergent BC-box motifs. These molecules selectively assemble with a Cul5-E3 ligase to suppress the antiviral activity of autologous cytidine deaminase APOBEC3G. A previously unrecognized Hx5Cx(17-18)Cx(3-5)H motif that is highly conserved among all primate lentiviral Vif proteins was found to be critical for the selective assembly and activity of Vif-Cul5-E3 ligase. Non-primate lentiviral Vif proteins, which lack this HCCH motif, displayed reduced interaction with Cul5. These data suggest that in addition to target protein specificity, substrate receptor proteins play important roles in cullin selection and functional assembly of cullin-Ring E3 ligases. The discovery of these viral substrate receptor molecules that recruit Cul5 through distinct mechanisms from cellular proteins may facilitate the identification of additional cellular factors that regulate cellular functions through Cul5-E3 ligase. Motifs in Vif that are absent from cellular proteins could also be targets for the development of innovative therapeutics.
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Affiliation(s)
- Kun Luo
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
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Farrow MA, Somasundaran M, Zhang C, Gabuzda D, Sullivan JL, Greenough TC. Nuclear localization of HIV type 1 Vif isolated from a long-term asymptomatic individual and potential role in virus attenuation. AIDS Res Hum Retroviruses 2005; 21:565-74. [PMID: 15989462 DOI: 10.1089/aid.2005.21.565] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recent reports have determined that HIV-1 Vif counteracts an innate antiviral cellular factor, Apobec3G. However, the function of Vif during HIV-1 pathogenesis remains poorly understood. To gain a better understanding of Vif function, the viral isolate from an HIV-1-infected long-term nonprogressor (LTNP) that displayed a Vif-mutant replication phenotype was studied. This LTNP has been infected since before 1983 and has no HIV-related disease in the absence of antiretroviral therapy. From separate samples, obtained on more than one study visit, virus grew in cocultures of LTNP cells with Vif-complementing T cell lines, but not the parental T cell lines. An unusual amino acid motif (KKRK) was found in the Vif sequence at positions 90 to 93. Since this motif commonly functions as a nuclear localization sequence, experiments were performed to determine the ability of this KKRK motif to mediate nuclear localization of Vif. Wild-type Vif displayed a predominantly cytoplasmic distribution. In contrast, the KKRK Vif showed a predominantly nuclear localization. The effect of the KKRK mutation on virus production and infectivity was also studied. The KKRK motif that mislocalizes Vif to the nucleus also reduces viral replication and infectivity in nonpermissive cells. Our data highlight the importance of Vif in HIV-1 pathogenesis and also provide a unique tool to investigate the interaction of Vif and Apobec3G.
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Affiliation(s)
- Melissa A Farrow
- Program in Molecular Medicine and Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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