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Patra AT, Tan E, Kok YJ, Ng SK, Bi X. Temporal insights into molecular and cellular responses during rAAV production in HEK293T cells. Mol Ther Methods Clin Dev 2024; 32:101278. [PMID: 39022743 PMCID: PMC11253160 DOI: 10.1016/j.omtm.2024.101278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 06/04/2024] [Indexed: 07/20/2024]
Abstract
The gene therapy field seeks cost-effective, large-scale production of recombinant adeno-associated virus (rAAV) vectors for high-dosage therapeutic applications. Although strategies like suspension cell culture and transfection optimization have shown moderate success, challenges persist for large-scale applications. To unravel molecular and cellular mechanisms influencing rAAV production, we conducted an SWATH-MS proteomic analysis of HEK293T cells transfected using standard, sub-optimal, and optimal conditions. Gene Ontology and pathway analysis revealed significant protein expression variations, particularly in processes related to cellular homeostasis, metabolic regulation, vesicular transport, ribosomal biogenesis, and cellular proliferation under optimal transfection conditions. This resulted in a 50% increase in rAAV titer compared with the standard protocol. Additionally, we identified modifications in host cell proteins crucial for AAV mRNA stability and gene translation, particularly regarding AAV capsid transcripts under optimal transfection conditions. Our study identified 124 host proteins associated with AAV replication and assembly, each exhibiting distinct expression pattern throughout rAAV production stages in optimal transfection condition. This investigation sheds light on the cellular mechanisms involved in rAAV production in HEK293T cells and proposes promising avenues for further enhancing rAAV titer during production.
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Affiliation(s)
- Alok Tanala Patra
- Bioprocessing Technology Institute (BTI), Agency for Science, Technology and Research (A∗STAR), Singapore 138668, Singapore
| | - Evan Tan
- Bioprocessing Technology Institute (BTI), Agency for Science, Technology and Research (A∗STAR), Singapore 138668, Singapore
| | - Yee Jiun Kok
- Bioprocessing Technology Institute (BTI), Agency for Science, Technology and Research (A∗STAR), Singapore 138668, Singapore
| | - Say Kong Ng
- Bioprocessing Technology Institute (BTI), Agency for Science, Technology and Research (A∗STAR), Singapore 138668, Singapore
| | - Xuezhi Bi
- Bioprocessing Technology Institute (BTI), Agency for Science, Technology and Research (A∗STAR), Singapore 138668, Singapore
- Duke-NUS Medical School, National University of Singapore, Singapore 169857, Singapore
- Food, Chemical and Biotechnology Cluster, Singapore Institute of Technology, Singapore 138683, Singapore
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2
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Sarker S. Wildlife Viruses: Impact on Human and Animal Health. Viruses 2024; 16:1244. [PMID: 39205217 PMCID: PMC11360671 DOI: 10.3390/v16081244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2024] [Accepted: 07/30/2024] [Indexed: 09/04/2024] Open
Abstract
In recent years, there has been a significant rise in the appearance of new viral infectious diseases among wildlife populations globally [...].
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Affiliation(s)
- Subir Sarker
- Biomedical Sciences and Molecular Biology, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, QLD 4811, Australia;
- Australian Institute of Tropical Health and Medicine, James Cook University, Townsville, QLD 4811, Australia
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3
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Cheng C, Tan MJA, Chan KWK, Choy MMJ, Roman N, Arnold DDR, Bifani AM, Kong SYZ, Bist P, Nath BK, Swarbrick CMD, Forwood JK, Vasudevan SG. Serotype-Specific Regulation of Dengue Virus NS5 Protein Subcellular Localization. ACS Infect Dis 2024; 10:2047-2062. [PMID: 38811007 PMCID: PMC11184549 DOI: 10.1021/acsinfecdis.4c00054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 05/01/2024] [Accepted: 05/02/2024] [Indexed: 05/31/2024]
Abstract
Dengue virus (DENV) nonstructural protein 5 (NS5), consisting of methyltransferase and RNA-dependent RNA polymerase (RdRp) domains, is critical for viral RNA synthesis within endoplasmic reticulum-derived replication complexes in the cytoplasm. However, a significant proportion of NS5 is localized to the nucleus of infected cells for DENV2, 3, and 4, whereas DENV1 NS5 is localized diffusely in the cytoplasm. We still have an incomplete understanding of how the DENV NS5 subcellular localization is regulated. Within NS5, two putative nuclear localization signal (NLS) sequences have been identified: NLSCentral residing in the palm of the RdRp domain as well as the recently discovered NLSC-term residing in the flexible region at the C-terminal of the RdRp domain. We have previously shown that DENV2 NS5 nuclear localization can be significantly reduced by single-point mutations to the NLSC-term. Here, we present biochemical, virological, and structural data demonstrating that the relative importance of either NLS in NS5 nuclear localization is unique to each of the four DENV serotypes. DENV1 NS5's cytoplasmic localization appears to be due to a functionally weak interaction between its NLSCentral and importin-α (IMPα), while DENV2 NS5 is almost exclusively nuclear through its NLSC-term's strong interaction with IMPα. Both NLSs of DENV3 NS5 appear to contribute to directing its nuclear localization. Lastly, in the case of DENV4, the regulation of its NS5 nuclear localization remains an enigma but appears to be associated with its NLSC-term.
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Affiliation(s)
- Colin
Xinru Cheng
- Programme
in Emerging Infectious Diseases, Duke-NUS
Medical School, Singapore 169857, Singapore
| | - Min Jie Alvin Tan
- Programme
in Emerging Infectious Diseases, Duke-NUS
Medical School, Singapore 169857, Singapore
| | - Kitti Wing Ki Chan
- Programme
in Emerging Infectious Diseases, Duke-NUS
Medical School, Singapore 169857, Singapore
| | - Milly Ming Ju Choy
- Programme
in Emerging Infectious Diseases, Duke-NUS
Medical School, Singapore 169857, Singapore
| | - Noelia Roman
- School
of Dentistry and Medical Sciences, Charles
Sturt University, Wagga
Wagga, NSW 2678, Australia
| | - Daniel D. R. Arnold
- Programme
in Emerging Infectious Diseases, Duke-NUS
Medical School, Singapore 169857, Singapore
- School
of Dentistry and Medical Sciences, Charles
Sturt University, Wagga
Wagga, NSW 2678, Australia
| | - Amanda Makha Bifani
- Programme
in Emerging Infectious Diseases, Duke-NUS
Medical School, Singapore 169857, Singapore
| | - Sean Yao Zu Kong
- Programme
in Emerging Infectious Diseases, Duke-NUS
Medical School, Singapore 169857, Singapore
| | - Pradeep Bist
- Programme
in Emerging Infectious Diseases, Duke-NUS
Medical School, Singapore 169857, Singapore
| | - Babu K. Nath
- School
of Dentistry and Medical Sciences, Charles
Sturt University, Wagga
Wagga, NSW 2678, Australia
| | - Crystall M. D. Swarbrick
- Programme
in Emerging Infectious Diseases, Duke-NUS
Medical School, Singapore 169857, Singapore
- Biosecurity
Research Program and Training Centre, Gulbali Institute, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
- Institute
for Glycomics, Griffith University, Southport 4222, Australia
| | - Jade K. Forwood
- School
of Dentistry and Medical Sciences, Charles
Sturt University, Wagga
Wagga, NSW 2678, Australia
- Biosecurity
Research Program and Training Centre, Gulbali Institute, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
| | - Subhash G. Vasudevan
- Programme
in Emerging Infectious Diseases, Duke-NUS
Medical School, Singapore 169857, Singapore
- Department
of Microbiology and Immunology, National
University of Singapore, Singapore 117545, Singapore
- Institute
for Glycomics, Griffith University, Southport 4222, Australia
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4
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Hoad M, Roby JA, Forwood JK. Structural basis for nuclear import of bat adeno-associated virus capsid protein. J Gen Virol 2024; 105:001960. [PMID: 38441555 PMCID: PMC10999750 DOI: 10.1099/jgv.0.001960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 01/22/2024] [Indexed: 03/07/2024] Open
Abstract
Adeno-associated viruses (AAV) are one of the world's most promising gene therapy vectors and as a result, are one of the most intensively studied viral vectors. Despite a wealth of research into these vectors, the precise characterisation of AAVs to translocate into the host cell nucleus remains unclear. Recently we identified the nuclear localization signals of an AAV porcine strain and determined its mechanism of binding to host importin proteins. To expand our understanding of diverse AAV import mechanisms we sought to determine the mechanism in which the Cap protein from a bat-infecting AAV can interact with transport receptor importins for translocation into the nucleus. Using a high-resolution crystal structure and quantitative assays, we were able to not only determine the exact region and residues of the N-terminal domain of the Cap protein which constitute the functional NLS for binding with the importin alpha two protein, but also reveal the differences in binding affinity across the importin-alpha isoforms. Collectively our results allow for a detailed molecular view of the way AAV Cap proteins interact with host proteins for localization into the cell nucleus.
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Affiliation(s)
- Mikayla Hoad
- School of Dentistry and Medical Sciences, Charles Sturt University, Wagga Wagga, NSW, 2678, Australia
| | - Justin A. Roby
- School of Dentistry and Medical Sciences, Charles Sturt University, Wagga Wagga, NSW, 2678, Australia
- Gulbali Institute, Charles Sturt University, Wagga Wagga, NSW, 2678, Australia
| | - Jade K. Forwood
- School of Dentistry and Medical Sciences, Charles Sturt University, Wagga Wagga, NSW, 2678, Australia
- Gulbali Institute, Charles Sturt University, Wagga Wagga, NSW, 2678, Australia
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Cross EM, Akbari N, Ghassabian H, Hoad M, Pavan S, Ariawan D, Donnelly CM, Lavezzo E, Petersen GF, Forwood JK, Alvisi G. A functional and structural comparative analysis of large tumor antigens reveals evolution of different importin α-dependent nuclear localization signals. Protein Sci 2024; 33:e4876. [PMID: 38108201 PMCID: PMC10807245 DOI: 10.1002/pro.4876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 12/19/2023]
Abstract
Nucleocytoplasmic transport regulates the passage of proteins between the nucleus and cytoplasm. In the best characterized pathway, importin (IMP) α bridges cargoes bearing basic, classical nuclear localization signals (cNLSs) to IMPβ1, which mediates transport through the nuclear pore complex. IMPα recognizes three types of cNLSs via two binding sites: the major binding site accommodates monopartite cNLSs, the minor binding site recognizes atypical cNLSs, while bipartite cNLSs simultaneously interact with both major and minor sites. Despite the growing knowledge regarding IMPα-cNLS interactions, our understanding of the evolution of cNLSs is limited. We combined bioinformatic, biochemical, functional, and structural approaches to study this phenomenon, using polyomaviruses (PyVs) large tumor antigens (LTAs) as a model. We characterized functional cNLSs from all human (H)PyV LTAs, located between the LXCXE motif and origin binding domain. Surprisingly, the prototypical SV40 monopartite NLS is not well conserved; HPyV LTA NLSs are extremely heterogenous in terms of structural organization, IMPα isoform binding, and nuclear targeting abilities, thus influencing the nuclear accumulation properties of full-length proteins. While several LTAs possess bipartite cNLSs, merkel cell PyV contains a hybrid bipartite cNLS whose upstream stretch of basic amino acids can function as an atypical cNLS, specifically binding to the IMPα minor site upon deletion of the downstream amino acids after viral integration in the host genome. Therefore, duplication of a monopartite cNLS and subsequent accumulation of point mutations, optimizing interaction with distinct IMPα binding sites, led to the evolution of bipartite and atypical NLSs binding at the minor site.
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Affiliation(s)
- Emily M. Cross
- School of Dentistry and Medical SciencesCharles Sturt UniversityWagga WaggaAustralia
- Diamond Light SourceHarwell Science and Innovation CampusDidcotUnited Kingdom
| | - Nasim Akbari
- Department of Molecular MedicineUniversity of PadovaPadovaItaly
| | | | - Mikayla Hoad
- School of Dentistry and Medical SciencesCharles Sturt UniversityWagga WaggaAustralia
| | - Silvia Pavan
- Department of Molecular MedicineUniversity of PadovaPadovaItaly
| | - Daryl Ariawan
- Dementia Research CentreMacquarie UniversitySydneyAustralia
| | - Camilla M. Donnelly
- School of Dentistry and Medical SciencesCharles Sturt UniversityWagga WaggaAustralia
| | - Enrico Lavezzo
- Department of Molecular MedicineUniversity of PadovaPadovaItaly
| | | | - Jade K. Forwood
- School of Dentistry and Medical SciencesCharles Sturt UniversityWagga WaggaAustralia
- Gulbali InstituteCharles Sturt UniversityWagga WaggaAustralia
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6
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Alvisi G, Manaresi E, Cross EM, Hoad M, Akbari N, Pavan S, Ariawan D, Bua G, Petersen GF, Forwood J, Gallinella G. Importin α/β-dependent nuclear transport of human parvovirus B19 nonstructural protein 1 is essential for viral replication. Antiviral Res 2023; 213:105588. [PMID: 36990397 DOI: 10.1016/j.antiviral.2023.105588] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/08/2023] [Accepted: 03/25/2023] [Indexed: 03/30/2023]
Abstract
Human parvovirus B19 (B19V) is a major human pathogen causing a variety of diseases, characterized by a selective tropism to human progenitor cells in bone marrow. In similar fashion to all Parvoviridae members, the B19V ssDNA genome is replicated within the nucleus of infected cells through a process which involves both cellular and viral proteins. Among the latter, a crucial role is played by non-structural protein (NS)1, a multifunctional protein involved in genome replication and transcription, as well as modulation of host gene expression and function. Despite the localization of NS1 within the host cell nucleus during infection, little is known regarding the mechanism of its nuclear transport pathway. In this study we undertake structural, biophysical, and cellular approaches to characterize this process. Quantitative confocal laser scanning microscopy (CLSM), gel mobility shift, fluorescence polarization and crystallographic analysis identified a short sequence of amino acids (GACHAKKPRIT-182) as the classical nuclear localization signal (cNLS) responsible for nuclear import, mediated in an energy and importin (IMP) α/β-dependent fashion. Structure-guided mutagenesis of key residue K177 strongly impaired IMPα binding, nuclear import, and viral gene expression in a minigenome system. Further, treatment with ivermectin, an antiparasitic drug interfering with the IMPα/β dependent nuclear import pathway, inhibited NS1 nuclear accumulation and viral replication in infected UT7/Epo-S1 cells. Thus, NS1 nuclear transport is a potential target of therapeutic intervention against B19V induced disease.
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Affiliation(s)
- Gualtiero Alvisi
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy.
| | - Elisabetta Manaresi
- Department of Pharmacy and Biotechnology, University of Bologna, 40138, Bologna, Italy
| | - Emily M Cross
- School of Dentistry and Medical Sciences, Charles Sturt University, Wagga Wagga, NSW, 2650, Australia
| | - Mikayla Hoad
- School of Dentistry and Medical Sciences, Charles Sturt University, Wagga Wagga, NSW, 2650, Australia
| | - Nasim Akbari
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy
| | - Silvia Pavan
- Department of Molecular Medicine, University of Padova, 35121, Padova, Italy
| | - Daryl Ariawan
- Dementia Research Centre, Macquarie University, Sydney, NSW, 2109, Australia
| | - Gloria Bua
- Department of Pharmacy and Biotechnology, University of Bologna, 40138, Bologna, Italy
| | - Gayle F Petersen
- School of Dentistry and Medical Sciences, Charles Sturt University, Wagga Wagga, NSW, 2650, Australia
| | - Jade Forwood
- School of Dentistry and Medical Sciences, Charles Sturt University, Wagga Wagga, NSW, 2650, Australia
| | - Giorgio Gallinella
- Department of Pharmacy and Biotechnology, University of Bologna, 40138, Bologna, Italy
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