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Guo QR, Cao YJ. Applications of genetic code expansion technology in eukaryotes. Protein Cell 2024; 15:331-363. [PMID: 37847216 PMCID: PMC11074999 DOI: 10.1093/procel/pwad051] [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: 07/04/2023] [Accepted: 09/26/2023] [Indexed: 10/18/2023] Open
Abstract
Unnatural amino acids (UAAs) have gained significant attention in protein engineering and drug development owing to their ability to introduce new chemical functionalities to proteins. In eukaryotes, genetic code expansion (GCE) enables the incorporation of UAAs and facilitates posttranscriptional modification (PTM), which is not feasible in prokaryotic systems. GCE is also a powerful tool for cell or animal imaging, the monitoring of protein interactions in target cells, drug development, and switch regulation. Therefore, there is keen interest in utilizing GCE in eukaryotic systems. This review provides an overview of the application of GCE in eukaryotic systems and discusses current challenges that need to be addressed.
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Affiliation(s)
- Qiao-ru Guo
- State Key Laboratory of Chemical Oncogenomic, Guangdong Provincial Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Yu J Cao
- State Key Laboratory of Chemical Oncogenomic, Guangdong Provincial Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
- Institute of Chemical Biology, Shenzhen Bay Laboratory, Shenzhen 518132, China
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2
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Board NL, Yuan Z, Wu F, Moskovljevic M, Ravi M, Sengupta S, Mun SS, Simonetti FR, Lai J, Tebas P, Lynn K, Hoh R, Deeks SG, Siliciano JD, Montaner LJ, Siliciano RF. Bispecific antibodies promote natural killer cell-mediated elimination of HIV-1 reservoir cells. Nat Immunol 2024; 25:462-470. [PMID: 38278966 PMCID: PMC10907297 DOI: 10.1038/s41590-023-01741-5] [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: 06/08/2023] [Accepted: 12/28/2023] [Indexed: 01/28/2024]
Abstract
The persistence of CD4+ T cells carrying latent human immunodeficiency virus-1 (HIV-1) proviruses is the main barrier to a cure. New therapeutics to enhance HIV-1-specific immune responses and clear infected cells will probably be necessary to achieve reduction of the latent reservoir. In the present study, we report two single-chain diabodies (scDbs) that target the HIV-1 envelope protein (Env) and the human type III Fcγ receptor (CD16). We show that the scDbs promoted robust and HIV-1-specific natural killer (NK) cell activation and NK cell-mediated lysis of infected cells. Cocultures of CD4+ T cells from people with HIV-1 on antiretroviral therapy (ART) with autologous NK cells and the scDbs resulted in marked elimination of reservoir cells that was dependent on latency reversal. Treatment of human interleukin-15 transgenic NSG mice with one of the scDbs after ART initiation enhanced NK cell activity and reduced reservoir size. Thus, HIV-1-specific scDbs merit further evaluation as potential therapeutics for clearance of the latent reservoir.
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Affiliation(s)
- Nathan L Board
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Zhe Yuan
- The Wistar Institute, Philadelphia, PA, USA
| | - Fengting Wu
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Milica Moskovljevic
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Meghana Ravi
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Srona Sengupta
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sung Soo Mun
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Francesco R Simonetti
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Jun Lai
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Pablo Tebas
- Presbyterian Hospital-University of Pennsylvania Hospital, Philadelphia, PA, USA
| | - Kenneth Lynn
- Presbyterian Hospital-University of Pennsylvania Hospital, Philadelphia, PA, USA
| | - Rebecca Hoh
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Steven G Deeks
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Janet D Siliciano
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | | | - Robert F Siliciano
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Howard Hughes Medical Institute, Baltimore, MD, USA.
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3
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Butler ND, Kunjapur AM. Selective and Site-Specific Incorporation of Nonstandard Amino Acids Within Proteins for Therapeutic Applications. Methods Mol Biol 2024; 2720:35-53. [PMID: 37775656 DOI: 10.1007/978-1-0716-3469-1_3] [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] [Indexed: 10/01/2023]
Abstract
The incorporation of nonstandard amino acids (nsAAs) within protein sequences has broadened the chemical functionalities available for use in the study, prevention, or treatment of disease. The ability to genetically encode the introduction of nsAAs at precise sites of target recombinant proteins has enabled numerous applications such as bioorthogonal conjugation, thrombin inhibition, intrinsic biological containment of live organisms, and immunochemical termination of self-tolerance. Genetic systems that perform critical steps in enabling nsAA incorporation are known as orthogonal translation systems or orthogonal aminoacyl-tRNA synthetase/tRNA pairs. In Escherichia coli, several of these have been designed to accept novel nsAAs. Certain endogenous proteins, codon context, and standard amino acid concentrations can affect the yield of recombinant protein, the rate of nsAA incorporation within off-target proteins, and the rate of misincorporation due to near-cognate suppression or misacylation of orthogonal tRNA with standard amino acids. As a result, a significant body of work has been performed in engineering the E. coli genome to alleviate these issues. Here, we describe common methods applicable to nsAA incorporation within proteins in E. coli for sufficient purity and characterization for downstream therapeutic applications.
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Affiliation(s)
- Neil D Butler
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, USA
| | - Aditya M Kunjapur
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE, USA.
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4
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Wang TY, Meng FD, Sang GJ, Zhang HL, Tian ZJ, Zheng H, Cai XH, Tang YD. A novel viral vaccine platform based on engineered transfer RNA. Emerg Microbes Infect 2023; 12:2157339. [PMID: 36482724 PMCID: PMC9769134 DOI: 10.1080/22221751.2022.2157339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In recent years, an increasing number of emerging and remerging virus outbreaks have occurred and the rapid development of vaccines against these viruses has been crucial. Controlling the replication of premature termination codon (PTC)-containing viruses is a promising approach to generate live but replication-defective viruses that can be used for potent vaccines. Here, we used anticodon-engineered transfer RNAs (ACE-tRNAs) as powerful precision switches to control the replication of PTC-containing viruses. We showed that ACE-tRNAs display higher potency of reading through PTCs than genetic code expansion (GCE) technology. Interestingly, ACE-tRNA has a site preference that may influence its read-through efficacy. We further attempted to use ACE-tRNAs as a novel viral vaccine platform. Using a human immunodeficiency virus type 1 (HIV-1) pseudotyped virus as an RNA virus model, we found that ACE-tRNAs display high potency for read-through viral PTCs and precisely control their production. Pseudorabies virus (PRV), a herpesvirus, was used as a DNA virus model. We found that ACE-tRNAs display high potency for reading through viral PTCs and precisely controlling PTC-containing virus replication. In addition, PTC-engineered PRV completely attenuated and lost virulence in mice in vivo, and immunization with PRV containing a PTC elicited a robust immune response and provided complete protection against wild-type PRV challenge. Overall, replication-controllable PTC-containing viruses based on ACE-tRNAs provide a new strategy to rapidly attenuate virus infection and prime robust immune responses. This technology can be used as a platform for rapidly developing viral vaccines in the future.
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Affiliation(s)
- Tong-Yun Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People’s Republic of China,Heilongjiang Provincial Key Laboratory of Veterinary Immunology, Harbin, People's Republic of China
| | - Fan-Dan Meng
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People’s Republic of China,Heilongjiang Provincial Key Laboratory of Veterinary Immunology, Harbin, People's Republic of China
| | - Guo-Ju Sang
- Heilongjiang Provincial Key Laboratory of Veterinary Immunology, Harbin, People's Republic of China
| | - Hong-Liang Zhang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People’s Republic of China
| | - Zhi-Jun Tian
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People’s Republic of China
| | - Hao Zheng
- Shanghai Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China,Hao Zheng Shanghai Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Shanghai150001, People’s Republic of China
| | - Xue-Hui Cai
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People’s Republic of China,Heilongjiang Provincial Key Laboratory of Veterinary Immunology, Harbin, People's Republic of China,Heilongjiang Provincial Research Center for Veterinary Biomedicine, Harbin, People's Republic of China,Xue-Hui Cai State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin 150001, People’s Republic of China; Heilongjiang Provincial Key Laboratory of Veterinary Immunology, Harbin150001, People’s Republic of China
| | - Yan-Dong Tang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, People’s Republic of China,Heilongjiang Provincial Key Laboratory of Veterinary Immunology, Harbin, People's Republic of China, Yan-Dong Tang
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5
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White KS, Walker JA, Wang J, Autissier P, Miller AD, Abuelezan NN, Burrack R, Li Q, Kim WK, Williams KC. Simian immunodeficiency virus-infected rhesus macaques with AIDS co-develop cardiovascular pathology and encephalitis. Front Immunol 2023; 14:1240946. [PMID: 37965349 PMCID: PMC10641955 DOI: 10.3389/fimmu.2023.1240946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 10/03/2023] [Indexed: 11/16/2023] Open
Abstract
Despite effective antiretroviral therapy, HIV co-morbidities remain where central nervous system (CNS) neurocognitive disorders and cardiovascular disease (CVD)-pathology that are linked with myeloid activation are most prevalent. Comorbidities such as neurocogntive dysfunction and cardiovascular disease (CVD) remain prevalent among people living with HIV. We sought to investigate if cardiac pathology (inflammation, fibrosis, cardiomyocyte damage) and CNS pathology (encephalitis) develop together during simian immunodeficiency virus (SIV) infection and if their co-development is linked with monocyte/macrophage activation. We used a cohort of SIV-infected rhesus macaques with rapid AIDS and demonstrated that SIV encephalitis (SIVE) and CVD pathology occur together more frequently than SIVE or CVD pathology alone. Their co-development correlated more strongly with activated myeloid cells, increased numbers of CD14+CD16+ monocytes, plasma CD163 and interleukin-18 (IL-18) than did SIVE or CVD pathology alone, or no pathology. Animals with both SIVE and CVD pathology had greater numbers of cardiac macrophages and increased collagen and monocyte/macrophage accumulation, which were better correlates of CVD-pathology than SIV-RNA. Animals with SIVE alone had higher levels of activated macrophage biomarkers and cardiac macrophage accumulation than SIVnoE animals. These observations were confirmed in HIV infected individuals with HIV encephalitis (HIVE) that had greater numbers of cardiac macrophages and fibrosis than HIV-infected controls without HIVE. These results underscore the notion that CNS and CVD pathologies frequently occur together in HIV and SIV infection, and demonstrate an unmet need for adjunctive therapies targeting macrophages.
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Affiliation(s)
- Kevin S. White
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Joshua A. Walker
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - John Wang
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Patrick Autissier
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Andrew D. Miller
- Department of Biomedical Sciences, Section of Anatomic Physiology, Cornell University College of Veterinary Medicine, Ithaca, NY, United States
| | - Nadia N. Abuelezan
- Connel School of Nursing, Boston College, Chestnut Hill, MA, United States
| | - Rachel Burrack
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Qingsheng Li
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Woong-Ki Kim
- Division of Microbiology, Tulane National Primate Research Center, Covington, LA, United States
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6
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Chen L, Xin X, Zhang Y, Li S, Zhao X, Li S, Xu Z. Advances in Biosynthesis of Non-Canonical Amino Acids (ncAAs) and the Methods of ncAAs Incorporation into Proteins. Molecules 2023; 28:6745. [PMID: 37764520 PMCID: PMC10534643 DOI: 10.3390/molecules28186745] [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: 09/03/2023] [Revised: 09/18/2023] [Accepted: 09/18/2023] [Indexed: 09/29/2023] Open
Abstract
The functional pool of canonical amino acids (cAAs) has been enriched through the emergence of non-canonical amino acids (ncAAs). NcAAs play a crucial role in the production of various pharmaceuticals. The biosynthesis of ncAAs has emerged as an alternative to traditional chemical synthesis due to its environmental friendliness and high efficiency. The breakthrough genetic code expansion (GCE) technique developed in recent years has allowed the incorporation of ncAAs into target proteins, giving them special functions and biological activities. The biosynthesis of ncAAs and their incorporation into target proteins within a single microbe has become an enticing application of such molecules. Based on that, in this study, we first review the biosynthesis methods for ncAAs and analyze the difficulties related to biosynthesis. We then summarize the GCE methods and analyze their advantages and disadvantages. Further, we review the application progress of ncAAs and anticipate the challenges and future development directions of ncAAs.
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Affiliation(s)
- Liang Chen
- College of Bioengineering, Beijing Polytechnic, Beijing 100176, China; (X.X.); (Y.Z.); (S.L.); (X.Z.); (S.L.); (Z.X.)
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7
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Tietjen I, Schonhofer C, Sciorillo A, Naidu ME, Haq Z, Kannan T, Kossenkov AV, Rivera-Ortiz J, Mounzer K, Hart C, Gyampoh K, Yuan Z, Beattie KD, Rali T, Shuda McGuire K, Davis RA, Montaner LJ. The Natural Stilbenoid (-)-Hopeaphenol Inhibits HIV Transcription by Targeting Both PKC and NF-κB Signaling and Cyclin-Dependent Kinase 9. Antimicrob Agents Chemother 2023; 67:e0160022. [PMID: 36975214 PMCID: PMC10112218 DOI: 10.1128/aac.01600-22] [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: 11/29/2022] [Accepted: 02/27/2023] [Indexed: 03/29/2023] Open
Abstract
Despite effective combination antiretroviral therapy (cART), people living with HIV (PLWH) continue to harbor replication-competent and transcriptionally active virus in infected cells, which in turn can lead to ongoing viral antigen production, chronic inflammation, and increased risk of age-related comorbidities. To identify new agents that may inhibit postintegration HIV beyond cART, we screened a library of 512 pure compounds derived from natural products and identified (-)-hopeaphenol as an inhibitor of HIV postintegration transcription at low to submicromolar concentrations without cytotoxicity. Using a combination of global RNA sequencing, plasmid-based reporter assays, and enzyme activity studies, we document that hopeaphenol inhibits protein kinase C (PKC)- and downstream NF-κB-dependent HIV transcription as well as a subset of PKC-dependent T-cell activation markers, including interleukin-2 (IL-2) cytokine and CD25 and HLA-DRB1 RNA production. In contrast, it does not substantially inhibit the early PKC-mediated T-cell activation marker CD69 production of IL-6 or NF-κB signaling induced by tumor necrosis factor alpha (TNF-α). We further show that hopeaphenol can inhibit cyclin-dependent kinase 9 (CDK9) enzymatic activity required for HIV transcription. Finally, it inhibits HIV replication in peripheral blood mononuclear cells (PBMCs) infected in vitro and dampens viral reactivation in CD4+ cells from PLWH. Our study identifies hopeaphenol as a novel inhibitor that targets a subset of PKC-mediated T-cell activation pathways in addition to CDK9 to block HIV expression. Hopeaphenol-based therapies could complement current antiretroviral therapy otherwise not targeting cell-associated HIV RNA and residual antigen production in PLWH.
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Affiliation(s)
- Ian Tietjen
- The Wistar Institute, Philadelphia, Pennsylvania, USA
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Cole Schonhofer
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | | | - Maya E. Naidu
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Zahra Haq
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | | | | | | | - Karam Mounzer
- Jonathan Lax Immune Disorders Treatment Center, Philadelphia Field Initiating Group for HIV-1 Trials, Philadelphia, Pennsylvania, USA
| | - Colin Hart
- The Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Kwasi Gyampoh
- The Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Zhe Yuan
- The Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Karren D. Beattie
- Griffith Institute for Drug Discovery, School of Environment and Science, Griffith University, Brisbane, Queensland, Australia
| | - Topul Rali
- School of Natural and Physical Sciences, The University of Papua New Guinea, Port Moresby, Papua New Guinea
| | | | - Rohan A. Davis
- Griffith Institute for Drug Discovery, School of Environment and Science, Griffith University, Brisbane, Queensland, Australia
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Human Papillomavirus Genome Copy Number Is Maintained by S-Phase Amplification, Genome Loss to the Cytosol during Mitosis, and Degradation in G 1 Phase. J Virol 2023; 97:e0187922. [PMID: 36749071 PMCID: PMC9972943 DOI: 10.1128/jvi.01879-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The current model of human papillomavirus (HPV) replication is comprised of three modes of replication. Following infectious delivery, the viral genome is amplified during the establishment phase to reach up to some hundred copies per cell. The HPV genome copy number remains constant during the maintenance stage. The differentiation of infected cells induces HPV genome amplification. Using highly sensitive in situ hybridization (DNAscope) and freshly HPV16-infected as well as established HPV16-positive cell lines, we observed that the viral genome is amplified in each S phase of undifferentiated keratinocytes cultured as monolayers. The nuclear viral genome copy number is reset to pre-S-phase levels during mitosis. The majority of the viral genome fails to tether to host chromosomes and is lost to the cytosol. Cytosolic viral genomes gradually decrease during cell cycle progression. The loss of cytosolic genomes is blocked in the presence of NH4Cl or other drugs that interfere with lysosomal acidification, suggesting the involvement of autophagy in viral genome degradation. These observations were also made with HPV31 cell lines obtained from patient samples. Cytosolic viral genomes were not detected in UMSCC47 cells carrying integrated HPV16 DNA. Analyses of organotypic raft cultures derived from keratinocytes harboring episomal HPV16 revealed the presence of cytosolic viral genomes as well. We conclude that HPV maintains viral genome copy numbers by balancing viral genome amplification during S phase with the loss of viral genomes to the cytosol during mitosis. It seems plausible that restrictions to viral genome tethering to mitotic chromosomes reset genome copy numbers in each cell cycle. IMPORTANCE HPV genome maintenance is currently thought to be achieved by regulating the expression and activity of the viral replication factors E1 and E2. In addition, the E8^E2 repressor has been shown to be important for restricting genome copy numbers by competing with E1 and E2 for binding to the viral origin of replication and by recruiting repressor complexes. Here, we demonstrate that the HPV genome is amplified in each S phase. The nuclear genome copy number is reset during mitosis by a failure of the majority of the genomes to tether to mitotic chromosomes. Rather, HPV genomes accumulate in the cytoplasm of freshly divided cells. Cytosolic viral DNA is degraded in G1 in a lysosome-dependent manner, contributing to the genome copy reset. Our data imply that the mode of replication during establishment and maintenance is the same and further suggest that restrictions to genome tethering significantly contribute to viral genome maintenance.
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9
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Jiang HK, Ambrose NL, Chung CZ, Wang YS, Söll D, Tharp JM. Split aminoacyl-tRNA synthetases for proximity-induced stop codon suppression. Proc Natl Acad Sci U S A 2023; 120:e2219758120. [PMID: 36787361 PMCID: PMC9974479 DOI: 10.1073/pnas.2219758120] [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: 11/18/2022] [Accepted: 01/16/2023] [Indexed: 02/15/2023] Open
Abstract
Synthetic biology tools for regulating gene expression have many useful biotechnology and therapeutic applications. Most tools developed for this purpose control gene expression at the level of transcription, and relatively few methods are available for regulating gene expression at the translational level. Here, we design and engineer split orthogonal aminoacyl-tRNA synthetases (o-aaRS) as unique tools to control gene translation in bacteria and mammalian cells. Using chemically induced dimerization domains, we developed split o-aaRSs that mediate gene expression by conditionally suppressing stop codons in the presence of the small molecules rapamycin and abscisic acid. By activating o-aaRSs, these molecular switches induce stop codon suppression, and in their absence stop codon suppression is turned off. We demonstrate, in Escherichia coli and in human cells, that split o-aaRSs function as genetically encoded AND gates where stop codon suppression is controlled by two distinct molecular inputs. In addition, we show that split o-aaRSs can be used as versatile biosensors to detect therapeutically relevant protein-protein interactions, including those involved in cancer, and those that mediate severe acute respiratory syndrome-coronavirus-2 infection.
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Affiliation(s)
- Han-Kai Jiang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06511
- Institute of Biological Chemistry, Academia Sinica, Taipei11529, Taiwan
- Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei11529, Taiwan
- Department of Chemistry, National Tsing Hua University, Hsinchu100044, Taiwan
| | - Nicole L. Ambrose
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06511
| | - Christina Z. Chung
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06511
| | - Yane-Shih Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei11529, Taiwan
- Chemical Biology and Molecular Biophysics Program, Taiwan International Graduate Program, Academia Sinica, Taipei11529, Taiwan
- Institute of Biochemical Sciences, National Taiwan University, Taipei10617, Taiwan
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT06511
- Department of Chemistry, Yale University, New Haven, CT06511
| | - Jeffery M. Tharp
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN46202
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10
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Cheng Y, Burrack RK, Li Q. Spatially Resolved and Highly Multiplexed Protein and RNA In Situ Detection by Combining CODEX With RNAscope In Situ Hybridization. J Histochem Cytochem 2022; 70:571-581. [PMID: 35848523 PMCID: PMC9393509 DOI: 10.1369/00221554221114174] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Highly multiplexed protein and RNA in situ detection on a single tissue section concurrently is highly desirable for both basic and applied biomedical research. CO-detection by inDEXing (CODEX) is a new and powerful platform to visualize up to 60 protein biomarkers in situ, and RNAscope in situ hybridization (RNAscope) is a novel RNA detection system with high sensitivity and unprecedent specificity at a single-cell level. Nevertheless, to our knowledge, the combination of CODEX and RNAscope remained unreported until this study. Here, we report a simple and reproducible combination of CODEX and RNAscope. We also determined the cross-reactivities of CODEX anti-human antibodies to rhesus macaques, a widely used animal model of human disease.
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Affiliation(s)
- Yilun Cheng
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska–Lincoln, Lincoln, Nebraska
| | - Rachel K. Burrack
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska–Lincoln, Lincoln, Nebraska
| | - Qingsheng Li
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska–Lincoln, Lincoln, Nebraska
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11
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Zhu X, Zhaoyang Zhang, Bin Jia, Yuan Y. Current advances of biocontainment strategy in synthetic biology. Chin J Chem Eng 2022. [DOI: 10.1016/j.cjche.2022.07.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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12
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Tembeni B, Sciorillo A, Invernizzi L, Klimkait T, Urda L, Moyo P, Naidoo-Maharaj D, Levitties N, Gyampoh K, Zu G, Yuan Z, Mounzer K, Nkabinde S, Nkabinde M, Gqaleni N, Tietjen I, Montaner LJ, Maharaj V. HPLC-Based Purification and Isolation of Potent Anti-HIV and Latency Reversing Daphnane Diterpenes from the Medicinal Plant Gnidia sericocephala ( Thymelaeaceae). Viruses 2022; 14:1437. [PMID: 35891417 PMCID: PMC9318819 DOI: 10.3390/v14071437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/21/2022] [Accepted: 06/24/2022] [Indexed: 11/17/2022] Open
Abstract
Despite the success of combination antiretroviral therapy (cART), HIV persists in low- and middle-income countries (LMIC) due to emerging drug resistance and insufficient drug accessibility. Furthermore, cART does not target latently-infected CD4+ T cells, which represent a major barrier to HIV eradication. The “shock and kill” therapeutic approach aims to reactivate provirus expression in latently-infected cells in the presence of cART and target virus-expressing cells for elimination. An attractive therapeutic prototype in LMICs would therefore be capable of simultaneously inhibiting viral replication and inducing latency reversal. Here we report that Gnidia sericocephala, which is used by traditional health practitioners in South Africa for HIV/AIDS management to supplement cART, contains at least four daphnane-type compounds (yuanhuacine A (1), yuanhuacine as part of a mixture (2), yuanhuajine (3), and gniditrin (4)) that inhibit viral replication and/or reverse HIV latency. For example, 1 and 2 inhibit HIV replication in peripheral blood mononuclear cells (PBMC) by >80% at 0.08 µg/mL, while 1 further inhibits a subtype C virus in PBMC with a half-maximal effective concentration (EC50) of 0.03 µM without cytotoxicity. Both 1 and 2 also reverse HIV latency in vitro consistent with protein kinase C activation but at 16.7-fold lower concentrations than the control prostratin. Both 1 and 2 also reverse latency in primary CD4+ T cells from cART-suppressed donors with HIV similar to prostratin but at 6.7-fold lower concentrations. These results highlight G. sericocephala and components 1 and 2 as anti-HIV agents for improving cART efficacy and supporting HIV cure efforts in resource-limited regions.
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Affiliation(s)
- Babalwa Tembeni
- Department of Chemistry, University of Pretoria, Pretoria 0028, South Africa; (B.T.); (L.I.); (P.M.); (D.N.-M.)
| | - Amanda Sciorillo
- The Wistar Institute, Philadelphia, PA 19104, USA; (A.S.); (N.L.); (K.G.); (G.Z.); (Z.Y.); (I.T.)
| | - Luke Invernizzi
- Department of Chemistry, University of Pretoria, Pretoria 0028, South Africa; (B.T.); (L.I.); (P.M.); (D.N.-M.)
| | - Thomas Klimkait
- Molecular Virology, Department of Biomedicine, University of Basel, 4031 Basel, Switzerland; (T.K.); (L.U.)
| | - Lorena Urda
- Molecular Virology, Department of Biomedicine, University of Basel, 4031 Basel, Switzerland; (T.K.); (L.U.)
| | - Phanankosi Moyo
- Department of Chemistry, University of Pretoria, Pretoria 0028, South Africa; (B.T.); (L.I.); (P.M.); (D.N.-M.)
| | - Dashnie Naidoo-Maharaj
- Department of Chemistry, University of Pretoria, Pretoria 0028, South Africa; (B.T.); (L.I.); (P.M.); (D.N.-M.)
- Agricultural Research Council-Vegetables, Industrial and Medicinal Plants, Private Bag X293, Pretoria 0001, South Africa
| | - Nathan Levitties
- The Wistar Institute, Philadelphia, PA 19104, USA; (A.S.); (N.L.); (K.G.); (G.Z.); (Z.Y.); (I.T.)
| | - Kwasi Gyampoh
- The Wistar Institute, Philadelphia, PA 19104, USA; (A.S.); (N.L.); (K.G.); (G.Z.); (Z.Y.); (I.T.)
| | - Guorui Zu
- The Wistar Institute, Philadelphia, PA 19104, USA; (A.S.); (N.L.); (K.G.); (G.Z.); (Z.Y.); (I.T.)
| | - Zhe Yuan
- The Wistar Institute, Philadelphia, PA 19104, USA; (A.S.); (N.L.); (K.G.); (G.Z.); (Z.Y.); (I.T.)
| | - Karam Mounzer
- Jonathan Lax Immune Disorders Treatment Center, Philadelphia Fight Community Health Centers, Philadelphia, PA 19107, USA;
| | | | - Magugu Nkabinde
- Ungangezulu Indigenous Remedies, J Uitval, Wasbank 2920, South Africa; (S.N.); (M.N.)
| | - Nceba Gqaleni
- Africa Health Research Institute, Congella 4013, South Africa;
- Discipline of Traditional Medicine, University of KwaZulu-Natal, Durban 4001, South Africa
- Faculty of Health Sciences, Durban University of Technology, Durban 4001, South Africa
| | - Ian Tietjen
- The Wistar Institute, Philadelphia, PA 19104, USA; (A.S.); (N.L.); (K.G.); (G.Z.); (Z.Y.); (I.T.)
| | - Luis J. Montaner
- The Wistar Institute, Philadelphia, PA 19104, USA; (A.S.); (N.L.); (K.G.); (G.Z.); (Z.Y.); (I.T.)
| | - Vinesh Maharaj
- Department of Chemistry, University of Pretoria, Pretoria 0028, South Africa; (B.T.); (L.I.); (P.M.); (D.N.-M.)
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13
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Wang M, Sciorillo A, Read S, Divsalar DN, Gyampoh K, Zu G, Yuan Z, Mounzer K, Williams DE, Montaner LJ, de Voogd N, Tietjen I, Andersen RJ. Ansellone J, a Potent in Vitro and ex Vivo HIV-1 Latency Reversal Agent Isolated from a Phorbas sp. Marine Sponge. JOURNAL OF NATURAL PRODUCTS 2022; 85:1274-1281. [PMID: 35522580 DOI: 10.1021/acs.jnatprod.1c01225] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Five new minor sesterterpenoids, ansellones H (4), I (5), J (6), and K (7) and phorone C (8), have been isolated from a Phorbas sp. marine sponge collected in British Columbia. Their structures have been elucidated by detailed analysis of NMR and MS data. Ansellone J (6) and phorone C (8) are potent in vitro HIV-1 latency reversal agents that are more potent than the reference compound and control protein kinase C activator prostratin (3). The most potent Phorbas sesterterpenoid, ansellone J (6), was evaluated for HIV latency reversal in a primary cell context using CD4+ T cells obtained directly from four combination antiretroviral therapy-suppressed donors with HIV. To a first approximation, ansellone J (6) induced HIV latency reversal at levels similar to prostratin (3) ex vivo, but at a 10-fold lower concentration.
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Affiliation(s)
- Meng Wang
- Departments of Chemistry and Earth Ocean & Atmospheric Sciences, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Amanda Sciorillo
- The Wistar Institute, Philadelphia, Pennsylvania 19104, United States
| | - Silven Read
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Donya Naz Divsalar
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Kwasi Gyampoh
- The Wistar Institute, Philadelphia, Pennsylvania 19104, United States
| | - Guorui Zu
- The Wistar Institute, Philadelphia, Pennsylvania 19104, United States
| | - Zhe Yuan
- The Wistar Institute, Philadelphia, Pennsylvania 19104, United States
| | - Karam Mounzer
- Jonathan Lax Immune Disorders Treatment Center, Philadelphia FIGHT Community Health Centers, Philadelphia, Pennsylvania 19107, United States
| | - David E Williams
- Departments of Chemistry and Earth Ocean & Atmospheric Sciences, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Luis J Montaner
- The Wistar Institute, Philadelphia, Pennsylvania 19104, United States
| | - Nicole de Voogd
- Naturalis Biodiversity Center, P.O. Box 9517, 2300 RA Leiden, The Netherlands
| | - Ian Tietjen
- The Wistar Institute, Philadelphia, Pennsylvania 19104, United States
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Raymond J Andersen
- Departments of Chemistry and Earth Ocean & Atmospheric Sciences, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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14
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Generation of Premature Termination Codon (PTC)-Harboring Pseudorabies Virus (PRV) via Genetic Code Expansion Technology. Viruses 2022; 14:v14030572. [PMID: 35336979 PMCID: PMC8950157 DOI: 10.3390/v14030572] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 02/28/2022] [Accepted: 03/09/2022] [Indexed: 12/27/2022] Open
Abstract
Despite many efforts and diverse approaches, developing an effective herpesvirus vaccine remains a great challenge. Traditional inactivated and live-attenuated vaccines always raise efficacy or safety concerns. This study used Pseudorabies virus (PRV), a swine herpes virus, as a model. We attempted to develop a live but replication-incompetent PRV by genetic code expansion (GCE) technology. Premature termination codon (PTC) harboring PRV was successfully rescued in the presence of orthogonal system MbpylRS/tRNAPyl pair and unnatural amino acids (UAA). However, UAA incorporating efficacy seemed extremely low in our engineered PRV PTC virus. Furthermore, we failed to establish a stable transgenic cell line containing orthogonal translation machinery for PTC virus replication, and we demonstrated that orthogonal tRNAPyl is a key limiting factor. This study is the first to demonstrate that orthogonal translation system-mediated amber codon suppression strategy could precisely control PRV-PTC engineered virus replication. To our knowledge, this is the first reported PTC herpesvirus generated by GCE technology. Our work provides a proof-of-concept for generating UAAs-controlled PRV-PTC virus, which can be used as a safe and effective vaccine.
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15
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Therapeutic peptides: current applications and future directions. Signal Transduct Target Ther 2022; 7:48. [PMID: 35165272 PMCID: PMC8844085 DOI: 10.1038/s41392-022-00904-4] [Citation(s) in RCA: 437] [Impact Index Per Article: 218.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 01/13/2022] [Accepted: 01/17/2022] [Indexed: 02/08/2023] Open
Abstract
Peptide drug development has made great progress in the last decade thanks to new production, modification, and analytic technologies. Peptides have been produced and modified using both chemical and biological methods, together with novel design and delivery strategies, which have helped to overcome the inherent drawbacks of peptides and have allowed the continued advancement of this field. A wide variety of natural and modified peptides have been obtained and studied, covering multiple therapeutic areas. This review summarizes the efforts and achievements in peptide drug discovery, production, and modification, and their current applications. We also discuss the value and challenges associated with future developments in therapeutic peptides.
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16
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Guo J, Niu W. Genetic Code Expansion Through Quadruplet Codon Decoding. J Mol Biol 2021; 434:167346. [PMID: 34762896 PMCID: PMC9018476 DOI: 10.1016/j.jmb.2021.167346] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/25/2021] [Accepted: 10/30/2021] [Indexed: 12/31/2022]
Abstract
Noncanonical amino acid mutagenesis has emerged as a powerful tool for the study of protein structure and function. While triplet nonsense codons, especially the amber codon, have been widely employed, quadruplet codons have attracted attention for the potential of creating additional blank codons for noncanonical amino acids mutagenesis. In this review, we discuss methodologies and applications of quadruplet codon decoding in genetic code expansion both in vitro and in vivo.
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Affiliation(s)
- Jiantao Guo
- Department of Chemistry, University of Nebraska-Lincoln, United States; The Nebraska Center for Integrated Biomolecular Communication (NCIBC), University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States.
| | - Wei Niu
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, United States; The Nebraska Center for Integrated Biomolecular Communication (NCIBC), University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States
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17
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Hao R, Ma K, Ru Y, Li D, Song G, Lu B, Liu H, Li Y, Zhang J, Wu C, Zhang G, Hu H, Luo J, Zheng H. Amber codon is genetically unstable in generation of premature termination codon (PTC)-harbouring Foot-and-mouth disease virus (FMDV) via genetic code expansion. RNA Biol 2021; 18:2330-2341. [PMID: 33849391 DOI: 10.1080/15476286.2021.1907055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The foot-and-mouth disease virus (FMDV) is the causative agent of FMD, a highly infectious and devastating viral disease of domestic and wild cloven-hoofed animals. FMD affects livestock and animal products' national and international trade, causing severe economic losses and social consequences. Currently, inactivated vaccines play a vital role in FMD control, but they have several limitations. The genetic code expansion technology provides powerful strategies for generating premature termination codon (PTC)-harbouring virus as a live but replication-incompetent viral vaccine. However, this technology has not been explored for the design and development of new FMD vaccines. In this study, we first expanded the genetic code of the FMDV genome via a transgenic cell line containing an orthogonal translation machinery. We demonstrated that the transgenic cells stably integrated the orthogonal pyltRNA/pylRS pair into the genome and enabled efficient, homogeneous incorporation of unnatural amino acids into target proteins in mammalian cells. Next, we constructed 129 single-PTC FMDV mutants and four dual-PTC FMDV mutants after considering the tolerance, location, and potential functions of those mutated sites. Amber stop codons individually substituted the selected amino acid codons in four viral proteins (3D, L, VP1, and VP4) of FMDV. We successfully rescued PTC-FMDV mutants, but the amber codon unexpectedly showed a highly degree of mutation rate during PTC-FMDV packaging and replication. Our findings highlight that the genetic code expansion technology for the generation of PTC-FMD vaccines needs to be further improved and that the genetic stability of amber codons during the packaging and replication of FMDV is a concern.
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Affiliation(s)
- Rongzeng Hao
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, OIE/National Foot and Mouth Diseases Reference Laboratory, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Kun Ma
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, OIE/National Foot and Mouth Diseases Reference Laboratory, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Yi Ru
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, OIE/National Foot and Mouth Diseases Reference Laboratory, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Dan Li
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, OIE/National Foot and Mouth Diseases Reference Laboratory, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Gaoyuan Song
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, OIE/National Foot and Mouth Diseases Reference Laboratory, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Bingzhou Lu
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, OIE/National Foot and Mouth Diseases Reference Laboratory, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Huanan Liu
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, OIE/National Foot and Mouth Diseases Reference Laboratory, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Yajun Li
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, OIE/National Foot and Mouth Diseases Reference Laboratory, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Jiaoyan Zhang
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, OIE/National Foot and Mouth Diseases Reference Laboratory, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Chunping Wu
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, OIE/National Foot and Mouth Diseases Reference Laboratory, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Guicai Zhang
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, OIE/National Foot and Mouth Diseases Reference Laboratory, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Haitao Hu
- Department of Microbiology and Immunology, Sealy Center for Vaccine Development and Institute for Human Infections and Immunity, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Jianxun Luo
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, OIE/National Foot and Mouth Diseases Reference Laboratory, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Haixue Zheng
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, OIE/National Foot and Mouth Diseases Reference Laboratory, Chinese Academy of Agricultural Sciences, Lanzhou, China
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18
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Flavonoid-based inhibition of cyclin-dependent kinase 9 without concomitant inhibition of histone deacetylases durably reinforces HIV latency. Biochem Pharmacol 2021; 186:114462. [PMID: 33577894 DOI: 10.1016/j.bcp.2021.114462] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 02/01/2021] [Accepted: 02/03/2021] [Indexed: 12/12/2022]
Abstract
While combination antiretroviral therapy (cART) durably suppresses HIV replication, virus persists in CD4+ T-cells that harbor latent but spontaneously inducible and replication-competent provirus. One strategy to inactivate these viral reservoirs involves the use of agents that continue to reinforce HIV latency even after their withdrawal. To identify new chemical leads with such properties, we investigated a series of naturally-occurring flavones (chrysin, apigenin, luteolin, and luteolin-7-glucoside (L7G)) and functionally-related cyclin dependent kinase 9 (CDK9) inhibitors (flavopiridol and atuveciclib) which are reported or presumed to suppress HIV replication in vitro. We found that, while all compounds inhibit provirus expression induced by latency-reversing agents in vitro, only aglycone flavonoids (chrysin, apigenin, luteolin, flavopiridol) and atuveciclib, but not the glycosylated flavonoid L7G, inhibit spontaneous latency reversal. Aglycone flavonoids and atuveciclib, but not L7G, also inhibit CDK9 and the HIV Tat protein. Aglycone flavonoids do not reinforce HIV latency following their in vitro withdrawal, which corresponds with their ability to also inhibit class I/II histone deacetylases (HDAC), a well-established mechanism of latency reversal. In contrast, atuveciclib and flavopiridol, which exhibit little or no HDAC inhibition, continue to reinforce latency for 9 to 14+ days, respectively, following their withdrawal in vitro. Finally, we show that flavopiridol also inhibits spontaneous ex vivo viral RNA production in CD4+ T cells from donors with HIV. These results implicate CDK9 inhibition (in the absence of HDAC inhibition) as a potentially favorable property in the search for compounds that durably reinforce HIV latency.
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19
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Fok JA, Mayer C. Genetic-Code-Expansion Strategies for Vaccine Development. Chembiochem 2020; 21:3291-3300. [PMID: 32608153 PMCID: PMC7361271 DOI: 10.1002/cbic.202000343] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 06/29/2020] [Indexed: 12/16/2022]
Abstract
By providing long-term protection against infectious diseases, vaccinations have significantly reduced death and morbidity worldwide. In the 21st century, (bio)technological advances have paved the way for developing prophylactic vaccines that are safer and more effective as well as enabling the use of vaccines as therapeutics to treat human diseases. Here, we provide a focused review of the utility of genetic code expansion as an emerging tool for the development of vaccines. Specifically, we discuss how the incorporation of immunogenic noncanonical amino acids can aid in eliciting immune responses against adverse self-proteins and highlight the potential of an expanded genetic code for the construction of replication-incompetent viruses. We close the review by discussing the future prospects and remaining challenges for the application of these approaches in the development of both prophylactic and therapeutic vaccines in the near future.
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Affiliation(s)
- Jelle A. Fok
- Stratingh Institute for ChemistryUniversity of GroningenNijenborgh 49474 AGGroningen (TheNetherlands
| | - Clemens Mayer
- Stratingh Institute for ChemistryUniversity of GroningenNijenborgh 49474 AGGroningen (TheNetherlands
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20
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Gang D, Park HS. Noncanonical Amino Acids in Synthetic Biosafety and Post-translational Modification Studies. Chembiochem 2020; 22:460-468. [PMID: 32794239 DOI: 10.1002/cbic.202000437] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 08/11/2020] [Indexed: 11/06/2022]
Abstract
The incorporation of noncanonical amino acids (ncAAs) has been extensively studied because of its broad applicability. In the past decades, various in vitro and in vivo ncAA incorporation approaches have been developed to generate synthetic recombinant proteins. Herein, we discuss the methodologies for ncAA incorporation, and their use in diverse research areas, such as in synthetic biosafety and for studies of post-translational modifications.
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Affiliation(s)
- Donghyeok Gang
- Department of Chemistry, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Korea
| | - Hee-Sung Park
- Department of Chemistry, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon, 341418, Korea
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21
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He X, Chen Y, Beltran DG, Kelly M, Ma B, Lawrie J, Wang F, Dodds E, Zhang L, Guo J, Niu W. Functional genetic encoding of sulfotyrosine in mammalian cells. Nat Commun 2020; 11:4820. [PMID: 32973160 PMCID: PMC7515910 DOI: 10.1038/s41467-020-18629-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 08/27/2020] [Indexed: 12/22/2022] Open
Abstract
Protein tyrosine O-sulfation (PTS) plays a crucial role in extracellular biomolecular interactions that dictate various cellular processes. It also involves in the development of many human diseases. Regardless of recent progress, our current understanding of PTS is still in its infancy. To promote and facilitate relevant studies, a generally applicable method is needed to enable efficient expression of sulfoproteins with defined sulfation sites in live mammalian cells. Here we report the engineering, in vitro biochemical characterization, structural study, and in vivo functional verification of a tyrosyl-tRNA synthetase mutant for the genetic encoding of sulfotyrosine in mammalian cells. We further apply this chemical biology tool to cell-based studies on the role of a sulfation site in the activation of chemokine receptor CXCR4 by its ligand. Our work will not only facilitate cellular studies of PTS, but also paves the way for economical production of sulfated proteins as therapeutic agents in mammalian systems.
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Affiliation(s)
- Xinyuan He
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, USA
| | - Yan Chen
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, USA
| | - Daisy Guiza Beltran
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, USA
| | - Maia Kelly
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, USA
| | - Bin Ma
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, USA
| | - Justin Lawrie
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, USA
| | - Feng Wang
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Eric Dodds
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, USA
| | - Limei Zhang
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, USA
| | - Jiantao Guo
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, USA.
| | - Wei Niu
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, USA.
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22
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Design of fluorescent protein-based sensors through a general protection-deprotection strategy. Methods Enzymol 2020; 640:63-82. [PMID: 32560806 DOI: 10.1016/bs.mie.2020.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Engineered fluorescent proteins have been extensively used in biological research for the study of gene expression, protein function and trafficking, and protein-protein interactions. In addition, fluorescent proteins have also been engineered to act as biosensing agents to detect intracellular signaling molecules and other small-molecule metabolites. Although they have been engineered extensively to achieve novel properties, fluorescent proteins are traditionally modified using the 20 canonical amino acids. This limits the number of functional groups that are available to the design and construction of novel fluorescent proteins. The expansion of the genetic code through the incorporation of noncanonical amino acids presents an opportunity to add new functionalities with the intent of modifying chemical and physical properties of fluorescent proteins. Herein we provide a general procedure for the site-specific incorporation of noncanonical amino acids into fluorescent proteins in live cells. We will also discuss a noncanonical amino acid-containing fluorescent protein sensor that is based on a general protection-deprotection design strategy, for the selective detection and quantification of Hg2+.
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23
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Nödling AR, Spear LA, Williams TL, Luk LYP, Tsai YH. Using genetically incorporated unnatural amino acids to control protein functions in mammalian cells. Essays Biochem 2019; 63:237-266. [PMID: 31092687 PMCID: PMC6610526 DOI: 10.1042/ebc20180042] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 03/14/2019] [Accepted: 03/19/2019] [Indexed: 02/07/2023]
Abstract
Genetic code expansion allows unnatural (non-canonical) amino acid incorporation into proteins of interest by repurposing the cellular translation machinery. The development of this technique has enabled site-specific incorporation of many structurally and chemically diverse amino acids, facilitating a plethora of applications, including protein imaging, engineering, mechanistic and structural investigations, and functional regulation. Particularly, genetic code expansion provides great tools to study mammalian proteins, of which dysregulations often have important implications in health. In recent years, a series of methods has been developed to modulate protein function through genetically incorporated unnatural amino acids. In this review, we will first discuss the basic concept of genetic code expansion and give an up-to-date list of amino acids that can be incorporated into proteins in mammalian cells. We then focus on the use of unnatural amino acids to activate, inhibit, or reversibly modulate protein function by translational, optical or chemical control. The features of each approach will also be highlighted.
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Affiliation(s)
| | - Luke A Spear
- School of Chemistry, Cardiff University, Cardiff, Wales, United Kingdom
| | - Thomas L Williams
- School of Chemistry, Cardiff University, Cardiff, Wales, United Kingdom
| | - Louis Y P Luk
- School of Chemistry, Cardiff University, Cardiff, Wales, United Kingdom
| | - Yu-Hsuan Tsai
- School of Chemistry, Cardiff University, Cardiff, Wales, United Kingdom
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24
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Miao H, Yu C, Yao A, Xuan W. Rational design of a function-based selection method for genetically encoding acylated lysine derivatives. Org Biomol Chem 2019; 17:6127-6130. [PMID: 31172146 DOI: 10.1039/c9ob00992b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A foundation of genetic code expansion is the evolution of orthogonal aminoacyl-tRNA synthetase to recognize a non-canonical amino acid, which typically involves read-through of amber stop codon in the genes used in selection. The process is time-consuming, labor-intensive, and susceptible to certain bias. As a complementation, herein, we rationally designed a function-based method to directed evolution of aminoacyl-tRNA synthetase for acylated lysine derivatives.
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Affiliation(s)
- Hui Miao
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
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25
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Kato Y. Translational Control using an Expanded Genetic Code. Int J Mol Sci 2019; 20:ijms20040887. [PMID: 30781713 PMCID: PMC6412442 DOI: 10.3390/ijms20040887] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/14/2019] [Accepted: 02/15/2019] [Indexed: 11/16/2022] Open
Abstract
A bio-orthogonal and unnatural substance, such as an unnatural amino acid (Uaa), is an ideal regulator to control target gene expression in a synthetic gene circuit. Genetic code expansion technology has achieved Uaa incorporation into ribosomal synthesized proteins in vivo at specific sites designated by UAG stop codons. This site-specific Uaa incorporation can be used as a controller of target gene expression at the translational level by conditional read-through of internal UAG stop codons. Recent advances in optimization of site-specific Uaa incorporation for translational regulation have enabled more precise control over a wide range of novel important applications, such as Uaa-auxotrophy-based biological containment, live-attenuated vaccine, and high-yield zero-leakage expression systems, in which Uaa translational control is exclusively used as an essential genetic element. This review summarizes the history and recent advance of the translational control by conditional stop codon read-through, especially focusing on the methods using the site-specific Uaa incorporation.
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Affiliation(s)
- Yusuke Kato
- Division of Biotechnology, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Oowashi 1-2, Tsukuba, Ibaraki 305-8634, Japan.
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26
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da Silva LT, Santillo BT, de Almeida A, Duarte AJDS, Oshiro TM. Using Dendritic Cell-Based Immunotherapy to Treat HIV: How Can This Strategy be Improved? Front Immunol 2018; 9:2993. [PMID: 30619346 PMCID: PMC6305438 DOI: 10.3389/fimmu.2018.02993] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 12/04/2018] [Indexed: 11/13/2022] Open
Abstract
Harnessing dendritic cells (DC) to treat HIV infection is considered a key strategy to improve anti-HIV treatment and promote the discovery of functional or sterilizing cures. Although this strategy represents a promising approach, the results of currently published trials suggest that opportunities to optimize its performance still exist. In addition to the genetic and clinical characteristics of patients, the efficacy of DC-based immunotherapy depends on the quality of the vaccine product, which is composed of precursor-derived DC and an antigen for pulsing. Here, we focus on some factors that can interfere with vaccine production and should thus be considered to improve DC-based immunotherapy for HIV infection.
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Affiliation(s)
- Laís Teodoro da Silva
- Laboratorio de Investigacao em Dermatologia e Imunodeficiencias, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Bruna Tereso Santillo
- Laboratorio de Investigacao em Dermatologia e Imunodeficiencias, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Alexandre de Almeida
- Laboratorio de Investigacao em Dermatologia e Imunodeficiencias, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Alberto Jose da Silva Duarte
- Laboratorio de Investigacao em Dermatologia e Imunodeficiencias, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
| | - Telma Miyuki Oshiro
- Laboratorio de Investigacao em Dermatologia e Imunodeficiencias, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil
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27
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Li Q, Kim WK. Reply to Letter to the Editor. J Neuroimmune Pharmacol 2018; 14:7-8. [PMID: 30506435 DOI: 10.1007/s11481-018-09828-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 11/25/2018] [Indexed: 10/27/2022]
Affiliation(s)
- Qingsheng Li
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Woong-Ki Kim
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA, USA.
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28
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Ko A, Kang G, Hattler JB, Galadima HI, Zhang J, Li Q, Kim WK. Macrophages but not Astrocytes Harbor HIV DNA in the Brains of HIV-1-Infected Aviremic Individuals on Suppressive Antiretroviral Therapy. J Neuroimmune Pharmacol 2018; 14:110-119. [PMID: 30194646 PMCID: PMC6391194 DOI: 10.1007/s11481-018-9809-2] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 08/30/2018] [Indexed: 11/28/2022]
Abstract
The question of whether the human brain is an anatomical site of persistent HIV-1 infection during suppressive antiretroviral therapy (ART) is critical, but remains unanswered. The presence of virus in the brains of HIV patients whose viral load is effectively suppressed would demonstrate not only the potential for CNS to act as an anatomical HIV reservoir, but also the urgent need to understand the factors contributing to persistent HIV behind the blood-brain barrier. Here, we investigated for the first time the presence of cells harboring HIV DNA and RNA in the brains from subjects with undetectable plasma viral load and sustained viral suppression, as identified by the National NeuroAIDS Tissue Consortium. Using new, highly sensitive in situ hybridization techniques, RNAscope and DNAscope, in combination with immunohistochemistry, we were able to detect HIV-1 in the brains of all virally suppressed cases and found that brain macrophages and microglia, but not astrocytes, were the cells harboring HIV DNA in the brain. This study demonstrated that HIV reservoirs persist in brain macrophages/microglia during suppressive ART, which cure/treatment strategies will need to focus on targeting.
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Affiliation(s)
- Allen Ko
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA, USA
| | - Guobin Kang
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Julian B Hattler
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA, USA
| | - Hadiza I Galadima
- Graduate Program in Public Health, Eastern Virginia Medical School, Norfolk, VA, USA.,School of Community and Environmental Health, College of Health Sciences, Old Dominion University, Norfolk, VA, USA
| | - Junfeng Zhang
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA.,Department of Human Anatomy, Xi'an Medical University, Shaanxi, China
| | - Qingsheng Li
- Nebraska Center for Virology, School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA.
| | - Woong-Ki Kim
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA, USA.
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29
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Huang Y, Liu T. Therapeutic applications of genetic code expansion. Synth Syst Biotechnol 2018; 3:150-158. [PMID: 30345400 PMCID: PMC6190509 DOI: 10.1016/j.synbio.2018.09.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 09/16/2018] [Accepted: 09/18/2018] [Indexed: 12/05/2022] Open
Abstract
In nature, a limited, conservative set of amino acids are utilized to synthesize proteins. Genetic code expansion technique reassigns codons and incorporates noncanonical amino acids (ncAAs) through orthogonal aminoacyl-tRNA synthetase (aaRS)/tRNA pairs. The past decade has witnessed the rapid growth in diversity and scope for therapeutic applications of this technology. Here, we provided an update on the recent progress using genetic code expansion in the following areas: antibody-drug conjugates (ADCs), bispecific antibodies (BsAb), immunotherapies, long-lasting protein therapeutics, biosynthesized peptides, engineered viruses and cells, as well as other therapeutic related applications, where the technique was used to elucidate the mechanisms of biotherapeutics and drug targets.
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Affiliation(s)
| | - Tao Liu
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China
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30
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Kato Y. Tight Translational Control Using Site-Specific Unnatural Amino Acid Incorporation with Positive Feedback Gene Circuits. ACS Synth Biol 2018; 7:1956-1963. [PMID: 29979867 DOI: 10.1021/acssynbio.8b00204] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Tight regulatory system for gene expression, which is ideally controlled by unnatural and bio-orthogonal substances, is a keystone for successful construction of synthetic gene circuits. Here, we present a widely applicable approach to construct tight protein translational switches using site-specific unnatural amino acid (Uaa) incorporation systems. As a key mechanism to obtain excellent tightness, we installed gene circuits for positive feedback derepression. This mechanism dramatically suppressed leakage translation in the absence of the Uaa. In a translational switch with the feedback circuit in Escherichia coli, a 1.4 × 103 ON/OFF ratio was achieved which was 3 × 102-fold greater than that of the parent system and was comparable to that of the well-known tight expression system using the araBAD promoter and the araC regulator. This method offers an avenue for generation of novel tight genetic switches from over a hundred site-specific unnatural amino acid incorporation systems which have already been established. These tight translational switches will facilitate the development of fine gene control systems in synthetic biology, especially for Uaa-auxotrophy-based biological containments and live attenuated vaccines.
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Affiliation(s)
- Yusuke Kato
- Division of Biotechnology, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Oowashi 1-2, Tsukuba, Ibaraki 305-8634, Japan
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31
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Kelemen RE, Erickson SB, Chatterjee A. Synthesis at the interface of virology and genetic code expansion. Curr Opin Chem Biol 2018; 46:164-171. [PMID: 30086446 DOI: 10.1016/j.cbpa.2018.07.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 05/18/2018] [Accepted: 07/13/2018] [Indexed: 01/24/2023]
Abstract
How a virus efficiently invades its host cell and masterfully engineers its properties provides valuable lessons and resources for the emerging discipline of synthetic biology, which seeks to create engineered biological systems with novel functions. Recently, the toolbox of synthetic biology has also been enriched by the genetic code expansion technology, which has provided access to a large assortment of unnatural amino acids with novel chemical functionalities that can be site-specifically incorporated into proteins in living cells. The synergistic interplay of these two disciplines holds much promise to advance their individual progress, while creating new paradigms for synthetic biology. In this review we seek to provide an account of the recent advances at the interface of these two research areas.
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Affiliation(s)
- Rachel E Kelemen
- Department of Chemistry, Boston College, 2609 Beacon Street, 246B Merkert Chemistry Center, Chestnut Hill, MA 02467, United States
| | - Sarah B Erickson
- Department of Chemistry, Boston College, 2609 Beacon Street, 246B Merkert Chemistry Center, Chestnut Hill, MA 02467, United States
| | - Abhishek Chatterjee
- Department of Chemistry, Boston College, 2609 Beacon Street, 246B Merkert Chemistry Center, Chestnut Hill, MA 02467, United States.
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Chen Y, Wan Y, Wang N, Yuan Z, Niu W, Li Q, Guo J. Controlling the Replication of a Genomically Recoded HIV-1 with a Functional Quadruplet Codon in Mammalian Cells. ACS Synth Biol 2018; 7:1612-1617. [PMID: 29787233 DOI: 10.1021/acssynbio.8b00096] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Large efforts have been devoted to genetic code engineering in the past decade, aiming for unnatural amino acid mutagenesis. Recently, an increasing number of studies were reported to employ quadruplet codons to encode unnatural amino acids. We and others have demonstrated that the quadruplet decoding efficiency could be significantly enhanced by an extensive engineering of tRNAs bearing an extra nucleotide in their anticodon loops. In this work, we report the identification of tRNA mutants derived from directed evolution to efficiently decode a UAGA quadruplet codon in mammalian cells. Intriguingly, the trend of quadruplet codon decoding efficiency among the tested tRNA variants in mammalian cells was largely the same as that in E. coli. We subsequently demonstrate the utility of quadruplet codon decoding by the construction of the first HIV-1 mutant that lacks any in-frame amber nonsense codons and can be precisely activated by the decoding of a genomically embedded UAGA codon with an unnatural amino acid. Such conditionally activatable HIV-1 mutant can likely facilitate both fundamental investigations of HIV-1 as well as vaccine developments. The use of quadruplet codon, instead of an amber nonsense codon, to control HIV-1 replication has the advantage in that the correction of a frameshift caused by a quadruplet codon is much less likely than the reversion of an amber codon back into a sense codon in HIV-1.
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33
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Wang L. Engineering the Genetic Code in Cells and Animals: Biological Considerations and Impacts. Acc Chem Res 2017; 50:2767-2775. [PMID: 28984438 DOI: 10.1021/acs.accounts.7b00376] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Expansion of the genetic code allows unnatural amino acids (Uaas) to be site-specifically incorporated into proteins in live biological systems, thus enabling novel properties selectively introduced into target proteins in vivo for basic biological studies and for engineering of novel biological functions. Orthogonal components including tRNA and aminoacyl-tRNA synthetase (aaRS) are expressed in live cells to decode a unique codon (often the amber stop codon UAG) as the desired Uaa. Initially developed in E. coli, this methodology has now been expanded in multiple eukaryotic cells and animals. In this Account, we focus on addressing various biological challenges for rewriting the genetic code, describing impacts of code expansion on cell physiology and discussing implications for fundamental studies of code evolution. Specifically, a general method using the type-3 polymerase III promoter was developed to efficiently express prokaryotic tRNAs as orthogonal tRNAs and a transfer strategy was devised to generate Uaa-specific aaRS for use in eukaryotic cells and animals. The aaRSs have been found to be highly amenable for engineering substrate specificity toward Uaas that are structurally far deviating from the native amino acid, dramatically increasing the stereochemical diversity of Uaas accessible. Preparation of the Uaa in ester or dipeptide format markedly increases the bioavailability of Uaas to cells and animals. Nonsense-mediated mRNA decay (NMD), an mRNA surveillance mechanism of eukaryotic cells, degrades mRNA containing a premature stop codon. Inhibition of NMD increases Uaa incorporation efficiency in yeast and Caenorhabditis elegans. In bacteria, release factor one (RF1) competes with the orthogonal tRNA for the amber stop codon to terminate protein translation, leading to low Uaa incorporation efficiency. Contradictory to the paradigm that RF1 is essential, it is discovered that RF1 is actually nonessential in E. coli. Knockout of RF1 dramatically increases Uaa incorporation efficiency and enables Uaa incorporation at multiple sites, making it feasible to use Uaa for directed evolution. Using these strategies, the genetic code has been effectively expanded in yeast, mammalian cells, stem cells, worms, fruit flies, zebrafish, and mice. It is also intriguing to find out that the legitimate UAG codons terminating endogenous genes are not efficiently suppressed by the orthogonal tRNA/aaRS in E. coli. Moreover, E. coli responds to amber suppression pressure promptly using transposon insertion to inactivate the introduced orthogonal aaRS. Persistent amber suppression evading transposon inactivation leads to global proteomic changes with a notable up-regulation of a previously uncharacterized protein YdiI, for which an unexpected function of expelling plasmids is discovered. Genome integration of the orthogonal tRNA/aaRS in mice results in minor changes in RNA transcripts but no significant physiological impairment. Lastly, the RF1 knockout E. coli strains afford a previously unavailable model organism for studying otherwise intractable questions on code evolution in real time in the laboratory. We expect that genetically encoding Uaas in live systems will continue to unfold new questions and directions for studying biology in vivo, investigating the code itself, and reprograming genomes for synthetic biology.
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Affiliation(s)
- Lei Wang
- Department of Pharmaceutical Chemistry
and the Cardiovascular Research Institute, University of California, San
Francisco, California 94158, United States
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