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Sanders DW, Jumper CC, Ackerman PJ, Bracha D, Donlic A, Kim H, Kenney D, Castello-Serrano I, Suzuki S, Tamura T, Tavares AH, Saeed M, Holehouse AS, Ploss A, Levental I, Douam F, Padera RF, Levy BD, Brangwynne CP. SARS-CoV-2 requires cholesterol for viral entry and pathological syncytia formation. eLife 2021; 10:e65962. [PMID: 33890572 PMCID: PMC8104966 DOI: 10.7554/elife.65962] [Citation(s) in RCA: 128] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 04/01/2021] [Indexed: 12/27/2022] Open
Abstract
Many enveloped viruses induce multinucleated cells (syncytia), reflective of membrane fusion events caused by the same machinery that underlies viral entry. These syncytia are thought to facilitate replication and evasion of the host immune response. Here, we report that co-culture of human cells expressing the receptor ACE2 with cells expressing SARS-CoV-2 spike, results in synapse-like intercellular contacts that initiate cell-cell fusion, producing syncytia resembling those we identify in lungs of COVID-19 patients. To assess the mechanism of spike/ACE2-driven membrane fusion, we developed a microscopy-based, cell-cell fusion assay to screen ~6000 drugs and >30 spike variants. Together with quantitative cell biology approaches, the screen reveals an essential role for biophysical aspects of the membrane, particularly cholesterol-rich regions, in spike-mediated fusion, which extends to replication-competent SARS-CoV-2 isolates. Our findings potentially provide a molecular basis for positive outcomes reported in COVID-19 patients taking statins and suggest new strategies for therapeutics targeting the membrane of SARS-CoV-2 and other fusogenic viruses.
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Affiliation(s)
- David W Sanders
- Department of Chemical and Biological Engineering, Princeton UniversityPrincetonUnited States
| | - Chanelle C Jumper
- Department of Chemical and Biological Engineering, Princeton UniversityPrincetonUnited States
| | - Paul J Ackerman
- Department of Chemical and Biological Engineering, Princeton UniversityPrincetonUnited States
| | - Dan Bracha
- Department of Chemical and Biological Engineering, Princeton UniversityPrincetonUnited States
| | - Anita Donlic
- Department of Chemical and Biological Engineering, Princeton UniversityPrincetonUnited States
| | - Hahn Kim
- Princeton University Small Molecule Screening Center, Princeton UniversityPrincetonUnited States
- Department of Chemistry, Princeton UniversityPrincetonUnited States
| | - Devin Kenney
- Department of Microbiology, Boston University School of MedicineBostonUnited States
- National Emerging Infectious Diseases Laboratories, Boston UniversityBostonUnited States
| | - Ivan Castello-Serrano
- Department of Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Saori Suzuki
- Department of Molecular Biology, Princeton UniversityPrincetonUnited States
| | - Tomokazu Tamura
- Department of Molecular Biology, Princeton UniversityPrincetonUnited States
| | - Alexander H Tavares
- National Emerging Infectious Diseases Laboratories, Boston UniversityBostonUnited States
- Department of Biochemistry, Boston University School of MedicineBostonUnited States
| | - Mohsan Saeed
- National Emerging Infectious Diseases Laboratories, Boston UniversityBostonUnited States
- Department of Biochemistry, Boston University School of MedicineBostonUnited States
| | - Alex S Holehouse
- Department of Biochemistry and Molecular Biophysics, Washington University School of MedicineSt. LouisUnited States
| | - Alexander Ploss
- Department of Molecular Biology, Princeton UniversityPrincetonUnited States
| | - Ilya Levental
- Department of Molecular Physiology and Biological Physics, University of VirginiaCharlottesvilleUnited States
| | - Florian Douam
- Department of Microbiology, Boston University School of MedicineBostonUnited States
- National Emerging Infectious Diseases Laboratories, Boston UniversityBostonUnited States
| | - Robert F Padera
- Department of Pathology, Brigham and Women’s Hospital and Harvard Medical SchoolBostonUnited States
| | - Bruce D Levy
- Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital and Harvard Medical SchoolBostonUnited States
| | - Clifford P Brangwynne
- Department of Chemical and Biological Engineering, Princeton UniversityPrincetonUnited States
- Howard Hughes Medical InstitutePrincetonUnited States
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Aebischer-Gumy C, Moretti P, Ollier R, Ries Fecourt C, Rousseau F, Bertschinger M. SPLICELECT™: an adaptable cell surface display technology based on alternative splicing allowing the qualitative and quantitative prediction of secreted product at a single-cell level. MAbs 2021; 12:1709333. [PMID: 31955651 PMCID: PMC6973322 DOI: 10.1080/19420862.2019.1709333] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We describe a mammalian expression construct (SPLICELECT™) that allows the redirection of a proportion of a secreted protein onto the cell surface using alternative splicing: whereas the majority of the RNA is spliced into a transcript encoding a secreted protein, a weak splice donor site yields a secondary transcript encoding, in addition, a C-terminal transmembrane domain. The different sequence elements can be modified in order to modulate the level of cell surface display and of secretion in an independent manner. In this work, we demonstrated that the cell surface display of stable cell lines is correlated with the level of the secreted protein of interest, but also with the level of heterodimerization in the case of a bispecific antibody. It was also shown that this construct may be useful for rapid screening of multiple antibody candidates in binding assays following transient transfection. Thus, the correlation of product quantity and quality of the secreted and of membrane-displayed product in combination with the flexibility of the construct with regards to cell surface display/secretion levels make SPLICELECT™ a valuable tool with many potential applications, not limited to industrial cell line development or antibody engineering.
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Affiliation(s)
- Christel Aebischer-Gumy
- Cell Sciences, Ichnos Sciences SA (formerly Glenmark Pharmaceuticals SA), La Chaux-de-Fonds, Switzerland
| | - Pierre Moretti
- Cell Sciences, Ichnos Sciences SA (formerly Glenmark Pharmaceuticals SA), La Chaux-de-Fonds, Switzerland
| | - Romain Ollier
- Antibody Engineering, Ichnos Sciences SA (formerly Glenmark Pharmaceuticals SA), La Chaux-de-Fonds, Switzerland
| | - Christelle Ries Fecourt
- Antibody Engineering, Ichnos Sciences SA (formerly Glenmark Pharmaceuticals SA), La Chaux-de-Fonds, Switzerland
| | - François Rousseau
- Antibody Engineering, Ichnos Sciences SA (formerly Glenmark Pharmaceuticals SA), La Chaux-de-Fonds, Switzerland
| | - Martin Bertschinger
- Cell Sciences, Ichnos Sciences SA (formerly Glenmark Pharmaceuticals SA), La Chaux-de-Fonds, Switzerland
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3
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Qudrat A, Truong K. Modular assembly of synthetic proteins that span the plasma membrane in mammalian cells. BMC Biotechnol 2016; 16:88. [PMID: 27938351 PMCID: PMC5148844 DOI: 10.1186/s12896-016-0320-7] [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: 06/11/2016] [Accepted: 12/07/2016] [Indexed: 11/26/2022] Open
Abstract
Background To achieve synthetic control over how a cell responds to other cells or the extracellular environment, it is important to reliably engineer proteins that can traffic and span the plasma membrane. Using a modular approach to assemble proteins, we identified the minimum necessary components required to engineer such membrane-spanning proteins with predictable orientation in mammalian cells. Results While a transmembrane domain (TM) fused to the N-terminus of a protein is sufficient to traffic it to the endoplasmic reticulum (ER), an additional signal peptidase cleavage site downstream of this TM enhanced sorting out of the ER. Next, a second TM in the synthetic protein helped anchor and accumulate the membrane-spanning protein on the plasma membrane. The orientation of the components of the synthetic protein were determined through measuring intracellular Ca2+ signaling using the R-GECO biosensor and through measuring extracellular quenching of yellow fluorescent protein variants by saturating acidic and salt conditions. Conclusions This work forms the basis of engineering novel proteins that span the plasma membrane to potentially control intracellular responses to extracellular conditions. Electronic supplementary material The online version of this article (doi:10.1186/s12896-016-0320-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anam Qudrat
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street Room 407, Rosebrugh Building, Toronto, ON, M5S 3G9, Canada
| | - Kevin Truong
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street Room 407, Rosebrugh Building, Toronto, ON, M5S 3G9, Canada. .,Edward S. Rogers, Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Circle, Toronto, ON, M5S 3G4, Canada.
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4
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Hsieh YT, Lin HP, Chen BM, Huang PT, Roffler SR. Effect of Cellular Location of Human Carboxylesterase 2 on CPT-11 Hydrolysis and Anticancer Activity. PLoS One 2015; 10:e0141088. [PMID: 26509550 PMCID: PMC4624787 DOI: 10.1371/journal.pone.0141088] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 10/03/2015] [Indexed: 01/08/2023] Open
Abstract
CPT-11 is an anticancer prodrug that is clinically used for the treatment of metastatic colorectal cancer. Hydrolysis of CPT-11 by human carboxylesterase 2 (CE2) generates SN-38, a topoisomerase I inhibitor that is the active anti-tumor agent. Expression of CE2 in cancer cells is under investigation for the tumor-localized activation of CPT-11. CE2 is normally expressed in the endoplasmic reticulum of cells but can be engineered to direct expression of active enzyme on the plasma membrane or as a secreted form. Although previous studies have investigated different locations of CE2 expression in cancer cells, it remains unclear if CE2 cellular location affects CPT-11 anticancer activity. In the present study, we directly compared the influence of CE2 cellular location on substrate hydrolysis and CPT-11 cytotoxicity. We linked expression of CE2 and enhanced green fluorescence protein (eGFP) via a foot-and-mouth disease virus 2A (F2A) peptide to facilitate fluorescence-activated cell sorting to achieve similar expression levels of ER-located, secreted or membrane-anchored CE2. Soluble CE2 was detected in the medium of cells that expressed secreted and membrane-anchored CE2, but not in cells that expressed ER-retained CE2. Cancer cells that expressed all three forms of CE2 were more sensitive to CPT-11 as compared to unmodified cancer cells, but the membrane-anchored and ER-retained forms of CE2 were consistently more effective than secreted CE2. We conclude that expression of CE2 in the ER or on the membrane of cancer cells is suitable for enhancing CPT-11 anticancer activity.
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Affiliation(s)
- Yuan-Ting Hsieh
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Hsuan-Pei Lin
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Bing-Mae Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Ping-Ting Huang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Steve R. Roffler
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
- * E-mail:
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5
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Huang CC, Kuo KK, Cheng TC, Chuang CH, Kao CH, Hsieh YC, Cheng KH, Wang JY, Cheng CM, Chen CS, Cheng TL. Development of Membrane-Bound GM-CSF and IL-18 as an Effective Tumor Vaccine. PLoS One 2015; 10:e0133470. [PMID: 26186692 PMCID: PMC4506079 DOI: 10.1371/journal.pone.0133470] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 06/25/2015] [Indexed: 12/30/2022] Open
Abstract
The development of effective adjuvant is the key factor to boost the immunogenicity of tumor cells as a tumor vaccine. In this study, we expressed membrane-bound granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-18 (IL-18) as adjuvants in tumor cells to stimulate immune response. B7 transmembrane domain fused GM-CSF and IL-18 was successfully expressed in the cell membrane and stimulated mouse splenocyte proliferation. Co-expression of GM-CSF and IL-18 reduced tumorigenesis (P<0.05) and enhanced tumor protective efficacy (P<0.05) significantly in comparison with GM-CSF alone. These results indicated that the combination of GM-CSF andIL-18 will enhance the immunogenicity of a cell-based anti-tumor vaccine. This membrane-bound approach can be applied to other cytokines for the development of novel vaccine strategies.
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Affiliation(s)
- Chien-Chiao Huang
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Kung-Kai Kuo
- Department of Surgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Ta-Chun Cheng
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan
- Graduate Institute of Pharmacognosy, Taipei Medical University, Taipei, Taiwan
| | - Chih-Hung Chuang
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan
- Center for Biomarkers and Biotech Drugs, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chien-Han Kao
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yuan-Chin Hsieh
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Kuang-Hung Cheng
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Jaw-Yuan Wang
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Surgery, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chiu-Min Cheng
- Department of Aquaculture, National Kaohsiung Marine University, Kaohsiung, Taiwan
| | - Chien-Shu Chen
- School of Pharmacy, China Medical University, Taichung, Taiwan
- * E-mail: (CSC); (TLC)
| | - Tian-Lu Cheng
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Center for Biomarkers and Biotech Drugs, Kaohsiung Medical University, Kaohsiung, Taiwan
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan
- * E-mail: (CSC); (TLC)
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6
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Lin YC, Chen BM, Lu WC, Su CI, Prijovich ZM, Chung WC, Wu PY, Chen KC, Lee IC, Juan TY, Roffler SR. The B7-1 cytoplasmic tail enhances intracellular transport and mammalian cell surface display of chimeric proteins in the absence of a linear ER export motif. PLoS One 2013; 8:e75084. [PMID: 24073236 PMCID: PMC3779271 DOI: 10.1371/journal.pone.0075084] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 08/12/2013] [Indexed: 11/18/2022] Open
Abstract
Membrane-tethered proteins (mammalian surface display) are increasingly being used for novel therapeutic and biotechnology applications. Maximizing surface expression of chimeric proteins on mammalian cells is important for these applications. We show that the cytoplasmic domain from the B7-1 antigen, a commonly used element for mammalian surface display, can enhance the intracellular transport and surface display of chimeric proteins in a Sar1 and Rab1 dependent fashion. However, mutational, alanine scanning and deletion analysis demonstrate the absence of linear ER export motifs in the B7 cytoplasmic domain. Rather, efficient intracellular transport correlated with the presence of predicted secondary structure in the cytoplasmic tail. Examination of the cytoplasmic domains of 984 human and 782 mouse type I transmembrane proteins revealed that many previously identified ER export motifs are rarely found in the cytoplasmic tail of type I transmembrane proteins. Our results suggest that efficient intracellular transport of B7 chimeric proteins is associated with the structure rather than to the presence of a linear ER export motif in the cytoplasmic tail, and indicate that short (less than ~ 10-20 amino acids) and unstructured cytoplasmic tails should be avoided to express high levels of chimeric proteins on mammalian cells.
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Affiliation(s)
- Yi-Chieh Lin
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Bing-Mae Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Wei-Cheng Lu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Chien-I Su
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | | | - Wen-Chuan Chung
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Pei-Yu Wu
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Kai-Chuan Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - I-Chiao Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Ting-Yi Juan
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Steve R. Roffler
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
- * E-mail:
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7
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Yang C, Xie H, Zhang JK, Su BL. Anchoring proteins to Escherichia coli cell membranes using hydrophobic anchors derived from a Bacillus subtilis integral membrane protein. Protein Expr Purif 2012; 85:60-5. [DOI: 10.1016/j.pep.2012.06.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 06/11/2012] [Accepted: 06/20/2012] [Indexed: 12/01/2022]
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8
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Cancer immunotherapy using a membrane-bound interleukin-12 with B7-1 transmembrane and cytoplasmic domains. Mol Ther 2012; 20:927-37. [PMID: 22334018 DOI: 10.1038/mt.2012.10] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Interleukin-12 (IL-12) has potent antitumor activity, but its clinical application is limited by severe systemic toxicity, which might be alleviated by the use of membrane-anchored IL-12. In the present study, a new membrane-bound IL-12 containing murine single-chain IL-12 and B7-1 transmembrane and cytoplasmic domains (scIL-12-B7TM) was constructed and its efficacy in cancer treatment examined and its protective antitumor mechanism investigated. Surface expression of scIL-12-B7TM on colon adenocarcinoma cells significantly inhibited the growth of subcutaneous tumors, suppressed lung metastasis, and resulted in local and systemic suppression of unmodified tumors. Intratumoral injection of an adenoviral vector encoding scIL-12-B7TM not only resulted in complete regression of a majority of local tumors, but also significantly suppressed the growth of distant, untreated tumors. Moreover, mice that had been treated with scIL-12-B7TM developed memory responses against subsequent tumor challenge. Immunohistochemical staining and in vivo depletion of lymphocyte subpopulations demonstrated that both CD8(+) T cells and CD4(+) T cells contributed to the antitumor activity of scIL-12-B7TM. Importantly, the potent antitumor activities of scIL-12-B7TM were achieved with only negligible amounts of IL-12 in the circulation. Our data demonstrate that cancer immunotherapy using membrane-bound IL-12 has the advantage of minimizing systemic IL-12 levels without compromising its antitumor efficacy.
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9
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Enhancement of CPT-11 antitumor activity by adenovirus-mediated expression of β-glucuronidase in tumors. Cancer Gene Ther 2011; 18:381-9. [PMID: 21350582 DOI: 10.1038/cgt.2011.3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
CPT-11 is a clinically important prodrug that requires conversion into the active metabolite SN-38, a potent topoisomerase I poison, for antitumor activity. However, SN-38 is rapidly metabolized to the inactive SN-38 glucuronide (SN-38G) in the liver, which reduces the amount of SN-38 available for killing cancer cells. Here, we investigated if local expression of β-glucuronidase (βG) on cancer cells to catalytically convert SN38G to SN38 could enhance the antitumor activity of CPT-11. βG was tethered on the plasma membrane of three different human cancer cell lines: human colon carcinoma (LS174T), lung adenocarcinoma (CL1-5) and bladder carcinoma (EJ). Surface β-glucuronidase-expressing cells were 20 to 80-fold more sensitive to SN-38G than the parental cells. Intravenous CPT-11 produced significantly greater suppression of CL1-5 and LS174 T tumors that expressed βG as compared with unmodified tumors. Furthermore, an adenoviral vector expressing membrane-tethered βG (Ad.βG) increased the sensitivity of cancer cells to SN-38G even at multiplicity of infections as low as 0.16, indicating bystander killing of non-transduced cancer cells. Importantly, intratumoral injection of Ad.βG significantly enhanced the in vivo antitumor activity of CPT-11 as compared with treatment with CPT-11 or Ad vectors alone. This study shows that Ad.βG has potential to boost the therapeutic index of CPT-11.
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10
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Chuang KH, Wang HE, Cheng TC, Tzou SC, Tseng WL, Hung WC, Tai MH, Chang TK, Roffler SR, Cheng TL. Development of a universal anti-polyethylene glycol reporter gene for noninvasive imaging of PEGylated probes. J Nucl Med 2010; 51:933-41. [PMID: 20484433 DOI: 10.2967/jnumed.109.071977] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED A reporter gene can provide important information regarding the specificity and efficacy of gene or cell therapies. Although reporter genes are increasingly used in experimental and clinical studies, a highly specific yet nonimmunogenic reporter that can track genes and cells in vivo by multiple imaging technologies still awaits development. In this study, we constructed a versatile and nonimmunogenic reporter gene to noninvasively image gene expression or cell delivery by optical imaging, MRI, and small-animal PET. METHODS We cloned and expressed a membrane-anchored anti-polyethylene glycol (PEG) reporter that consists of the Fab fragment of a mouse anti-PEG monoclonal antibody, AGP3, fused to the C-like extracellular-transmembrane-cytosolic domains of the mouse B7-1 receptor. Binding of PEGylated probes (PEG-NIR797 for optical imaging, PEG-superparamagnetic iron oxide for MRI, and (124)I-PEG for small-animal PET) were examined in vitro and in vivo. In addition, we compared the specificity, immunogenicity, and probe toxicity of the anti-PEG reporter with the gold standard reporter gene, type 1 herpes simplex virus thymidine kinase (HSV-tk). Finally, we derived a humanized anti-PEG reporter and evaluated its imaging function in vivo with subcutaneous and metastatic tumor models in mice. RESULTS The cells or tumors that stably expressed anti-PEG reporters selectively accumulated various PEGylated imaging probes and could be detected by optical imaging, MRI, and small-animal PET. Importantly, the anti-PEG reporter displayed an imaging specificity comparable to the HSV-tk reporter but did not provoke immune responses or cause toxicity to the host. Furthermore, the humanized anti-PEG reporter retained high imaging specificity in vivo. CONCLUSION The highly specific and nonimmunogenic anti-PEG reporter may be paired with PEGylated probes to provide a valuable system to image gene expression or cell delivery in experimental and clinical studies.
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Affiliation(s)
- Kuo-Hsiang Chuang
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
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11
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Lei Y, Joo KI, Zarzar J, Wong C, Wang P. Targeting lentiviral vector to specific cell types through surface displayed single chain antibody and fusogenic molecule. Virol J 2010; 7:35. [PMID: 20149250 PMCID: PMC2830192 DOI: 10.1186/1743-422x-7-35] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Accepted: 02/11/2010] [Indexed: 02/07/2023] Open
Abstract
Background Viral delivery remains one of the most commonly used techniques today in the field of gene therapy. However, one of the remaining hurdles is the off-targeting effect of viral delivery. To overcome this obstacle, we recently developed a method to incorporate an antibody and a fusogenic molecule (FM) as two distinct molecules into the lentiviral surface. In this report, we expand this strategy to utilize a single chain antibody (SCAb) for targeted transduction. Results Two versions of the SCAb were generated to pair with our various engineered FMs by linking the heavy chain and the light chain variable domains of the anti-CD20 antibody (αCD20) via a GS linker and fusing them to the hinge-CH2-CH3 region of human IgG. The resulting protein was fused to either a HLA-A2 transmembrane domain or a VSVG transmembrane domain for anchoring purpose. Lentiviral vectors generated with either version of the SCAb and a selected FM were then characterized for binding and fusion activities in CD20-expressing cells. Conclusion Certain combinations of the SCAb with various FMs could result in an increase in viral transduction. This two-molecule lentiviral vector system design allows for parallel optimization of the SCAb and FMs to improve targeted gene delivery.
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Affiliation(s)
- Yuning Lei
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089, USA
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12
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Chen KC, Wu CH, Chang CY, Lu WC, Tseng Q, Prijovich ZM, Schechinger W, Liaw YC, Leu YL, Roffler SR. Directed evolution of a lysosomal enzyme with enhanced activity at neutral pH by mammalian cell-surface display. ACTA ACUST UNITED AC 2009; 15:1277-86. [PMID: 19101472 DOI: 10.1016/j.chembiol.2008.10.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2008] [Revised: 09/08/2008] [Accepted: 10/20/2008] [Indexed: 01/02/2023]
Abstract
Human beta-glucuronidase, due to low intrinsic immunogenicity in humans, is an attractive enzyme for tumor-specific prodrug activation, but its utility is hindered by low activity at physiological pH. Here we describe the development of a high-throughput screening procedure for enzymatic activity based on the stable retention of fluorescent reaction product in mammalian cells expressing properly folded glycoproteins on their surface. We utilized this procedure on error-prone PCR and saturation mutagenesis libraries to isolate beta-glucuronidase tetramers that were up to 60-fold more active (k(cat)/K(m)) at pH 7.0 and were up to an order of magnitude more effective at catalyzing the conversion of two structurally disparate glucuronide prodrugs to anticancer agents. The screening procedure described here can facilitate investigation of eukaryotic enzymes requiring posttranslational modifications for biological activity.
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Affiliation(s)
- Kai-Chuan Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
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13
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Abstract
Secreted and intracellular proteins including antibodies, cytokines, major histocompatibility complex molecules, antigens, and enzymes can be redirected to and anchored on the surface of mammalian cells to reveal novel functions and properties such as reducing systemic toxicity, altering the in vivo distribution of drugs and extending the range of useful drugs, creating novel, specific signaling receptors and reshaping protein immunogenicity. The present review highlights progress in designing vectors to target and retain chimeric proteins on the surface of mammalian cells. Comparison of chimeric proteins indicates that selection of the proper cytoplasmic domain and introduction of oligiosaccharides near the cell surface can dramatically enhance surface expression, especially for single-chain antibodies. We also describe progress and limitations of employing surface-tethered proteins for preferential activation of prodrugs at cancer cells, imaging gene expression in living animals, performing high-throughput screening, selectively activating immune cells in tumors, producing new adhesion molecules, creating local immune privileged sites, limiting the distribution of soluble factors such as cytokines, and enhancing polypeptide immunogenicity. Surface-anchored chimeric proteins represent a rich source for developing new techniques and creating novel therapeutics.
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Affiliation(s)
- Tian-Lu Cheng
- Faculty of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan
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14
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Volná P, Jarjour J, Baxter S, Roffler SR, Monnat RJ, Stoddard BL, Scharenberg AM. Flow cytometric analysis of DNA binding and cleavage by cell surface-displayed homing endonucleases. Nucleic Acids Res 2007; 35:2748-58. [PMID: 17426121 PMCID: PMC1885675 DOI: 10.1093/nar/gkm182] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
LAGLIDADG homing endonucleases (LHEs) cleave 18–24 bp DNA sequences and are promising enzymes for applications requiring sequence-specific DNA cleavage amongst genome-sized DNA backgrounds. Here, we report a method for cell surface display of LHEs, which facilitates analysis of their DNA binding and cleavage properties by flow cytometry. Cells expressing surface LHEs can be stained with fluorescently conjugated double-stranded oligonucleotides (dsOligos) containing their respective target sequences. The signal is absolutely sequence specific and undetectable with dsOligos carrying single base-pair substitutions. LHE–dsOligo interactions facilitate rapid enrichment and viable recovery of rare LHE expressing cells by both fluorescence-activated cell sorting (FACS) and magnetic cell sorting (MACS). Additionally, dsOligos conjugated with unique fluorophores at opposite termini can be tethered to the cell surface and used to detect DNA cleavage. Recapitulation of DNA binding and cleavage by surface-displayed LHEs provides a high-throughput approach to library screening that should facilitate rapid identification and analysis of enzymes with novel sequence specificities.
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Affiliation(s)
- Petra Volná
- Department of Pediatrics, University of Washington, Box 359300-CW, Seattle WA 98195, USA, Children's Hospital, & Regional Medical Center, 307 Westlake Ave N Suite 300, Seattle WA 98109, USA, Department of Immunology, University of Washington, 1959 Pacific Street NE, Seattle WA 98195, USA, Department of Pathology, University of Washington, Seattle WA 98195, USA, Institute of Biochemical Sciences, Academia Sinica, 128 Yen-chiu-yuan Rd., sec. 2, Tapei, Taiwan, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, A3-025, Seattle WA 98109, USA
| | - Jordan Jarjour
- Department of Pediatrics, University of Washington, Box 359300-CW, Seattle WA 98195, USA, Children's Hospital, & Regional Medical Center, 307 Westlake Ave N Suite 300, Seattle WA 98109, USA, Department of Immunology, University of Washington, 1959 Pacific Street NE, Seattle WA 98195, USA, Department of Pathology, University of Washington, Seattle WA 98195, USA, Institute of Biochemical Sciences, Academia Sinica, 128 Yen-chiu-yuan Rd., sec. 2, Tapei, Taiwan, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, A3-025, Seattle WA 98109, USA
| | - Sarah Baxter
- Department of Pediatrics, University of Washington, Box 359300-CW, Seattle WA 98195, USA, Children's Hospital, & Regional Medical Center, 307 Westlake Ave N Suite 300, Seattle WA 98109, USA, Department of Immunology, University of Washington, 1959 Pacific Street NE, Seattle WA 98195, USA, Department of Pathology, University of Washington, Seattle WA 98195, USA, Institute of Biochemical Sciences, Academia Sinica, 128 Yen-chiu-yuan Rd., sec. 2, Tapei, Taiwan, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, A3-025, Seattle WA 98109, USA
| | - Steve R. Roffler
- Department of Pediatrics, University of Washington, Box 359300-CW, Seattle WA 98195, USA, Children's Hospital, & Regional Medical Center, 307 Westlake Ave N Suite 300, Seattle WA 98109, USA, Department of Immunology, University of Washington, 1959 Pacific Street NE, Seattle WA 98195, USA, Department of Pathology, University of Washington, Seattle WA 98195, USA, Institute of Biochemical Sciences, Academia Sinica, 128 Yen-chiu-yuan Rd., sec. 2, Tapei, Taiwan, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, A3-025, Seattle WA 98109, USA
| | - Raymond J. Monnat
- Department of Pediatrics, University of Washington, Box 359300-CW, Seattle WA 98195, USA, Children's Hospital, & Regional Medical Center, 307 Westlake Ave N Suite 300, Seattle WA 98109, USA, Department of Immunology, University of Washington, 1959 Pacific Street NE, Seattle WA 98195, USA, Department of Pathology, University of Washington, Seattle WA 98195, USA, Institute of Biochemical Sciences, Academia Sinica, 128 Yen-chiu-yuan Rd., sec. 2, Tapei, Taiwan, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, A3-025, Seattle WA 98109, USA
| | - Barry L. Stoddard
- Department of Pediatrics, University of Washington, Box 359300-CW, Seattle WA 98195, USA, Children's Hospital, & Regional Medical Center, 307 Westlake Ave N Suite 300, Seattle WA 98109, USA, Department of Immunology, University of Washington, 1959 Pacific Street NE, Seattle WA 98195, USA, Department of Pathology, University of Washington, Seattle WA 98195, USA, Institute of Biochemical Sciences, Academia Sinica, 128 Yen-chiu-yuan Rd., sec. 2, Tapei, Taiwan, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, A3-025, Seattle WA 98109, USA
| | - Andrew M. Scharenberg
- Department of Pediatrics, University of Washington, Box 359300-CW, Seattle WA 98195, USA, Children's Hospital, & Regional Medical Center, 307 Westlake Ave N Suite 300, Seattle WA 98109, USA, Department of Immunology, University of Washington, 1959 Pacific Street NE, Seattle WA 98195, USA, Department of Pathology, University of Washington, Seattle WA 98195, USA, Institute of Biochemical Sciences, Academia Sinica, 128 Yen-chiu-yuan Rd., sec. 2, Tapei, Taiwan, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, A3-025, Seattle WA 98109, USA
- *To whom correpondence should be addressed +1 206 987 7314+1 206 987 7310
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15
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Johansson DX, Brismar H, Persson MAA. Fluorescent protein pair emit intracellular FRET signal suitable for FACS screening. Biochem Biophys Res Commun 2007; 352:449-55. [PMID: 17126816 DOI: 10.1016/j.bbrc.2006.11.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2006] [Accepted: 11/09/2006] [Indexed: 11/24/2022]
Abstract
The fluorescent proteins ECFP and HcRed were shown to give an easily resolved FRET-signal when expressed as a fusion inside mammalian cells. HeLa-tat cells expressing ECFP, pHcRed, or the fusion protein pHcRed-ECFP were analyzed by flow cytometry after excitation of ECFP. Cells expressing HcRed-ECFP, or ECFP and HcRed, were mixed and FACS-sorted for FRET positive cells: HcRed-ECFP cells were greatly enriched (72 times). Next, cloned human antibodies were fused with ECFP and expressed anchored to the ER membrane. Their cognate antigens (HIV-1 gp120 or gp41) were fused to HcRed and co-expressed in the ER. An increase of 13.5+/-1.5% (mean+/-SEM) and 8.0+/-0.7% in ECFP fluorescence for the specific antibodies reacting with gp120 or gp41, respectively, was noted after photobleaching. A positive control (HcRed-ECFP) gave a 14.8+/-2.6% increase. Surprisingly, the unspecific antibody (anti-TT) showed 12.1+/-1.1% increase, possibly because overexpression in the limited ER compartment gave false FRET signals.
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Affiliation(s)
- Daniel X Johansson
- Karolinska Institutet, Department of Medicine, Karolinska Hospital, 171 76 Stockholm, Sweden
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16
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Chen KC, Cheng TL, Leu YL, Prijovich ZM, Chuang CH, Chen BM, Roffler SR. Membrane-localized activation of glucuronide prodrugs by β-glucuronidase enzymes. Cancer Gene Ther 2006; 14:187-200. [PMID: 16977328 DOI: 10.1038/sj.cgt.7700999] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Gene-mediated enzyme prodrug therapy (GDEPT) seeks to increase the therapeutic index of anti-neoplastic agents by promoting selective activation of relatively nontoxic drug derivatives at sites of specific enzyme expression. Glucuronide prodrugs are attractive for GDEPT due to their low toxicity, bystander effect in the interstitial tumor space and the large range of possible glucuronide drug targets. In this study, we expressed human, murine and Esherichia coli beta-glucuronidase on tumor cells and examined their in vitro and in vivo efficacy for the activation of glucuronide prodrugs of 9-aminocamptothecin and p-hydroxy aniline mustard. We show that (1) fusion of beta-glucuronidase to the Ig-like C(2)-type and Ig-hinge-like domains of the B7-1 antigen followed by the B7-1 transmembrane domain anchored high levels of active murine and human beta-glucuronidase on cells, (2) strong bystander killing of tumor cells was achieved in vitro by murine beta-glucuronidase activation of prodrug, (3) potent in vivo anti-tumor activity was achieved by prodrug treatment of tumors that expressed murine beta-glucuronidase and (4) the p-hydroxy aniline prodrug was more effective in vivo than the 9-aminocamptothecin prodrug. Our results demonstrate that surface expression of murine beta-glucuronidase for activation of a glucuronide prodrug of p-hydroxy aniline mustard may be useful for more selective therapy of cancer.
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Affiliation(s)
- K-C Chen
- Division of Cancer Research, Institute of Biomedical Sciences, Academia Sinica, Section 2 Academia Road No. 128, Taipei 11529, Taiwan
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17
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Kim SA, Liang CM, Cheng IC, Cheng YC, Chiao MT, Tseng CJ, Lee F, Jong MH, Tao MH, Yang NS, Liang SM. DNA vaccination against foot-and-mouth disease via electroporation: study of molecular approaches for enhancing VP1 antigenicity. J Gene Med 2006; 8:1182-91. [PMID: 16927362 DOI: 10.1002/jgm.941] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Foot-and-mouth disease virus (FMDV) affects susceptible livestock animals and causes disastrous economic impact. Immunization with plasmid expressing VP1 that contains the major antigenic epitope(s) of FMDV as cytoplasmic protein (cVP1) failed to elicit full protection against FMDV challenge. MATERIALS AND METHODS In this study, mice were immunized via electroporation with four cDNA expression vectors that were constructed to express VP1 of FMDV, as cytoplasmic (cVP1), secreted (sVP1), membrane-anchored (mVP1) or capsid precursor protein (P1), respectively, to evaluate whether expression of VP1 in specific subcellular compartment(s) would result in better immune responses. RESULTS Electroporation enhanced immune responses to vectors expressing cVP1 or P1 and expedited the immune responses to vectors expressing sVP1 or mVP1. Immunization of mice via electroporation with mVP1 cDNA was better than sVP1 or cVP1 cDNA in eliciting neutralizing antibodies and viral clearance protection. Vaccination with P1 cDNA, nonetheless, yielded the best immune responses and protection among all four cDNAs that we tested. CONCLUSIONS These results suggest that the antigenicity of a VP1 DNA vaccine can be significantly enhanced by altering the cellular localization of the VP1 antigen. Electroporation is a useful tool for enhancing the immune responses of vectors expressing VP1 or P1. By mimicking FMDV more closely than that of transgenic VP1 and eliciting immune responses favorably toward Th2, transgenic P1 may induce more neutralizing antibodies and better protection against FMDV challenge.
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Affiliation(s)
- Suk-Am Kim
- Institute of BioAgricultural Sciences, Academia Sinica, Taipei, Taiwan, ROC
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18
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Roffler SR, Wang HE, Yu HM, Chang WD, Cheng CM, Lu YL, Chen BM, Cheng TL. A membrane antibody receptor for noninvasive imaging of gene expression. Gene Ther 2005; 13:412-20. [PMID: 16267569 DOI: 10.1038/sj.gt.3302671] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Monitoring gene expression is important to optimize gene therapy protocols and ensure that the proper tissue distribution is achieved in clinical practice. We developed a noninvasive imaging system based on the expression of artificial antibody receptors to trap hapten-labeled imaging probes. Functional membrane-bound anti-dansyl antibodies (DNS receptor) were stably expressed on melanoma cells in vitro and in vivo. A bivalent (DNS)2-diethylenetriaminepentaacetic 111Indium probe specifically bound to cells that expressed DNS receptors but not control scFv receptors. Importantly, the 111In probe preferentially localized to DNS receptors but not control receptors on tumors in mice as assessed by gamma camera imaging. By 48 h after intravenous injection, the uptake of the probe in tumors expressing DNS receptors was 72 times greater than the amount of probe in the blood. This targeting strategy may allow noninvasive assessment of the location, extent and persistence of gene expression in living animals and in the clinic.
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Affiliation(s)
- S R Roffler
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
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19
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Chang YW, Chen SC, Cheng EC, Ko YP, Lin YC, Kao YR, Tsay YG, Yang PC, Wu CW, Roffler SR. CD13 (aminopeptidase N) can associate with tumor-associated antigen L6 and enhance the motility of human lung cancer cells. Int J Cancer 2005; 116:243-52. [PMID: 15812828 DOI: 10.1002/ijc.21089] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Cancer metastasis is a multiple-step process that involves the regulated interaction of diverse cellular proteins. We recently reported that the expression of tumor-associated antigen L6 (TAL6) promoted the invasiveness of lung cancer cells and was inversely correlated with disease-free survival of squamous lung carcinoma patients. We now report that CD13 (aminopeptidase N) can associate with TAL6 and can enhance cancer cell migration. CD13 was shown by coimmunoprecipitation to associate in vitro with TAL6 on several cancer cell lines and to associate in vivo by antibody-mediated copatching immunofluorescence. CD13 was selectively expressed on highly invasive CL1-5 lung cancer cells as compared to poorly invasive CL1-0 lung cancer cells. The role of CD13 aminopeptidase activity in regulating cell motility was investigated with chemical inhibitors, specific antibodies and a catalytically inactive CD13 protein. Inhibition of CD13 aminopeptidase activity by nontoxic concentrations of leuhistin modestly decreased the migration of CL1-5 cells. In contrast, binding of CD13 by specific antibodies significantly reduced both the migration and the invasion of CL1-5 cells. Poorly invasive CL1-0 cells that stably expressed CD13 displayed significantly (p < or = 0.0005) enhanced cell migration (300% of control). Expression of an enzymatically inactive CD13 mutant on CL1-0 cells also significantly (p < or = 0.0005) enhanced cell migration (200% of control). Our results show that TAL6 and CD13 can form a complex on lung cancer cells, that these molecules can modulate cell migration and invasion and that the influence of CD13 on cell motility did not strictly depend on its aminopeptidase activity.
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Affiliation(s)
- Yu-Wen Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
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20
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Zhang T, He X, Tsang TC, Harris DT. Transgenic TCR expression: comparison of single chain with full-length receptor constructs for T-cell function. Cancer Gene Ther 2005; 11:487-96. [PMID: 15153936 DOI: 10.1038/sj.cgt.7700703] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Genetic modification of T lymphocytes with T-cell receptor (TCR) genes provides a novel tool for adoptive immunotherapy. However, the efficiency of full-length TCR (flTCR)-transduced T cells could be limited by factors such as incorrect pairing between exogenous and endogenous TCR chains and downregulation of the CD3 complex. To overcome these hurdles, one promising strategy is to use three-domain single-chain TCRs (3D-scTCR), in which TCR Valpha and Vbeta chains are joined by a linker with signal transduction domains fused at the carboxyl termini as signal transducers and amplifiers. Our results showed that surface expression of scTCRs on T cells after retroviral transduction was affected by the origin of the transmembrane (TM) region and placement of signaling domains. scTCR-modified T cells were functional as shown by cytokine (IL-2 and IFN-gamma) release in response to antigen stimulation and cytolytic activity against specific target cells. CD8 and CD28, but not the complete CD3 complex, could enhance the scTCR-induced T cell activation. Compared with flTCR-modified T cells and native CTLs, scTCR-modified T cells require higher thresholds of antigen stimulation (approximately 10(-8) M peptide) to be functional. Despite the low efficiency of scTCRs, our data provide insight into further improvements in generating efficient scTCRs for in vivo applications.
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MESH Headings
- Animals
- Antigens/immunology
- Cell Line
- Cell Membrane/metabolism
- Cells, Cultured
- Interferon-gamma/biosynthesis
- Interleukin-2/biosynthesis
- Mice
- Receptors, Antigen, T-Cell/chemistry
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/immunology
- Receptors, Antigen, T-Cell/metabolism
- Recombinant Proteins/genetics
- Recombinant Proteins/metabolism
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- Transduction, Genetic
- Transgenes/genetics
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Affiliation(s)
- Tong Zhang
- Gene Therapy Group, Department of Microbiology and Immunology, University of Arizona, Tucson, Arizona 85721, USA
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21
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Liao KW, Chen BM, Liu TB, Tzou SC, Lin YM, Lin KF, Su CI, Roffler SR. Stable expression of chimeric anti-CD3 receptors on mammalian cells for stimulation of antitumor immunity. Cancer Gene Ther 2004; 10:779-90. [PMID: 14502231 DOI: 10.1038/sj.cgt.7700637] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Expression of CD80 or CD86 costimulatory molecules on tumor cells can produce rejection of immunogenic but not poorly immunogenic tumors. We have previously shown that anti-CD3 single-chain antibodies expressed on the surface of cells can directly activate T cells. We therefore investigated whether anti-CD3 "receptors" could enhance CD86-mediated rejection of poorly immunogenic tumors. Expression of anti-CD3 receptors on cells was increased by introduction of membrane-proximal "spacer" domains containing glycosylation sites between the single-chain antibody and the transmembrane domain of the chimeric receptors. Removal of glycosylation sites in the spacer reduced surface expression due to increased shedding of chimeric receptors from the cell surface. Induction of T-cell proliferation by anti-CD3 receptors did not correlate with the expression level of chimeric protein, but rather depended on the physical properties of the spacer. Anti-CD3 receptors effectively induced T-cell cytotoxicity, whereas coexpression with CD80 or CD86 was required for generating T-cell proliferation and IL-2 secretion. Although expression of CD86 did not significantly delay the growth of poorly immunogenic B16-F1 tumors, expression of anti-CD3 receptors with CD86 produced complete tumor rejections in 50% of mice and induced significant protection against wild-type B16-F1 tumor cells. Our results show that spacer domains can dramatically influence the surface expression and the biological activity of chimeric antibody receptors. The strong antitumor activity produced by anti-CD3 receptors and CD86 on tumor cells indicates that this strategy may be beneficial for the gene-mediated therapy of poorly immunogenic tumors.
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Affiliation(s)
- Kuang-Wen Liao
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan, Republic of China
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22
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Cheng TL, Liao KW, Tzou SC, Cheng CM, Chen BM, Roffler SR. Hapten-directed targeting to single-chain antibody receptors. Cancer Gene Ther 2004; 11:380-8. [PMID: 15044963 DOI: 10.1038/sj.cgt.7700712] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Artificial recombinant receptors may be useful for selectively targeting imaging and therapeutic agents to sites of gene expression. To evaluate this approach, we developed transgenes to express highly on cells a single-chain antibody (scFv) against the hapten 4-ethoxymethylene-2-phenyl-2-oxazoline-5-one (phOx). A phOx enzyme conjugate was created by covalently attaching phOx molecules to polyethylene glycol (PEG)-modified beta-glucuronidase. Cells expressing phOx scFv but not control scFv receptors were selectively killed after exposure to ss-glucuronidase derivatized with phOx and PEG (phOx-beta G-PEG) and a glucuronide prodrug (p-hydroxy aniline mustard beta-D-glucuronide, HAMG) of p-hydroxyaniline mustard. Targeted activation of HAMG produced bystander killing of receptor-negative cells in mixed populations containing as few as 10% phOx-receptor-positive cells. Functional phOx scFv receptors were stably expressed on B16-F1 melanoma tumors in vivo. Treatment of mice bearing established phOx-receptor-positive tumors with phOx-beta G-PEG and HAMG significantly (P< or =.0005) suppressed tumor growth as compared with treatment with beta G-PEG and HAMG or prodrug alone. phOx was unstable in the serum, suggesting alternative haptens may be more suitable for in vivo applications. Our results show that therapeutic agents can be targeted to artificial hapten receptors in vitro and in vivo. The expression of artificial receptors on target cells may allow preferential delivery of therapeutic or imaging molecules to sites of transgene expression.
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Affiliation(s)
- Tian-Lu Cheng
- School of Biomedical Science and Environmental Biology, and MedicoGenomic Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
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