Radiolabelling of Polyclonally Expanded Human Regulatory T Cells (Treg) with <sup>89</sup>Zr-oxine for Medium-Term <i>In Vivo</i> Cell Tracking
Regulatory T cells (Tregs) are a promising candidate cell therapy to treat autoimmune diseases and aid the longevity of transplanted solid organs. Despite increasing numbers of clinical trials using human Treg therapy, important questions pertaining to their <i>in vivo</i> fate, distribu...
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MDPI AG
2023-02-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/28/3/1482 |
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| author | Jacinta Jacob Alessia Volpe Qi Peng Robert I. Lechler Lesley A. Smyth Giovanna Lombardi Gilbert O. Fruhwirth |
| author_facet | Jacinta Jacob Alessia Volpe Qi Peng Robert I. Lechler Lesley A. Smyth Giovanna Lombardi Gilbert O. Fruhwirth |
| author_sort | Jacinta Jacob |
| collection | DOAJ |
| description | Regulatory T cells (Tregs) are a promising candidate cell therapy to treat autoimmune diseases and aid the longevity of transplanted solid organs. Despite increasing numbers of clinical trials using human Treg therapy, important questions pertaining to their <i>in vivo</i> fate, distribution, and function remain unanswered. Treg accumulation in relevant tissues was found to be crucial for Treg therapy efficacy, but existing blood-borne biomarkers are unlikely to accurately reflect the tissue state. Non-invasive Treg tracking by whole-body imaging is a promising alternative and can be achieved by direct radiolabelling of Tregs and following the radiolabelled cells with positron emission tomography (PET). Our goal was to evaluate the radiolabelling of polyclonal Tregs with <sup>89</sup>Zr to permit their <i>in vivo</i> tracking by PET/CT for longer than one week with current preclinical PET instrumentation. We used [<sup>89</sup>Zr]Zr(oxinate)<sub>4</sub> as the cell-labelling agent and achieved successful radiolabelling efficiency of human Tregs spanning 0.1–11.1 Bq <sup>89</sup>Zr/Treg cell, which would be compatible with PET tracking beyond one week. We characterized the <sup>89</sup>Zr-Tregs, assessing their phenotypes, and found that they were not tolerating these intracellular <sup>89</sup>Zr amounts, as they failed to survive or expand in a <sup>89</sup>Zr-dose-dependent manner. Even at 0.1 Bq <sup>89</sup>Zr per Treg cell, while <sup>89</sup>Zr-Tregs remained functional as determined by a five-day-long effector T cell suppression assay, they failed to expand beyond day 3 <i>in vitro</i>. Moreover, PET imaging revealed signs of <sup>89</sup>Zr-Treg death after adoptive transfer <i>in vivo</i>. In summary, <sup>89</sup>Zr labelling of Tregs at intracellular radioisotope amounts compatible with cell tracking over several weeks did not achieve the desired outcomes, as <sup>89</sup>Zr-Tregs failed to expand and survive. Consequently, we conclude that indirect Treg labelling is likely to be the most effective alternative method to satisfy the requirements of this cell tracking scenario. |
| first_indexed | 2024-03-11T09:32:42Z |
| format | Article |
| id | doaj.art-c2ce8a9f7b0347a791e20018dcb780c4 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-11T09:32:42Z |
| publishDate | 2023-02-01 |
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| spelling | doaj.art-c2ce8a9f7b0347a791e20018dcb780c42023-11-16T17:33:09ZengMDPI AGMolecules1420-30492023-02-01283148210.3390/molecules28031482Radiolabelling of Polyclonally Expanded Human Regulatory T Cells (Treg) with <sup>89</sup>Zr-oxine for Medium-Term <i>In Vivo</i> Cell TrackingJacinta Jacob0Alessia Volpe1Qi Peng2Robert I. Lechler3Lesley A. Smyth4Giovanna Lombardi5Gilbert O. Fruhwirth6MRC Centre for Transplantation, Peter Gorer Department of Immunobiology, School of Immunology and Microbial Science, King’s College London, Guy’s Hospital, Tower Wing, 5th Floor, Great Maze Pond, London SE1 9RT, UKImaging Therapies and Cancer Group, Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King’s College London, Guy’s Campus, New Hunt’s House, 2nd Floor, Great Maze Pond, London SE1 1UL, UKMRC Centre for Transplantation, Peter Gorer Department of Immunobiology, School of Immunology and Microbial Science, King’s College London, Guy’s Hospital, Tower Wing, 5th Floor, Great Maze Pond, London SE1 9RT, UKMRC Centre for Transplantation, Peter Gorer Department of Immunobiology, School of Immunology and Microbial Science, King’s College London, Guy’s Hospital, Tower Wing, 5th Floor, Great Maze Pond, London SE1 9RT, UKSchool of Health, Sport and Bioscience, Stratford Campus, University of East London, London E15 4LZ, UKMRC Centre for Transplantation, Peter Gorer Department of Immunobiology, School of Immunology and Microbial Science, King’s College London, Guy’s Hospital, Tower Wing, 5th Floor, Great Maze Pond, London SE1 9RT, UKImaging Therapies and Cancer Group, Comprehensive Cancer Centre, School of Cancer and Pharmaceutical Sciences, King’s College London, Guy’s Campus, New Hunt’s House, 2nd Floor, Great Maze Pond, London SE1 1UL, UKRegulatory T cells (Tregs) are a promising candidate cell therapy to treat autoimmune diseases and aid the longevity of transplanted solid organs. Despite increasing numbers of clinical trials using human Treg therapy, important questions pertaining to their <i>in vivo</i> fate, distribution, and function remain unanswered. Treg accumulation in relevant tissues was found to be crucial for Treg therapy efficacy, but existing blood-borne biomarkers are unlikely to accurately reflect the tissue state. Non-invasive Treg tracking by whole-body imaging is a promising alternative and can be achieved by direct radiolabelling of Tregs and following the radiolabelled cells with positron emission tomography (PET). Our goal was to evaluate the radiolabelling of polyclonal Tregs with <sup>89</sup>Zr to permit their <i>in vivo</i> tracking by PET/CT for longer than one week with current preclinical PET instrumentation. We used [<sup>89</sup>Zr]Zr(oxinate)<sub>4</sub> as the cell-labelling agent and achieved successful radiolabelling efficiency of human Tregs spanning 0.1–11.1 Bq <sup>89</sup>Zr/Treg cell, which would be compatible with PET tracking beyond one week. We characterized the <sup>89</sup>Zr-Tregs, assessing their phenotypes, and found that they were not tolerating these intracellular <sup>89</sup>Zr amounts, as they failed to survive or expand in a <sup>89</sup>Zr-dose-dependent manner. Even at 0.1 Bq <sup>89</sup>Zr per Treg cell, while <sup>89</sup>Zr-Tregs remained functional as determined by a five-day-long effector T cell suppression assay, they failed to expand beyond day 3 <i>in vitro</i>. Moreover, PET imaging revealed signs of <sup>89</sup>Zr-Treg death after adoptive transfer <i>in vivo</i>. In summary, <sup>89</sup>Zr labelling of Tregs at intracellular radioisotope amounts compatible with cell tracking over several weeks did not achieve the desired outcomes, as <sup>89</sup>Zr-Tregs failed to expand and survive. Consequently, we conclude that indirect Treg labelling is likely to be the most effective alternative method to satisfy the requirements of this cell tracking scenario.https://www.mdpi.com/1420-3049/28/3/1482adoptive cell transfercell trackingimmunotherapyPET/CTtransplantationZr-89-oxine |
| spellingShingle | Jacinta Jacob Alessia Volpe Qi Peng Robert I. Lechler Lesley A. Smyth Giovanna Lombardi Gilbert O. Fruhwirth Radiolabelling of Polyclonally Expanded Human Regulatory T Cells (Treg) with <sup>89</sup>Zr-oxine for Medium-Term <i>In Vivo</i> Cell Tracking Molecules adoptive cell transfer cell tracking immunotherapy PET/CT transplantation Zr-89-oxine |
| title | Radiolabelling of Polyclonally Expanded Human Regulatory T Cells (Treg) with <sup>89</sup>Zr-oxine for Medium-Term <i>In Vivo</i> Cell Tracking |
| title_full | Radiolabelling of Polyclonally Expanded Human Regulatory T Cells (Treg) with <sup>89</sup>Zr-oxine for Medium-Term <i>In Vivo</i> Cell Tracking |
| title_fullStr | Radiolabelling of Polyclonally Expanded Human Regulatory T Cells (Treg) with <sup>89</sup>Zr-oxine for Medium-Term <i>In Vivo</i> Cell Tracking |
| title_full_unstemmed | Radiolabelling of Polyclonally Expanded Human Regulatory T Cells (Treg) with <sup>89</sup>Zr-oxine for Medium-Term <i>In Vivo</i> Cell Tracking |
| title_short | Radiolabelling of Polyclonally Expanded Human Regulatory T Cells (Treg) with <sup>89</sup>Zr-oxine for Medium-Term <i>In Vivo</i> Cell Tracking |
| title_sort | radiolabelling of polyclonally expanded human regulatory t cells treg with sup 89 sup zr oxine for medium term i in vivo i cell tracking |
| topic | adoptive cell transfer cell tracking immunotherapy PET/CT transplantation Zr-89-oxine |
| url | https://www.mdpi.com/1420-3049/28/3/1482 |
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