Abstract
Background Survival after lung transplantation (LTx) is hampered by uncontrolled inflammation and alloimmunity. Regulatory T-cells (Tregs) are being studied as a cellular therapy in solid organ transplantation. Whether these systemically administered Tregs can function at the appropriate location and time is an important concern. We hypothesised that in vitro-expanded recipient-derived Tregs can be delivered to donor lungs prior to LTx via ex vivo lung perfusion (EVLP), maintaining their immunomodulatory ability.
Methods In a rat model, Wistar Kyoto (WKy) CD4+CD25high Tregs were expanded in vitro prior to EVLP. Expanded Tregs were administered to Fisher 344 (F344) donor lungs during EVLP; left lungs were transplanted into WKy recipients. Treg localisation and function post-transplant were assessed. In a proof-of-concept experiment, cryopreserved expanded human CD4+CD25+CD127low Tregs were thawed and injected into discarded human lungs during EVLP.
Results Rat Tregs entered the lung parenchyma and retained suppressive function. Expanded Tregs had no adverse effect on donor lung physiology during EVLP; lung water as measured by wet-to-dry weight ratio was reduced by Treg therapy. The administered cells remained in the graft at 3 days post-transplant where they reduced activation of intra-graft effector CD4+ T-cells; these effects were diminished by day 7. Human Tregs entered the lung parenchyma during EVLP where they expressed key immunoregulatory molecules (CTLA4+, 4-1BB+, CD39+ and CD15s+).
Conclusions Pre-transplant Treg administration can inhibit alloimmunity within the lung allograft at early time points post-transplant. Our organ-directed approach has potential for clinical translation.
Abstract
A recipient-derived lung allograft-directed regulatory T-cell therapy administered prior to transplantation is feasible in rat and human lungs and demonstrates evidence of immune regulation post-transplant https://bit.ly/3D8MCBo
Footnotes
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Author contributions: S.C. Juvet conceived and designed the project. S.C. Juvet, E. Miyamoto, A. Takahagi, M. Cypel, T. Martinu, M. Liu, and S. Keshavjee contributed to the interpretation of data and critically revised the manuscript. E. Miyamoto and A. Ohsumi developed the method of rat Treg injection. E. Miyamoto and A. Takahagi performed rat EVLP and transplantation. E. Miyamoto, K.M. Boonstra, J.M. Umana and B. Joe isolated and expanded Tregs and performed suppression assays and flow cytometry. D. Hwang and T. Martinu performed histological grading of acute lung injury in the lung graft. E. Miyamoto, K.F. Bei and D. Vosoughi performed immunohistochemistry and immunofluorescence staining and analysis. E. Miyamoto and S.C. Juvet contributed to the statistical analysis.
Conflict of interest: E. Miyamoto reports fellowships from The Kyoto University Foundation, Japan; the Cell Science Research Foundation, Japan; and the International Society for Heart and Lung Transplantation, during the conduct of the study.
Conflict of interest: A. Takahagi has nothing to disclose.
Conflict of interest: A. Ohsumi has nothing to disclose.
Conflict of interest: T. Martinu has nothing to disclose.
Conflict of interest: D. Hwang has nothing to disclose.
Conflict of interest: K.M. Boonstra has nothing to disclose.
Conflict of interest: B. Joe has nothing to disclose.
Conflict of interest: J.M. Umana has nothing to disclose.
Conflict of interest: K.F. Bei has nothing to disclose.
Conflict of interest: D. Vosoughi has nothing to disclose.
Conflict of interest: M. Liu has nothing to disclose.
Conflict of interest: M. Cypel reports being co-founder of Perfusix Canada and Traferox Technologies Inc. Toronto, and reports consultancy for Lung Bioengineering and United Therapeutics, during the conduct of the study.
Conflict of interest: S. Keshavjee reports being co-founder of Perfusix Canada and Traferox Technologies Inc. Toronto, and reports consultancy for Lung Bioengineering and United Therapeutics, during the conduct of the study.
Conflict of interest: S.C. Juvet reports grants from Ontario Institute for Regenerative Medicine and Cystic Fibrosis Canada, during the conduct of the study.
Support statement: This work was supported by an Ontario Institute for Regenerative Medicine – Medicine by Design New Ideas Grant (#NI17-107) and the Cystic Fibrosis Canada Marsha Morton New Investigator Award (#559984) (both to S.C. Juvet). E. Miyamoto was supported by Research Fellowships from the Cell Science Research Foundation (Japan, 2016), The Kyoto University Foundation (Japan, 2016) and the International Society for Heart and Lung Transplantation (2018). M. Cypel and S. Keshavjee are co-founders of Perfusix Canada, Traferox Technologies Inc. Toronto, and consultants for Lung Bioengineering and United Therapeutics. Funding information for this article has been deposited with the Crossref Funder Registry.
- Received March 17, 2021.
- Accepted August 17, 2021.
- Copyright ©The authors 2022. For reproduction rights and permissions contact permissions{at}ersnet.org
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