Human CD8+ Tregs expressing a MHC-specific CAR display enhanced suppression of human skin rejection and GVHD in NSG mice

Abstract : Polyclonal CD8+CD45RClow/- Tregs are potent regulatory cells able to control solid organ transplantation rejection and even induce tolerance. However, donor major histocompatibility complex (MHC)-specific Tregs are more potent than polyclonal Tregs in suppressing T-cell responses and preventing acute as well as chronic rejection in rodent models. The difficulty of identifying disease-relevant antigens able to stimulate Tregs has reduced the possibility of obtaining antigen-specific Tregs. To bypass this requirement and gain the advantage of antigen specificity, and thus improve the therapeutic potential of CD8+ Tregs, we stably introduced a chimeric antigen receptor (CAR) derived from a HLA-A*02 antigen-specific antibody (A2-CAR) in human CD8+ Tregs and developed a clinically compatible protocol of transduction and expansion. We demonstrated that A2-CAR CD8+ Tregs were not phenotypically altered by the process, were specifically activated, and did not exhibit cytotoxic activity toward HLA-A*02+ kidney endothelial cells (ECs). We showed that A2-CAR CD8+ Tregs were more potent suppressors of immune responses induced by HLA-A*02 mismatch than control-CAR CD8+ Tregs, both in vitro and in vivo, in models of human skin graft rejection and graft-versus-host disease (GVHD) in NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) mice. We showed that integrity of human skin graft was preserved with A2-CAR CD8+ Tregs at least 100 days in vivo after administration, and that interaction between the A2-CAR CD8+ Tregs and HLA-A*02+ kidney ECs resulted in a fine-tuned and protolerogenic activation of the ECs without cytotoxicity. Together, our results demonstrated the relevance of the CAR engineering approach to develop antigen-specific CAR-CD8+ Tregs for clinical trials in transplantation, and potentially in other diseases.
Document type :
Journal articles
Complete list of metadatas

Cited literature [51 references]  Display  Hide  Download

https://www.hal.inserm.fr/inserm-02376064
Contributor : Ana Paula Dutra Azevedo <>
Submitted on : Friday, November 22, 2019 - 12:35:49 PM
Last modification on : Saturday, November 23, 2019 - 1:27:32 AM

File

 Restricted access
To satisfy the distribution rights of the publisher, the document is embargoed until : jamais

Please log in to resquest access to the document

Identifiers

Collections

Citation

Séverine Bézie, Béatrice Charreau, Nadège Vimond, Juliette Lasselin, Nathalie Gérard, et al.. Human CD8+ Tregs expressing a MHC-specific CAR display enhanced suppression of human skin rejection and GVHD in NSG mice. Blood Advances, The American Society of Hematology, 2019, 3 (22), pp.3522-3538. ⟨10.1182/bloodadvances.2019000411⟩. ⟨inserm-02376064⟩

Share

Metrics

Record views

27