Human HLA-DR+CD27+ regulatory T cells show enhanced antigen-specific suppressive function
Xiaoqian Ma, Lu Cao, Martina Raneri, Hannah Wang, Qi Cao, Yuanfei Zhao, Naiara G. Bediaga, Gaetano Naselli, Leonard C. Harrison, Wayne J. Hawthorne, Min Hu, Shounan Yi, Philip J. O’Connell
Xiaoqian Ma, Lu Cao, Martina Raneri, Hannah Wang, Qi Cao, Yuanfei Zhao, Naiara G. Bediaga, Gaetano Naselli, Leonard C. Harrison, Wayne J. Hawthorne, Min Hu, Shounan Yi, Philip J. O’Connell
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Research Article Immunology Transplantation

Human HLA-DR+CD27+ regulatory T cells show enhanced antigen-specific suppressive function

Abstract

Regulatory T cells (Tregs) have potential for the treatment of autoimmune diseases and graft rejection. Antigen specificity and functional stability are considered critical for their therapeutic efficacy. In this study, expansion of human Tregs in the presence of porcine PBMCs (xenoantigen-expanded Tregs, Xn-Treg) allowed the selection of a distinct Treg subset, coexpressing the activation/memory surface markers HLA-DR and CD27 with enhanced proportion of FOXP3+Helios+ Tregs. Compared with their unsorted and HLA-DR+CD27+ double-positive (DP) cell–depleted Xn-Treg counterparts, HLA-DR+CD27+ DP-enriched Xn-Tregs expressed upregulated Treg function markers CD95 and ICOS with enhanced suppression of xenogeneic but not polyclonal mixed lymphocyte reaction. They also had less Treg-specific demethylation in the region of FOXP3 and were more resistant to conversion to effector cells under inflammatory conditions. Adoptive transfer of porcine islet recipient NOD/SCID IL2 receptor γ–/– mice with HLA-DR+CD27+ DP-enriched Xn-Tregs in a humanized mouse model inhibited porcine islet graft rejection mediated by 25-fold more human effector cells. The prolonged graft survival was associated with enhanced accumulation of FOXP3+ Tregs and upregulated expression of Treg functional genes, IL10 and cytotoxic T lymphocyte antigen 4, but downregulated expression of effector Th1, Th2, and Th17 cytokine genes, within surviving grafts. Collectively, human HLA-DR+CD27+ DP-enriched Xn-Tregs expressed a specific regulatory signature that enabled identification and isolation of antigen-specific and functionally stable Tregs with potential as a Treg-based therapy.

Authors

Xiaoqian Ma, Lu Cao, Martina Raneri, Hannah Wang, Qi Cao, Yuanfei Zhao, Naiara G. Bediaga, Gaetano Naselli, Leonard C. Harrison, Wayne J. Hawthorne, Min Hu, Shounan Yi, Philip J. O’Connell

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Figure 5

Evaluation of NICC xenograft survival and function in vivo.

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Evaluation of NICC xenograft survival and function in vivo. HLA-DR+CD27+...
HLA-DR+CD27+ DP-enriched Xn-Tregs are more capable of suppressing islet xenograft injection. (A) Flow cytometric measurement of percentage of human leukocytes (CD45+ cells, CD4+ and CD8+ T cells) in the spleen of mice receiving human PBMCs (CD4+CD25+CD127–/lo depleted) alone at 35 days, and different types of human expanded Tregs combined with PBMCs at 60 days after human cell transfer. Data are shown as mean ± SD of at least 3 independent experiments (n ≥ 8 mice of each group). (B) Representative immunohistochemical examination for human CD4 and CD8 and porcine insulin of graft samples from mice receiving no cells (NICC alone day 90 posttransplantation) or human PBMCs (NICC + PBMC day 35 after NICC transplantation). Original magnification, ×200. (C) Porcine C-peptide was measured at day 60 posttransplantation and control PBMC group at day 30. Data are represented as mean ± SD (n ≥ 8 mice of each group, except control PBMC group with n = 5). (D) Representative immunohistochemical staining of graft samples from the same mice as in A for human CD4 and CD8 and porcine insulin, glucagon, and somatostatin. Original magnification, ×200. One-way ANOVA with Tukey’s multiple-comparison test (A) and Kruskal-Wallis test (C): *P < 0.05; **P < 0.01; ****P < 0.0001.