通过胞啃作用从浆细胞样树突状细胞获取MHC II类分子赋予CD8CD45RC调节性T细胞供体特异性免疫耐受。

Trogocytosis-mediated acquisition of MHC class II molecules from plasmacytoid dendritic cells confers donor-specific immune tolerance to CD8CD45RC regulatory T cells.

作者信息

Zhao Yang, Zhou Lin, Yuan Zhu-Hui, Jia Ya-Nan, Chen Qing, Ren Zhang-Yong, Zhang Xin-Xue, Lang Ren, He Qiang, Li Xian-Liang

机构信息

Department of Hepatobiliary and Pancreaticosplenic Surgery, Beijing ChaoYang Hospital, Capital Medical University, Beijing 100020, China.

Department of Radiation Oncology, Cancer Center of Peking University Third Hospital, Peking University Third Hospital, Haidian District, 49 Huayuan North Road, Beijing, China.

出版信息

Mol Immunol. 2025 Aug;184:40-50. doi: 10.1016/j.molimm.2025.06.001. Epub 2025 Jun 6.

DOI:10.1016/j.molimm.2025.06.001

PMID:40482606

Abstract

OBJECTIVE

Donor-specific suppression by MHC-IICD8CD45RCregulatory T cells (Tregs) was observed in our prior study, here we endeavor to investigate the mechanism underlying generation of the MHC-IICD8CD45RCTregs.

METHODS

The presence of MHC-IICD8CD45RCTregs within tolerated grafts was confirmed using a multicolor immunofluorescence technique in spontaneous tolerant rat liver transplant model. We aimed to elucidate the generation mechanism of MHC-IICD8CD45RCTregs by purifying naive CD8CD45RCTregs and plasmacytoid dendritic cells (pDCs) from recipients and co-culturing them to induce trogocytosis. Initially, we examined the immunophenotype and cytokine secretion of MHC-IICD8CD45RCTreg using flow cytometry. Trogocytosis of peptide-MHC class II complexes was visualized using a confocal microscope. Subsequently, we analyzed the donor-specific inhibitory effect of MHC-IICD8CD45RCTregs using CFSE-based lymphocyte proliferation analysis. Finally, we explored the possible transfer mechanisms of MHC class II using IFN-γ stimulation and 1-MT to block indoleamine-(2,3)-dioxygenase (IDO).

RESULTS

In the spontaneously tolerant rat liver transplants, MHC-IICD8CD45RCTregs and IL-10 expression were upregulated. Our in vitro study revealed that trogocytosis occurring between naive CD8CD45RCTregs and pDCs could induce MHC-IICD8CD45RCTregs. The semi-direct pathway represents the primary mode of Trogocytosis-mediated transfer of MHC-II molecules from pDCs to CD8CD45RCTregs. The MHC-IICD8CD45RCTregs exhibited high secretion of IL-10 and IFN-γ. Co-culturing with MHC-IICD8CD45RCTregs significantly suppressed the proliferation of CD4CD25effector T cells. Moreover, this inhibitory effect was donor-specific and could be overcome in the presence of third-party antigen-presenting cells. Our data also suggested that blocking the IFN-γ/IDO signaling pathway could inhibit the generation of trogocytosis-mediated MHC-IICD8CD45RCTregs.

CONCLUSIONS

MHC-IICD8CD45RCTregs generated through trogocytosis exhibit donor-specific suppressive function. Moreover, in vitro generation of MHC-IICD8CD45RCTregs offers a potential alternative approach to induce donor-specific immune tolerance through adoptive transfer.

摘要

目的

在我们之前的研究中观察到MHC-II⁺CD8⁺CD45RC⁺调节性T细胞（Tregs）对供体特异性的抑制作用，在此我们致力于研究MHC-II⁺CD8⁺CD45RC⁺Tregs产生的潜在机制。

方法

在自发耐受的大鼠肝移植模型中，使用多色免疫荧光技术确认耐受移植物中MHC-II⁺CD8⁺CD45RC⁺Tregs的存在。我们旨在通过从受体中纯化初始CD8⁺CD45RC⁺Tregs和浆细胞样树突状细胞（pDCs）并将它们共培养以诱导胞啃作用，来阐明MHC-II⁺CD8⁺CD45RC⁺Tregs的产生机制。首先，我们使用流式细胞术检测MHC-II⁺CD8⁺CD45RC⁺Treg的免疫表型和细胞因子分泌。使用共聚焦显微镜观察肽-MHC II类复合物的胞啃作用。随后，我们使用基于CFSE的淋巴细胞增殖分析来分析MHC-II⁺CD8⁺CD45RC⁺Tregs对供体特异性的抑制作用。最后，我们使用IFN-γ刺激和1-MT阻断吲哚胺-（2,3）-双加氧酶（IDO）来探索MHC II类分子可能的转移机制。

结果

在自发耐受的大鼠肝移植中，MHC-II⁺CD8⁺CD45RC⁺Tregs和IL-10表达上调。我们的体外研究表明，初始CD8⁺CD45RC⁺Tregs与pDCs之间发生的胞啃作用可诱导MHC-II⁺CD8⁺CD45RC⁺Tregs。半直接途径代表了胞啃作用介导的MHC-II分子从pDCs转移至CD8⁺CD45RC⁺Tregs的主要方式。MHC-II⁺CD8⁺CD45RC⁺Tregs表现出IL-10和IFN-γ的高分泌。与MHC-II⁺CD8⁺CD45RC⁺Tregs共培养可显著抑制CD4⁺CD25⁻效应T细胞的增殖。此外，这种抑制作用是供体特异性的，并且在存在第三方抗原呈递细胞的情况下可被克服。我们的数据还表明，阻断IFN-γ/IDO信号通路可抑制胞啃作用介导的MHC-II⁺CD8⁺CD45RC⁺Tregs的产生。