Transplantation Research Center, College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea.
Division of Nephrology, Department of Internal Medicine, Seoul St. Mary's Hospital, The College of Medicine, The Catholic University of Korea, Seoul 06591, Republic of Korea.
Int J Mol Sci. 2024 Jan 23;25(3):1378. doi: 10.3390/ijms25031378.
Sensitization to HLA can result in allograft loss for kidney transplantation (KT) patients. Therefore, it is required to develop an appropriate desensitization (DSZ) technique to remove HLA-donor-specific anti-HLA antibody (DSA) before KT. The aim of this research was to investigate whether combined use of the IL-6 receptor-blocking antibody, tocilizumab (TCZ), and bone-marrow-derived mesenchymal stem cells (BM-MSCs) could attenuate humoral immune responses in an allo-sensitized mouse model developed using HLA.A2 transgenic mice. Wild-type C57BL/6 mice were sensitized with skin allografts from C57BL/6-Tg (HLA-A2.1)1Enge/J mice and treated with TCZ, BM-MSC, or both TCZ and BM-MSC. We compared HLA.A2-specific IgG levels and subsets of T cells and B cells using flow cytometry among groups. HLA.A2-specific IgG level was decreased in all treated groups in comparison with that in the allo-sensitized control (Allo-CONT) group. Its decrease was the most significant in the TCZ + BM-MSC group. Regarding the B cell subset, combined use of TCZ and BM-MSC increased proportions of pre-pro B cells but decreased proportions of mature B cells in BM ( < 0.05 vs. control). In the spleen, an increase in transitional memory was observed with a significant decrease in marginal, follicular, and long-lived plasma B cells ( < 0.05 vs. control) in the TCZ + BM-MSC group. In T cell subsets, Th2 and Th17 cells were significantly decreased, but Treg cells were significantly increased in the TCZ+BM-MSC group compared to those in the Allo-CONT group in the spleen. Regarding RNA levels, IL-10 and Foxp3 showed increased expression, whereas IL-23 and IFN-γ showed decreased expression in the TCZ + BM-MSC group. In conclusion, combined use of TCZ and BM-MSC can inhibit B cell maturation and up-regulate Treg cells, finally resulting in the reduction of HLA.A2-specific IgG in a highly sensitized mouse model. This study suggests that the combined use of TCZ and BM-MSC can be proposed as a novel strategy in a desensitization protocol for highly sensitized patients.
针对 HLA 的致敏可导致肾移植（KT）患者移植物丢失。因此，在 KT 前需要开发适当的脱敏（DSZ）技术来清除 HLA-供体特异性抗 HLA 抗体（DSA）。本研究旨在探讨白细胞介素 6 受体阻断抗体托珠单抗（TCZ）和骨髓间充质干细胞（BM-MSCs）联合应用是否能减轻 HLA.A2 转基因小鼠模型中同种致敏诱导的体液免疫反应。野生型 C57BL/6 小鼠通过皮肤同种异体移植致敏 C57BL/6-Tg（HLA-A2.1）1Enge/J 小鼠，并用 TCZ、BM-MSC 或 TCZ 和 BM-MSC 联合治疗。我们通过流式细胞术比较了各组间 HLA.A2 特异性 IgG 水平和 T 细胞、B 细胞亚群。与同种致敏对照（Allo-CONT）组相比，所有治疗组的 HLA.A2 特异性 IgG 水平均降低，其中 TCZ+BM-MSC 组降低最显著。关于 B 细胞亚群，TCZ 和 BM-MSC 联合使用可增加 BM 中前-B 细胞的比例，但降低成熟 B 细胞的比例（<0.05 与对照组相比）。在脾脏中，TCZ+BM-MSC 组过渡记忆增加，边缘、滤泡和长寿浆细胞 B 细胞显著减少（<0.05 与对照组相比）。在 T 细胞亚群中，与 Allo-CONT 组相比，TCZ+BM-MSC 组 Th2 和 Th17 细胞显著减少，而 Treg 细胞显著增加。关于 RNA 水平，TCZ+BM-MSC 组中 IL-10 和 Foxp3 的表达增加，而 IL-23 和 IFN-γ 的表达减少。综上所述，TCZ 和 BM-MSC 的联合应用可以抑制 B 细胞成熟并上调 Treg 细胞，最终导致高度致敏小鼠模型中 HLA.A2 特异性 IgG 的减少。这项研究表明，TCZ 和 BM-MSC 的联合应用可以作为高度致敏患者脱敏方案中的一种新策略。
