Department of General Surgery, Tianjin Medical University General Hospital, Tianjin, China.
Tianjin General Surgery Institute, Tianjin Medical University General Hospital, Tianjin, China.
Scand J Immunol. 2022 Aug;96(2):e13171. doi: 10.1111/sji.13171. Epub 2022 Apr 14.
Heart transplantation has become the only 'cure' for end-stage heart diseases, but acute allograft rejection is the major obstacle to the survival of patients. Our previous studies showed that IL-35 gene-modified adipose-derived mesenchymal stem cells (IL-35-ASCs) can effectively inhibit graft rejection and prolong the survival of transplanted hearts in mice. This study further explored the mechanism of IL-35-ASCs, especially focusing on the important role of IL-35-ASC-derived exosomes (IL-35-ASCexos) in inhibiting acute rejection. IL-35-ASCs were constructed in vitro and pretreated with IL-35 neutralizing antibody and GW4869 (an inhibitor of neutral sphingomyelinase that impairs exosome biogenesis/release). Then, pretreated IL-35-ASCs and CD4 T cells were cocultured in Transwell plates, and changes in regulatory T cells (Tregs) and cytokines were detected. Then, IL-35-ASCexos were extracted, identified and analysed, and their immunoregulatory effects on CD4 T cells were studied through coculture experiments. Finally, IL-35-ASCexos were applied to a mouse heart transplantation model to investigate the therapeutic effects on acute rejection of the allograft. The coculture experiment showed that the IL-35-neutralizing antibody could not completely block the immunosuppressive function of IL-35-ASCs, while GW4869 could effectively reduce their immunoregulatory characteristics. Similar to IL-35-ASCs, IL-35-ASCexos also have powerful immunosuppressive properties, effectively upregulating the Treg ratio in vivo and in vitro and prolonging graft survival. As the main effectors of IL-35-ASCs, these findings highlight the therapeutic potential of IL-35-ASCexos in inhibiting acute cardiac rejection of the allograft. Although the specific mechanism remains unclear and needs to be further explored, IL-35-ASCexos therapy is expected to become a new method to inhibit acute graft rejection.
心脏移植已成为治疗终末期心脏病的唯一“疗法”，但急性移植物排斥反应是影响患者生存的主要障碍。我们之前的研究表明，IL-35 基因修饰的脂肪间充质干细胞（IL-35-ASCs）可有效抑制移植物排斥反应，并延长小鼠移植心脏的存活时间。本研究进一步探讨了 IL-35-ASCs 的作用机制，特别是聚焦于 IL-35-ASC 来源的外泌体（IL-35-ASCexos）在抑制急性排斥反应中的重要作用。我们在体外构建了 IL-35-ASCs，并使用 IL-35 中和抗体和 GW4869（一种抑制中性鞘磷脂酶的抑制剂，可损害外泌体的生物发生/释放）预处理。然后，将预处理的 IL-35-ASCs 和 CD4 T 细胞在 Transwell 板中共培养，并检测调节性 T 细胞（Tregs）和细胞因子的变化。然后，提取、鉴定和分析了 IL-35-ASCexos，并通过共培养实验研究了它们对 CD4 T 细胞的免疫调节作用。最后，将 IL-35-ASCexos 应用于小鼠心脏移植模型，以研究其对同种异体移植物急性排斥反应的治疗作用。共培养实验表明，IL-35 中和抗体不能完全阻断 IL-35-ASCs 的免疫抑制功能，而 GW4869 可以有效降低其免疫调节特性。与 IL-35-ASCs 相似，IL-35-ASCexos 也具有强大的免疫抑制特性，可有效上调体内和体外 Treg 比例，并延长移植物存活时间。作为 IL-35-ASCs 的主要效应物，这些发现突出了 IL-35-ASCexos 在抑制同种异体移植物急性心脏排斥反应中的治疗潜力。尽管具体机制尚不清楚，需要进一步探讨，但 IL-35-ASCexos 治疗有望成为抑制急性移植物排斥反应的新方法。
