Huang Yajun, Lai Junlin, Chen Xing, Yang Jinfeng, Li Chenghao, Wang Yixuan, Chen Yuqi, Xia Tian, Luo Yijie, Yim Wai Yen, Ding Xiangchao, Wang Guohua
Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Department of Reconstructive and Plastic Surgery, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, 441000, People's Republic of China.
Sci Rep. 2025 Jul 1;15(1):22327. doi: 10.1038/s41598-025-08315-5.
The interactions between CD40 and tumor necrosis factor receptor-associated factor 6 (TRAF6) are implicated in chronic inflammation and fibrosis. Given their poorly understood role in chronic transplant rejection, our study focused on investigating the CD40-TRAF6 interactions in murine models of cardiac transplantation, particularly in relation to cardiac allograft vasculopathy (CAV). We established murine heart transplantation models using BALB/C to C57BL/6 and H-2bm12 to C57BL/6 pairings. A specific antagonist for TRAF6 was administered post-transplantation, either alone or in combination with cyclosporin A (CsA). We analyzed cells infiltrating the cardiac allografts and splenic immune cells. Additionally, We explore the potential mechanistic effects of TRAF6 inhibition in CAV by bone marrow-derived macrophages (BMDMs) co-culture. The inhibition of CD40-TRAF6 interaction significantly prolonged the survival of cardiac allografts. When combined with CsA, this treatment induced long-term survival of the allografts. Specifically, in the H-2bm12 to C57BL/6 heart transplantation model, inhibiting TRAF6 mitigated the development of CAV. This blockade led to a decrease in CD11b + and CD4 + cells within the allografts. In vitro experiments showed that TRAF6 inhibition had limited effects on mixed lymphocyte culture responses and minimally affected the proliferation of naive CD4 + cells activated by CD3/CD28. Furthermore, BMDMs under CD40-TRAF6 inhibition were more likely to differentiate into an anti-inflammatory phenotype, and their migration capability was reduced. Our findings demonstrate that inhibiting the TRAF6 pathway can significantly ameliorate both acute and chronic allograft rejection. The combination with CsA appears to have a synergistic effect, suggesting that targeting the TRAF6 could be a beneficial co-strategy for managing alloimmune responses. Importantly, our results position TRAF6 as a promising complementary target for enhancing outcomes in CAV.
CD40与肿瘤坏死因子受体相关因子6（TRAF6）之间的相互作用与慢性炎症和纤维化有关。鉴于它们在慢性移植排斥反应中的作用尚不清楚，我们的研究重点是在心脏移植小鼠模型中研究CD40-TRAF6的相互作用，特别是与心脏移植血管病变（CAV）的关系。我们使用BALB/C到C57BL/6以及H-2bm12到C57BL/6的配对建立了小鼠心脏移植模型。移植后单独或与环孢素A（CsA）联合给予TRAF6的特异性拮抗剂。我们分析了浸润心脏同种异体移植物的细胞和脾脏免疫细胞。此外，我们通过骨髓来源的巨噬细胞（BMDM）共培养探索了TRAF6抑制在CAV中的潜在机制作用。抑制CD40-TRAF6相互作用显著延长了心脏同种异体移植物的存活时间。当与CsA联合使用时，这种治疗诱导了同种异体移植物的长期存活。具体而言，在H-2bm12到C57BL/6心脏移植模型中，抑制TRAF6减轻了CAV的发展。这种阻断导致同种异体移植物内CD11b +和CD4 +细胞减少。体外实验表明，TRAF6抑制对混合淋巴细胞培养反应的影响有限，对由CD3/CD28激活的幼稚CD4 +细胞的增殖影响最小。此外，在CD40-TRAF6抑制下的BMDM更有可能分化为抗炎表型，并且它们的迁移能力降低。我们的研究结果表明，抑制TRAF6途径可以显著改善急性和慢性同种异体移植排斥反应。与CsA联合使用似乎具有协同作用，这表明靶向TRAF6可能是管理同种免疫反应的有益联合策略。重要的是，我们的结果将TRAF6定位为改善CAV结局的有前景的补充靶点。
