Wang Wenhao, Lu Jiansen, Song Ying, Zeng Chun, Wang Yongkui, Yang Cheng, Huang Bin, Dai Yifan, Yang Jian, Lai Liangxue, Wang Liping, Cai Daozhang, Bai Xiaochun
Department of Orthopaedics, Shandong Provincial Hospital Affliated to Shandong First Medical University, Jinan, China.
Academy of Orthopedics, Guangdong Province, Department of Orthopedics, The Third Affiliated Hospital, Southern Medical University, Guangzhou, Guangdong, China.
Front Bioeng Biotechnol. 2022 Sep 12;10:990769. doi: 10.3389/fbioe.2022.990769. eCollection 2022.
Since xenografts offer a wide range of incomparable advantages, they can be a better option than allografts but only if the possibility of immunological rejection can be eliminated. In this study, we investigated the ability of α1,3-galactosyltransferase (α1,3-GT) gene knockout (GTKO) pig cancellous bone to promote the repair of a femoral condyle bone defect and its influence on heterologous immune rejection. Cylindrical bone defects created in a rhesus monkey model were transplanted with GTKO bone, WT bone or left empty. For immunological evaluation, T lymphocyte subsets CD4 and CD8 in peripheral blood were assayed by flow cytometry, and the IL-2 and IFN-γ contents of peripheral blood serum were analyzed by ELISA at 2, 5, 7, 10, and 14 days post-surgery. Micro-CT scans and histological assessment were conducted at 4 and 8 weeks after implantation. Compared with WT-pig bone, the heterologous immunogenicity of GTKO-pig bone was reduced. The defect filled with fresh GTKO-pig bone was tightly integrated with the graft. Histological analysis showed that GTKO-pig cancellous bone showed better osseointegration and an appropriate rate of resorption. Osteoblast phenotype progression in the GTKO group was not affected, which revealed that GTKO-pig bone could not only fill and maintain the bone defect, but also promote new bone formation. GTKO-pig cancellous bone decreased the ratio of CD4 to CD8 T cells and cytokines (IFN-γ and IL-2) to inhibit xenotransplant rejection. Moreover, GTKO group increased more bone formation by micro-CT analysis and osteoblastic markers (Runx2, OSX and OCN). Together, GTKO-pig cancellous bone showed better bone repair than WT-pig cancellous bone.
由于异种移植物具有一系列无可比拟的优势，因此它们可能是比同种异体移植物更好的选择，但前提是能够消除免疫排斥的可能性。在本研究中，我们研究了α1,3-半乳糖基转移酶（α1,3-GT）基因敲除（GTKO）猪松质骨促进股骨髁骨缺损修复的能力及其对异种免疫排斥的影响。在恒河猴模型中创建圆柱形骨缺损，分别移植GTKO骨、野生型（WT）骨或不进行移植。为了进行免疫评估，在术后2、5、7、10和14天通过流式细胞术检测外周血中的T淋巴细胞亚群CD4和CD8，并通过酶联免疫吸附测定（ELISA）分析外周血血清中的白细胞介素-2（IL-2）和干扰素-γ（IFN-γ）含量。在植入后4周和8周进行显微计算机断层扫描（Micro-CT）和组织学评估。与WT猪骨相比，GTKO猪骨的异种免疫原性降低。填充新鲜GTKO猪骨的缺损与移植物紧密整合。组织学分析表明，GTKO猪松质骨表现出更好的骨整合和适当的吸收速率。GTKO组中成骨细胞表型进展未受影响，这表明GTKO猪骨不仅可以填充和维持骨缺损，还可以促进新骨形成。GTKO猪松质骨降低了CD4与CD8 T细胞的比例以及细胞因子（IFN-γ和IL-2）以抑制异种移植排斥。此外，通过Micro-CT分析和成骨细胞标志物（Runx2、OSX和OCN），GTKO组的骨形成增加更多。总之，GTKO猪松质骨比WT猪松质骨表现出更好的骨修复效果。
