Twin Cities, Department of Surgery, Experimental Surgical Services, University of Minnesota, Minneapolis, Minnesota, USA.
Institute of Cardiovascular Sciences, University College London, London, UK.
Xenotransplantation. 2024 May-Jun;31(3):e12865. doi: 10.1111/xen.12865.
Recent clinical xenotransplantation and human decedent studies demonstrate that clinical hyperacute rejection of genetically engineered porcine organs can be reliably avoided but that antibody mediated rejection (AMR) continues to limit graft survival. We previously identified porcine glycans and proteins which are immunogenic after cardiac xenotransplantation in non-human primates, but the clinical immune response to antigens present in glycan depleted triple knockout (TKO) donor pigs is poorly understood. In this study we use fluorescence barcoded human embryonic kidney cells (HEK) and HEK cell lines expressing porcine glycans (Gal and SDa) or proteins (tetraspanin-29 [CD9], membrane cofactor protein [CD46], protectin, membrane attack complex inhibition factor [CD59], endothelial cell protein C receptor, and Annexin A2) to screen antibody reactivity in human serum from 160 swine veterinarians, a serum source with potential occupational immune challenge from porcine tissues and pathogens. High levels of anti-Gal IgM were present in all samples and lower levels of anti-SDa IgM were present in 41% of samples. IgM binding to porcine proteins, primarily CD9 and CD46, previously identified as immunogenic in pig to non-human primate cardiac xenograft recipients, was detected in 28 of the 160 swine veterinarian samples. These results suggest that barcoded HEK cell lines expressing porcine protein antigens can be useful for screening human patient serum. A comprehensive analysis of sera from clinical xenotransplant recipients to define a panel of commonly immunogenic porcine antigens will likely be necessary to establish an array of porcine non-Gal antigens for effective monitoring of patient immune responses and allow earlier therapies to reverse AMR.
最近的临床异种移植和人类遗体研究表明，可以可靠地避免基因工程猪器官的临床超急性排斥反应，但抗体介导的排斥反应（AMR）仍然限制移植物的存活。我们之前已经鉴定出在非人类灵长类动物心脏异种移植后具有免疫原性的猪聚糖和蛋白质，但对聚糖耗尽三敲除（TKO）供体猪中存在的抗原的临床免疫反应了解甚少。在这项研究中，我们使用荧光条形码人胚肾细胞（HEK）和表达猪聚糖（Gal 和 SDa）或蛋白质（四跨膜蛋白 29 [CD9]、膜辅因子蛋白 [CD46]、保护素、膜攻击复合物抑制因子 [CD59]、内皮细胞蛋白 C 受体和 Annexin A2）的 HEK 细胞系来筛选 160 名猪兽医的人血清中的抗体反应，这是一种血清来源，可能会因猪组织和病原体而受到潜在的职业免疫挑战。所有样本中均存在高水平的抗-Gal IgM，而 41%的样本中存在低水平的抗-SDa IgM。在 160 名猪兽医样本中的 28 名中检测到针对猪蛋白的 IgM 结合，这些蛋白主要是 CD9 和 CD46，先前在猪到非人类灵长类动物心脏异种移植受者中被鉴定为免疫原性。这些结果表明，表达猪蛋白抗原的条形码 HEK 细胞系可用于筛选人类患者血清。对临床异种移植受者的血清进行全面分析，以确定一组常见的免疫原性猪抗原，这可能对于建立一组有效的猪非 Gal 抗原以有效监测患者的免疫反应并允许早期进行逆转 AMR 的治疗是必要的。
