BACKGROUND Xenotransplantation has made significant advances recently using pigs genetically engineered to remove carbohydrate antigens, either alone or with addition of various human complement, coagulation, and anti-inflammatory ''transgenes''. Here we evaluated results associated with gene-edited (GE) pig hearts transplanted in baboons using an established costimulation-based immunosuppressive regimen and a cold-perfused graft preservation technique. METHODS Eight baboons received heterotopic abdominal heart transplants from 3-GE (GalKO.β4GalNT2KO.hCD55, n = 3), 9-GE (GalKO.β4GalNT2KO.GHRKO.hCD46.hCD55. TBM.EPCR.hCD47. HO-1, n = 3) or 10-G (9-GE+CMAHKO, n = 2) pigs using Steen's cold continuous perfusion for ischemia minimization. Immunosuppression (IS) included induction with anti-thymocyte globulin and αCD20, ongoing αCD154, MMF, and tapered corticosteroid. RESULTS All three 3-GE grafts functioned well initially, but failed within 5 days. One 9-GE graft was lost intraoperatively due to a technical issue and another was lost at POD 13 due to antibody mediated rejection (AMR) in a baboon with a strongly positive pre-operative cross-match. One 10-GE heart failed at POD113 with combined cellular and antibody mediated rejection. One 9-GE and one 10-GE hearts had preserved graft function with normal myocardium on protocol biopsies, but exhibited slowly progressive graft hypertrophy until elective necropsy at POD393 and 243 respectively. Elevated levels of IL-6, MCP-1, C-reactive protein, and human thrombomodulin were variably associated with conditioning, the transplant procedure, and clinically significant postoperative events. CONCLUSION Relative to reference genetics without thrombo-regulatory and anti-inflammatory gene expression, 9- or 10-GE pig hearts exhibit promising performance in the context of a clinically applicable regimen including ischemia minimization and αCD154-based IS, justifying further evaluation in an orthotopic model.

中文翻译：

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通过缺血最小化和基于 CD154 共刺激阻断的免疫抑制延长 9 基因和 10 基因编辑的猪心脏异种移植物的存活率。


背景 异种移植最近取得了重大进展，使用基因工程猪去除碳水化合物抗原，单独或添加各种人类补体、凝血和抗炎“转基因”。在这里，我们使用已建立的基于共刺激的免疫抑制方案和冷灌注移植物保存技术评估了与移植狒狒体内的基因编辑 （GE） 猪心脏相关的结果。方法 8 只狒狒接受了 3-GE （GalKO.β4GalNT2KO.hCD55， n = 3）、9-GE （GalKO.β4GalNT2KO.GHRKO.hCD46.hCD55.隧道掘进机。EPCR.hCD47. HO-1， n = 3） 或 10-G （9-GE+CMAHKO， n = 2） 猪使用 Steen 冷连续灌注最大限度地减少缺血。免疫抑制 （IS） 包括抗胸腺细胞球蛋白和 αCD20 诱导、持续的 αCD154 、 MMF 和逐渐减量的皮质类固醇。结果 3 例 3-GE 移植物最初功能良好，但在 5 天内失败。由于技术问题，一个 9-GE 移植物在术中丢失，另一个在术前交叉配型呈强阳性的狒狒中由于抗体介导的排斥反应 （AMR） 在 POD 13 丢失。1 例 10-GE 心脏在 POD113 失败，伴有细胞和抗体联合介导的排斥反应。1 例 9-GE 和 1 例 10-GE 心脏在方案活检中保留了移植物功能，心肌正常，但表现出缓慢进行性移植物肥大，直到分别在 POD393 和 243 进行择期尸检。IL-6 、 MCP-1 、 C 反应蛋白和人血栓调节蛋白水平升高与条件反射、移植手术和有临床意义的术后事件存在差异。 结论 相对于没有血栓调节和抗炎基因表达的参考遗传学，9 或 10 GE 猪心脏在临床适用方案（包括缺血最小化和基于 αCD154 的 IS）的背景下表现出有希望的性能，证明在原位模型中进一步评估是合理的。