Fibronectin from alpha 1,3-galactosyltransferase knockout pigs is a xenoantigen
Fibronectin from alpha 1,3-galactosyltransferase knockout pigs is a xenoantigen
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DOI：
10.1016/j.jss.2013.04.012
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发表时间：
2013-10-01
影响因子：
2.2
通讯作者：
Tector, A. Joseph
中科院分区：
文献类型：
--
作者：
Chihara, Ray K.;Lutz, Andrew J.;Tector, A. Joseph
背景资料：尽管开发了α 1，3-半乳糖基转移酶敲除（GTKO）猪，但抗体介导的排斥仍然是异种移植的障碍。来自GTKO猪的纤连蛋白（Fn）被鉴定为狒狒中的异种抗原。N-羟乙酰神经氨酸（Neu 5Gc），类似于半乳糖α 1，3-半乳糖，是在猪中发现的抗原性碳水化合物。我们评估了人抗体的反应性，并进行了初步的抗原表位表征Fn从GTKO pigs.Materials和方法：GTKO猪主动脉内皮细胞（AEC）分离和评估抗体介导的补体依赖性细胞毒性（CDC）。纯化人和GTKO猪Fn并使用免疫印迹分析。评估GTKO猪和人AEC吸收的人血清的CDC和抗GTKO猪Fn抗体。评估GTKO猪蛋白的Neu 5Gc。结果：与同种异体人AEC相比，GTKO猪AEC具有更强的人源抗体结合、补体沉积和CDC。GTKO猪AEC吸收的人血清导致抗GTKO猪Fn抗体减少。在GTKO猪Fn和其他蛋白质上鉴定了Neu 5Gc。hIgG-GTKOp Fn可与多种GTKO猪蛋白发生交叉反应，并富集抗Neu 5Gc抗体。结论：去除GTKO猪AEC的抗原表位可提高异种移植物的相容性。GTKO猪Fn具有抗原表位，其中一个被鉴定为Neu 5Gc，其可能负责hIgG-GTKOp Fn的病理学和交叉反应性。Neu 5Gc的基因敲除似乎对于解决非Neu 5Gc GTKO猪Fn抗原表位的意义和鉴定是必要的。(C)2013 Elsevier Inc. All rights reserved.
Background: Antibody-mediated rejection continues to be an obstacle for xenotransplantation despite development of alpha 1,3-galactosyltransferase knockout (GTKO) pigs. Fibronectin (Fn) from GTKO pigs was identified as a xenoantigen in baboons. N-glycolylneuraminic acid (Neu5Gc), similar to galactose alpha 1,3-galactose, is an antigenic carbohydrate found in pigs. We evaluated human antibody reactivity and performed initial antigenic epitope characterization of Fn from GTKO pigs.Materials and methods: GTKO pig aortic endothelial cells (AEC) were isolated and assessed for antibody-mediated complement-dependent cytotoxicity (CDC). Human and GTKO pig Fn were purified and analyzed using immunoblots. GTKO pig and human AEC absorbed human sera were assessed for CDC and anti-GTKO pig Fn antibodies. GTKO pig proteins were assessed for Neu5Gc. Immunoaffinity-purified human IgG anti-GTKO pig (hIgG-GTKOp) Fn using a GTKO pig Fn column were evaluated for cross-reactivity with other proteins.Results: GTKO pig AEC had greater human antibody binding, complement deposition and CDC compared with allogeneic human AEC. Human sera absorbed with GTKO pig AEC resulted in diminished anti-GTKO pig Fn antibody. Neu5Gc was identified on GTKO pig Fn and other proteins. The hIgG-GTKOp Fn cross-reacted with multiple GTKO pig proteins and was enriched with anti-Neu5Gc antibody.Conclusions: Removal of antigenic epitopes from GTKO pig AEC would improve xenograft compatibility. GTKO pig Fn has antigenic epitopes, one identified as Neu5Gc, which may be responsible for pathology and cross-reactivity of hIgG-GTKOp Fn. Genetic knockout of Neu5Gc appears necessary to address significance and identification of non-Neu5Gc GTKO pig Fn antigenic epitopes. (C) 2013 Elsevier Inc. All rights reserved.