Strahan K M, Gu F, Preece A F, Gustavsson I, Andersson L, Gustafsson K
Division of Cell and Molecular Biology, Institute of Child Health, London, UK.
Immunogenetics. 1995;41(2-3):101-5. doi: 10.1007/BF00182319.
Human serum contains natural antibodies (NAb), which can bind to endothelial cell surface antigens of other mammals. This is believed to be the major initiating event in the process of hyperacute rejection of pig to primate xenografts. Recent work has implicated galactosyl alpha 1,3 galactosyl beta 1,4 N-acetyl-glucosaminyl carbohydrate epitopes, on the surface of pig endothelial cells, as a major target of human natural antibodies. This epitope is made by a specific galactosyltransferase (alpha 1,3 GT) present in pigs but not in higher primates. We have now cloned and sequenced a full-length pig alpha 1,3 GT cDNA. The predicted 371 amino acid protein sequence shares 85% and 76% identity with previously characterized cattle and mouse alpha 1,3 GT protein sequences, respectively. By using fluorescence and isotopic in situ hybridization, the GGTA1 gene was mapped to the region q2.10-q2.11 of pig chromosome 1, providing further evidence of homology between the subterminal region of pig chromosome 1q and human chromosome 9q, which harbors the locus encoding the AB0 blood group system as well as a human pseudogene homologous to the pig GGTA1 gene.
人血清中含有天然抗体（NAb），其可与其他哺乳动物的内皮细胞表面抗原结合。这被认为是猪到灵长类动物异种移植超急性排斥反应过程中的主要起始事件。最近的研究表明，猪内皮细胞表面的半乳糖基α1,3半乳糖基β1,4 N-乙酰葡糖胺碳水化合物表位是人类天然抗体的主要靶标。该表位由猪中存在但高等灵长类动物中不存在的一种特定半乳糖基转移酶（α1,3 GT）产生。我们现已克隆并测序了猪α1,3 GT的全长cDNA。预测的371个氨基酸的蛋白质序列与先前鉴定的牛和小鼠α1,3 GT蛋白质序列分别具有85%和76%的同一性。通过荧光和同位素原位杂交，将GGTA1基因定位到猪1号染色体的q2.10 - q2.11区域，这进一步证明了猪1号染色体1q亚末端区域与人类9号染色体q之间的同源性，人类9号染色体q包含编码AB0血型系统的基因座以及与猪GGTA1基因同源的人类假基因。
