Sumitran S, Liu J, Czech K A, Christensson B, Widner H, Holgersson J
Division of Clinical Immunology, Karolinska Institute, Huddinge, S-141 86, Lund, Sweden.
Exp Neurol. 1999 Oct;159(2):347-61. doi: 10.1006/exnr.1999.7181.
Transplantation of porcine embryonic brain cells, including dopaminergic neurons, from ventral mesencephalon (VM) is considered a potential treatment for patients with Parkinson's disease. In the present study, we characterized the distribution among VM cells of the major porcine endothelial xenoantigen, the Galalpha1,3Gal epitope, and evaluated the cytotoxic effect of anti-Galalpha1,3Gal antibody-depleted and nondepleted human AB serum on VM cells. Overall levels of Galalpha1,3Gal-epitope expression was very low on the VM cell population using Bandeiraea simplicifolia IB(4) lectin staining of resuspended VM cells in flow cytometric analyses or staining of SDS-PAGE-separated, solubilized VM cell membrane proteins in Western blot analyses. Lectin-histochemical staining of sections of pig embryonal VM regions with BSA IB(4) lectin showed staining restricted to endothelial cells and microglia. In the presence of complement, both nondepleted and anti-Galalpha1,3Gal antibody-depleted AB sera were shown to be cytotoxic to VM cells as assessed in microcytotoxicity- and flow cytometry-based cytotoxicity assays. Purified IgM and IgG were both cytotoxic in the presence of complement. Three major VM cell membrane antigens of approximately 210, 105, and 50 kDa were reactive with natural IgM antibodies present in pooled human AB sera. Thus, antibody-dependent cytotoxicity may contribute to pig to human brain cell xenorejection, necessitating donor tissue modifications prior to a more widespread utilization of neural tissue xenografting.
移植来自腹侧中脑（VM）的猪胚胎脑细胞（包括多巴胺能神经元）被认为是帕金森病患者的一种潜在治疗方法。在本研究中，我们对猪主要内皮异种抗原Galα1,3Gal表位在VM细胞中的分布进行了表征，并评估了抗Galα1,3Gal抗体去除和未去除的人AB血清对VM细胞的细胞毒性作用。在流式细胞术分析中，使用简单叶豆凝集素IB(4)对重悬的VM细胞进行染色，或在蛋白质印迹分析中对SDS-PAGE分离的、可溶解的VM细胞膜蛋白进行染色，结果显示VM细胞群体上Galα1,3Gal表位的总体表达水平非常低。用BSA IB(4)凝集素对猪胚胎VM区域切片进行凝集素组织化学染色，结果显示染色仅限于内皮细胞和小胶质细胞。在补体存在的情况下，基于微量细胞毒性和流式细胞术的细胞毒性试验评估显示，未去除和抗Galα1,3Gal抗体去除的AB血清对VM细胞均具有细胞毒性。纯化的IgM和IgG在补体存在时均具有细胞毒性。三种主要的VM细胞膜抗原，分子量约为210、105和50 kDa，与混合人AB血清中存在的天然IgM抗体发生反应。因此，抗体依赖性细胞毒性可能导致猪到人的脑细胞异种排斥，在更广泛地应用神经组织异种移植之前需要对供体组织进行修饰。
