Liu BingQian, Cheng ChuanYu, Wu YuDong, Wei JinXing, Li GuangSan, Ma TengXiang
Department of Urology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.
Sci China C Life Sci. 2008 Mar;51(3):199-204. doi: 10.1007/s11427-008-0019-7.
The expression of human alpha-1,2-fucosyltransferase (HT) or complement regulatory proteins has been proved as an strategy to overcome hypercute rejection in discordant xenogeneic organ transplantation. In this study, we examined whether peripheral blood mononuclear cells (PBMCs) from polytransgenic mice expressing the human HT, and complement regulatory proteins (DAF and CD59), can provide more effective protection against xenograft rejection. Transgenic mice were produced by co-injection of gene constructs for human HT, DAF and/or CD59. Flow Cytometry (FCM) was used to screen the positive transgenic mice. PBMCs from transgenic mice were incubated with 15% human serum to evaluate natural antibody binding, complement activation and expression of adhesion molecules. Three transgenes were strongly expressed in PBMCs of transgenic mice, and HT expression significantly reduced expression of the major xenoepitope galactose-alpha-1,3-galactose (alpha-Gal). Functional studies with PBMCs showed that co-expression of HT and DAF or CD59 markedly increased their resistance to human serum-mediated cytolysis when compared with single transgenic PBMCs. Moreover, the combined expression of triple transgenes in PBMCs led to the greatest protection against human serum-mediated cytolysis, avoided hyperacute rejection and reduced expression of adhesion molecules. Strong co-expression of triple transgenes was completely protected from xenograft hyperacute rejection and partially inhibited acute vascular rejection. The studies suggest that engineering mice to express triple molecules represents an critical step toward prolonging xenograft survival and might be more suitable for xenotransplantation.
人类α-1,2-岩藻糖基转移酶（HT）或补体调节蛋白的表达已被证明是克服不匹配异种器官移植中超急性排斥反应的一种策略。在本研究中，我们检测了来自表达人类HT及补体调节蛋白（衰变加速因子[DAF]和CD59）的多转基因小鼠的外周血单个核细胞（PBMC）是否能为异种移植排斥提供更有效的保护。通过共注射人类HT、DAF和/或CD59的基因构建体来制备转基因小鼠。采用流式细胞术（FCM）筛选阳性转基因小鼠。将转基因小鼠的PBMC与15%人血清孵育，以评估天然抗体结合、补体激活及黏附分子的表达。三个转基因在转基因小鼠的PBMC中均有强烈表达，且HT的表达显著降低了主要异种抗原决定簇半乳糖-α-1,3-半乳糖（α-Gal）的表达。对PBMC的功能研究表明，与单个转基因PBMC相比，HT与DAF或CD59的共表达显著增强了它们对人血清介导的细胞溶解的抗性。此外，PBMC中三个转基因的联合表达对人血清介导的细胞溶解提供了最大程度的保护，避免了超急性排斥反应，并降低了黏附分子的表达。三个转基因的强共表达完全防止了异种移植的超急性排斥反应，并部分抑制了急性血管排斥反应。这些研究表明，构建表达三种分子的小鼠是延长异种移植存活时间的关键一步，可能更适合于异种移植。
