The suppression of the delayed-type xenograft rejection

构建了细胞膜结合形式的孔因子I（fI-PI）、丝氨酸蛋白酶（SP）结构域的轻链（SP-PI）和轻链加上重链的COOH末端45个氨基酸（SP+45-PI）。用SP-PI转染的CHO细胞对人血清诱导的细胞裂解也有明显的抑制作用，而用SP+45-PI转染的CHO细胞则无抑制作用。建立了表达这些分子的CHO细胞系和猪内皮细胞（PEC）系。结果表明，补体介导的NK细胞溶解活性随补体串联数的增加而增加，并有明显的增加趋势。Δ-SCR 2-β和Δ-SCR 3-β不能抑制补体介导的和NK介导的PEC裂解。然而，delta-SCR 4-CR 4显示出明显的补体调节作用，但对NK细胞没有影响。结果表明，α-Gal对NK细胞有直接的抑制作用，其作用机制可能与SCR 2 - 4有关。转基因猪实验研究了GnT-III转基因猪的胰岛是否能延长其在食蟹猴体内的存活时间。虽然从GnT-III转基因猪中分离的成年猪胰岛比食蟹猴中野生型猪的胰岛存活时间更长，但GnT-III转基因猪的NPCC几乎没有延长。

Complement regulatory proteinThe cell membrane-bound forms of hole factor I (fI-PI), the light chain of the serine protease (SP) domain (SP-PI), and the light chain plus the COOH-terminal 45 amino acid of the heavy chain (SP+45-PI) were constructed. CHO cell transfectants with SP-PI also showed a clear inhibition in cell lysis by human serum, whereas CHO cell transfectants with SP+45-PI showed no inhibition.Tandem DAFcDNAs of the delta-SCR1-DAF, the double-DAF, the triple-DAF, and the tetra-DAF were established. CHO cell lines and pig endothelial cell (PEC) line expressing these molecules were established. The clear tendency was found in which the higher the tandem number of DAF increase, the more it affects the complement-mediated lysis.DAF function for NK cellWe report on an investigation of the effect of DAF on NK cell-mediated cytolysis. Delta-SCR2-DAF and delta-SCR3-DAF failed to suppress both complement-mediated and NK-mediated PEC lyses. However, delta-SCR4-DAF showed a clear complement regulatory effect, but had no effect on NK cells. The data suggest DAF has the direct inhibitory function on NK cells via SCR2-4.The antigenicity of pig isletsAdult pig islets expressed negligible amounts of α-Gal epitope, and α1,3GT activity was also undetectable. However, α-Gal was clearly expressed on the neonatal porcine islet-like cell clusters (NPCCs) cell surface.Transgenic pig experimentsThe issue of whether islets from GnT-III transgenic pigs can prolong their survival in cynomolgus monkeys was examined. While adult pig islets isolated from GnT-III transgenic pigs survived longer than those from wild-type pigs in the cynomolgus monkey, NPCCs from GnT-III transgenic pigs indicated little prolongation.