Grumet F C, Krishnaswamy S, See-Tho K, Filvaroff E, Hiraki D D
Department of Pathology, Stanford University School of Medicine, California.
Hum Immunol. 1994 Jul;40(3):228-34. doi: 10.1016/0198-8859(94)90073-6.
A soluble HLA-B7 molecule, designated sB7 and generated by genetically engineering the B7 gene to remove the transmembrane and cytoplasmic domains, was tested as a tolerogen. Supernatants from cultures of C1R cells transfected with the gene for sB7 were harvested and concentrated, as were control supernatants. From days -17 to -1, C57Bl/6 mice were pretreated with a total of 11 intraperitoneal doses of 1.0 microgram each of sB7 or appropriate control supernatant, and then were challenged intraperitoneally on each of days 0, 7, and 14 with 10(6) C1R-B7 cells (expressing surface HLA-B7). Antibody kinetics revealed (1) anti-B7 was not induced after sB7 pretreatment; (2) the anti-B7 response of sB7-pretreated mice was marginal and of apparent low avidity compared with the brisk anti-B7 response of control mice; (3) none of the mice made antibody to a control HLA antigen, A24; (4) all mice made strong antibody responses to the non-B7 surface antigens of C1R; (5) free sB7 did not appear in the blood of the treated mice; and (6) all mice appeared to be generally healthy. These data show soluble B7 antigen is not immunogenic and appears to specifically block humoral immune response to cell membrane-bound HLA-B7 in a nontoxic manner.
一种可溶性HLA - B7分子，命名为sB7，通过对B7基因进行基因工程改造以去除跨膜和细胞质结构域而产生，作为一种耐受原进行了测试。收获并用基因转染sB7的C1R细胞培养物的上清液并进行浓缩，对照上清液也同样处理。从第 - 17天到第 - 1天，给C57Bl / 6小鼠腹腔内预先注射总共11次剂量、每次1.0微克的sB7或适当的对照上清液，然后在第0、7和14天分别用10⁶个C1R - B7细胞（表达表面HLA - B7）进行腹腔内攻击。抗体动力学显示：（1）sB7预处理后未诱导出抗B7抗体；（2）与对照小鼠强烈的抗B7反应相比，sB7预处理小鼠的抗B7反应微弱且亲和力明显较低；（3）没有小鼠产生针对对照HLA抗原A24的抗体；（4）所有小鼠对C1R的非B7表面抗原产生强烈的抗体反应；（5）游离的sB7未出现在处理过的小鼠血液中；（6）所有小鼠总体上看起来健康。这些数据表明可溶性B7抗原无免疫原性，并且似乎以无毒方式特异性阻断对细胞膜结合的HLA - B7的体液免疫反应。
