Baskin J G, Ryan T M, Vakil M, Kearney J F, Lamon E W
Birmingham Veterans Administration Medical Center, AL.
J Immunol. 1990 Jul 1;145(1):202-8.
BALB/c mice were inoculated i.p. with graded doses of a DNP-specific, IgM mAb (designated 57.1). Injection with unmodified 57.1 in the absence of adjuvants resulted in the generation of an anti-Id response (Ab2) and an anti-anti-Id response (Ab3). The generation of serum anti-Id antibodies was found to be thymus dependent. Nude mice immunized with 57.1 were unable to produce a serum Ab2 response above nonimmunized controls whereas euthymic mice receiving identical doses of 57.1 produced strong Ab2 responses. To examine the specificity of serum anti-Id, sera from mice receiving 57.1 were screened against a panel of mAb representing at least five distinct VH gene families. Serum titers were significantly higher against 57.1 than against any of the other antibodies in the panel. Three of the antibodies in this panel bind FD5-1, a monoclonal anti-Id (Ab2) that also binds 57.1. However, sera from mice receiving 57.1 bound 57.1 only. Thus, the serum Ab2 response appears to be highly specific for idiotopes on 57.1. The predominant isotype of these anti-Id antibodies was IgG1. The number of isotypes detected increased in a dose dependent manner with all IgG subclasses having anti-Id specificity in sera from animals receiving the higher doses of 57.1. Further analysis of the serum demonstrated that approximately 8% of the Ab2 response was paratope-specific (inhibitable by the monovalent hapten DNP-lysine). The same sera were analyzed for the presence of Ab3 by binding to the monoclonal anti-Id antibody FD5-1. Lower serum titers of Ab3 were generated in comparison to serum titers of Ab2. Analysis of the binding specificity of the Ab3 response revealed that DNP-BSA was able to partially inhibit the binding of serum IgM and IgG Ab3 to FD5-1. A subset of the Ab3 response. Ab1' that is specific for DNP was observed in a direct binding assay where detectable amounts of DNP binding IgM, IgG1, and IgG3 isotypes were present. We have thus described a complete circuit (Ab1----Ab2----Ab3) of antibodies within the Id network by immunizing animals with an unmodified mAb in the absence of Ag or adjuvants.
将不同剂量的一种针对二硝基苯（DNP）特异性的IgM单克隆抗体（命名为57.1）腹腔注射接种到BALB/c小鼠体内。在无佐剂情况下注射未修饰的57.1会导致抗独特型反应（Ab2）和抗抗独特型反应（Ab3）的产生。发现血清抗独特型抗体的产生依赖胸腺。用57.1免疫的裸鼠无法产生高于未免疫对照的血清Ab2反应，而接受相同剂量57.1的正常胸腺小鼠则产生强烈的Ab2反应。为检测血清抗独特型的特异性，用一组代表至少五个不同VH基因家族的单克隆抗体筛选接受57.1的小鼠血清。血清针对57.1的滴度显著高于针对该组中任何其他抗体的滴度。该组中的三种抗体与FD5 - 1结合，FD5 - 1是一种也与57.1结合的单克隆抗独特型抗体（Ab2）。然而，接受57.1的小鼠血清仅与57.1结合。因此，血清Ab2反应似乎对57.1上的独特型具有高度特异性。这些抗独特型抗体的主要同种型是IgG1。检测到的同种型数量呈剂量依赖性增加，在接受较高剂量57.1的动物血清中，所有IgG亚类都具有抗独特型特异性。对血清的进一步分析表明，约8%的Ab2反应是互补决定区特异性的（可被单价半抗原DNP - 赖氨酸抑制）。通过与单克隆抗独特型抗体FD5 - 1结合分析相同血清中Ab3的存在情况。与Ab2的血清滴度相比，产生的Ab3血清滴度较低。对Ab3反应的结合特异性分析表明，DNP - BSA能够部分抑制血清IgM和IgG Ab3与FD5 - 1的结合。在直接结合试验中观察到Ab3反应的一个亚群，即对DNP特异性的Ab1'，其中存在可检测量的结合DNP的IgM（免疫球蛋白M）、IgG1和IgG3同种型。因此，我们通过在无抗原或佐剂情况下用未修饰的单克隆抗体免疫动物，描述了独特型网络内完整的抗体循环（Ab1→Ab2→Ab3）。
