Schmitt C, Dellagi K, Mihaesco E, Brouet J C
J Immunol. 1987 Mar 1;138(5):1442-6.
Monoclonal IgM from patients with peripheral neuropathy frequently have anti-myelin-associated glycoprotein (MAG) activity. We investigated the idiotypes of 10 monoclonal anti-MAG by using rabbit polyclonal antisera. Three groups of anti-idiotypic antisera could be distinguished. Four sera reacted only with the immunizing protein. Two sera reacted with a single other anti-MAG IgM in addition to the immunizing one. Immunoenzymatic studies showed that these two couples of anti-MAG IgM reacted identically with 100% cross-inhibition, indicating that the whole set of idiotypes identified by the rabbit antiserum was present on both IgM antibodies. The four other anti-idiotypic sera reacted with the homologous IgM, as well as with most of the other anti-MAG IgM. In contrast to the previous antisera the binding of these four sera to the homologous IgM could not be inhibited by other cross-reacting anti-MAG IgM. However, when a heterologous IgM was used for coating, these antisera with one exception showed complete cross-inhibition. The absence of inhibition by purified MAG of the patient of the anti-idiotypic antisera sera suggests that these antibodies are most likely to be directed against framework determinants rather than against combining site epitopes.
患有周围神经病变患者的单克隆IgM常常具有抗髓鞘相关糖蛋白（MAG）活性。我们使用兔多克隆抗血清研究了10种单克隆抗MAG的独特型。可区分出三组抗独特型抗血清。四株抗血清仅与免疫原性蛋白发生反应。两株抗血清除了与免疫原性抗MAG IgM发生反应外，还与另一株抗MAG IgM发生反应。免疫酶学研究表明，这两对抗MAG IgM以100%交叉抑制的方式表现出相同的反应，这表明兔抗血清鉴定出的整个独特型集存在于这两种IgM抗体上。另外四株抗独特型抗血清与同源IgM以及大多数其他抗MAG IgM发生反应。与之前的抗血清不同，这四株抗血清与同源IgM的结合不能被其他交叉反应性抗MAG IgM所抑制。然而，当使用异源IgM进行包被时，除了一例之外，这些抗血清均表现出完全交叉抑制。纯化的MAG不能抑制患者抗独特型抗血清的反应，这表明这些抗体很可能针对的是构架决定簇而非结合位点表位。
