Borda Tania, Perez Rivera Ricardo, Joensen Lilian, Gomez Ricardo M, Sterin-Borda Leonor
Pharmacology Department, School of Medicine and Dentistry, University of Buenos Aires, Argentina.
J Immunol. 2002 Apr 1;168(7):3667-74. doi: 10.4049/jimmunol.168.7.3667.
We demonstrated the presence of circulating Abs from schizophrenic patients able to interact with cerebral frontal cortex-activating muscarinic acetylcholine receptors (mAChR). Sera and purified IgG from 21 paranoid schizophrenic and 25 age-matched normal subjects were studied by indirect immunofluorescence, flow cytometry, immunoblotting, dot blot, ELISA, and radioligand competition assays. Rat cerebral frontal cortex membranes and/or a synthetic peptide, with an amino acid sequence identical with that of human M(1) mAChR, were used as Ags. By indirect immunofluorescence and flow cytometry procedures, we proved that serum-purified IgG fraction from schizophrenic patients reacted to neural cell surfaces from rat cerebral frontal cortex. The same Abs were able to inhibit the binding of the specific M(1) mAChR radioligand [(3)H]pirenzepine. Immunoblotting experiments showed that IgG from schizophrenic patients revealed a band with a molecular mass coincident to that labeled by an anti-M(1) mAChR Ab. Using synthetic peptide for dot blot and ELISA, we demonstrated that these Abs reacted against the second extracellular loop of human cerebral M(1) mAChR. Also, the corresponding affinity-purified antipeptide Ab displayed an agonistic-like activity associated to specific receptor activation, increasing cyclic GMP production and inositol phosphate accumulation, and protein kinase C translocation. This paper gave support to the participation of an autoimmune process in schizophrenia.
我们证明了精神分裂症患者体内存在能够与大脑额叶皮质激活型毒蕈碱型乙酰胆碱受体（mAChR）相互作用的循环抗体。通过间接免疫荧光、流式细胞术、免疫印迹、斑点印迹、酶联免疫吸附测定（ELISA）和放射性配体竞争测定，对21名偏执型精神分裂症患者和25名年龄匹配的正常受试者的血清和纯化IgG进行了研究。大鼠大脑额叶皮质膜和/或与人M(1) mAChR氨基酸序列相同的合成肽用作抗原。通过间接免疫荧光和流式细胞术方法，我们证明了精神分裂症患者血清纯化的IgG组分与大鼠大脑额叶皮质的神经细胞表面发生反应。相同的抗体能够抑制特异性M(1) mAChR放射性配体[(3)H]哌仑西平的结合。免疫印迹实验表明，精神分裂症患者的IgG显示出一条分子量与抗M(1) mAChR抗体标记的条带一致的条带。使用合成肽进行斑点印迹和ELISA，我们证明了这些抗体与人脑M(1) mAChR的第二个细胞外环发生反应。此外，相应的亲和纯化抗肽抗体表现出与特异性受体激活相关的激动样活性，增加环磷酸鸟苷（cGMP）的产生和肌醇磷酸的积累，以及蛋白激酶C的转位。本文支持自身免疫过程参与精神分裂症的观点。
