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Antibodies against astrocyte M 1 and M 2 muscarinic cholinoceptor from schizophrenic patients' sera
Author(s) -
Borda Tania,
Gomez Ricardo,
Berría Maria I.,
SterinBorda Leonor
Publication year - 2003
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/glia.10312
Subject(s) - muscarinic acetylcholine receptor , biology , radioligand assay , microbiology and biotechnology , antibody , immunofluorescence , astrocyte , western blot , antigen , acetylcholine receptor , receptor , flow cytometry , radioligand , immunology , endocrinology , biochemistry , central nervous system , gene
We demonstrated the presence of circulating antibodies from schizophrenic patients able to interact with cultured astrocytes activating muscarinic acetylcholine receptors (mAChRs). Sera and purified IgG from 15 paranoid schizophrenic and 15 age‐matched normal subjects were studied by indirect immunofluorescence (IFI), flow cytometry, dot blot, enzyme immunoassay (ELISA), and radioligand competition assays. Astrocyte membranes and/or a synthetic peptide, with identical amino acid sequence of human M 1 and M 2 mAChR, were used as antigens. By IFI and flow cytometry procedures, we proved that serum purified IgG fraction from schizophrenic patients, reacted to astrocyte cell surface. The same antibodies were able to inhibit the binding of the specific mAChR radioligand 3 H‐QNB. Using synthetic peptide for dot blot and ELISA, we demonstrated that these antibodies reacted against the second extracellular loop of human cerebral M 1 and M 2 mAChR. Also, the corresponding affinity‐purified antipeptide antibody displayed an agonistic‐like activity associated to specific M 1 and M 2 mAChR activation, increasing inositol phosphates accumulation and decreasing cyclic AMP production, respectively. This article gives support to the participation of an autoimmune process in schizophrenia disease. © 2004 Wiley‐Liss, Inc.