Autoimmune response to M3 muscarinic acetylcholine receptor in Sjogren's syndrome

为阐明自身免疫反应对M3毒毒碱乙酰胆碱受体（M3R）在干燥综合征（SS）中的致病作用1)ss3中抗M3R抗体的疾病特异性2)ss3中M3R反应性T细胞的检测1)采用基于M3R肽（N端，1、2、3右胞环）的ELISA法检测类风湿性关节炎（RA） （N=21）、系统性红斑狼疮（SLE） （N=21）、原发性胆汁性肝硬化（PBC） （N=84）血清中抗M3R抗体。RA（42.9%）、SLE（28.6%）、PBC（90.5%）、AA（16.7%）中N端抗体阳性。1stloop抗体阳性率分别为33.3%、28.6%、72.6%、0%，2ndloop抗体阳性率分别为33.3%、57.1%、76.2%、0%，3rdloop抗体阳性率分别为33.3%、28.6%、69.0%、0%。2)用M3R混合肽（N端，1、2、3胞外环）刺激SS （N=3）和对照（N=3）分离的PBMC。用ifn - γ macs细胞因子分泌法检测1只SS中产生M3R反应性ifn - γ的CD4+T细胞，对照组未检测到。综上所述，抗M3R抗体不具有SS特异性，SS中检测到M3R反应性T细胞。

To clarify the pathogenic roles of autoimmune response to M3 muscarinic acetylcholine receptor (M3R) in Sjogren’s syndrome (SS)1) the disease specificity of anti-M3R antibodies in SS2) the detection of M3R reactive T cells in SS.1) Anti-M3R antibodies were examined by M3R peptides (N terminal, 1st, 2nd, 3rdextracellular loops) based ELISA in sera from rheumatoid arthritis (RA) (N=21), systemic lupus erythematosus (SLE) (N=21), primary biliary cirrhosis (PBC) (N=84), and acquired anhidrosis (AA) (N=12)Antibodies for N terminal were positive in 42.9% of RA, 28.6% of SLE, 90.5% of PBC, 16.7% of AA. Antibodies for 1stloop were positive in 33.3%, 28.6%, 72.6%, 0%, for 2ndloop, 33.3%, 57.1%, 76.2%, 0%, for 3rdloop, 33.3%, 28.6%, 69.0%, 0%, respectively. 2) PBMC isolated from SS (N=3) and controls (N=3) were stimulated with M3R mix peptides (N terminal, 1st, 2nd, 3rd extracellular loops). M3R reactive IFNγproducing CD4+T cells were detected by IFNγMACS cytokine secretion assay in one SS, but not in controls. In conclusion, it was revealed that anti-M3R antibodies were not SS-specific, and M3R reactive T cells were detected in SS.