Siapka Sorana, Patrinou-Georgoula Meropi, Vlachoyiannopoulos Panayiotis G, Guialis Apostolia
RNA Processing Programme, Institute of Biological Research and Biotechnology, The National Hellenic Research Foundation, Vassileos Constantinou Avenue, Athens 116 35, Greece.
Autoimmunity. 2007 May;40(3):223-33. doi: 10.1080/08916930701352357.
Spliceosomal small nuclear ribonucleoproteins (U-snRNPs) are frequent and specific targets of autoantibodies in systemic rheumatic diseases. The abundant, functionally related heterogeneous nuclear ribonucleoprotein complexes (hnRNPs) have later defined as a new target of autoantibodies, of which their immunochemical/immunogenic and pathogenic properties are still under investigation. Among hnRNP proteins, those belonging to the A/B type are considered as the major autoantigens targeted by antibodies in sera of patients suffering with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD). By performing an extensive screening using rat liver 40S hnRNP antigenic material, we document here the existence of multiple specificities of anti-hnRNP A/B autoantibodies in sera of Greek patients suffering with a spectrum of systemic rheumatic diseases. This included patients with SLE, Sjogren's syndrome (SS), Scleroderma (SSc) and a specific group of patients mostly with undifferentiated disease (UD patients). In total, four distinct types of anti-hnRNP A/B autoantibodies have been recognized. The first two referred to the known anti-hnRNPA2(RA33) and anti-hnRNP A1; the latter appearing very rarely. The third was of the new type selectively reacting with hnRNP B2 and an hnRNP A3 variant, while the fourth was a rare case of anti-hnRNP B2 alone. In addition, a novel specificity of autoantibodies against hnRNP L protein was identified in association with anti-hnRNP A/B antibodies. The co-existence within a serum of autoantibodies having variable specificity for hnRNP A/B and L autoantigens was shown. Specific immunochemical features of the identified autoantibodies are presented and a possible mechanism of autoepitope spreading within protein components of hnRNP complexes is discussed.
剪接体小核核糖核蛋白（U - snRNPs）是系统性风湿性疾病中自身抗体常见且特异性的靶标。丰富的、功能相关的异质性核糖核蛋白复合物（hnRNPs）后来被定义为自身抗体的新靶标，其免疫化学/免疫原性和致病性仍在研究中。在hnRNP蛋白中，属于A/B型的那些被认为是类风湿关节炎（RA）、系统性红斑狼疮（SLE）和混合性结缔组织病（MCTD）患者血清中抗体靶向的主要自身抗原。通过使用大鼠肝脏40S hnRNP抗原物质进行广泛筛选，我们在此记录了希腊患有一系列系统性风湿性疾病患者血清中抗hnRNP A/B自身抗体存在多种特异性。这包括SLE、干燥综合征（SS）、硬皮病（SSc）患者以及一组主要患有未分化疾病的特定患者群体（未分化疾病患者）。总共识别出四种不同类型的抗hnRNP A/B自身抗体。前两种指已知的抗hnRNPA2（RA33）和抗hnRNP A1；后者非常罕见。第三种是新型，与hnRNP B2和一种hnRNP A3变体选择性反应，而第四种是仅抗hnRNP B2的罕见情况。此外，还鉴定出一种针对hnRNP L蛋白的自身抗体新特异性，与抗hnRNP A/B抗体相关。显示了血清中对hnRNP A/B和L自身抗原有不同特异性的自身抗体共存情况。呈现了所鉴定自身抗体的特异性免疫化学特征，并讨论了自身表位在hnRNP复合物蛋白质成分中扩散的可能机制。
