Pratesi Federico, Tommasi Cristina, Anzilotti Consuelo, Chimenti Daniele, Migliorini Paola
University of Pisa, Pisa, Italy.
Arthritis Rheum. 2006 Mar;54(3):733-41. doi: 10.1002/art.21629.
To test the hypothesis that deimination of viral sequences containing Arg-Gly repeats could generate epitopes recognized by anti-citrullinated protein antibodies (ACPAs) that are present in rheumatoid arthritis (RA) sera.
Multiple antigen peptides derived from Epstein-Barr virus (EBV)-encoded Epstein-Barr nuclear antigen 1 (EBNA-1) were synthesized, substituting the arginines with citrulline, and were used to screen RA sera. Anti-cyclic citrullinated peptide antibodies were purified by affinity chromatography and tested on a panel of in vitro deiminated proteins. Their ability to bind in vivo deiminated proteins was evaluated by immunoprecipitation, using EBV-infected cell lines.
Antibodies specific for a peptide corresponding to the EBNA-1(35-58) sequence containing citrulline in place of arginine (viral citrullinated peptide [VCP]) were detected in 50% of RA sera and in <5% of normal and disease control sera. In addition, affinity-purified anti-VCP antibodies from RA sera reacted with filaggrin-derived citrullinated peptides, with deiminated fibrinogen, and with deiminated recombinant EBNA-1. Moreover, anti-VCP antibodies immunoprecipitated, from the lysate of calcium ionophore-stimulated lymphoblastoid cell lines, an 80-kd band that was reactive with a monoclonal anti-EBNA-1 antibody and with anti-modified citrulline antibodies.
These data indicate that ACPAs react with a viral deiminated protein and suggest that EBV infection may play a role in the induction of these RA-specific antibodies.
检验以下假说，即含有精氨酸 - 甘氨酸重复序列的病毒序列脱氨作用可产生类风湿关节炎（RA）血清中存在的抗瓜氨酸化蛋白抗体（ACPA）所识别的表位。
合成源自爱泼斯坦 - 巴尔病毒（EBV）编码的爱泼斯坦 - 巴尔核抗原1（EBNA - 1）的多种抗原肽，用瓜氨酸替代精氨酸，并用于筛选RA血清。通过亲和层析纯化抗环瓜氨酸化肽抗体，并在一组体外脱氨蛋白上进行检测。使用EBV感染的细胞系，通过免疫沉淀评估它们结合体内脱氨蛋白的能力。
在50%的RA血清中检测到对对应于EBNA - 1（35 - 58）序列的肽具有特异性的抗体，该肽含有瓜氨酸替代精氨酸（病毒瓜氨酸化肽[VCP]），而在<5%的正常和疾病对照血清中检测到该抗体。此外，来自RA血清的亲和纯化抗VCP抗体与丝聚蛋白衍生的瓜氨酸化肽、脱氨纤维蛋白原以及脱氨重组EBNA - 1发生反应。此外，抗VCP抗体从钙离子载体刺激的淋巴母细胞系裂解物中免疫沉淀出一条80-kd条带，该条带与单克隆抗EBNA - 1抗体和抗修饰瓜氨酸抗体反应。
这些数据表明ACPA与病毒脱氨蛋白发生反应，并提示EBV感染可能在这些RA特异性抗体的诱导中起作用。
