Brouwer R, Vree Egberts W, Jongen P H, van Engelen B G, van Venrooij W J
University of Nijmegen, The Netherlands.
Arthritis Rheum. 1998 Aug;41(8):1428-37. doi: 10.1002/1529-0131(199808)41:8<1428::AID-ART12>3.0.CO;2-J.
To investigate the incidence of autoantibodies directed to deproteinized transfer RNA(His) (tRNA(His)) in anti-Jo-1 positive myositis patients and to determine the major B cell epitope.
One hundred sixty-seven myositis sera were screened by immunoblotting and enzyme-linked immunosorbent assay for the presence of anti-Jo-1 antibody. Autoantibodies directed to deproteinized RNA were detected by immunoprecipitation. Ribonuclease cleavage experiments were performed to determine the tRNA(His)-specific features important for recognition.
Approximately one-third of the anti-Jo-1 positive sera also contained autoantibodies recognizing tRNA(His). This recognition was independent of modified bases, but the presence of stabilizing Mg2+ ions appeared to be essential for efficient immunoprecipitation. Transfer RNA(His)-specific features in the anticodon loop were not protected from ribonuclease cleavage by bound antibodies, while protection of bases located in the D and T loops was observed.
A significant number of anti-Jo-1 positive myositis sera contain anti-tRNA(His) activity. Formation of the major autoepitope on tRNA(His) is strongly dependent on proper folding of this molecule mediated by an interaction between D and T loops which is stabilized by either modified residues or Mg2+ ions.
研究抗 Jo-1 阳性肌炎患者中针对去蛋白化转移 RNA(His)（tRNA(His)）自身抗体的发生率，并确定主要的 B 细胞表位。
通过免疫印迹和酶联免疫吸附测定法对 167 份肌炎血清进行筛查，以检测抗 Jo-1 抗体的存在。通过免疫沉淀法检测针对去蛋白化 RNA 的自身抗体。进行核糖核酸酶切割实验以确定对识别重要的 tRNA(His)特异性特征。
约三分之一的抗 Jo-1 阳性血清也含有识别 tRNA(His)的自身抗体。这种识别与修饰碱基无关，但稳定的 Mg2+离子的存在似乎是有效免疫沉淀所必需的。反密码子环中的 tRNA(His)特异性特征未受到结合抗体对核糖核酸酶切割的保护，而观察到 D 环和 T 环中的碱基受到保护。
大量抗 Jo-1 阳性肌炎血清含有抗 tRNA(His)活性。tRNA(His)上主要自身表位的形成强烈依赖于该分子由 D 环和 T 环之间的相互作用介导的正确折叠，这种相互作用由修饰残基或 Mg2+离子稳定。
