Steenbakkers Peter G A, Baeten Dominique, Rovers Eric, Veys Eric M, Rijnders Antonius W M, Meijerink Jan, De Keyser Filip, Boots Annemieke M H
Department of Pharmacology, N. V. Organon, Oss, The Netherlands.
J Immunol. 2003 Jun 1;170(11):5719-27. doi: 10.4049/jimmunol.170.11.5719.
Recently human cartilage gp-39 (HC gp-39) was identified as a candidate autoantigen in rheumatoid arthritis (RA). To further investigate the relevance of this Ag in RA, we have generated a set of five mAbs to a combination epitope of complexes of HC gp-39(263-275) and the RA-associated DR alpha beta 10401 HLA class II molecules. FACS studies revealed that these mAb recognize specific complexes on homozygous DR alpha beta 10401-positive B lymphoblastoid cells pulsed with HC gp-39(263-275). The best mAb, 12A, was further characterized using a set of irrelevant DR alpha beta 10401-binding peptides and truncated/elongated versions of HC gp-39(263-275) itself. The minimal epitope recognized in combination with DR alpha beta 10401 was HC gp-39(263-273). Peptides not encompassing HC gp-39(263-273) were not recognized. Three of five mAb were able to inhibit (up to 90%) the response of HC gp-39(263-275)-specific DR alpha beta 10401-restricted T cell hybridomas to peptide-pulsed APC or purified complexes. Using mAb 12A, we have been able to identify and localize dendritic cells that present DR alpha beta 10401/HC gp-39(263-275) complexes in synovial tissue of DR alpha beta 1*0401-positive RA patients, indicating local presentation of the HC gp-39(263-275) epitope in the inflamed target tissue by professional APC. These data support a role of HC gp-39 in the local autoimmune response that leads to chronic inflammation and joint destruction.
最近，人软骨糖蛋白-39（HC gp-39）被确定为类风湿关节炎（RA）中的一种候选自身抗原。为了进一步研究该抗原在RA中的相关性，我们针对HC gp-39（263-275）与RA相关的DRαβ10401 HLA II类分子复合物的组合表位制备了一组五种单克隆抗体。流式细胞术研究表明，这些单克隆抗体识别用HC gp-39（263-275）脉冲处理的纯合DRαβ10401阳性B淋巴母细胞上的特异性复合物。使用一组无关的DRαβ10401结合肽以及HC gp-39（263-275）本身的截短/延长版本，对最佳单克隆抗体12A进行了进一步表征。与DRαβ10401结合识别的最小表位是HC gp-39（263-273）。不包含HC gp-39（263-273）的肽未被识别。五种单克隆抗体中的三种能够抑制（高达90%）HC gp-39（263-275）特异性DRαβ10401限制性T细胞杂交瘤对肽脉冲处理的抗原呈递细胞或纯化复合物的反应。使用单克隆抗体12A，我们能够在DRαβ10401阳性RA患者的滑膜组织中识别并定位呈递DRαβ1*0401/HC gp-39（263-275）复合物的树突状细胞，这表明专业抗原呈递细胞在炎症靶组织中局部呈递HC gp-39（263-275）表位。这些数据支持HC gp-39在导致慢性炎症和关节破坏的局部自身免疫反应中的作用。
