Eichler W
Faculty of Biosciences, Pharmaceutics and Psychology, University of Leipzig, Germany.
J Leukoc Biol. 2000 Oct;68(4):561-7.
Different adhesive capacity in interactions with CD55 has been ascribed to the isoforms of the leukocyte CD97 antigen, CD97 (EGF 1,2,5), CD97 (EGF 1,2,3,5), and CD97 (EGF 1,2,3,4,5). In the study, coexpression of the three CD97 isoforms and predominance of CD97 (EGF 1,2,5) transcripts in leukocytes are demonstrated. The contribution of CD97 (EGF 1,2,3,5) and CD97 (EGF 1,2,3,4,5) to total CD97 levels varied among most cell types only slightly, although relatively higher mRNA levels of both isoforms were detected in U 937 cells and monocytes. In peripheral blood lymphocytes, CD97 isoforms did not show clear variation after PMA stimulation and were down-regulated equally after CD97 cross-linking. Moreover, the CD97 isoform pattern was not altered in monocytes after interferon-gamma stimulation and in synovial T cells from patients with rheumatoid arthritis. CD97 mRNA levels did not necessarily correspond to CD97 surface density. The findings suggest that adhesive activity of CD97 toward CD55 is unlikely to be regulated by differential CD97 isoform expression.
白细胞CD97抗原的不同亚型，即CD97（EGF 1,2,5）、CD97（EGF 1,2,3,5）和CD97（EGF 1,2,3,4,5），在与CD55相互作用时具有不同的黏附能力。在该研究中，证实了这三种CD97亚型在白细胞中的共表达以及CD97（EGF 1,2,5）转录本在白细胞中的优势地位。在大多数细胞类型中，CD97（EGF 1,2,3,5）和CD97（EGF 1,2,3,4,5）对总CD97水平的贡献仅略有不同，尽管在U 937细胞和单核细胞中检测到这两种亚型的mRNA水平相对较高。在外周血淋巴细胞中，CD97亚型在PMA刺激后未显示明显变化，在CD97交联后均同等程度地下调。此外，在γ干扰素刺激后的单核细胞以及类风湿关节炎患者的滑膜T细胞中，CD97亚型模式未改变。CD97 mRNA水平不一定与CD97表面密度相对应。这些发现表明，CD97对CD55的黏附活性不太可能受CD97亚型差异表达的调节。
