Navenot J M, Villanova M, Lucas-Héron B, Malandrini A, Blanchard D, Louboutin J P
Etablissement de Transfusion Sanguine Loire-Atlantique-Vendée, Nantes,France.
Muscle Nerve. 1997 Jan;20(1):92-6. doi: 10.1002/(sici)1097-4598(199701)20:1<92::aid-mus12>3.0.co;2-3.
Control of complement deposition on autologous cells is mediated by a group of complement regulatory membrane proteins acting at different levels of the complement cascade. Decay accelerating factor (CD55) prevents the assembly of C3 convertases and CD59 membrane inhibitor of reactive lysis (MIRL) restricts homologous complement lysis by the membrane attack complex of complement (MAC) by inhibition of C5b-8 catalyzed insertion of C9. The aim of this work was to study the eventual expression of CD55 and CD59 on human skeletal muscle fibers. Highly sensitive immunoblotting using murine monoclonal antibodies showed that CD59, but not CD55, was present in skeletal muscle fibers. Immunocytochemistry with a monoclonal antibody against CD59 demonstrated a dense granular immunostaining mainly localized at the level of the sarcolemma. Thus, CD59, but not CD55, is expressed on normal skeletal muscle fibers. CD59 may play a prominent role in preventing MAC deposition and subsequent complement-mediated damage in myopathies where the complement system activation is involved.
补体在自体细胞上的沉积调控是由一组补体调节膜蛋白介导的，这些蛋白作用于补体级联反应的不同水平。衰变加速因子（CD55）可阻止C3转化酶的组装，而CD59膜反应性溶解抑制因子（MIRL）通过抑制C5b-8催化的C9插入，限制补体膜攻击复合物（MAC）引起的同源补体溶解。本研究的目的是探讨CD55和CD59在人骨骼肌纤维上的最终表达情况。使用鼠单克隆抗体进行的高度敏感免疫印迹显示，骨骼肌纤维中存在CD59，但不存在CD55。用抗CD59单克隆抗体进行的免疫细胞化学显示，密集的颗粒状免疫染色主要位于肌膜水平。因此，正常骨骼肌纤维上表达的是CD59而非CD55。在涉及补体系统激活的肌病中，CD59可能在防止MAC沉积及随后的补体介导损伤方面发挥重要作用。
