CD20分子

CD20 分子   CD20 常用单克隆抗体或代号： B1,Leu16 主要表达细胞： B,FDC [B] 分子质量(kDa)和结构： p33(非糖基化穿膜磷蛋白) 功    能： Ca2+通道,调节B细胞活化和增殖   CD20 Aka L26 33kd phosphoprotein with 3 hydrophobic regions that traverse the cell membrane, creating a structure similar to an ion channel Delivers early signal in B cell activation, allowing resting B cells to respond to later antigens Rituximab is a chimeric murine-human anti-CD20 antibody used for treatment of B cell lymphomas Uses: commonly used marker for B cells Positive staining (normal): Most B cells (after CD19 and CD10 expression, before CD21/22 expression and surface immunoglobulin expression), retained on mature B cells until plasma cell development; also follicular dendritic cells Positive staining (disease): 90% of B cell lymphomas, 40% of pre B ALL/LBL; 80% of lymphocyte predominant Hodgkin’s lymphoma, dimly expressed in T cells (benign and neoplastic), spindle cell thymomas Negative staining: non-hemaoietic cells, most T cells, plasma cells Micro images: large B cell lymphoma, CNS diffuse large B cell lymphoma (figure A), lymphoplasmacytic lymphoma/ Waldenström macroglobulinemia in brain-figure D Micro images (Mod Path subscribers): post-transplant lymphoproliferative disorder References: Mod Path 2002;15:647