Silvestri F, Banavali S, Baccarani M, Preisler H D
University of Cincinnati, OH.
Haematologica. 1992 May-Jun;77(3):265-73.
CD34, which was first detected in hemopoietic and lymphopoietic progenitors, is a heavily glycosylated Type I transmembrane protein that does not share any significant similarity with other transmembrane proteins. Its functions are still unknown. Several monoclonal antibodies were raised against CD34, and at least 4 different epitopes could be recognized. CD34 expression is confined to a few cell lines, to 1-4% of adult bone marrow mononuclear cells (including marrow-repopulating cells, all multipotent and committed myeloid progenitors, B and T lymphoid precursors, osteoclast precursors, and most likely the precursors for stromal cells), and to less than 1% of peripheral blood mononuclear cells. In non-lymphohemopoietic tissues its expression is confined to endothelial cells and to some cells of the skin. In malignancies, CD34 expression is not fully elucidated. Immature hemolymphopoietic malignancies (namely acute leukemias) and the blast cells of chronic myeloid leukemia are frequently positive. Chronic lymphoproliferative disorders and lymphomas are negative. Among other tumors, only vascular derived tumors are positive. Clinical applications of CD34+ cells include autologous transplantation of putative CD34+ stem cells isolated by positive selection from the bone marrow, and transplantation of autologous peripheral blood stem cells, using the proportion and number of CD34+ cells as a guideline for the harvesting procedure.
CD34最初在造血和淋巴细胞祖细胞中被检测到，是一种高度糖基化的I型跨膜蛋白，与其他跨膜蛋白没有任何显著的相似性。其功能仍然未知。已产生了几种针对CD34的单克隆抗体，并且可以识别至少4种不同的表位。CD34的表达局限于少数细胞系、1%至4%的成人骨髓单个核细胞（包括骨髓重建细胞、所有多能和定向髓系祖细胞、B和T淋巴细胞前体、破骨细胞前体，以及很可能还有基质细胞的前体），以及不到1%的外周血单个核细胞。在非淋巴造血组织中，其表达局限于内皮细胞和皮肤的一些细胞。在恶性肿瘤中，CD34的表达尚未完全阐明。不成熟的血液系统恶性肿瘤（即急性白血病）和慢性髓性白血病的原始细胞通常呈阳性。慢性淋巴细胞增殖性疾病和淋巴瘤呈阴性。在其他肿瘤中，只有血管源性肿瘤呈阳性。CD34+细胞的临床应用包括通过从骨髓中阳性选择分离出的假定CD34+干细胞的自体移植，以及使用CD34+细胞的比例和数量作为采集程序的指导方针进行自体外周血干细胞移植。
