Andrews R G, Takahashi M, Segal G M, Powell J S, Bernstein I D, Singer J W
Blood. 1986 Nov;68(5):1030-5.
Antibody L4F3 is a murine monoclonal antibody that recognizes an antigen expressed on in vitro colony-forming cells, including virtually all CFU-GM, CFU-Meg, BFU-E, and CFU-Mix. In the present study we examined whether cells that do not express the L4F3 antigen include precursors of hematopoietic colony-forming cells. Colony-forming cells were depleted from marrow by treatment with L4F3 and complement. The remaining cells generated CFU-GM, BFU-E, and CFU-Mix when cultured in the presence of irradiated adherent cell layers from long-term marrow cultures. Marrow cells not expressing the L4F3 antigen, which were separated by cell-sorting techniques, were depleted of colony-forming cells but nevertheless generated CFU-GM when cultured over irradiated adherent cell layers. These data suggest that there are marrow precursors that do not express the L4F3 antigen and that give rise to colony-forming cells of multiple types. Negative selection techniques should allow the enrichment of these precursors of colony-forming cells, thereby enabling direct studies of these immature stem cells.
抗体L4F3是一种鼠单克隆抗体，可识别在体外集落形成细胞上表达的一种抗原，这些细胞几乎包括所有的粒系巨噬系集落形成单位（CFU-GM）、巨核系集落形成单位（CFU-Meg）、爆式红系集落形成单位（BFU-E）和混合集落形成单位（CFU-Mix）。在本研究中，我们检测了不表达L4F3抗原的细胞是否包括造血集落形成细胞的前体。通过用L4F3和补体处理，从骨髓中去除集落形成细胞。当在来自长期骨髓培养的经辐照的贴壁细胞层存在的情况下培养时，剩余的细胞产生了CFU-GM、BFU-E和CFU-Mix。通过细胞分选技术分离的不表达L4F3抗原的骨髓细胞，其集落形成细胞被去除，但当在经辐照的贴壁细胞层上培养时仍产生CFU-GM。这些数据表明，存在不表达L4F3抗原但能产生多种类型集落形成细胞的骨髓前体。阴性选择技术应能使这些集落形成细胞前体得到富集，从而能够直接研究这些未成熟干细胞。
