CHARACTERIZATION OF MEMBRANE HOMING RECEPTORS IN 2 CLONED MURINE HEMATOPOIETIC PROGENITOR-CELL LINES
CHARACTERIZATION OF MEMBRANE HOMING RECEPTORS IN 2 CLONED MURINE HEMATOPOIETIC PROGENITOR-CELL LINES
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DOI：
10.1172/jci113975
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发表时间：
1989-03-01
影响因子：
15.9
通讯作者：
TAVASSOLI, M
中科院分区：
文献类型：
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作者：
MATSUOKA, T;HARDY, C;TAVASSOLI, M
为了表征归巢受体是负责识别和造血祖细胞的基质特异性结合，我们合成和125碘标记的一些neoglycoproteins。我们使用这些新糖蛋白作为配体，检测两个克隆的小鼠造血祖细胞系B6 SUT和FDCP-1的膜上的受体。两种细胞系均表现出具有半乳糖基和甘露糖基，但不具有岩藻糖基特异性的膜受体。B6 SUT半乳糖基受体显示单一受体群体，其Kd为约2.3 × 10 - 6。10-7 M和106个受体。甘露糖受体显示出两种组分，分别具有高亲和力和低亲和力，Kd约为2.5 × 10 - 6。10-8 M和1.0 ×10-7 M，分别约为7.4 × 10 - 4。105和3.7 ×每个细胞有105个受体还获得了FDCP-1的可比数据。置换实验表明，与受体结合的放射性配体可以逐渐被同源冷配体置换，给出典型的S形曲线。冷甘露糖基探针也可以以类似的方式置换放射性半乳糖基探针，但是冷半乳糖基探针置换放射性甘露糖基配体，其曲线显示两个相，进一步表明甘露糖基配体的两个受体组分。成熟的鼠中性粒细胞和红细胞以及人中性粒细胞、单核细胞和红细胞未显示受体。这些受体在结合基质细胞的功能意义，证明了通过定量的结合51铬标记的祖细胞的克隆的基质细胞系，D2 X，之前和之后酶促去除膜糖缀合物的各种碳水化合物残基。酶促去除半乳糖基和甘露糖基，但岩藻糖基，残基几乎完全消除了结合。这些发现有力地表明，这些归巢受体存在于早期造血祖细胞的表面。随着成熟，细胞失去了它们的受体，因此成熟细胞可以释放到血流中。
To characterize homing receptors that are responsible for the recognition and specific binding of hemopoietic progenitor cells to the stroma, we synthesized and 125I-labeled a number of neoglycoproteins. We used these neoglycoproteins as ligand to detect receptors on the membrane of two cloned murine hemopoietic progenitor cell lines, B6SUT and FDCP-1. Both cell lines demonstrated membrane receptors with galactosyl and mannosyl, but not fucosyl, specificities. B6SUT galactosyl receptors showed a single receptor population with a Kd of about 2.3 .times. 10-7 M and 106 receptors per cell. Mannosyl receptors demonstrated two components with high and low affinities respectively with Kd of about 2.5 .times. 10-8 M and 1.0 .times. 10-7 M, and respectively about 7.4 .times. 105 and 3.7 .times. 105 receptors per cell. Comparable data were also obtained for FDCP-1. Displacement experiments indicated that radioactive ligands bound to receptors could be increasingly displaced by homologous cold ligand giving typical sigmoid-shaped curves. Cold mannosyl probe could also displace radioactive galactosyl probe in a similar manner, but cold galactosyl probe displaced radioactive mannosyl ligand with a curve demonstrating two phases, further suggesting two receptor components for the mannosyl ligand. Mature murine neutrophils and red cells as well as human neutrophils, monocytes, and red cells showed no receptors. The functional significance of these receptors in binding to stromal cells was demonstrated by quantitation of the binding of 51Cr-labeled progenitor cells to the cloned stromal cell line, D2X, before and after enzymatic removal of various carbohydrate residues of membrane glycoconjugates. Enzymatic removal of galactosyl and mannosyl, but not fucosyl, residues almost totally eliminated the binding. The findings strongly suggest that these homing receptors are present on the surface of early hemopoietic progenitor cells. With maturation the cells lose their receptors, so that mature cells can be released into the blood stream.