Ryan D H, Nuccie B L, Abboud C N, Liesveld J L
Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, NY 14642.
J Immunol. 1990 Jul 15;145(2):477-84.
Murine B cell precursors can be induced to proliferate in culture if allowed to bind to bone marrow derived adherent cells prepared under specific conditions. We studied the binding of human B cell precursor subpopulations to various in vitro microenvironments to determine which conditions may potentially be suitable models for human B precursor differentiation. Using the markers CD10, CD34, and CD20, B lineage populations of increasing maturation were quantitated: CD10+/CD34+, CD10+/CD20-, CD10+/CD20+, and CD10-/CD20+ cells in marrow, and CD10-/CD20+ mature B cells in peripheral blood. The adhesion of subpopulations of blood and marrow-derived light density cells to adherent cell layers or matrix was studied following a 2-h incubation in 24-well plates. The absolute number of bound B lineage cells was determined by cell counts and flow cytometry analysis. The adherence of B lineage cells to passaged human marrow fibroblasts (BM-FB) was highest in the most immature CD10+/CD34+ cells (34.3 +/- 4.2%), decreasing steadily with each stage of maturation to the peripheral blood B cells (11.2 +/- 2.4%). Increased adhesion of CD10+ B cell precursors relative to CD10-/CD20+ marrow B cells was confirmed by adhesion studies using sorted cells. The two most immature B lineage cells (CD10+CD34+ and CD10+/CD20-) showed more adherence to BM-FB than any other cell type tested, except for monocytes. Only B lineage precursor cells, erythroid precursors and CD10-/CD34+ cells showed significantly greater binding to BM-FB than to plastic. B lineage precursors bound equally well to primary and passaged human marrow fibroblasts, but bound significantly less well to passaged human foreskin fibroblasts, primary human marrow stroma, extracellular matrix of marrow fibroblasts, or fibronectin. These results suggest that specific binding to marrow fibroblasts is part of the differentiation program of early B lineage precursors. This binding activity gradually and predictably decreases during B lineage differentiation, in contrast to expression of other binding receptors, such as LFA-1 and CD44, which increase during B lineage maturation.
如果允许鼠源B细胞前体与在特定条件下制备的骨髓来源的贴壁细胞结合，它们可在培养中被诱导增殖。我们研究了人B细胞前体亚群与各种体外微环境的结合情况，以确定哪些条件可能是适合人B前体分化的模型。使用CD10、CD34和CD20标志物，对成熟度不断增加的B谱系群体进行定量：骨髓中的CD10+/CD34+、CD10+/CD20-、CD10+/CD20+和CD10-/CD20+细胞，以及外周血中的CD10-/CD20+成熟B细胞。在24孔板中孵育2小时后，研究血液和骨髓来源的低密度细胞亚群与贴壁细胞层或基质的粘附情况。通过细胞计数和流式细胞术分析确定结合的B谱系细胞的绝对数量。B谱系细胞与传代的人骨髓成纤维细胞（BM-FB）的粘附在最不成熟的CD10+/CD34+细胞中最高（34.3±4.2%），随着成熟阶段的推进稳步下降，直至外周血B细胞（11.2±2.4%）。使用分选细胞进行的粘附研究证实，相对于CD10-/CD20+骨髓B细胞，CD10+B细胞前体的粘附增加。除单核细胞外，两种最不成熟的B谱系细胞（CD10+CD34+和CD10+/CD20-）对BM-FB的粘附比测试的任何其他细胞类型都更多。只有B谱系前体细胞、红系前体细胞和CD10-/CD34+细胞与BM-FB的结合明显高于与塑料的结合。B谱系前体与原代和传代的人骨髓成纤维细胞结合良好，但与传代的人包皮成纤维细胞、原代人骨髓基质、骨髓成纤维细胞的细胞外基质或纤连蛋白的结合明显较差。这些结果表明，与骨髓成纤维细胞的特异性结合是早期B谱系前体分化程序的一部分。与其他结合受体如LFA-1和CD44的表达不同，这种结合活性在B谱系分化过程中逐渐且可预测地降低，LFA-1和CD44的表达在B谱系成熟过程中增加。
