Anklesaria P, Greenberger J S, Fitzgerald T J, Sullenbarger B, Wicha M, Campbell A
Department of Radiation Oncology, University of Massachusetts Medical School, Worcester.
Blood. 1991 Apr 15;77(8):1691-8.
Mutant Sl/Sld mice exhibit decreased marrow hematopoiesis. The defect is known to reside in the marrow microenvironment of these animals, which is reproduced in vitro by primary marrow explants as well as by cloned marrow stromal cell lines. Bone marrow progenitor cells are incapable of adhering to primary Sl/Sld stromal cells or cloned stromal cell lines derived from them to form cobblestone-islands and proliferate. The role of hemonectin, a marrow-specific adhesion protein in the defective hematopoiesis of the Sl/Sld mice, was studied. Indirect immunoperoxidase staining of marrow in situ from Sl/Sld mice showed little specific staining while specific staining was seen in a pericellular distribution in marrow from +/+ mice. Hemonectin expression in several cloned stromal cell lines from Sl/Sld mice was compared by immunoblotting with that in cloned stromal cell lines from normal +/+ littermates. Cell line Sld3, which has the least hematopoiesis supportive capacity in vitro, showed no detectable hemonectin by immunoblotting, while Sld1 and Sld2 showed detectable but greatly reduced amounts compared with normal +/+ 2.4, GBI/6, and D2XRII. Confluent cultures incubated with purified hemonectin and engrafted with enriched progenitors showed a significant increase in the cumulative number of cobbleston-islands and day 14 spleen colony-forming units (CFU-s) forming progenitors (39.15 +/- 3.6/dish; 16.3 +/- 3.1/dish, respectively), compared with untreated Sld3 cultures (cobblestone-islands 8.1 +/- 3.6/dish; CFU-s forming progenitors 8.8 +/- 0.05/dish). Hemonectin-mediated progenitor cell binding to the Sld3 stromal cells was specifically inhibited by antihemonectin but not by preimmune serum. These data support the role of hemonectin in early progenitor-stromal cell interactions.
突变型Sl/Sld小鼠的骨髓造血功能下降。已知该缺陷存在于这些动物的骨髓微环境中，体外培养的原代骨髓外植体以及克隆的骨髓基质细胞系都能重现这一缺陷。骨髓祖细胞无法附着于原代Sl/Sld基质细胞或源自它们的克隆基质细胞系以形成鹅卵石岛并增殖。研究了血粘连蛋白（一种骨髓特异性粘附蛋白）在Sl/Sld小鼠造血功能缺陷中的作用。对Sl/Sld小鼠骨髓进行原位间接免疫过氧化物酶染色显示特异性染色很少，而在+/+小鼠的骨髓中可见特异性染色呈细胞周分布。通过免疫印迹比较了来自Sl/Sld小鼠的几种克隆基质细胞系与来自正常+/+同窝小鼠的克隆基质细胞系中血粘连蛋白的表达。在体外具有最小造血支持能力的细胞系Sld3，通过免疫印迹未检测到血粘连蛋白，而Sld1和Sld2与正常+/+ 2.4、GBI/6和D2XRII相比，检测到但含量大大降低。用纯化的血粘连蛋白孵育汇合培养物并接种富集祖细胞后，与未处理的Sld3培养物相比，鹅卵石岛的累积数量和第14天形成脾集落单位（CFU-s）的祖细胞数量显著增加（分别为39.15±3.6/培养皿；16.3±3.1/培养皿）（鹅卵石岛8.1±3.6/培养皿；形成CFU-s的祖细胞8.8±0.05/培养皿）。血粘连蛋白介导的祖细胞与Sld3基质细胞的结合被抗血粘连蛋白特异性抑制，而免疫前血清则无此作用。这些数据支持血粘连蛋白在早期祖细胞 - 基质细胞相互作用中的作用。
