Identification of stromal cell products that interact with pre-B cells.
Identification of stromal cell products that interact with pre-B cells.
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DOI：
10.1083/jcb.134.3.771
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发表时间：
1996-08
期刊：
影响因子：
--
通讯作者：
Kincade PW
中科院分区：
文献类型：
--
作者：
Oritani K;Kincade PW
我们对淋巴造血微环境的理解是不完整的，并且开发了一种新的克隆策略来鉴定与B谱系淋巴细胞前体结合的分子。使用细胞分选程序从含有信号序列并因此可能编码跨膜或分泌蛋白的基质细胞mRNA中初始富集cDNA。第二步涉及将文库表达为可溶性IG融合蛋白。最后，筛选代表这些蛋白质的库识别前B细胞的能力。这种方法导致双糖链蛋白聚糖、多配体蛋白聚糖4、I型胶原蛋白、丛生蛋白、基质糖蛋白sc 1、骨粘连蛋白和一种未知分子（命名为SIM）的克隆。SIM的全长cDNA显示它是一种I型跨膜蛋白，其胞内结构域与肌球蛋白重链及相关蛋白具有弱同源性。用IG融合蛋白对建立的细胞系和新鲜分离的造血细胞进行染色，揭示了对二价阳离子的反应性和差异依赖性的不同模式。双糖链蛋白聚糖，sc 1，和SIM-Ig融合蛋白选择性增加白细胞介素7依赖的前B细胞增殖。整个SIM蛋白的过表达影响293 T细胞的形态，而细胞外部分的表达没有影响。因此，已经鉴定出一系列与血细胞前体相互作用的基质细胞表面分子。其中三种促进了前B细胞在培养中的存活和/或增殖，并且都值得进一步研究与淋巴造血的关系。
Our understanding of lympho-hematopoietic microenvironments is incomplete, and a new cloning strategy was developed to identify molecules that bind to B lineage lymphocyte precursors. A cell sorting procedure was used for initial enrichment of cDNAs from stromal cell mRNA that contained signal sequences and were therefore likely to encode transmembrane or secreted proteins. A second step involved expression of the library as soluble Ig fusion proteins. Finally, pools representing these proteins were screened for the ability to recognize pre-B cells. This approach resulted in the cloning of biglycan, syndecan 4, collagen type I, clusterin, matrix glycoprotein sc1, osteonectin, and one unknown molecule (designated SIM). The full-length cDNA of SIM revealed that it is a type I transmembrane protein, and its intracellular domain has weak homology with myosin heavy chain and related proteins. Staining of established cell lines and freshly isolated hematopoietic cells with the Ig fusion proteins revealed distinct patterns of reactivity and differential dependence on divalent cations. Biglycan-, sc1-, and SIM-Ig fusion proteins selectively increased interleukin 7-dependent proliferation of pre-B cells. Overexpression of the entire SIM protein affected the morphology of 293T cells, while expression of just the extracellular portion was without effect. Thus, a series of stromal cell surface molecules has been identified that interact with blood cell precursors. Three of them promoted the survival and/or proliferation of pre-B cells in culture, and all merit further study in relation to lympho-hematopoiesis.