Crocker P R, Morris L, Gordon S
Sir William Dunn School of Pathology, University of Oxford, UK.
Blood Cells. 1991;17(1):83-91; discussion 91-6.
We have defined two receptors involved in the binding of erythroblasts and other developing hematopoietic cells to murine macrophages. With 14-day-old fetal liver macrophages, which exclusively interact with erythroid cells in vivo, a divalent cation-dependent adhesion receptor, EbR, is able to mediate reversible attachment of erythroblasts in vitro. With adult resident bone marrow macrophages, which naturally bind a mixture of myeloid and erythroid cells, two distinct receptors are involved. Most of the binding is mediated by an EbR-like divalent cation-dependent receptor. The remainder is mediated by a divalent cation-independent receptor, SER, which was originally discovered by its ability to bind unopsonized sheep erythrocytes. To date, the molecular nature of EbR is unknown, but the failure of certain antisera and specific inhibitors to block its activity indicates that EbR may be a novel macrophage adhesion receptor. SER has recently been characterized by means of a monoclonal antibody selected on the basis of its ability to block binding of sheep erythrocytes. SER is a 185-K plasma membrane glycoprotein expressed specifically by resident bone marrow macrophages. Inhibition experiments have demonstrated that SER is able to mediate binding of erythroid and myeloid cells via recognition of sialylated glycoconjugates. The possible functions of EbR and SER in macrophage-hematopoietic cell interactions are discussed.
我们已经确定了两种参与成红细胞和其他发育中的造血细胞与小鼠巨噬细胞结合的受体。对于14日龄的胎肝巨噬细胞，其在体内仅与红系细胞相互作用，一种二价阳离子依赖性黏附受体EbR能够在体外介导成红细胞的可逆附着。对于成年驻留骨髓巨噬细胞，其天然结合髓系和红系细胞的混合物，则涉及两种不同的受体。大部分结合是由一种类似EbR的二价阳离子依赖性受体介导的。其余部分则由一种二价阳离子非依赖性受体SER介导，SER最初是因其能够结合未调理的绵羊红细胞而被发现的。迄今为止，EbR的分子性质尚不清楚，但某些抗血清和特异性抑制剂未能阻断其活性，这表明EbR可能是一种新型的巨噬细胞黏附受体。SER最近已通过基于其阻断绵羊红细胞结合能力筛选出的单克隆抗体进行了表征。SER是一种185-K的质膜糖蛋白，由驻留骨髓巨噬细胞特异性表达。抑制实验表明，SER能够通过识别唾液酸化糖缀合物介导红系和髓系细胞的结合。本文讨论了EbR和SER在巨噬细胞-造血细胞相互作用中的可能功能。
