Zhang Jiquan Q, Biedermann Björn, Nitschke Lars, Crocker Paul R
Division of Cell Biology and Immunology, The Wellcome Trust Biocentre at Dundee, University of Dundee, Dundee, GB.
Eur J Immunol. 2004 Apr;34(4):1175-84. doi: 10.1002/eji.200324723.
Murine (m) Siglec-E and mSiglec-F are recently discovered murine sialic acid-binding Ig-like lectins with tyrosine-based inhibitory signaling motifs. They are postulated to be the orthologs of human (h) siglec-7, -8 or -9 and siglec-5, respectively. We report here the first detailed characterization of mSiglec-E, and compare its expression pattern with mSiglec-F. Similar to hSiglec-7, mSiglec-E preferred alpha 2-8-linked disialic acid over alpha 2-3- and alpha 2-6-linked sialic acids. Using a specific Ab, FACS analysis demonstrated that mSiglec-E was expressed mainly on neutrophils in blood and their immature precursors in bone marrow. mSiglec-E was present on peritoneal cavity macrophages and on subsets of mature NK cells and splenic dendritic cells. mSiglec-E was also found ona novel population of peritoneal cavity B-1a-like cells and a subset of splenic B cells enriched in transitional T2 and marginal zone B cells. In striking contrast to mSiglec-E, mSiglec-F was expressed predominantly on eosinophils in blood and their precursors in the bone marrow. The distinct and largely non-overlapping expression profiles of mSiglec-E and mSiglec-F suggest that they play non-redundant roles in the innate immune system. mSiglec-E is likely to modulate the functions of several types of effector cells, whereas mSiglec-F is likely to be more restricted to eosinophil biology.
小鼠（m）Siglec-E和mSiglec-F是最近发现的具有基于酪氨酸的抑制性信号基序的小鼠唾液酸结合免疫球蛋白样凝集素。据推测，它们分别是人（h）siglec-7、-8或-9以及siglec-5的直系同源物。我们在此报告mSiglec-E的首次详细特征，并将其表达模式与mSiglec-F进行比较。与hSiglec-7相似，mSiglec-E优先结合α2-8连接的二唾液酸，而不是α2-3和α2-6连接的唾液酸。使用特异性抗体，流式细胞术分析表明mSiglec-E主要表达于血液中的中性粒细胞及其骨髓中的未成熟前体。mSiglec-E存在于腹腔巨噬细胞、成熟NK细胞亚群和脾树突状细胞上。在新型腹腔B-1a样细胞群和富含过渡性T2和边缘区B细胞的脾B细胞亚群中也发现了mSiglec-E。与mSiglec-E形成鲜明对比的是，mSiglec-F主要表达于血液中的嗜酸性粒细胞及其骨髓中的前体。mSiglec-E和mSiglec-F截然不同且基本不重叠的表达谱表明它们在先天免疫系统中发挥非冗余作用。mSiglec-E可能调节多种效应细胞的功能，而mSiglec-F可能更局限于嗜酸性粒细胞生物学。
