Krahling S, Callahan M K, Williamson P, Schlegel R A
Department of Biochemistry and Molecular Biology, Penn State University, University Park, Pennsylvania 16802, USA.
Cell Death Differ. 1999 Feb;6(2):183-9. doi: 10.1038/sj.cdd.4400473.
Although different macrophages exploit different cell surface receptors to recognize apoptotic lymphocytes, indirect evidence suggested that the phosphatidylserine (PS) that appears on the surface of lymphocytes undergoing apoptosis participates in specific recognition by all types of macrophages. To test this possibility directly, annexin V, a protein that specifically binds to PS, was used to mask this phospholipid on the apoptotic cell surface. Preincubation of apoptotic lymphocytes with annexin V blocked phagocytosis by elicited mouse peritoneal macrophages, macrophages of the mouse J774 cell line and mouse bone marrow macrophages. Similarly, annexin V was able to inhibit phagocytosis of lipid-symmetric erythrocytes, another target cell upon which PS is exposed. Together these results demonstrate directly that macrophages of all types depend on the PS exposed on the surface of apoptotic lymphocytes for recognition and phagocytosis.
尽管不同的巨噬细胞利用不同的细胞表面受体来识别凋亡淋巴细胞，但间接证据表明，凋亡淋巴细胞表面出现的磷脂酰丝氨酸（PS）参与了所有类型巨噬细胞的特异性识别。为了直接验证这种可能性，膜联蛋白V（一种与PS特异性结合的蛋白质）被用于掩盖凋亡细胞表面的这种磷脂。凋亡淋巴细胞与膜联蛋白V预孵育可阻断诱导的小鼠腹腔巨噬细胞、小鼠J774细胞系巨噬细胞和小鼠骨髓巨噬细胞的吞噬作用。同样，膜联蛋白V能够抑制脂质对称红细胞（另一种暴露有PS的靶细胞）的吞噬作用。这些结果共同直接证明，所有类型的巨噬细胞都依赖凋亡淋巴细胞表面暴露的PS进行识别和吞噬。
