Phagocytosis of liposomes by macrophages: intracellular fate of liposomal malaria antigen.
Phagocytosis of liposomes by macrophages: intracellular fate of liposomal malaria antigen.
复制标题
巨噬细胞对脂质体的吞噬作用：脂质体疟疾抗原的细胞内命运。
DOI：
10.1016/0005-2736(91)90191-a
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发表时间：
1991
期刊：
影响因子：
--
通讯作者：
Alving,CR
中科院分区：
文献类型：
--
作者：
Verma,JN;Wassef,NM;Wirtz,RA;Atkinson,CT;Aikawa,M;Loomis,LD;Alving,CR
含有合成的重组蛋白的脂质体被巨噬细胞吞噬，并且内化的蛋白质被回收到细胞表面，在那里通过酶联免疫吸附测定法检测。通过脉冲追踪实验测定脂质体包封的蛋白质从脂质体的初始吞噬到蛋白质在巨噬细胞表面上的出现的通过时间。用含有蛋白质的脂质体脉冲巨噬细胞，并用空脂质体追逐，反之亦然。细胞表面蛋白抗原表达的量和速率取决于巨噬细胞摄取的包裹蛋白的量。虽然脂质体被迅速采取了巨噬细胞，脂质体封装的蛋白抗原表达的细胞表面上的一段时间（至少24小时）。通过免疫金电子显微镜在巨噬细胞的空泡内观察到脂质体。脂质体沿着液泡的外围积聚，并且其中许多脂质体显然在很长一段时间内（> 6 h）保持完整。然而，在这些空泡周围的细胞质中也检测到非脂质体游离蛋白，并得出结论，细胞质中的游离蛋白可能在通往巨噬细胞表面的途中。暴露于氯化铵的细胞没有抑制脂质体抗原表位的细胞表面上的外观，这表明，脂质体抗原表位在表面上的表达不是一个pH敏感的现象。脂质体佐剂脂质A对脂质体蛋白表面表达的速率或程度没有显著影响。
Liposomes containing a synthetic recombinant protein were phagocytosed by macrophages, and the internalized protein was recycled to the cell surfaces where it was detected by enzyme-linked immunosorbent assay. The transit time of the liposome-encapsulated protein from initial phagocytosis of liposomes to appearance of protein on the surfaces of macrophages was determined by pulse-chase experiments. The macrophages were pulsed with liposomes containing protein and chased with empty liposomes, and vice versa. The amount and rate of protein antigen expression at the cell surfaces depended on the quantity of encapsulated protein ingested by the macrophages. Although liposomes were rapidly taken up by macrophages, the liposome-encapsulated protein was antigenically expressed for a prolonged period (at least 24 h) on the cell surface. Liposomes were visualized inside vacuoles in the macrophages by immunogold electron microscopy. The liposomes accumulated along the peripheries of the vacuoles and many of them apparently remained intact for a long time (> 6 h). However, nonliposomal free protein was also detected in the cytoplasm surrounding these vacuoles, and it was concluded that the free protein in the cytoplasm was probably en route to the macrophage surface. Exposure of the cells to ammonium chloride did not inhibit the appearance of liposomal antigenic epitopes on the cell surface, and this suggests that expression of the liposomal antigenic epitopes at the surface was not a pH-sensitive phenomenon. There was no significant effect of a liposomal adjuvant, lipid A, on the rate or extent of surface expression of the liposomal protein.