The interaction of soluble horseradish peroxidase with mouse peritoneal macrophages in vitro.
The interaction of soluble horseradish peroxidase with mouse peritoneal macrophages in vitro.
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DOI：
10.1083/jcb.55.1.186
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发表时间：
1972-10
期刊：
影响因子：
--
通讯作者：
Cohn ZA
中科院分区：
文献类型：
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作者：
Steinman RM;Cohn ZA
利用灵敏的生化和细胞化学技术研究了可溶性辣根过氧化物酶（HRP）与小鼠巨噬细胞均质单层的体外相互作用。HRP在细胞外和细胞内的区隔性已被定量评估。很大一部分与血清衍生层结合，该层覆盖在培养容器表面，可通过适当的洗涤除去。巨噬细胞将HRP作为溶质内化到胞泡中，而不会将糖蛋白与质膜结合。摄取与培养基中HRP的浓度成正比。在广泛的浓度范围内，1 × 106个细胞每小时摄取0.0025%的给药负荷。细胞化学上，所有可证实的HRP都被隔离在空泡器的内吞囊泡和次级溶酶体中。摄取后，HRP的酶活性呈指数型失活，半衰期为7-9小时，直到酶不再被检测到。当巨噬细胞吞噬了微量标记的HRP-125I后，细胞相关的同位素在20-30小时的一个半小时内消失，它们将单碘酪氨酸- 125i释放到培养基中。我们无法获得证据证明大量的HRP（约2%）在摄取后可以被胞外排出，可以完整地存在于细胞表面，或者可以被细胞外消化。很难将这些观察结果与巨噬细胞被认为在诱导免疫反应中起突出作用的几种假设机制相一致。
The in vitro interaction of soluble horseradish peroxidase (HRP) with homogeneous mono layers of mouse macrophages has been studied using sensitive biochemical and cytochemical techniques. The compartmentalization of HRP in extracellular and intracellular sites has been quantitatively evaluated. A significant fraction is bound to a serum-derived layer, which coats the surface of culture vessels and may be removed by appropriate washes. Macrophages interiorize HRP as a solute in pinocytic vesicles without appreciable binding of the glycoprotein to the plasma membrane. Uptake is directly proportional to the concentration of HRP in the culture medium. 1 x 106 cells ingest 0.0025% of the administered load per hr over a wide range of concentrations. Cytochemically, all demonstrable HRP is sequestered within the endocytic vesicles and secondary lysosomes of the vacuolar apparatus. After uptake, the enzymatic activity of HRP is inactivated exponentially with a half-life of 7–9 hr, until enzyme is no longer detectable. When macrophages have pinocytosed trace-labeled HRP-125I, cell-associated isotope disappears with a t ½ of 20–30 hr and they release monoiodotyrosine-125I into the culture medium. We were unable to obtain evidence that significant amounts of HRP (>2%) can be exocytosed after uptake, can exist intact on the cell surface, or can be digested extracellularly. It is difficult to reconcile these observations with several of the postulated mechanisms whereby macrophages are thought to play a prominent role in the induction of an immune response.