Nabholz M, Combe M C, Corthésy P, Lowenthal J, Gabathuler R
Eur J Immunol. 1987 Jun;17(6):783-90. doi: 10.1002/eji.1830170608.
We have analyzed different parameters of the interleukin 2 receptor (IL2R) traffic in a murine IL2-dependent T cell line, B6.1. These cells express about 10(5) IL2R, of which approximately 10% are of high affinity (HAR). About 90% of all mature immunoprecipitable receptor molecules in the cell are on the cell surface. Measurements of the half life and of the rate of receptor synthesis indicate that these cells produce approximately 500 receptor molecules per cell and min. IL2 deprival for less than 6 h does not affect this rate. B6.1 cells internalize IL2 via their HAR only, with a maximal rate of about 500 molecules per cell and min. Among the receptors present at a given time on the cell surface, about 15% are internalized within 30 min. Receptor internalization is independent of IL2. The data obtained argue against rapid recycling of the HAR. The rate of receptor synthesis can be reconciled with the rate of IL2 internalization and the observation that internalization occurs only via HAR by assuming that cell surface low-affinity receptors can be transformed into HAR by associating with other molecules.
我们分析了小鼠白介素2依赖性T细胞系B6.1中白介素2受体（IL2R）转运的不同参数。这些细胞表达约10⁵个IL2R，其中约10%为高亲和力（HAR）受体。细胞中所有可免疫沉淀的成熟受体分子约90%位于细胞表面。受体半衰期和合成速率的测量表明，这些细胞每细胞每分钟产生约500个受体分子。剥夺IL2少于6小时不影响该速率。B6.1细胞仅通过其HAR内化IL2，最大速率约为每细胞每分钟500个分子。在细胞表面特定时间存在的受体中，约15%在30分钟内被内化。受体内化与IL2无关。所获得的数据反对HAR的快速循环。通过假设细胞表面低亲和力受体可通过与其他分子结合转化为HAR，受体合成速率可与IL2内化速率以及内化仅通过HAR发生的观察结果相协调。
