Comparative evaluation of the effect of pharmacological agents on endocytosis and coendocytosis of IgE by rat basophilic leukaemia cells.
Comparative evaluation of the effect of pharmacological agents on endocytosis and coendocytosis of IgE by rat basophilic leukaemia cells.
复制标题
药物对大鼠嗜碱性白血病细胞 IgE 内吞作用和共内吞作用影响的比较评价。
作者：
K. Furuichi;C. Ra;C. Isersky;J. Rivera
IgE与大鼠嗜碱性白血病（RBL）细胞结合的聚集导致介质的胞吐作用、抗原聚集的小鼠IgE抗DNP的内吞作用以及一些未聚集的单体大鼠IgE（IR 162）和/或未结合受体的共内吞作用。我们在这里描述的相对影响内吞作用和共内吞作用的各种药物，阻止或增强胞吐作用。我们以前已经表明，不像胞吐，内吞作用的RBL和正常大鼠肥大细胞是独立的细胞外钙。我们在这里表明，钙螯合剂或拮抗剂的存在下也没有影响的内吞作用的交联IgE。然而，非交联IgE的共胞吞作用被细胞外钙的消除和钙螯合剂如EDTA或EGTA-Mg 2+的加入部分抑制。此外，添加钙拮抗剂，如Ni 2+和Co 2+（5 mM）的孵育混合物含有Ca 2+（1 mM）导致共内吞作用的完全抑制，而不影响内吞作用。其他胞吐抑制剂如叠氮化钠（10- 2 M）、槲皮素（10- 4 M）和双丁酰环腺苷酸（10-2 M）可完全阻断共胞吞作用，但对胞吞作用无影响。叠氮化钠（10 mM）与2-脱氧葡萄糖（10 mM）的组合有效地抑制（90%）内吞作用。细胞松弛素B（10-4 M），这是增强5-羟色胺的释放，没有影响的程度上观察到的内吞作用或共内吞作用后20分钟开始的聚集。因此，在RBL细胞中，内吞作用、共内吞作用和胞吐作用对某些药理学药物表现出可区分的敏感性。
The aggregation of IgE bound to rat basophilic leukaemia (RBL) cells leads to the exocytosis of mediators, the endocytosis of the antigen-aggregated mouse IgE anti-DNP, as well as the coendocytosis of some unaggregated monomeric rat IgE (IR162) and/or unbound receptors. We describe here the relative effect on endocytosis and coendocytosis of various pharmacological agents that block or enhance exocytosis. We have previously shown that, unlike exocytosis, endocytosis by RBL and normal rat mast cells was independent of extracellular calcium. We show here that the presence of calcium chelators or antagonists also had no effect on endocytosis of cross-linked IgE. However, coendocytosis of non-cross-linked IgE was partially inhibited by the elimination of extracellular calcium and the addition of calcium chelators such as EDTA or EGTA-Mg2+. Moreover, the addition of calcium antagonists such as Ni2+ and Co2+ (5 mM) to an incubation mixture containing Ca2+ (1 mM) resulted in the complete inhibition of coendocytosis without affecting endocytosis. Other inhibitors of exocytosis such as sodium azide (10-2M), quercetin (10-4M) and dibutyryl cyclic AMP (10-2 M) blocked coendocytosis completely but had no effect on endocytosis. Sodium azide (10 mM) in combination with 2-deoxyglucose (10 mM) effectively inhibited (90%) endocytosis. Cytochalasin B (10-4 M), which was shown to enhance serotonin release, had no effect on the extent of endocytosis or coendocytosis observed 20 min after the initiation of aggregation. Thus, in RBL cells, endocytosis, coendocytosis and exocytosis exhibit distinguishable sensitivities to some pharmacological drugs.