交联膜CD23分子对B淋巴细胞增殖及细胞内第二信使物质的影响

Cross—linking Membranous CD23 Molecules on B Lymphocytes Affect Its Proliferation and Second Messenger

本文旨在探讨 B 细胞膜表面 CD23分子可能具有的功能和所介导的第二信使物质的改变。以 CD23分子的天然配体 IgE 及抗 CD23单抗作为交联剂,观察分析了交联 B 细胞膜表面 CD23分子后,对B 细胞增殖的影响,以及交联所导致的细胞内一些第二信使物质的改变。结果显示:(1)抗 CD23单抗及 IgE免疫复合物(IgEIC)对活化 B 细胞增殖,依据其浓度不同,呈现促进和抑制双向调节效应。这种双向效应依赖于可上调 CD23表达的淋巴因子 IL-4的存在;(2)单价结合 CD23分子的 IgE 对活化 B 细胞增殖无影响;(3)对于 B 细胞有促增殖浓度的抗 CD23单抗和 IgE IC,可引起活化 B 细胞内 cAMP 水平的升高,而对胞内cGMP 水平无明显影响;(4)抗 CD23单抗能诱导活化 B 细胞胞浆游离 Ca^(2+)浓度快速而短暂的升高。

The possible roles of CD23 molecule on B cells were analyzed through cross—linking CD23 molecules on tonsillar B lymphocytes with CD23 natural ligands IgE and anti—CD23 McAb.After cross—linking CD23 molecules on activated B cells,the change of B cell proliferation and second messengers were observed.The results showed:(1)Double—valence anti—CD23 McAb and multi—valence IgE immune complex(IgEIC)had a two—way effect on B cells proliferation,on high concentrations,they inhibited the proliferation of a etivated B cells by sAo In con trast with a certain lower concentration,they promoted the proliferation of activted B cells.The two—way effect depended on IL—4 which functions to up—regulate CD23;(2)mono —valence IgE had no observeable effects on B cells proliferation;(3)IgEIC and antl—CD23 McAb at the same concentration as stimulating B cell proliferation increased the intracellular CAMP levls,but not cGMP levels.(4)Anti—CD23 McAb provoked the transent increase of in tracellular free(Ca^(2+)).