Distribution of IL-5 receptor-positive B cells. Expression of IL-5 receptor on Ly-1(CD5)+ B cells.
Distribution of IL-5 receptor-positive B cells. Expression of IL-5 receptor on Ly-1(CD5)+ B cells.
复制标题
IL-5 受体阳性 B 细胞的分布。
作者：
Y. Hitoshi;N. Yamaguchi;S. Mita;E. Sonoda;S. Takaki;A. Tominaga;K. Takatsu
通过小鼠骨髓瘤细胞和来自用 IL-5 依赖性早期 B 细胞系 (T88-M) 膜富集部分免疫的大鼠的脾细胞之间的融合，制备针对鼠 IL-5R 的 mAb。选择两种 mAb（H7 和 T21），因为它们能够竞争性抑制 35S 标记的 IL-5 的受体结合以及 IL-5 的生物活性。 mAb 在不同细胞系上识别的结合位点数量与 IL-5 反应性相关。大多数表面IgM+腹膜B细胞是H7+，超过70%也是Ly-1(CD5)dull+，并且对IL-5作出高频率的多克隆IgM产生反应。相当大比例的脾 B 细胞与这些 mAb 发生反应，尽管数量比腹膜 B 细胞少（少 1 个对数），并且一小部分 H7dull+ 脾 B 细胞似乎是 Ly-1(CD5)dull+，200 个脾 B 细胞中有 1 个对 IL-5 产生反应以产生 IgM。这些结果表明 IL-5R+ B 细胞可能由 B 细胞亚群组成。有趣的是，骨髓细胞的淋巴细胞群被 H7 和 T21 染色，而骨髓细胞群仅被 T21 染色为明亮的颜色。最后，H7 和 T21 mAb 均从 IL-5R+ T88-M 细胞的 125I 标记细胞裂解物中特异性沉淀出 Mr 60,000 的蛋白质。从腹膜B细胞的细胞裂解物中沉淀出具有相似大小（Mr 55,000至60,000）的IL-5R。 T21 mAb（而非 H7 mAb）从骨髓细胞的细胞裂解物中沉淀出 110,000 Mr 110,000 的蛋白质。
mAb to murine IL-5R were prepared by means of fusion between mouse myeloma cells and spleen cells from a rat immunized with membrane-enriched fractions of IL-5-dependent early B cell line (T88-M). Two mAb (H7 and T21) were selected for their competitive inhibition of receptor binding by 35S-labeled IL-5 and of IL-5 biologic activities. The number of binding sites recognized by the mAb on different cell lines correlated with IL-5 responsiveness. Most surface IgM+ peritoneal B cells were H7+ and more than 70% were also Ly-1(CD5)dull+, and responded to IL-5 for polyclonal IgM production in a high frequency. A significant proportion of splenic B cells reacted with these mAb, although lower number (one-log less) than peritoneal B cells and a small proportion of H7dull+ splenic B cells seems to be Ly-1(CD5)dull+, 1 of 200 splenic B cells responded to IL-5 for IgM production. These results suggest that IL-5R+ B cells may consist of a subpopulation of B cells. Intriguingly, lymphoid populations of bone marrow cells were stained with H7 and T21, whereas myeloid populations were brightly stained with only T21. Finally, both H7 and T21 mAb specifically precipitated a protein of a Mr 60,000 from 125I-labeled cell lysates of IL-5R+ T88-M cells. The IL-5R with similar size (Mr 55,000 to 60,000) was precipitated from the cell lysates of peritoneal B cells. T21 mAb but not H7 mAb precipitated a protein of a Mr 110,000 from the cell lysates of bone marrow cells.