Allison K C, Strober W, Harriman G R
Mucosal Immunity Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892.
J Immunol. 1991 Jun 15;146(12):4197-203.
Regulation of IL-5R expression in normal, non-Ly-1 (CD5) B cells was evaluated. Freshly isolated unfractionated spleen B cells express little or no detectable IL-5R. In contrast, B cells stimulated with anti-Ig-dextran conjugates express substantial numbers of IL-5R. Phenotypic analysis of the B cells responding to anti-Ig-dextran, and expressing IL-5R, demonstrates that these cells do not express Ly-1 or Mac-1. Scatchard analysis of B cells stimulated with anti-IgD-dextran reveals two classes of IL-5R: a high affinity receptor with a Kd of 17 pM and approximately 300 receptors/cell, and a low affinity receptor with a Kd of 0.6 nM and approximately 1000 receptors/cell. Peak receptor expression in response to anti-IgD-dextran is seen 72 h after stimulation and with a dose of 10 ng/ml. The induced receptors are functional, because both proliferation and Ig secretion by B cells treated with anti-IgD-dextran are enhanced by IL-5. Other B cell mitogens such as LPS, soluble anti-Ig/IL-4, or phorbol esters/ionomycin are poor inducers of the IL-5R. Finally, not only does LPS fail to induce significant IL-5R expression on spleen B cells, it suppresses both high and low affinity IL-5R expression induced by anti-IgD-dextran. These data indicate that normal, non-Ly-1 B cells are capable of expressing both high and low affinity IL-5R but that receptor expression is critically dependent on the type of stimulus provided to the B cell. A stimulus that produces extensive cross-linking of surface Ig on B cells, i.e., anti-Ig-dextran, is very effective in inducing IL-5R whereas a variety of other B cell mitogens are ineffective.
对正常的非Ly-1（CD5）B细胞中白细胞介素-5受体（IL-5R）表达的调控进行了评估。新鲜分离的未分级脾B细胞表达很少或检测不到IL-5R。相比之下，用抗Ig-葡聚糖偶联物刺激的B细胞表达大量的IL-5R。对抗Ig-葡聚糖作出反应并表达IL-5R的B细胞进行表型分析表明，这些细胞不表达Ly-1或Mac-1。用抗IgD-葡聚糖刺激的B细胞的Scatchard分析显示有两类IL-5R：一类高亲和力受体，解离常数（Kd）为17 pM，每个细胞约有300个受体；另一类低亲和力受体，Kd为0.6 nM，每个细胞约有1000个受体。在刺激后72小时，用10 ng/ml的剂量可观察到抗IgD-葡聚糖刺激后受体表达达到峰值。诱导产生的受体具有功能，因为用抗IgD-葡聚糖处理的B细胞的增殖和免疫球蛋白分泌都因IL-5而增强。其他B细胞有丝分裂原，如脂多糖（LPS）、可溶性抗Ig/白细胞介素-4或佛波酯/离子霉素，都是IL-5R的低效诱导剂。最后，LPS不仅不能诱导脾B细胞上显著的IL-5R表达，还会抑制抗IgD-葡聚糖诱导的高亲和力和低亲和力IL-5R表达。这些数据表明，正常的非Ly-1 B细胞能够表达高亲和力和低亲和力的IL-5R，但受体表达严重依赖于给予B细胞的刺激类型。一种能使B细胞表面免疫球蛋白广泛交联的刺激，即抗Ig-葡聚糖，在诱导IL-5R方面非常有效，而其他多种B细胞有丝分裂原则无效。
