Jia L, Hara H, Okochi T, Negoro S
Department of Medicine III, Osaka University Medical School, Japan.
Int J Immunopharmacol. 1992 Jul;14(5):809-19. doi: 10.1016/0192-0561(92)90079-z.
The expression of the beta-endorphin receptor on both activated and unstimulated mouse spleen cells was studied. Results showed that unstimulated cells have only one type of beta-endorphin receptor with a specific low affinity (Kd = 1.034 +/- 0.0237 x 10(-7) M, 25,000 sites/cell). After Con A stimulation, cells express two types of receptors, one with a low affinity (Kd = 1.034 +/- 0.024 x 10(-7) M, 320,000 sites/cell) and the other with a high affinity (Kd = 1.052 +/- 0.033 x 10(-9) M, 49,000 sites/cell). The kinetic experiments during 4 days after Con A activation indicated that the receptor of high affinity emerged from 24 to 72 h, while the low affinity one increased in number after stimulation. The receptor numbers of both high and low affinity ones reached a maximum peak at 72 h, then began to decline. The addition of exogenous rIL-2 depressed the Con A-induced increment of the receptor numbers of both the high and low affinity ones, but enhanced the proliferative response of the cells. It is suggested that the degree of the expression of the receptors does not simply depend on the mitogenic degree of the cells. In addition, our experiment demonstrated that splenocytes cultured in medium with or without Con A or Con A + rIL-2 for 96 h did not secrete any detectable amount of beta-endorphin with use of the RIA assay, which is sensitive enough to detect the much lower levels of beta-endorphin than that necessary for biological effects. We suggest that the expression of the high affinity beta-endorphin receptor on the activated T-lymphocytes may have to precede the production of IL-2 to potentiate the T-cell proliferative response. The mechanisms and modes of interaction between the neuroendocrine system and the immune system were discussed.
研究了活化和未刺激的小鼠脾细胞上β-内啡肽受体的表达。结果表明，未刺激的细胞只有一种具有特定低亲和力的β-内啡肽受体（Kd = 1.034 +/- 0.0237 x 10(-7) M，25,000个位点/细胞）。经刀豆蛋白A刺激后，细胞表达两种类型的受体，一种具有低亲和力（Kd = 1.034 +/- 0.024 x 10(-7) M，320,000个位点/细胞），另一种具有高亲和力（Kd = 1.052 +/- 0.033 x 10(-9) M，49,000个位点/细胞）。刀豆蛋白A激活后4天内的动力学实验表明，高亲和力受体在24至72小时出现，而低亲和力受体在刺激后数量增加。高亲和力和低亲和力受体的数量在72小时达到最大峰值，然后开始下降。添加外源性重组白细胞介素-2可抑制刀豆蛋白A诱导的高亲和力和低亲和力受体数量的增加，但增强了细胞的增殖反应。提示受体表达程度并不简单取决于细胞的促有丝分裂程度。此外，我们的实验表明，在含有或不含有刀豆蛋白A或刀豆蛋白A + 重组白细胞介素-2的培养基中培养96小时的脾细胞，使用放射免疫分析未检测到任何可检测量的β-内啡肽，该分析灵敏度足以检测比生物学效应所需水平低得多的β-内啡肽水平。我们认为活化的T淋巴细胞上高亲和力β-内啡肽受体的表达可能必须先于白细胞介素-2的产生，以增强T细胞增殖反应。讨论了神经内分泌系统与免疫系统之间相互作用的机制和方式。
