Kooijman R, Scholtens L E, Rijkers G T, Zegers B J
Department of Immunology, University Hospital for Children and Youth Het Wilhelmina Kinderziekenhuis, Utrecht, The Netherlands.
J Endocrinol. 1995 Nov;147(2):203-9. doi: 10.1677/joe.0.1470203.
Insulin-like growth factor-I (IGF-I) has been implicated in playing a regulatory role in T cell development and in T cell function. We demonstrate the presence of type I IGF receptors on human thymocytes using radioligand binding assays and flowcytometric analysis. The relative potencies of IGF-I, IGF-II and insulin for competition with 125I- IGF-I indicate the presence of type I IGF receptors. Scatchard analysis revealed that the average number of receptors per thymocyte is 257 +/- 28 with a Kd of 0.12 +/- 0.01. With multicolour flowcytometry using a type I IGF receptor specific monoclonal antibody (alpha IR3), we show that CD4-CD8- cells express 3-4 times more receptors per cell as compared with CD4+CD8+, CD4+CD8- and CD4-CD8+ cells. IGF-I directly stimulated DNA synthesis of thymocytes and potentiated DNA synthesis in mitogen-activated thymocytes. These results indicate that IGF-I can influence T cell development in humans at the level of the thymus.
胰岛素样生长因子-I（IGF-I）已被证实对T细胞发育和T细胞功能发挥调节作用。我们通过放射性配体结合试验和流式细胞术分析，证明了人胸腺细胞上存在I型IGF受体。IGF-I、IGF-II和胰岛素与125I-IGF-I竞争的相对效力表明存在I型IGF受体。Scatchard分析显示，每个胸腺细胞的平均受体数量为257±28，解离常数（Kd）为0.12±0.01。使用I型IGF受体特异性单克隆抗体（αIR3）进行多色流式细胞术分析，我们发现与CD4+CD8+、CD4+CD8-和CD4-CD8+细胞相比，CD4-CD8-细胞每个细胞表达的受体多3至4倍。IGF-I直接刺激胸腺细胞的DNA合成，并增强有丝分裂原激活的胸腺细胞中的DNA合成。这些结果表明，IGF-I可在胸腺水平影响人类T细胞发育。
