Güneş H, Mastro A M
Pennsylvania State University, Department of Biochemistry and Molecular Biology, University Park 16802, USA.
Mol Cell Endocrinol. 1996 Mar 1;117(1):41-52. doi: 10.1016/0303-7207(95)03724-1.
In vivo and in vitro studies have indicated that the anterior pituitary hormone prolactin (PRL) is an immunoregulator and functions in the development of the neonatal immune system. In this study, prolactin receptor (PRL-R) expression from birth to adulthood as well as the effect of milk ingestion on the PRL-R expression were examined in splenocytes and thymocytes of neonatal rats. Three approaches were taken to measure PRL-R expression: (i) polymerase chain reaction (RT-PCR); (ii) antibody to PRL-R and Western blotting; (iii) antibody to PRL-R and flow cytometry. RT-PCR analysis revealed the short and long form of PRL-R mRNA in both spleen and thymus at every age tested. However, the long form of PRL-R mRNA was always more abundant than that of the short form. In addition, antipeptide antibody against the long form of PRL-R recognized 84 and 42 kD proteins in the spleen, but only the 84 kD protein in the thymus. A monoclonal antibody U6 recognized 38 and 40 kD proteins in both the spleen and thymus. Although the mRNA level of PRL-R was relatively low at birth and increased with age in both the spleen and thymus, the levels of protein bands detected with both antibodies correlated with development in the spleen; whereas the levels remained steady in the thymus. Therefore, we concluded that the expression of PRL-R at the protein level is developmentally regulated in the spleen but not in the thymus. Finally, milk ingestion in the first seven hours decreased the percentage of cells expressing cell surface PRL-R, suggesting that milk-borne PRL may have a direct effect on lymphocytes.
体内和体外研究表明，垂体前叶激素催乳素（PRL）是一种免疫调节剂，在新生儿免疫系统发育中发挥作用。在本研究中，检测了新生大鼠脾细胞和胸腺细胞从出生到成年期催乳素受体（PRL-R）的表达，以及摄入乳汁对PRL-R表达的影响。采用了三种方法来测量PRL-R的表达：（i）聚合酶链反应（RT-PCR）；（ii）PRL-R抗体和蛋白质印迹法；（iii）PRL-R抗体和流式细胞术。RT-PCR分析显示，在每个测试年龄的脾脏和胸腺中均存在短型和长型PRL-R mRNA。然而，长型PRL-R mRNA总是比短型更丰富。此外，针对长型PRL-R的抗肽抗体在脾脏中识别出84 kD和42 kD的蛋白质，但在胸腺中仅识别出84 kD的蛋白质。单克隆抗体U6在脾脏和胸腺中均识别出38 kD和40 kD的蛋白质。虽然PRL-R的mRNA水平在出生时相对较低，且在脾脏和胸腺中均随年龄增加，但两种抗体检测到的蛋白条带水平与脾脏发育相关；而在胸腺中水平保持稳定。因此，我们得出结论，PRL-R在蛋白质水平的表达在脾脏中受发育调控，而在胸腺中不受调控。最后，在出生后前7小时摄入乳汁降低了表达细胞表面PRL-R的细胞百分比，表明乳汁中的PRL可能对淋巴细胞有直接作用。
