Department of Animal Science, College of Life Sciences and Food Engineering, Hebei University of Engineering, Handan, China.
Immunology. 2020 May;160(1):52-63. doi: 10.1111/imm.13180. Epub 2020 Mar 17.
As a pineal gland hormone, melatonin acts through its receptors to modulate the immune system. The immune system is composed of primary and secondary organs, and immune organs are adapted to the presence of the fetal alloantigen during pregnancy. However, it is unclear whether melatonin affects maternal immune organs during early pregnancy in sheep. In this study, the ovine thymus, lymph node, spleen and liver were sampled at day 16 of the oestrous cycle, and at days 13, 16 and 25 of pregnancy. The expression of melatonin receptor 1A (MT1), melatonin receptor 1B (MT2) and cluster of differentiation 4 (CD4) was detected by quantitative real-time polymerase chain reaction, Western blot and immunohistochemistry experiments. Our results showed that during early pregnancy there was an upregulation of MT1 mRNA and protein in the thymus, lymph node and liver, and there was a downregulation in the spleen. The expression of MT2 mRNA and protein was increased in the thymus but decreased in the spleen and liver, and there was no significant change in the lymph node during early pregnancy. CD4 protein was upregulated in the thymus, lymph node and liver, but there were no significant changes in the spleen during early pregnancy. In conclusion, early pregnancy induces tissue-specific expression of MT1, MT2 and CD4, which may be due to the different functions of the thymus, lymph node, spleen and liver. Further, melatonin is involved in immune regulation of the maternal thymus, lymph node, spleen and liver during early pregnancy in sheep.
作为松果腺激素，褪黑素通过其受体作用来调节免疫系统。免疫系统由初级和次级器官组成，免疫器官适应于妊娠期间胎儿同种异体抗原的存在。然而，褪黑素是否影响绵羊妊娠早期的母体免疫器官尚不清楚。在这项研究中，在发情周期的第 16 天以及妊娠第 13、16 和 25 天采集绵羊的胸腺、淋巴结、脾脏和肝脏样本。通过定量实时聚合酶链反应、Western blot 和免疫组织化学实验检测褪黑素受体 1A（MT1）、褪黑素受体 1B（MT2）和分化簇 4（CD4）的表达。我们的结果表明，在妊娠早期，胸腺、淋巴结和肝脏中的 MT1 mRNA 和蛋白表达上调，而脾脏中的表达下调。MT2 mRNA 和蛋白的表达在胸腺中增加，但在脾脏和肝脏中减少，而在淋巴结中没有明显变化。CD4 蛋白在胸腺、淋巴结和肝脏中上调，但在妊娠早期脾脏中没有明显变化。总之，妊娠早期诱导 MT1、MT2 和 CD4 的组织特异性表达，这可能是由于胸腺、淋巴结、脾脏和肝脏的不同功能所致。此外，褪黑素参与了绵羊妊娠早期母体胸腺、淋巴结、脾脏和肝脏的免疫调节。
