Silva Alberto B, Aw Danielle, Palmer Donald B
Host Response and Genes and Development Groups, Department of Veterinary Basic Sciences, Royal Veterinary College, Royal College Street, London NW1 0TU, UK.
Dev Comp Immunol. 2008;32(4):410-20. doi: 10.1016/j.dci.2007.08.002. Epub 2007 Aug 28.
The function of lymphoid organs and immune cells is often modulated by peptides and hormones produced by the neuroendocrine and immune systems. We have previously reported the intrathymic expression of neuropeptides in the thymus of different species and that neuropeptides can influence murine thymocyte development in vitro. To further explore the evolutionary nature of neuroendocrine interactions in the thymus, we identified the expression of calcitonin-gene-related peptide, neuropeptide Y, somatostatin (SOM), substance P and vasointestinal polypeptide, as well as their receptors on chicken thymic epithelial cells (TEC) and thymocytes by immunofluorescence and reverse transcription polymerase chain reaction (RT-PCR). All the studied neuropeptides and their receptors were found to be expressed in both TEC and thymocytes, suggesting that intrathymic neuroendocrine interactions may take place within the avian thymus. In order to elucidate whether such interactions play a role in avian thymocyte development, neuropeptides and their antagonists were added to embryonic thymus organ cultures and found to influence chicken thymopoiesis. In particular, an antagonist of SOM increased the proportion of double-positive thymocytes, while SOM itself appeared to inhibit the early stages of thymocyte development. Taken together, these data provide further evidence to suggest that neuropeptides play a conserved role in vertebrate thymocyte development.
淋巴器官和免疫细胞的功能常常受到神经内分泌系统和免疫系统产生的肽类和激素的调节。我们之前报道过不同物种胸腺中神经肽的胸腺内表达情况，并且神经肽在体外能够影响小鼠胸腺细胞的发育。为了进一步探究胸腺中神经内分泌相互作用的进化本质，我们通过免疫荧光和逆转录聚合酶链反应（RT-PCR）鉴定了降钙素基因相关肽、神经肽Y、生长抑素（SOM）、P物质和血管活性肠肽在鸡胸腺上皮细胞（TEC）和胸腺细胞上的表达情况，以及它们的受体。结果发现，所有研究的神经肽及其受体在TEC和胸腺细胞中均有表达，这表明胸腺内的神经内分泌相互作用可能在禽类胸腺中发生。为了阐明这种相互作用是否在禽类胸腺细胞发育中发挥作用，我们将神经肽及其拮抗剂添加到胚胎胸腺器官培养物中，发现它们会影响鸡的胸腺生成。特别是，SOM的拮抗剂增加了双阳性胸腺细胞的比例，而SOM本身似乎抑制胸腺细胞发育的早期阶段。综上所述，这些数据提供了进一步的证据，表明神经肽在脊椎动物胸腺细胞发育中发挥着保守作用。
