Weinstock J V, Elliott D
Department of Medicine, University of Iowa, Iowa City 52242, USA.
Eur J Endocrinol. 2000 Oct;143 Suppl 1:S15-9. doi: 10.1530/eje.0.143s015.
Somatostatin is part of an immunoregulatory circuit that helps limit interferon-gamma (IFNgamma) production at sites of chronic inflammation. In murine schistosomiasis. parasite eggs induce focal, chronic granulomatous inflammation in the liver and intestines. These granulomas produce somatostatin 1-14 and express somatostatin receptor subtype number 2 (SSTR2), which is the exclusive somatostatin receptor present in this inflammation. Granuloma and splenic macrophages as well as macrophage cell lines make somatostatin. There appears to be no other inflammatory cell source of the peptide. Various inflammatory mediators induce this expression, whereas substance P inhibits somatostatin production. Somatostatin can suppress IFN-gamma secretion from T cells via interaction with the SSTR2 receptor expressed on these cells. Other cells within the granuloma also display SSTR2. The effect of somatostatin on these other cell types remains unknown. The thymus of normal mice has a complete somatostatin regulatory circuit. The thymic epithelial and dendritic cells make somatostatin. Like the granulomas of murine schistosomiasis, the thymus expresses only SSTR2. Somatostatin likely has an important role in thymic T cell education and selection.
生长抑素是免疫调节回路的一部分，有助于限制慢性炎症部位的γ干扰素（IFNγ）产生。在小鼠血吸虫病中，寄生虫卵在肝脏和肠道中引发局灶性慢性肉芽肿性炎症。这些肉芽肿产生生长抑素1 - 14并表达生长抑素受体亚型2（SSTR2），这是这种炎症中唯一存在的生长抑素受体。肉芽肿和脾巨噬细胞以及巨噬细胞系产生生长抑素。该肽似乎没有其他炎症细胞来源。多种炎症介质诱导这种表达，而P物质抑制生长抑素的产生。生长抑素可通过与这些细胞上表达的SSTR2受体相互作用来抑制T细胞分泌IFNγ。肉芽肿内的其他细胞也表达SSTR2。生长抑素对这些其他细胞类型的作用尚不清楚。正常小鼠的胸腺有一个完整的生长抑素调节回路。胸腺上皮细胞和树突状细胞产生生长抑素。与小鼠血吸虫病的肉芽肿一样，胸腺仅表达SSTR2。生长抑素可能在胸腺T细胞的发育和选择中起重要作用。
