Laboratory of Immunogenetics and Allergology, Centre de Recherche Public de la Santé, Luxembourg, Luxembourg.
PLoS One. 2010 Dec 1;5(12):e15053. doi: 10.1371/journal.pone.0015053.
Nerve growth factor (NGF) is a neurotrophin crucial for the development and survival of neurons. It also acts on cells of the immune system which express the NGF receptors TrkA and p75(NTR) and can be produced by them. However, mouse NK cells have not yet been studied in this context.
METHODOLOGY/PRINCIPAL FINDINGS: We used cell culture, flow cytometry, confocal microscopy and ELISA assays to investigate the expression of NGF receptors by NK cells and their secretion of NGF. We show that resting NK cells express TrkA and that the expression is different on NK cell subpopulations defined by the relative presence of CD27 and CD11b. Expression of TrkA is dramatically increased in IL-2-activated NK cells. The p75(NTR) is expressed only on a very low percentage of NK cells. Functionally, NGF moderately inhibits NK cell degranulation, but does not influence proliferation or cytokine production. NK cells do not produce NGF.
CONCLUSIONS/SIGNIFICANCE: We demonstrate for the first time that mouse NK cells express the NGF receptor TrkA and that this expression is dynamically regulated.
神经生长因子（NGF）是一种对神经元的发育和存活至关重要的神经营养因子。它还作用于表达 NGF 受体 TrkA 和 p75（NTR）的免疫系统细胞，并可以由它们产生。然而，鼠 NK 细胞在这方面尚未被研究过。
方法/主要发现：我们使用细胞培养、流式细胞术、共聚焦显微镜和 ELISA 检测来研究 NK 细胞表达 NGF 受体及其分泌 NGF 的情况。我们表明，静止的 NK 细胞表达 TrkA，并且这种表达在通过相对存在 CD27 和 CD11b 定义的 NK 细胞亚群中有所不同。IL-2 激活的 NK 细胞中 TrkA 的表达显著增加。p75（NTR）仅在极少数 NK 细胞上表达。在功能上，NGF 适度抑制 NK 细胞脱颗粒，但不影响增殖或细胞因子产生。NK 细胞不产生 NGF。
结论/意义：我们首次证明了鼠 NK 细胞表达 NGF 受体 TrkA，并且这种表达是动态调节的。
