Blood-Brain Barrier Group, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
Neurosci Biobehav Rev. 2013 Feb;37(2):184-92. doi: 10.1016/j.neubiorev.2012.11.009. Epub 2012 Nov 29.
Interleukin (IL)-15 is a ubiquitously expressed cytokine existing in both intracellular and secretory forms. Here we review the expression, regulation, and functions of IL15 and its receptors in the brain. IL15 receptors show robust upregulation after neuroinflammation, suggesting a major role of IL15 signaling in cerebral function. Involvement of the IL15 system in neuropsychiatric behavior is reflected by the effects of IL15, IL15Rα, and IL2Rγ deletions on neurobehavior and neurotransmitters, the effects of IL15 treatment on neuronal activity, and the potential role of IL15 in neuroplasticity/neurogenesis. The results show that IL15 modulates GABA and serotonin transmission. This may underlie deficits in mood (depressive-like behavior and decreased normal anxiety) and memory, as well as activity level, sleep, and thermoregulation. Although IL15 has only a low level of permeation across the blood-brain barrier, peripheral IL15 is able to activate multiple signaling pathways in neurons widely distributed in CNS regions. The effects of IL15 in "preventing" neuropsychiatric symptoms in normal mice implicate a potential therapeutic role of this polypeptide cytokine.
白细胞介素 (IL)-15 是一种广泛表达的细胞因子，存在于细胞内和分泌形式中。在这里，我们综述了 IL15 及其受体在大脑中的表达、调节和功能。神经炎症后，IL15 受体表达明显上调，提示 IL15 信号在大脑功能中起主要作用。IL15 系统参与神经精神行为，这反映在 IL15、IL15Rα 和 IL2Rγ 缺失对神经行为和神经递质的影响、IL15 治疗对神经元活性的影响以及 IL15 在神经可塑性/神经发生中的潜在作用。结果表明，IL15 调节 GABA 和血清素传递。这可能是情绪（抑郁样行为和正常焦虑减少）和记忆以及活动水平、睡眠和体温调节缺陷的基础。尽管 IL15 只能少量渗透血脑屏障，但外周 IL15 能够激活广泛分布于中枢神经系统区域的神经元中的多种信号通路。IL15 在正常小鼠中“预防”神经精神症状的作用提示这种多肽细胞因子具有潜在的治疗作用。
