交感神经-免疫系统调节网络的研究进展

The regulating network between the sympathetic nervous system and immune system

淋巴器官受交感神经支配 ,这些神经支配淋巴器官中的血管平滑肌和实质区域 ,与血管平滑肌细胞和淋巴细胞呈非经典的突触联系 ,即交感神经末梢的曲张体非突触性地释放去甲肾上腺素 (norepinephrine ,NE) ,NE以旁分泌的方式扩散出去 ,作用于较大距离范围的血管平滑肌细胞和淋巴细胞 ,调节淋巴器官的血流、淋巴细胞的运输和淋巴细胞的功能。在免疫应答过程中 ,免疫细胞释放细胞因子 ,影响外周感觉神经的传入活动 ,继而改变交感神经的NE释放 ,从而影响免疫功能。T细胞上存在电压门控K+通道 ,K+通道代表了T细胞上主要的离子通道 ,T细胞激活后上调K+通道的表达和增加K+通道的通透性 ,交感神经可能通过减小K+通道的通透性从而抑制T细胞的功能。

Lymphoid organs are innervated by sympathetic nervous system which mainly terminates at both the smooth muscle of the vasculature and the parenchyma in the lymphoid organs. The sympathetic nervous fibers in the lymphoid organs do not make classical synaptic contacts with target cells. Norepinephrine (NE) is released nonsynaptically, i.e., from varicose axon terminals, and diffuses out to regulate immune cells in a paracrine way. Cytokines which are secreted by activated lymphocytes act directly on the peripheral sensory nerves and subsequently affect the release of NE from sympathetic nerves. The voltage-dependent potassium channels are presence in the murine and human lymphocytes, and they represent the predominant ion channels in the T cells. The activation of T cells up-regulates the expression of K + channels and amplifies the potassium conductance. The sympathetic nerves inhibit T cell function via decreasing the potassium conductance.