Immune-neuro Cross-talk with Confocal Laser Scanning Microscopy

神经和肥大细胞之间的通信是神经免疫相互作用的原型演示。以前，我们清楚地表明，神经肥大细胞串扰可以发生双向的中介转导细胞的情况下，使用体外共培养的方法和钙成像。在双向通信方面，我们证明了神经肽P物质是传出通信（即神经元到肥大细胞）的重要介质，但传入通信（即肥大细胞到神经元）的介质仍然未知。然后，我们研究了激活神经突起（上级颈神经节; SCG）与肥大细胞（大鼠嗜碱性白血病细胞; RBL）共培养的介质。向SCG和RBL共培养物中加入抗原，引起RBL内[Ca^<2+>]_i增加，并在一个滞后期后，引起SCG神经突内[Ca^<2+>]_i增加，神经突延伸到RBL与神经突连接处较远的距离（>150μm）。磷酸吡哆醛-6-偶氮苯基-2 '，4'-二磺酸（PPADS）或腺苷三磷酸双磷酸酶（分别为嘌呤能受体2拮抗剂或ATP水解酶）的预处理可阻止由RBL激活引起的SCG神经炎中的钙信号，但氯苯那敏或酮色林（分别为组胺或5-羟色胺受体拮抗剂）的预处理则不能。这些结果表明，激活肥大细胞释放的ATP是神经突起和肥大细胞之间传入信息传递的重要介质，而组胺和5-羟色胺则不起作用。此外，我们发现SynCAM和N-cadherin在肥大细胞和神经炎之间的突触样结构中的作用。

Communication between nerves and mast cells is a prototypic demonstration of neuro-immune interaction. Previously, we showed clearly that nerve-mast cell cross-talk can occur bidirectionally in the absence of an intermediary transducing cell using an in vitro co-culture approach and calcium imaging. In terms of bidirectional communication, we demonstrated that the neuropeptide substance P is an important mediator in efferent communication (i.e. neuron-to-mast cell), but the mediators in afferent communication (i.e. mast cell-to-neuron) have been still unknown. Then, we have studied the mediators to activate neurites (superior cervical ganglia ; SCG) cocultured with mast cells (rat basophilic leukemia cells ; RBLs). Addition of antigen to the cocultures of SCG and RBLs elicited the increase in the [Ca^<2+>]_i in RBLs and after a lag period induced the increase in the [Ca^<2+>]_i in SCG neuretes extending at a long distance (>150μm) from the site where the RBLs attached to the neurites. The pretreatment of pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS) or apyrase, which is a purinergic receptor 2 antagonist or an ATP hydrolyzing enzyme, respectively, prevented the calcium signals in SCG neuritis which were resulted as a consequence of RBL activation, but the pretreatment of chlorophenilamine or ketanserin, which is a histamine or serotonin receptor antagonist, respectively, did not. These results indicated that the ATP released from activated mast cells functioned as an important mediator in afferent communication between neurites and mast cells, but not histamine and serotonin. In addition, we found the roles of SynCAM and N-cadherin in the synaps-like structures between mast cells and neuritis.