Group 2 innate lymphoid cells (ILC2s) are tissue-resident cells prominent at barrier sites. Although precursors are found in blood, mature ILC2s can enter the circulation after small intestinal perturbation by migratory helminths and move to distant tissues to influence the local reparative response. Using fate-mapping and methods to bypass the lung or intestinal phases of Nippostrongylus brasiliensis infection, we show that blood ILC2s comprise heterogeneous populations derived from distinct tissues that are dependent on alarmins matched to the receptor profile of the specific tissue ILC2s. Activation of local ILC2s by tissue-specific alarmins induced their proliferation, lymph node migration, and blood dissemination, thus systemically distributing type 2 cytokines. These studies uncover a possible mechanism by which local innate responses transition to systemic type 2 responses by extrusion of activated sentinel ILC2s from tissue into the circulation.

中文翻译：

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组织特异性途径挤出激活的 ILC2 来传播 2 型免疫

第 2 组先天淋巴细胞 (ILC2) 是在屏障部位突出的组织驻留细胞。尽管在血液中发现了前体，但成熟的 ILC2 可以在游走性蠕虫扰动小肠后进入循环，并移动到远处组织以影响局部修复反应。使用命运图谱和绕过巴西圆线虫感染的肺或肠阶段的方法，我们发现血液ILC2包含来自不同组织的异质群体，这些群体依赖于与特定组织ILC2的受体谱相匹配的警报素。组织特异性警报素激活局部 ILC2，诱导其增殖、淋巴结迁移和血液传播，从而全身分布 2 型细胞因子。这些研究揭示了一种可能的机制，通过将激活的哨兵 ILC2 从组织挤出到循环中，局部先天反应转变为全身 2 型反应。