ILC3-derived acetylcholine promotes protease-driven allergic lung pathology

[...]in CD45+CD3–Lin– cells, in addition to increased levels of IL-5 and IL-13, a raised IL-17 level was detected in papain-challenged mice when compared with the levels in saline-treated controls (Fig 1, C). [...]anti-CD3 depletion of T cells did not protect against and in fact promoted papain-driven pathology (see Fig E2 in this article's Online Repository at www.jacionline.org). Total BALF immune cell infiltration was also reduced for all immune cell populations (Fig 1, E). [...]detection of both IL-13 and IL-17A, as well as IL-22, was reduced in Rorc–/– mice (Fig 1, E). Detection of cytokines in lung homogenates identified reduced IL-13 and IL-17A levels as well as reduced IL-22 levels, in RoRγtCreChATloxp mice as compared with in the controls (Fig 2, B). [...]disruption of ChAT in RoRγt+ cells was sufficient to recapitulate the reduced pathology seen in papain-challenged Rorc–/– mice (Fig 1). Papain challenge did not induce elevated CD4+ T-cell IL-17 levels irrespective of raised RoRγt+CD4+ T-cell numbers. [...]in the absence of T cells, papain-induced lung inflammation was maintained but abrogated when IL-23 or RoRγt function was disrupted.