Project description:Tissue-resident innate lymphoid cells (ILCs) help sustain barrier function and respond to local signals. ILCs are traditionally classified as ILC1, ILC2 or ILC3 on the basis of their expression of specific transcription factors and cytokines1. In the skin, disease-specific production of ILC3-associated cytokines interleukin (IL)-17 and IL-22 in response to IL-23 signalling contributes to dermal inflammation in psoriasis. However, it is not known whether this response is initiated by pre-committed ILCs or by cell-state transitions. Here we show that the induction of psoriasis in mice by IL-23 or imiquimod reconfigures a spectrum of skin ILCs, which converge on a pathogenic ILC3-like state. Tissue-resident ILCs were necessary and sufficient, in the absence of circulatory ILCs, to drive pathology. Single-cell RNA-sequencing (scRNA-seq) profiles of skin ILCs along a time course of psoriatic inflammation formed a dense transcriptional continuum—even at steady state—reflecting fluid ILC states, including a naive or quiescent-like state and an ILC2 effector state. Upon disease induction, the continuum shifted rapidly to span a mixed, ILC3-like subset also expressing cytokines characteristic of ILC2s, which we inferred as arising through multiple trajectories. We confirmed the transition potential of quiescent-like and ILC2 states using in vitro experiments, single-cell assay for transposase-accessible chromatin using sequencing (scATAC-seq) and in vivo fate mapping. Our results highlight the range and flexibility of skin ILC responses, suggesting that immune activities primed in healthy tissues dynamically adapt to provocations and, left unchecked, drive pathological remodelling.

2020-12-14 | GSE149622 | GEO

Transcription factor Bcl11b controls identity and function of mature innate lymphoid cells type II

Project description:Type-2 innate lymphoid cells (ILC2s) promote anti-helminth responses and contribute to allergies. Though Bcl11b has been previously considered a T-lineage identity transcription factor (TF) that restrains the innate-cell genetic programs, we report here that Bcl11b is highly expressed in mature ILC2s and acts upstream of the key ILC2 TFs Gfi1, Gata-3, and of IL-33 receptor IL1rl1 (T1ST2). Additionally, Bcl11b-/- ILC2s de-repressed Rorγt, Ahr and IL-23 receptor, normally expressed in type-3 ILCs (ILC3s). Consequently, Bcl11b-/- ILC2s lost ILC2 functions and gained ILC3 functions, expanding in response to the protease allergen papain, however producing IL-17 and IL-22, and not IL-5 and IL-13, causing lung neutrophilia rather than eosinophilia, and diminished mucus production. Our results broaden Bcl11b's role from a T-cell only TF, and establishes that Bcl11b sustains mature ILC2 genetic and functional programs and lineage fidelity through positive regulation of essential ILC2 TFs and negative regulation of pivotal ILC3 TFs. RNA-seq analysis on sorted ILC2s from the mLNs of Bcl11bF/F Cre-ERT2 and wildtype mice at steady state following tamoxifen mediated deletion of Bcl11b

2015-07-28 | E-GEOD-67437 | biostudies-arrayexpress

IL-6 effector function of group 2 innate lymphoid cells (ILC2) is NOD2 dependent.

Project description: Not available

| S-EPMC7611333 | biostudies-literature

IL-10-producing intestinal macrophages prevent excessive antibacterial innate immunity by limiting IL-23 synthesis.

Project description: Not available

| S-EPMC4428691 | biostudies-literature