Project description:The family of innate lymphoid cells (ILC) comprises the well-described conventional cytotoxic natural killer cells (NK cells) that patrol lymphoid and non-lymphoid organs to discriminate and eliminate stressed cells (i.e. infected and tumor cells) as well as other ILC subsets that are mainly located in epithelial tissue. How a tumor influences the phenotype and function of those ILC populations at different stages of carcinogenesis is of growing interest. We performed functional and transcriptomic analyses of purified NKp46+ innate lymphoid cells (ILC) from skins, cutaneous lesions and lymph nodes of mice subjected to chemically-induced skin carcinogenesis. We showed that isolated papilloma-derived NKp46+ ILC showed the most divergent gene expression profile compared to their surrounding skin and tumor counterpart. our study indicates that NKp46+ ILC isolated at pre-cancerous stage were enriched in ILC1 subset with less cytotoxic potential than NKp46+ ILC from tumors. These findings revealed a so far unappreciated behavior of NKp46+ ILC at different stages of skin carcinogenesis.
Project description:Innate lymphoid cells (ILCs) have emerged as essential players in the skin-associated immune system in health and inflammatory skin diseases. Their low numbers and lack of specific markers hampered extensive characterization and consequently resulted in limited knowledge of their protein expression. Here, we combined flow cytometry and state-of-the-art proteomics to comprehensively describe the proteins constitutively expressed by ILC2 and ILC3 subsets derived from healthy human skin and peripheral blood. We quantified 6666 proteins from skin ILC and identified 608 differentially expressed proteins in the investigated subsets. In addition to the current analyses, highlighting new functions of ILC, the ILC proteomic libraries and the proteomes of the ILC2 and ILC3 subsets will serve as valuable resources for future analyses of ILC function and are available at http://skin.science.
Project description:Understanding how cellular function is imprinted during development requires the identification of factors controlling lineage specification and commitment, and the intermediate progenitors in which they act. Using population level and single cell approaches, we examine transcriptional and functional heterogeneity within early innate lymphoid cells (ILC) progenitors. We identify a developmental bifurcation toward dendritic cell fate that reveals the uncommitted state of early specified ILC progenitors. We subsequently characterize an ILC-commitment checkpoint controlled by the transcription factor TCF-1. The present study reveals unexpected heterogeneity within early innate progenitor populations, and characterizes lineage infidelity that accompanies early ILC specification prior to commitment.
Project description:Innate lymphoid cells (ILCs) are highly plastic immune cells that have been separated into 3 main subsets, characterized by distinct phenotypic and functional profiles. Using single cell approaches, heightened heterogeneity of mouse ILCs has been recently appreciated, imprinted by tissue signals that shape their transcriptome and epigenome. Intra-subset diversity has also been observed in human ILCs. However, combined transcriptomic and epigenetic analyses of single ILCs in humans are lacking. Here we show high transcriptional and epigenetic heterogeneity among human circulating ILCs in healthy individuals. We describe phenotypically distinct subclusters within main circulating ILC populations. We show diverse chromatin accessibility within main ILC subsets, compatible with differentially poised states. We validate the use of this healthy donor-based analysis as resource dataset to infer ILC changes occurring in disease conditions. Overall, our work provides new insights in the complex human ILC biology. We anticipate our work to be a starting point to facilitate hypothesis-driven studies in patients, without the need to perform single cell OMICs using precious patients’ material
Project description:Innate lymphoid cells (ILCs) are highly plastic immune cells that have been separated into 3 main subsets, characterized by distinct phenotypic and functional profiles. Using single cell approaches, heightened heterogeneity of mouse ILCs has been recently appreciated, imprinted by tissue signals that shape their transcriptome and epigenome. Intra-subset diversity has also been observed in human ILCs. However, combined transcriptomic and epigenetic analyses of single ILCs in humans are lacking. Here we show high transcriptional and epigenetic heterogeneity among human circulating ILCs in healthy individuals. We describe phenotypically distinct subclusters within main circulating ILC populations. We show diverse chromatin accessibility within main ILC subsets, compatible with differentially poised states. We validate the use of this healthy donor-based analysis as resource dataset to infer ILC changes occurring in disease conditions. Overall, our work provides new insights in the complex human ILC biology. We anticipate our work to be a starting point to facilitate hypothesis-driven studies in patients, without the need to perform single cell OMICs using precious patients’ material
Project description:Innate lymphoid cells (ILC) represent innate versions of T helper and cytotoxic T cells that differentiate from committed ILC precursors (ILCP). Still, how ILCP relate to mature tissue-resident ILCs remains unclear. We observed that a population of CD117+ ILC from peripheral blood (PB) of healthy donors does not represent any conical ILC subset, but expressed marker (CD117) commonly expressed by hemato-lymphoid progenitors. We therefore hypothesized PB CD117+ ILC might include uncommitted lymphoid precursors. In order to further understand the identity of PB CD117+ ILC, we profiled the transcriptome of highly purified circulating CD117+ ILC compared to CD34+ HSC, the latter representing immature hematopoietic progenitors with multi-lineage potential. Clear differences in gene expression profiles emerged, with a large cluster of 1540 genes expressed at substantially higher levels in CD117+ ILC. In contrast, CD34+ HSC cells highly expressed genes involved in the broad development of diverse hematopoietic lineages. Compared to HSC, CD117+ ILC express high levels of TF that have been shown to be essential for murine ILC development and we did not detect transcripts characteristic of T and B cells development. Transcriptomic analysis suggested that CD117+ ILC represent lymphoid-biased progenitors carrying a TF expression profile resembling a multi-potent ILC precursor (ILCP).
Project description:Type 2 inflammation contributes to the pathology of skin diseases such as atopic dermatitis (AD) and urticaria. We previously found that AD-like inflammation induced by calcipotriol in mice is critically mediated by group 2 innate lymphoid cells (ILC2s), while T cells and B cells are dispensable given development of robust AD-like disease in RAG knockout mice. Indeed, we found that in RAG knockout mice AD-like inflammation was worse, with a proportion of ILC2s displaying increased markers of activation. The goal of this study was to characterize transcriptional and epigenomic changes in ILC populations with a history, or not, of expressing RAG1 in the setting of AD-like skin inflammation.