Project description:The goal of the study was to sequence mRNA from tuft cells (identified as CD11c-;CD45-;EpCAM+;IL-25+ using Flare25 reporter mice) in C57BL/6 and Aire-/- mice. The data were used to investigate thymic tuft cell heterogeneity with and without AIRE protein expression.
Project description:The goal of the study was to sequence mRNA from tuft cells (identified as CD45-;EpCAM+;IL-25+ using Flare25 reporter mice) in the epithelia of thymus and small intestine. As a control, non-tuft epithelial cells (CD45-;EpCAM+;IL-25-) were also isolated. The data were used to compare tuft cell markers between the small intestine and thymus.
Project description:The goal of the study was to sequence mRNA from tuft cells (identified as CD45-;EpCAM+;IL-25+ using Flare25 reporter mice) in the epithelia of 5 different murine tissues: trachea, thymus, colon, gall baldder, small intestine. As a control, non-tuft epithelial cells (CD45-;EpCAM+;IL-25-) were also isolated. The data were used to identify differentially expressed genes across tuft cells from different tissues and to define a transcriptional tuft cell "signature" that is common to all tissues analyzed but absent in the non-tuft epithelial cells.
Project description:While the lung bears significant regenerative capacity, severe viral pneumonia can chronically impair lung function by triggering dysplastic remodeling. The connection between these enduring changes and chronic disease remains poorly understood. We recently described the emergence of tuft cells within Krt5+ dysplastic regions after influenza injury. Using bulk and single cell transcriptomics, we characterized and delineated multiple distinct tuft cell populations that arise following influenza clearance. Distinct from intestinal tuft cells which rely on Type 2 immune signals for their expansion, neither IL-25 nor IL-4Ra signaling are required to drive tuft cell development in dysplastic/injured lungs. Furthermore, tuft cells were also observed upon bleomycin injury, suggesting that their development may be a general response to severe lung injury. While intestinal tuft cells promote growth and differentiation of surrounding epithelial cells, in the lungs of tuft cell deficient mice, Krt5+ dysplasia still occurs, goblet cell production is unchanged, and there remains no appreciable contribution of Krt5+ cells into more regionally appropriate alveolar Type 2 cells. Together, these findings highlight unexpected differences in signals necessary for lung tuft cell amplification and establish a framework for future elucidation of tuft cell functions in pulmonary health and disease.
Project description:T cell development and selection is orchestrated in the thymus by a specialized niche of diverse stromal populations. By transcriptional single cell sorting, we de novo characterize the entire stromal compartment of the thymus. We identified dozens of cell states within the thymic stroma, with thymic epithelial cells (TEC) showing the highest degree of heterogeneity. Our analysis highlights four major medullary TEC (mTEC I-IV) populations, with distinct molecular functions, epigenetic landscapes and lineage regulators. Specifically, mTEC-IV constitutes a new and highly divergent TEC lineage with molecular characteristics of the gut chemosensory epithelial tuft cells. Mice deficient of Pou2f3, a tuft cells master regulator, resulted in complete and specific depletion of mTEC-IV, without affecting other TEC populations. Overall, our study comprehensively defines all stroma cells in the thymus and identifies a new TEC lineage associated with chemosensory properties that may potentially link the adaptive immune system to environmental and neurological signals.
Project description:T cell development and selection is orchestrated in the thymus by a specialized niche of diverse stromal populations. By transcriptional single cell sorting, we de novo characterize the entire stromal compartment of the thymus. We identified dozens of cell states within the thymic stroma, with thymic epithelial cells (TEC) showing the highest degree of heterogeneity. Our analysis highlights four major medullary TEC (mTEC I-IV) populations, with distinct molecular functions, epigenetic landscapes and lineage regulators. Specifically, mTEC-IV constitutes a new and highly divergent TEC lineage with molecular characteristics of the gut chemosensory epithelial tuft cells. Mice deficient of Pou2f3, a tuft cells master regulator, resulted in complete and specific depletion of mTEC-IV, without affecting other TEC populations. Overall, our study comprehensively defines all stroma cells in the thymus and identifies a new TEC lineage associated with chemosensory properties that may potentially link the adaptive immune system to environmental and neurological signals.
Project description:T cell development and selection is orchestrated in the thymus by a specialized niche of diverse stromal populations. By transcriptional single cell sorting, we de novo characterize the entire stromal compartment of the thymus. We identified dozens of cell states within the thymic stroma, with thymic epithelial cells (TEC) showing the highest degree of heterogeneity. Our analysis highlights four major medullary TEC (mTEC I-IV) populations, with distinct molecular functions, epigenetic landscapes and lineage regulators. Specifically, mTEC-IV constitutes a new and highly divergent TEC lineage with molecular characteristics of the gut chemosensory epithelial tuft cells. Mice deficient of Pou2f3, a tuft cells master regulator, resulted in complete and specific depletion of mTEC-IV, without affecting other TEC populations. Overall, our study comprehensively defines all stroma cells in the thymus and identifies a new TEC lineage associated with chemosensory properties that may potentially link the adaptive immune system to environmental and neurological signals.
Project description:The zinc-finger transcription factor Ikaros (Ikzf1) modulates key gene expression programs important for hematopoietic development, and coding mutations in IKZF1 are found in patients with immunodeficiency, leukemia, and autoimmunity. While Ikaros has a well-established function in hematopoiesis, its role in other cell types is less well defined. Here, we uncover new functions for Ikaros in thymic epithelial lineage development and show that Ikzf1 expression in medullary thymic epithelial cells (mTECs) is required for both Autoimmune Regulator positive (Aire+) mTEC development and tissue-specific antigen (TSA) gene expression. Accordingly, TEC-specific deletion of Ikzf1 in mice results in a profound decrease in Aire+ mTECs, a global loss of TSA gene expression, and the development of autoimmunity. Moreover, Ikaros shapes thymic mimetic cell diversity and its deletion results in a dramatic expansion of thymic tuft cells and muscle-like mTECs and a loss of other Aire-dependent mimetic populations. Single-cell analysis reveals Ikaros modulates core transcriptional programs in TECs that correlate with the observed cellular changes. Our findings highlight a previously undescribed role for Ikaros in regulating epithelial lineage development and function, and suggest that failed thymic central tolerance could contribute to the autoimmunity seen in humans with IKZF1 mutations.