Project description:Langerhans cells (LC) coordinate immune homeostasis at the human epidermis, proficent in initiating tolerogenic immune responses. To investigate the transcriptomic mediators of human LC tolerogenic immune responses, we performed single cell RNA-sequencing of steady state LC extracted via Liberase TM digestion and migratory LCs extracted from epidermal sheets.
Project description:Langerhans cells (LC) coordinate immune homeostasis at the human epidermis, proficent in initiating immunogenic and tolerogenic immune responses. To investigate the transcriptomic mediators of human LC immunogenic vs tolerogenic immune responses, we performed single cell RNA-sequencing of migratory LCs extracted from epidermal sheets stimulated with or without TNF.
Project description:Langerhans cells (LCs) in the epidermis promote immune homeostasis, efficiently activating tolerogenic and immunogenic T cell responses. To understand genomic programming in human Langerhans cells we performed whole transcriptome (bulk RNA-seq and single cell RNA-seq) profiling and analysis of H3K4Me3 and H3K27Ac histone modifications across LC genome in primary human cells from 6 independent donors. Primary LCs were either unstimulated and stimulated with TNF-alpha. Additionally we performed a CRISPR editing experiment for IRF4
Project description:Atopic dermatitis (AD) is characterized by dysregulated T cell immunity and skin microbiome dysbiosis with predominance of Staphylococcus aureus (S. aureus). Emerging evidence suggests a role for S. aureus in exacerbating AD skin inflammation. Interestingly, specific glycosylation of S. aureus cell wall structures amplifies skin inflammation through interaction with Langerhans cells (LCs). However, the role of LCs in AD remains poorly characterized. Here, we performed single cell RNA-sequencing of primary epidermal LCs and dermal T cells isolated from skin biopsies of AD patients and healthy controls, alongside specific glycoanalysis of S. aureus strains isolated from the AD lesions. Our findings reveal four LC subpopulations, including two steady-state clusters (LC1 and LC1H) and two pro-inflammatory/matured subsets (LC2 and migratory LCs). The latter two subsets were enriched in AD skin. AD LCs showed enhanced expression of C-type lectin receptors, the high-affinity IgE receptor (FcεR1), and activation of prostaglandin and leukotrienes biosynthesis pathways, as well as upregulated transcriptional signatures related to T cell activation pathways and increased expression of CCL17 (specifically LC2) compared to healthy LCs. Correspondingly, T helper 2 and regulatory T cell populations were increased in AD lesions. Our study provides proof-of-concept for an active role of LCs in connecting the S. aureus-T cell axis in the AD inflammatory cycle.