Alpha/beta/gamma/delta T cells play a vital role in fetal human skin development and immunity
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ABSTRACT: T cells in adult human skin play a pivotal role in the defense against pathogens and tumors. While T cells can also be found in fetal human skin, little is known about their phenotype and function. Using single cell analyses, here we identify an unconventional naive T cell population expressing both alpha/beta and gamma/delta T cell receptors (TCRs) that was markedly enriched within early fetal skin and intestine but was untraceable in other fetal organs and peripheral blood. TCR sequencing data revealed that double-positive (DP) T cells displayed marginal or no overlap of CDR3 sequences with single-positive alpha/beta T cells. Gene signature, cytokine profile and in silico receptor-ligand interaction studies indicated that DP T cells contribute to skin development early in life. Finally, DP T cells were phosphoantigen-responsive suggesting that these cells participate in the protection of the fetus against pathogens in case of intrauterine infections. Together, our analyses unveil a unique and hitherto unrecognized cutaneous T cell type within the native skin microenvironment and point to fundamental differences in the adaptive immune surveillance of developing and adult human skin.
Project description:Much is still unknown about the molecular regulatory networks which govern the dermal papilla’s (DP) ability to induce hair follicle regeneration, a capacity which gradually decreases with age. DP and dermal sheath cup (DSC) cells from mature, anagen phase, hair follicles were manually microdissected from fresh frozen sections of 16-18 week human fetal scalp and 30-60 year old adult male scalp. Interfollicular dermal (IFD) fibroblasts were harvested for comparison. RNA-seq libraries from each cell population were prepared with Nugen’s Ovation RNA-Seq and Ultralow Library systems, sequenced to approximately 100 million total reads. A set of 121 genes was identified as significantly upregulated in fetal DP cells, as compared to both fetal DSC and IFD populations. Wnt/β-catenin, Shh, FGF, BMP, and Notch signaling pathways were significantly enriched among those genes differentially expressed between fetal and adult DP cells. Among them, Spondin-1, a Wnt agonist, was chosen for verification and can rescue hair follicle regeneration in skin reconstitution assays using cells from adult mice. Additionally, twenty-nine transcription factors were significantly upregulated in fetal DP compared to adult DP cells. Of those, seven transcription factor binding motifs were significantly enriched in the candidate promoter regions of differentially expressed genes between fetal and adult DP cells, suggesting a combinatorial regulatory role in the fetal DP phenotype. Further investigation into these regulators is warranted to determine if these proteins and/or associated pathways plays a role in the maintenance or modulation of DP cells to induce hair regeneration.
Project description:Local administration of IFN-α-producing proliferating myeloid cells (IFN-α-iPSC-pMCs) inhibited the tumor growth not only at the treatment site but also at the distant site (left). T cell receptor (TCR)-β chain repertoire and complementarity determining region 3 (CDR3) gene sequence analyses of tumor-infiltrating lymphocytes (TILs) showed marked enrichment of T cells with identical TCR-β chains in bilateral tumor tissues.
Project description:Using Tbx18Cre to target embryonic DP precursors, we ablate Sox2 early and efficiently, resulting in diminished hair shaft outgrowth. Transcriptional profiling of Sox2 null DPs reveals increased Bmp6 and decreased Bmp inhibitor Sostdc1, a direct Sox2 transcriptional target. FACS sort to isolate Sox2GFP/Integrin-alpha 9 double-positive DP cells from Sox2 HET and cKO P5 skin for transcriptional profiling
Project description:The aim of this study was to quantify the impact of NOD genetic vatiation on the transcriptional programs induced by the alpha beta-TCR at the DN to DP transition in the BDC2.5 TCR Tg model
Project description:Type I interferon (IFN-α/β) is the first line of defense against viral infection. Mouse models have been pivotal to our understanding of IFN-α/β in immunity, although validation of these findings in humans has not been possible. We investigated a previously healthy child with fatal susceptibility to the live-attenuated measles, mumps and rubella (MMR) vaccine. By targeted resequencing we identified a homozygous mutation in the high-affinity interferon-α/β receptor (IFNAR2), which rendered cells unresponsive to IFN-α/β and led to unrestricted replication of IFN-attenuated viruses. Reconstitution of patient cells with wild-type IFNAR2 restored IFN-α/β responsiveness and viral resistance. Despite the failure to control vaccine viruses, the patient showed no evidence of susceptibility to conventional viral pathogens in vivo and adaptive immunity appeared normal. Human IFNAR2 deficiency therefore reveals an essential role for IFN-α/β in resistance to attenuated viruses, but significant and unexpected redundancy overall in antiviral immunity. Total RNA isolated from IFNAR2-deficient patient (in triplicate) and control (three independent control lines) fibroblasts treated with IFNalpha, IFNbeta or IFNgamma (1000 IU/mL) for 10h
Project description:The aim of this study was to quantify the impact of NOD genetic vatiation on the transcriptional programs induced by the alpha beta-TCR at the DN to DP transition in the BDC2.5 TCR Tg model CD4 and CD8-complement mediated depletion followed by FACS Experiment type: BDC2.5 TCR Tg or polyclonal B6g7 versus NOD
Project description:In CSF bulk RNA sequence, patients with MS (pwMS) exhibited higher T cell receprot (TCR) clonality and specificity to EBV lytic proteins compared to controls. TCRs from pwMS showed greater clustering coefficient (i.e. TCR similarity) in complementarity-determining regions 3 (CDR3), particularly those predicted to target EBV antigens. Importantly, TCR clustering coefficient was associated with the expression of cytotoxic CD8 module genes in WGCNA, such as CD8A, GZMH, GZMK, and NKG7 and with interferon signaling module. scRNA-seq revealed a subpopulation of GZMK+GZMH+ double positive (DP) CD8 T cells expressing genes related to identified cytotoxicity and interferon signaling modules. These DP CD8 T cells had significantly higher predicted specificity for EBV proteins than other CD8 cells.
Project description:Vγ9Vδ2 T cells play an important role in the development and progression of psoriasis vulgaris (PV), but how they promote skin inflammation and the molecular mechanisms underlying Vγ9Vδ2 T cell dysfunction are poorly understood. Here, we show that circulating Vγ9Vδ2 T cells are decreased and exhibit enhanced proliferation and increased production of IFN-γ and TNF-α in PV patients. Monocytes from PV patients express higher levels of the phosphoantigen sensor butyrophilin 3A1 (BTN3A1) than monocytes from healthy controls. Blockade of BTN3A1 suppresses Vγ9Vδ2 T cell activation and abolishes the difference in Vγ9Vδ2 T cell activation between PV patients and healthy controls. The CD14+ cells in PV skin lesions highly express BTN3A1 and juxtapose to Vδ2 T cells. In addition, IFN-γ induces the up-regulation of BTN3A1 on monocytes. Collectively, our results demonstrate a crucial role of BTN3A1 on monocytes in regulating Vγ9Vδ2 T cell activation and highlight BTN3A1 as a potential therapeutic target for psoriasis.