Dataset Information

Expression data from blood of healthy controls and ns vitiligo patients

ABSTRACT: Vitiligo Blood Transcriptomics Provides New Insights into Disease Mechanisms and Identifies Potential Novel Therapeutic Targets Abstract Background: Significant gaps remain regarding the pathomechanisms underlying the autoimmune response in vitiligo (VL), where the loss of self-tolerance leads to the targeted killing of melanocytes. Specifically, there is incomplete information regarding alterations in the systemic environment that are relevant to the disease state. Methods: We undertook a genome-wide profiling approach to examine gene expression in the peripheral blood of VL patients and healthy controls in the context of our previously published VL-skin gene expression profile. We used several in silico bioinformatics-based analyses to provide new insights into disease mechanisms and suggest novel targets for future therapy. Results: Unsupervised clustering methods of the VL-blood dataset demonstrate a “disease-state”-specific set of co-expressed genes. Ontology enrichment analysis of 99 differentially expressed genes (DEGs) uncovers a down-regulated immune/inflammatory response, B-Cell antigen receptor (BCR) pathways, apoptosis and catabolic processes in VL-blood. There is evidence for both type I and II interferon (IFN) playing a role in VL pathogenesis. We used interactome analysis to identify several key blood associated transcriptional factors (TFs) from within (STAT1, STAT6 and NF-kB), as well as “hidden” (CREB1, MYC, IRF4, IRF1, and TP53) from the dataset that potentially affect disease pathogenesis. The TFs overlap with our reported lesional-skin transcriptional circuitry, underscoring their potential importance to the disease. We also identify a shared VL-blood and -skin transcriptional “hot spot” that maps to chromosome 6, and includes three VL-blood dysregulated genes (PSMB8, PSMB9 and TAP1) described as potential VL-associated genetic susceptibility loci. Finally, we provide bioinformatics-based support for prioritizing dysregulated genes in VL-blood or skin as potential therapeutic targets. Conclusions: We examined the VL-blood transcriptome in context with our (previously published) VL-skin transcriptional profile to address a major gap in knowledge regarding the systemic changes underlying skin-specific manifestation of vitiligo. Several transcriptional “hot spots” observed in both environments offer prioritized targets for identifying disease risk genes. Finally, within the transcriptional framework of VL, we identify five novel molecules (STAT1, PRKCD, PTPN6, MYC and FGFR2) that lend themselves to being targeted by drugs for future potential VL-therapy. We used microarrays to detail the global programme of gene expression underlying the disease state in vitiligo and established differentially expressed genes by comparing gene expression values from diseased patients to healthy controls.

ORGANISM(S): Homo sapiens

PROVIDER: GSE90880 | GEO | 2017/01/31

SECONDARY ACCESSION(S): PRJNA356272

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Post Kala Azar Dermal Leishmaniasis (PKDL) is a non-fatal dermal sequel of Visceral Leishmaniasis (VL), caused by protozoan parasite Leishmania donovani. On the global scenario, PKDL in mainly restricted to distinct zones of South Asia (India, Nepal and Bangladesh) and East Africa, mainly Sudan. In India, the most prominent fatal form of leishmaniasis present is VL, affecting entirely the eastern region of the country. The clinical presentation of VL and PKDL differ substantially; where VL patients suffer from sustained fever, hepatospleenomegaly, weight loss and anemia, PKDL patients manifest dermal lesions in the form of macular, nodular and polymorphic. Although, compared to VL, the mortality rate of PKDL is significantly lower, yet it is observed as a stigmatizing disease that brings a substantial socioeconomic burden, further intensified by a hesitancy of patients, to obtain treatment, or due to noncompliance. Lesions, especially the polymorphic forms, are parasite-rich, concluding that PKDL plays a crucial role in the anthroponotic transmission of VL. PKDL patients with Macular lesions, having comparatively lower parasitic load, and thus lacks detection sensitivity with standard techniques like rK39 (73% sensitivity), Leishmanin skin test (54% sensitivity) and Histopathological studies with patients’ skin biopsy sample (7-33% sensitivity) and is often misdiagnosed as Vitiligo cases. In order to completely eliminate Kala-azar in Southeast Asia, proper identification of various routes of the disease is essential, which could efficiently distinguish between cured PKDL and active PKDL as well as active PKDL from other cross disease like Leprosy and Vitiligo. Till now very less work has been done towards biomarker identification for PKDL from patients’ plasma. Most of the methods for disease identification are based on highly invasive tissue biopsy followed by PCR/qPCR. Recently investigations from our group have demonstrated the presence of novel glycoproteins in the circulating immune complexes (CICs) from serum, as biomarkers for early identification of PKDL patients. An Immune complex (IC), sometimes called an antigen-antibody complex, is a molecule formed from the integral binding of an antibody to a soluble antigen. After an antigen-antibody reaction, the immune complexes can be subject to any number of responses, including complement deposition, opsonisation, phagocytosis, or processing by proteases. Accumulation of ICs leads to a broad spectrum of pro-inflammatory effects, including activation of the complement cascade and induction of cytokine secretion. These complexes may also be deposited in tissues and vessel walls, leading to inflammation, tissue damage and, ultimately, disease manifestations. Immune complexes also affect disease progression and outcome in various disorders through the induction of pro-inflammatory or anti-inflammatory cytokines. In the present study we hypothesize that the CICs’ proteome is altered among PKDL patients with different dermal manifestations (Macular and Polymorphic) as compared to Cured individuals (CR) and Healthy controls (HI). The aim of this current study is to identify differentially expressed CIC proteomic profile among different forms PKDL patients as compared to HI. The differential protein expression of specific unique peptide fragments, representing specific proteins, could be used as diagnostic biomarkers in early detection of both Macular and Polymorphic PKDL cases. In this prospective study, we included PKDL patients with Macular and/or Polymorphic lesion, Cured individuals and HI. Among the enrolled patients, blood samples were collected from 20 primarily confirmed PKDL patients with Macular lesions, 20 primarily confirmed PKDL patients with Polymorphic lesions, 12 Cured individuals previously suffering from PKDL and 12 Healthy individuals; collected during the period of 2015-2016, stored at -80°C. Next the CICs were purified from PKDL patients’ plasma and LC MS/MS analysis was performed using Q-ExactivePlusOrbitrap mass spectrometer. This work for the first time revealed the differential CICs proteome profile among different forms of PKDL patients as compared to their Cured and Healthy counterparts.

Project description:Immunotherapy with checkpoint inhibitors is an efficient treatment for metastatic melanoma. Development of vitiligo upon immunotherapy represents a specific immune-related adverse event (irAE) diagnosed in 15% of patients and associated with a positive clinical response. Therefore, a detailed characterization of immune cells during vitiligo onset in melanoma patients would give insight into the immune mechanisms mediating both this irAE and the anti-tumor response. To better understand these aspects, we analyzed T cell subsets from peripheral blood of metastatic melanoma patients undergoing treatment with anti-programmed cell death protein (PD)-1 antibodies. Stratification of patients for developing or not developing vitiligo during therapy revealed an association between blood reduction of mucosal associated invariant T (MAIT), T helper (h) 17, natural killer (NK) CD56bright, and T regulatory (T-reg) cells and vitiligo onset. To deeply characterize the tumoral T cell response concomitant to vitiligo onset, we analyzed T cell content in skin biopsies collected from melanoma patients who developed vitiligo. Consistently with the observed blood reduction of Th17 cells in melanoma patients developing vitiligo during immunotherapy, we found an enrichment of Th17 cells in the vitiligo skin biopsy, suggesting a migration of Th17 cells from the blood into the autoimmune lesion. To further characterize T cells in vitiligo skin lesion of melanoma patients, we sequenced T cell receptor (TCR) of cells derived from biopsies of vitiligo and primary melanoma of the same patient. Interestingly, we found different TCR sequences between vitiligo and primary melanoma lesions, except for a few cases showing the same TCR sequences. In contrast, shared TCR sequences were identified between vitiligo and metastatic tissues of the same patient. These data indicate that T cell response against normal melanocytes, which is involved in vitiligo onset, is not mainly mediated by the reactivation of specific T cell clones infiltrating primary melanoma but may be elicited by T cell clones targeting metastatic tissues. Altogether, our data indicate that anti-PD-1 therapy induces a de novo immune response, composed of different T cell subtypes, whose role may be related to the development of vitiligo and the response against metastatic tumor.

Dataset Information

Expression data from blood of healthy controls and ns vitiligo patients

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure