Project description:Background: Atopic dermatitis (AD) is a common inflammatory skin disease with a TH2 immune polarity and is often colonized with Staphylococcus aureus. Despite recent advances in understanding Staphylococcus species infection and the impact of polar TH cytokines on the skin, the interactions between these factors in AD pathology are poorly understood. Methods: AD-related key immune biomarkers were measured by quantitative real-time PCR in human keratinocytes exposed heat-killed S. epidermidis or S. aureus with/without polar T-cell derived cytokines such as IFN-γ (TH1), IL-4/IL-13 (TH2), and IL-22 (TH22). Further analysis was performed by RNA-sequencing to define broader responses in both Staphylococcus species and polar cytokines. The similarity of gene expression patterns in AD skin lesions and stimulated keratinocytes was evaluated by gene-set variation analysis (GSVA). Results: Gene expression analysis exhibited distinct immune responses in keratinocytes depending on individual bacterial or polar cytokine exposure. Besides, numerous genes were synergistically upregulated by the combination exposure of bacteria and polar TH cytokines. Moreover, GSVA revealed that combined exposure of S. aureus and IL-4 + IL-13 exhibited significantly higher correlations with a genomic signature of AD skin lesions than their single exposure or combinations of other polar TH cytokines. Conclusions: Our findings provide novel insights into AD-related transcriptional activation and illustrate a potentially novel pathogenic function of S. aureus and IL-4/IL-13 interactions in AD.
Project description:Atopic dermatitis (AD) is a common, chronic inflammatory skin disease that seriously affects quality of life and is a major cause of skin diseases worldwide. Staphylococcus aureus (S. aureus) colonization on the skin plays an important role in the pathogenesis of AD; however, the mechanism of how it modulates skin immunity to exacerbate AD remains unclear. MicroRNAs are short non-coding RNAs that act as post-transcriptional regulators of genes. They are involved in the pathogenesis of various inflammatory skin diseases. In this study, we established miRNA expression profiles for keratinocytes stimulated with heat-killed S. aureus (HKSA). We found that miR-939 was highly upregulated in HKSA-stimulated keratinocytes and AD lesions. In vitro studies revealed that miR-939 increased the expression of matrix metalloproteinase genes, including MMP1, MMP3, and MMP9, as well as the cell adhesion molecule ICAM1 in human primary keratinocytes. In vivo studies indicated that miR-939 increased the expression of matrix metalloproteinases to promote the colonization of S. aureus and exacerbated S. aureus-induced AD-like skin inflammation. Taken together, these findings suggest that miR-939 is an important regulator of skin inflammation in AD.
Project description:MS/MS spectra were collected from Staphylococcus aureus bacteria isolated from patients with Atopic Dermatitis from lesional and nonlesional sites. Extractions were performed using 50/50 vol/vol ethyl acetate/methanol and extracts were loaded on SPE cartridges (Oasis HLB, Hydrophilic-Lipophilic-Balance, 30 mg with particle sizes of 30 um) before LC-MS/MS analysis.
Project description:Expressed on epidermal Langerhans cells, CD1a presents a range of self-lipid antigens found within the skin. However, the extent to which CD1a presents microbial ligands from skin bacteria is unclear. Here, we identified CD1a-dependent T cell responses to phosphatidylglycerol (PG), a ubiquitous bacterial membrane phospholipid, as well as to lysyl phosphatidylglycerol (lysylPG), a modified PG, present in the many gram positive bacteria, and highly abundant in Staphylococcus aureus. Specifically, PG and lysylPG together constitute the vast majority of the structural membrane lipids in Staphylococcus aureus. The crystal structure of the CD1a-lysylPG complex showed that the acyl chains were buried within the A′- and F′-pockets of CD1a, while the lysine-modified phosphoglycerol headgroup protruded from the F′-portal and was available for T cell receptor contact. Using lysylPG-loaded CD1a tetramers, we identified T cells in peripheral blood and in skin that respond to this lipid in a dose dependent manner. Tetramer+ CD4+ T cell lines secreted Th2 cytokines in response to lysylPG as well as to co-cultures of CD1a+ dendritic cells and Staphylococcus aureus. The expansion of CD4+ CD1a-lysylPG tetramer+ T cells in atopic dermatitis patients, indicates a response to a lipid made by bacteria associated with atopic dermatitis, and provide a link supporting involvement of PG-based lipid-specific T cells in the pathogenesis of dermatitis.
Project description:Staphylococcus aureus is one of the most important pathogens in humans and animals, multiply resistant strains are increasingly widespread, new agents are needed for the treatment of S. aureus. Rhein, a natural plant product, has potential antimicrobial activity against Staphylococcus aureus. We employed Affymetrix Staphylococcus aureus GeneChipsTM arrays to investigate the global transcriptional profiling of Staphylococcus aureus ATCC25923 treated with rhein. Results provided insight into mechanisms involved in rhein - Staphylococcus aureus interactions. Keywords: rhein response Staphylococcus aureus cells were exposed for 45 minutes to rhein at concentration of 8 µg/ml (1/2à MIC), 6 samples including 3 control samples are analyzed.
Project description:To determine if significant genomic changes are associated with the development of vancomycin intermediate Staphylococcus aureus, genomic DNA microarrays were performed to compare the initial vancomycin susceptible Staphylococcus aureus (VSSA) and a related vancomycin intermediate Staphylococcus aureus (VISA) isolate from five unique patients (five isolate pairs). Keywords: comparative genomic hybridization
Project description:Staphylococcus aureus (S. aureus) is an important human and animal pathogen, multiply resistant strains are increasingly widespread, new agents are needed for the treatment of S. aureus. magnolol has potent antimicrobial activity against S. aureus. We employed Affymetrix Staphylococcus aureus GeneChipsTM arrays to investigate the global transcriptional profiling of Staphylococcus aureus ATCC25923 treated with magnolol. Keywords: gene expression array-based, count Staphylococcus aureus cells were exposed for a certain time to magnolol at a certain concentration, 6 samples including 3 control samples are analyzed.
Project description:Staphylococcus aureus (S. aureus) is an important human and animal pathogen, multiply resistant strains are increasingly widespread, new agents are needed for the treatment of S. aureus. Cryptotanshinone, a natural plant product, has potent antimicrobial activity against S. aureus. We employed Affymetrix Staphylococcus aureus GeneChipsTM arrays to investigate the global transcriptional profiling of Staphylococcus aureus ATCC25923 treated with cryptotanshinone. Keywords: gene expression array-based, count Staphylococcus aureus cells were exposed for 45 minutes to cryptotanshinone at concentration of 2 µg/ml (1/2� MIC), 6 samples including 3 control samples are analyzed.