Project description:This study was carried out to evaluate the changes that occur in the skin after the development of cutaneous leishmaniasis, aiming at a comprehensive understanding of immune pathways and biological functions activated in lesions caused by L. braziliensis.
Project description:This study was carried out to evaluate the changes that occur in the skin after the development of cutaneous leishmaniasis, aiming at a comprehensive understanding of immune pathways and biological functions activated in lesions caused by L. braziliensis. This analysis was conducted on 8 skin ulcers from patients infected with L. braziliensis. The patients selected for the gene expression analysis had recent L. braziliensis infection that had not yet been treated. 8 controls samples are skin biopsies from healthy donors (non-infected).
Project description:The host immune response plays a critical role not only in protection from human leishmaniasis, but also in promoting disease severity. Although candidate gene approaches in mouse models of leishmaniasis have been extremely informative, a global understanding of the immune pathways active in lesions from human patients is lacking. To address this issue, genome-wide transcriptional profiling of Leishmania braziliensis-infected cutaneous lesions and normal skin controls was carried out. A signature of the L. braziliensis skin lesion was defined that includes over 2,000 differentially regulated genes. Pathway-level analysis of this transcriptional response revealed key biological pathways, as well as specific genes, associated with cutaneous pathology, generating a testable 'metapathway' model of immune-driven lesion pathology, and providing new insights for treatment of human leishmaniasis. Thirty-five skin biopsies were analyzed, including 10 normal skin biopsies (2 from North America and 8 from non-endemic area in Brazil), and 25 skin lesion biopsies (8 early cutaneous lesions, 17 late cutaneous lesions) obtained from Leishmania brazilensis-infected patients presenting at the Corte de Pedra Health Post in Corte de Pedra, Bahia, Brazil.
Project description:Atopic dermatitis (AD) is a common pruritic dermatitis with macroscopically nonlesional skin that is often abnormal. Therefore, we used high-density oligonucleotide arrays to identify cutaneous gene transcription changes associated with early AD inflammation as potential disease control targets. Skin biopsy specimens analyzed included normal skin from five healthy nonatopic adults and both minimally lesional skin and nearby or contralateral nonlesional skin from six adult AD patients. Keywords: disease state analysis We used high-density oligonucleotide Affymetrix Human U133A GeneChip arrays to identify cutaneous gene transcription changes associated with early AD inflammation as potential disease control targets. Skin biopsy specimens analyzed included normal skin from five healthy nonatopic adults and both minimally lesional skin and nearby or contralateral nonlesional skin from six adult AD patients.
Project description:Under steady state conditions, the immune system is poised to sense and respond to the microbiota. As such, immunity to the microbiota, including T cell responses, is expected to precede any inflammatory trigger. How this pool of preformed microbiota-specific T cells contributes to tissue pathologies remains unclear. Here, using an experimental model of psoriasis, we show that recall responses to commensal skin fungi can significantly aggravate tissue inflammation. Enhanced pathology caused by fungi pre-exposure depends on Th17 responses and neutrophil extracellular traps and recapitulates features of the transcriptional landscape of human lesional psoriatic skin. Together, our results propose that recall responses directed to skin fungi can directly promote skin inflammation and that exploration of tissue inflammation should be assessed in the context of recall responses to the microbiota.
Project description:How early exposure to the microbiota impacts long-term host immunity remains poorly understood. Here we show that the development of mucosal-associated invariant T (MAIT) cells depends on early-life exposure to microbes that synthesize riboflavin, such as Enterobacteriaceae. This microbial imprinting relies on a specific temporal window, after which MAIT cell development is permanently impaired. In adults, MAIT cells are a dominant population of IL-17A-producing lymphocytes within the skin that can subsequently respond to skin commensals in an IL-1 and antigen-dependent manner. Consequently, local activation of cutaneous MAIT cells promotes wound healing and limits skin inflammation. Together, our work uncovers a privileged interaction between defined members of the microbiota and MAIT cells that sequentially controls both tissue-imprinting and subsequent response to injury and inflammation.
Project description:Olfactomedin-4 (OLFM4) is an olfactomedin-domain-containing glycoprotein which regulates cell adhesion, proliferation, gastrointestinal inflammation, innate immunity and cancer metastasis. In the present study investigated its role in skin regeneration and wound healing. We found that OLFM4 expression is transiently upregulated in the proliferative phase of cutaneous wound healing in humans as well as in mice. Moreover, a significant increase in OLFM4 expression was detected in the skin of lesional psoriasis, a chronic inflammatory disease characterized by keratinocyte hyperproliferation. In vitro experiments demonstrated that OLFM4 can selectively stimulate keratinocyte proliferation and increase both keratinocyte and fibroblast migration ability. Using proteotransciptomic pathway analysis we revealed that transcription factors POU5F1/OCT4 and ESR1 acted as hubs for OLFM4-dependent signalling in keratinocytes. In vivo experiments utilizing mouse splinted full-thickness cutaneous wound healing model showed that application of recombinant OLFM4 protein can significantly improve wound healing time. Taken together, our results suggest that OLFM4 is a transiently upregulated inflammatory signal that promotes wound healing by supporting the functions of both dermal and epidermal cell compartments.
Project description:As a vector-borne disease, leishmaniasis is caused by a parasitic protozoans of leishmania genus and transmitted by female Phlebotomine sandflies. Depending on the body location where immotile form of the parasite namely amastigote is proliferated, three main clinical forms as cutaneous, muco-cutaneous and visceral leishmaniases are defined. While manifestation of cutaneous leishmaniasis is skin lesions on the exposed part of the body, enlarged lymph nodes, spleen or liver along with fever, fatigue and weight loss are the symptoms of visceral leishmaniasis. The most dangerous form is visceral leishmaniasis since it may end up with fatalities if patients are not treated. The purpose of this study was to investigate the difference between the protein expression profiles of leishmania isolates obtained from visceral and cutaneous leishmaniasis patients. To compare two sample groups to each other genetically, L.infantum was chosen since it causes both visceral and cutaneous leishmaniasis. Additionally, another sample group as cutaneous leishmaniasis caused by L.tropica was included to make the comparison both intra- and interspecies level. For protein profiling, both gel-based and gel-free proteomic approaches were carried out. In brief, a total of 15 samples, 5 from each group, were separated on pI 3-10 2D-PAGE gel. Additionally, 9 of those 15 samples, 3 from each group, were analyzed according to qualitative shotgun proteomics method and differential proteins were determined by drawing venn diagram.