A GWAS for cutaneous leishmaniasis in Brazil
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PROVIDER: EGAS00001004596 | EGA |
REPOSITORIES: EGA
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Project description:Among the most central questions in Leishmania research is why some species remain in the skin dermis at the site of infection by the sand fly vector whereas other species migrate to visceral organs where they cause fatal visceral leishmaniasis. Although L. donovani is the species typically responsible for visceral leishmaniasis, an atypical L. donovani strain is the etiologic agent for cutaneous leishmaniasis in Sri Lanka. To identify molecular determinants for visceral disease, we have analysed the phenotype and genotype of two L. donovani clinical isolates from Sri Lanka where one isolate was derived from a cutaneous leishmaniasis patient (CL) and the other from a visceral leishmaniasis patient (VL). These isolates cause dramatically different pathology when introduced into mice; notably the CL isolate has lost the ability to survive in visceral organs while the VL isolate was highly virulent in visceral organs of BALB/c mice. Whole genome sequencing of the CL and VL isolates revealed that these genomes were very similar as there were no gene deletions and few individual gene amplifications. Indels resulting in frame shifts and loss/gain of stop codons resulted in 13 distinct pseudogenes present in each of the CL and VL isolates. There were 154 non-synonymous SNPs specific to the CL isolate and 193 non-synonymous SNPs specific to the VL isolate. Genome wide gene expression analysis revealed several transcript level differences, including the A2 virulence gene resulting in higher expression of A2 proteins in the VL isolate than in the CL isolate. Genotypic variations relevant to pathology and tropism in Leishmania can be interrogated by reverse genetics. Experimentally increasing A2 expression in the CL isolate through gene transfer significantly increased itM-bM-^@M-^Ys ability to survive in the spleen of BALB/c mice and conversely, down-regulating A2 expression in the VL isolate abrogated attenuated its survival in BALB/c mice. These observations reveal that there are relatively few genetic differences between the CL and VL isolates apart from the A2 genes, but collectively these have profound effects on human disease and experimentally infected mice. 6 Samples in total, 3 each from VL and CL causing isolates were analyzed by Splice Leader RNASeq. These three samples from each of the isolates were grown to form one of the following three lifestages, Promastigotes, Macrophage derived Amastigotes, Axenic Amastigotes.
2013-12-31 | E-GEOD-48475 | biostudies-arrayexpress
Project description:Among the most central questions in Leishmania research is why some species remain in the skin dermis at the site of infection by the sand fly vector whereas other species migrate to visceral organs where they cause fatal visceral leishmaniasis. Although L. donovani is the species typically responsible for visceral leishmaniasis, an atypical L. donovani strain is the etiologic agent for cutaneous leishmaniasis in Sri Lanka. To identify molecular determinants for visceral disease, we have analysed the phenotype and genotype of two L. donovani clinical isolates from Sri Lanka where one isolate was derived from a cutaneous leishmaniasis patient (CL) and the other from a visceral leishmaniasis patient (VL). These isolates cause dramatically different pathology when introduced into mice; notably the CL isolate has lost the ability to survive in visceral organs while the VL isolate was highly virulent in visceral organs of BALB/c mice. Whole genome sequencing of the CL and VL isolates revealed that these genomes were very similar as there were no gene deletions and few individual gene amplifications. Indels resulting in frame shifts and loss/gain of stop codons resulted in 13 distinct pseudogenes present in each of the CL and VL isolates. There were 154 non-synonymous SNPs specific to the CL isolate and 193 non-synonymous SNPs specific to the VL isolate. Genome wide gene expression analysis revealed several transcript level differences, including the A2 virulence gene resulting in higher expression of A2 proteins in the VL isolate than in the CL isolate. Genotypic variations relevant to pathology and tropism in Leishmania can be interrogated by reverse genetics. Experimentally increasing A2 expression in the CL isolate through gene transfer significantly increased it’s ability to survive in the spleen of BALB/c mice and conversely, down-regulating A2 expression in the VL isolate abrogated attenuated its survival in BALB/c mice. These observations reveal that there are relatively few genetic differences between the CL and VL isolates apart from the A2 genes, but collectively these have profound effects on human disease and experimentally infected mice.
2013-12-31 | GSE48475 | GEO
Project description:In this study employed a systems analysis approach to study molecular signatures of cutaneous leishmaniasis (CL) caused by Leishmania tropica (L. tropica) in the skin lesions of ulcerativeCL (UCL) and non-ulcerative CL( NUCL) patients. Results from RNA-seq analysis determined shared and unique functional transcriptional pathways in the lesions of the UCL and Nucl patients. Several transcriptional pathways involved in inflammatory response were positively enriched in the CL lesions. These results enhance our understanding of human skin response to CL caused by L. tropica.
2022-11-01 | GSE216638 | GEO
Project description:Cutaneous leishmaniasis (CL) is prevalent in many low-income countries. Although CL is considered non-fatal, it has a major impact on public health systems of affected nations, causing social and economic problems due to disfiguration, morbidity, loss of productivity and medical costs for the public sector. Since no effective human vaccine against CL exists, it is crucial to understand better factors that may affect the outcome of the disease, including the impact of the pathogen on the host immune system. While transcriptomics analyses of the skin lesion in CL patients were recently reported, there is a dearth of information on the expression of immune-related genes in the blood of CL patients. We herein sought to profile the expression of immune-related genes in the blood of healed, asymptomatic and active CL patients.
2022-07-27 | GSE197222 | GEO
Project description:There is still no reliable human vaccination against cutaneous leishmaniasis (CL), a serious public health issue in many parts of underdeveloped nations like Morocco and Iran. There are few studies comparing the expression of immune-related genes in the skin lesions of CL patients infected with L. major and L. tropica. In this study, we used dcRT-MLPA to analyze the expression profiles of 144 immune response-related genes in CL patients from Morocco and Iran who had been exposed to L. major and L. tropica, respectively.
2024-07-01 | GSE220308 | GEO
Project description:We evaluated the trancriptome of primary cutaneous leisions caused by infection with Leishmania braziliensis. mRNA-seq technique was used to study the trancriptome of both host and parasite. A total of 10 samples was obtained from primary skin ulcers of two extreme clinical forms of American tegumentary leishmaniasis: (i) individuals that after antimonial treatment cured completely (localized cutaneous leishmaniasis - LCL, n=5) and (ii) individuals that developed mucosal lesions in naso and oropharynx areas long after initial healing of the cutaneous lesion (mucosal leishmaniasis - ML, n=5). The sequencing generated an average of 13+ 5 million reads per samples. The reads were aligned to Homo sapiens (USCS - hg19) and to Leishmania braziliensis (Wellcome Trust Sanger Institute - V2_29072008) genomes. Approximately, 15,000 human genes could be detected in the samples. Low amount of L. braziliensis reads did not allow the evaluation of parasite gene expression. LCL and ML samples showed different patterns of gene expression, indicating a more robust immune response in LCL individuals. In summary, this study demonstrated that next-generation sequencing can be used for identification of potentially important biological pathways and drug targets in the host-response to L. braziliensis infection and for characterization of a gene expression signature that could be used to predict the disease outcome. Moreover, we also showed the ability of this technique in, simultaneously, sequence host and pathogen mRNA. Examination of 10 fragments of cutaneous lesions: 5 from localized cutaneous leishmaniasis patients and 5 from mucosal leishmaniasis patients.
2012-10-24 | E-GEOD-33601 | biostudies-arrayexpress
Project description:The leishmaniases are globally important parasitic diseases for which no human vaccines are currently available. To facilitate vaccine development, we conducted an open label observational study to establish a controlled human infection model of sand fly-transmitted cutaneous leishmaniasis caused by L. major. Between 24th January and 12th August 2022, we exposed 14 (8F, 6M) participants to infected sand flies. The primary objective was to demonstrate effectiveness (attack rate) and safety (absence of CL lesion at 12 months), whereas secondary and exploratory objectives included rate of lesion development, parasite load and analysis of local immune responses using immunohistology and spatial transcriptomics. We estimated a take rate for CL development of 64% (9/14) based on all participants, increasing to 82% (9/11) if only participants with confirmed bites are included. Lesion development was terminated by therapeutic biopsy in 10 participants with confirmed bites. 30% (3/10) had either one (2/10) or two (1/10) lesion recurrences between 4-8 months after biopsy that were treated successfully with cryotherapy. No severe or serious adverse events were recorded, but scarring was evident as expected. All participants were lesion-free at long-term (>12 month) follow up. We provide the first comprehensive map of immune cell distribution and cytokine/chemokine expression in human CL lesions, revealing discrete immune niches. This controlled human infection model offers opportunities for rapid vaccine candidate selection and a greater understanding of immune-mediated protection and pathology.
2024-04-30 | GSE263298 | GEO
Project description:Leishmaniasis affects mainly the poorest population of the third world. Among visceral and cutaneous leishmaniasis (VL and CL, respectively), visceral leishmaniasis is the deadliest parasitic disease. There are no vaccines against leishmaniasis and the chemotherapeutic agents currently used are also insufficient. Pentavalent antimonials are being used for the effective treatment of Leishmaniasis. In this study, we characterized compounds with leishmanicidal activity, and determined its mode of action through the whole transcriptome analyiss. The Lesihmania strains were treated with previously identified selected anti-leishmanial compounds in promastigotes cultures on M199 medium (supplemented with L-glutamine, 10% heat-inactivated fetal bovine serum, 0.25% hemin, 40 mM NaHCO3, 100μM adenine, 40 mM HEPES, 100 U/mL penicillin and 100μg/mL streptomycin). Following the total RNA isolation, RNA-seq was performed using the Illumina NextSeq500 system. The genes expression profiling in the treated and control samples were determined using the standard bioinormatics tools, and then compared statistically.
2024-02-01 | GSE239675 | GEO
Project description:In addition to the recently published in situ transcriptomics of LCL skin lesions (Novais et al., Khouri et al.), we herein present the first systemic disease signature of localized cutaneous leishmaniasis (LCL), using Affymetrix microarrays (HuGene 1.0) followed by systems biology analysis of the PBMC transciptome of LCL patients (n=18), as compared to healthy controls (n=12).
2017-09-15 | GSE80008 | GEO
Project description:Recent work has identified roles for environmental, genetic and epigenetic factors in AD risk. Motivated by suspected roles for epigenetic modifications in AD, we performed a genome-wide screen of DNA methylation using the Illumina Infinium HumanMethylation450 array platform on bulk tissue samples from the superior temporal gyrus (STG) of AD cases and non-demented controls. We paired a sliding window approach with linear models that account for age, gender, ethnicity, and estimated cellular proportions (neuronal vs. glial), to characterize AD-associated differentially methylated regions (DMRs).
2015-12-18 | GSE76105 | GEO