Project description:In this study we set out to determine whole blood transcriptional profiles that might distinguish asymptomatic infection with Leishmania donovani from active disease, as well as to monitor the changes in transcriptional profiles that accompanied drug treatment. Amphotericin B provides improved therapy for visceral leishmaniasis (VL) caused by Leishmania donovani, with single dose liposomal-encapsulated Ambisome providing the best cure rates. The VL elimination program aims to reduce the incidence rate in the Indian subcontinent to <1/10,000 population/year. Ability to predict which asymptomatic individuals (e.g. anti-leishmanial IgG and/or Leishmania-specific modified Quantiferon positive) will progress to clinical VL would help in monitoring disease outbreaks. Here we examined whole blood transcriptional profiles associated with asymptomatic infection, active disease, and in treated cases. Two independent microarray experiments were performed, with analysis focussed primarily on differentially expressed genes (DEGs) concordant across both experiments. No DEGs were identified for IgG or Quantiferon positive asymptomatic groups compared to negative healthy endemic controls. We therefore concentrated on comparing concordant DEGs from active cases with all healthy controls, and in examining differences in the transcriptome following different regimens of drug treatment. In these comparisons 6 major themes emerged: (i) expression of genes and enrichment of gene sets associated with erythrocyte function in active cases; (ii) strong evidence for enrichment of gene sets involved in cell cycle in comparing active cases with healthy controls; (iii) identification of IFNG encoding interferon- as the major hub gene in concordant gene expression patterns across experiments comparing active cases with healthy controls or with treated cases; (iv) enrichment for interleukin signalling (IL-1/3/4/6/7/8) and a prominent role for CXCL10/9/11 and chemokine signalling pathways in comparing active cases with treated cases; (v) the novel identification of Aryl Hydrocarbon Receptor signalling as a significant canonical pathway when comparing active cases with healthy controls, and to a lesser extent with treated cases; and (vi) global expression profiling support for more effective cure at day 30 post-treatment with a single dose of liposomal encapsulated amphotericin B compared to multi-dose non-liposomal amphotericin B treatment over 30 days.

Project description:Immune traits (ITs) are potentially relevant criteria to characterize individualM-bM-^@M-^Ys immunocompetence. Thus, porcine ITs related to innate and adaptive immunity were studied by functional genomics approaches, with no initial focus on resistance to specific pathogens. Peripheral blood transcriptome was analysed in 60 days old Large White pigs (N=445) 3 weeks after vaccination against Mycoplasma hyopneumoniae. Groups of 4 to 10 animals classified in the extreme tails of CD4-/CD8+and TCRM-NM-3M-NM-4+ cell counts, phagocytosis, in vitro production of IL2, IL10, TNF and IFNG, and anti-Mycoplasma antibodies distributions were selected for transcriptome studies with a porcine generic array enriched with immunity-related genes (SLA-RI/NRSP8-13K). Among the ITs studied, transcriptome analysis revealed differentially expressed genes for CD4-/CD8+cell counts, phagocytosis, and in vitro production of IL2 and IL10. A subset of these genes was confirmed by real time qPCR. Gene set enrichment analysis showed a significant over-representation of immune response functions. An independent set of 74 no overlapping animals was employed for validation and a total of 5 potential gene biomarkers were found for prediction of immunocompetence. These biomarkers performed with 79% sensitivity (95% CI 61% to 97%) and 86% specificity (95% CI 72% to 100%). Considering the observed transcriptome differences in animals with extreme ITs levels, we conclude that gene expression profiling appears promising as a tool for biological monitoring of genetic variance in pigs. Test set: Two-condition experiment (High vs Low) for a total of 8 ITS. Three ITs were measured from total blood and referred to as in vivo ITs. They included the seric levels of IgG directed against Mycoplasma hyopneumoniae (IgG-Mh), and the cell counts for M-NM-1M-NM-2 T lymphocytes CD4- CD8+ (CD4- CD8+, or M-NM-3M-NM-4 T lymphocytes (TCRM-NM-3M-NM-4+)) . Additionally, five ITs were measured after in vitro tests, and were further referred to as in vitro ITs. They include the phagocytosis capacity (PHAG), and the in vitro production of TNFM-NM-1, IFNM-NM-3, IL2 and IL10 after in vitro stimulation of total blood diluted five times. For each IT included in the present report, pigs were selected at the higher and lower 10% of the Gaussian distribution in order to generate two extreme groups defined as High (H) and Low (L). Groups of 4 to 10 animals classified in the extreme tails of different ITs were selected. A two-channel microarray experiments were carried out using a common reference hybridization design. The standard reference RNA sample was prepared by pooling of total RNAs from different porcine tissues. As the reference is common to all the arrays, this design allowed an indirect comparison between the conditions of interest (H vs L groups). Additionally, in order to provide potential gene biomarkers to produce new insight into pig immunocompetence, the top 50 genes most differentially expressed genes when comparing H vs L groups in CD4-/CD8+ cell counts, phagocytosis, and in vitro production of IL2 and IL10 phenotypes were assessed across 74 animals (experimental animals non included) that were analyzed with the same SLA-RI/NRSP8-13K microarray. Validation set: A total of 74 animals were analyzed in order to validate potential gene biomarkers found in the following immune traits: CD4- CD8+ lymphocyte counts, phagocytosis capacity, IL2 and IL10 production. As no differentially gene expressions were detected between animals with High and Low levels of gamma delta T lymphocyte counts, IgG-Mh, and in vitro production of TNF-alpha or IFN-gamma immune traits, some of them were used in the validation set (n=50). None of experimental animals with extreme CD4- CD8+ lymphocyte counts, phagocytosis capacity, IL2 and IL10 production levels were included were included in the validation set.

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.

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.

Project description:Background & Aims: In most autoimmune disorders, crosstalk of B cells and CD4 T cells results in the accumulation of autoantibodies targeting specific self-antigen like the Soluble Liver Antigen (SLA or SepSecs) in autoimmune hepatitis (AIH). But the associated autoreactive CD4 T cells have not been characterized yet. Here we isolated and deeply characterized SLA-specific CD4 T cells in AIH patients. Methods: We used brief ex vivo re-stimulation with overlapping SLA-derived peptides to isolate and phenotype circulating SLA-specific CD4 T cells, and integrative single-cell RNA-seq (scRNA-seq) to characterize their transcriptome and T cell receptor (TCR) repertoire. Identified auto-reactive TCRs were reconstituted cloned and expressed in T cell hybridoma to identify dominant SLA-derived CD4 T cell epitopes. SLA-specific CD4 T cells were tracked in peripheral blood through TCR sequencing, to identify their phenotypic niche. We further characterized disease-associated peripheral blood T cells by high content flow cytometry in an additional cohort of n=42 AIH patients and n=17 non-alcoholic steatohepatitis (NASH) controls. Results: Frequency of autoreactive SLA-specific CD4 T cells was associated with anti-SLA autoantibodies and had a memory CD45RA-CD27+PD-1+CXCR5-CCR6- phenotype. ScRNA-seq revealed their pro-inflammatory/B-Helper profile (IL21, IFNG, TIGIT, CTLA4, NR3C1, CD109, KLRB1 and CLEC2D). SLA81-100 and SLA177-204 contain dominant T cell epitopes. Autoreactive TCR clonotypes were restricted to the memory PD-1+CXCR5- CD4 T cells which was significantly increased in the blood of AIH patients and supported B cell differentiation through IL-21. Finally, we identified a specific phenotype (CD45RA-PD-1+CD38+CXCR5-CD127-CD27+) of T cells linked to disease activity and IgG response during AIH. Conclusions: This work provides for the first time a deep characterization of rare circulating autoreactive CD4 T cells and the identification of their peripheral reservoir in AIH. We also propose a generic phenotype of pathogenic T cells related to AIH disease activity which will be essential to track, delineate and potentially target those pathogenic cells.

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Anti-Interleukin-10 unleashes transcriptional response to leishmanial antigen in whole blood of visceral leishmaniasis patients

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