ABSTRACT: Differential regulation of miRNA profiles of human cells experimentally infected by Leishmania donovani isolated from Indian Visceral Leishmaniasis and Post Kala-azar Dermal Leishmaniasis
Project description:In the present study, we carried out in-depth proteomic analysis of a clinical isolate of post kala-azar dermal leishmaniasis (PKDL) L. donovani promastigotes. The high-resolution mass spectrometry data was searched against protein database of L. donovani. This resulted in identification of 5, 283 unique proteins in L. donovani accounting for 61% of L. donovani proteome. This is one of the most in-depth proteome profile of L. donovani as well as across the different Leishmania species analyzed till date.
2022-03-13 | PXD020541 | Pride
Project description:Genome wide comparison of Leishmania donovani strains from Indian visceral leishmaniasis and para-kala-azar dermal leishmaniasis patients
Project description:The kinetoplastid protozoan parasite, Leishmania donovani, is the causative agent of kala azar or visceral leishmaniasis. Kala azar is a severe form of leishmaniasis that is fatal in the majority of untreated cases. Studies on proteomic analysis of L. donovani thus far have been carried out using homology-based identification based on related Leishmania species (L. infantum, L. major and L. braziliensis) whose genomes have been sequenced. Recently, the genome of L. donovani was fully sequenced and the data became publicly available. We took advantage of the availability of its genomic sequence to carry out a more accurate proteogenomic analysis of L. donovani proteome using our previously generated dataset. This resulted in identification of 17,504 unique peptides upon database-dependent search against the annotated proteins in L. donovani. These peptides were assigned to 3999 unique proteins in L. donovani. 2296 proteins were identified in both the life stages of L. donovani, while 613 and 1090 proteins were identified only from amastigote and promastigote stages, respectively. The proteomic data was also searched against six-frame translated L. donovani genome, which led to 255 genome search-specific peptides (GSSPs) resulting in identification of 20 novel genes and correction of 40 existing gene models in L. donovani.
2016-12-14 | PXD004338 | Pride
Project description:Leishmania donovani isolated from patients of Post kala azar derml Leishmaniasis (PKDL).
Project description:Visceral leishmaniasis (VL) in Sudan caused by Leishmania donovani is fatal in susceptible individuals if untreated. Treatment with Sodium Stibogluconate (SSG) leads to post kala azar dermal leishmaniasis (PKDL) in 58% of patients. Here Affymetrix microarrays were used to identify genes differentially expressed in lymph nodes (N=9 paired samples) pre- and post-treatment with SSG. Using the Bioconductor package limma, 438 genes from 28,869 post quality-control probe-sets were differentially expressed (Pnominal≤0.02) post- versus pre-treatment. Canonical pathway analysis using Ingenuity Pathway Analysis identified “Role of NFAT in Regulation of Immune Response” (Pnominal=1.35x10-5; PBH-adjusted=4.79x10-3), “B Cell Development” (Pnominal=2.04x10-4; PBH-adjusted=0.024), “Fcγ Receptor-mediated Phagocytosis in Macrophages and Monocytes” (Pnominal=2.04x10-4; PBH-adjusted=0.024), and “OX40 Signaling” (Pnominal=2.82x10-4; PBH-adjusted=0.025) as pathways differentially regulated post- versus pre-treatment. Major network hub genes included TP53, FN1, MYC, BCL2, JUN, SYK, RUNX2, MMP1 and ACTA2. Top endogenous upstream regulators included IL-7 (P=2.28x10-6), TNF (P=4.26x10-6), APP (P=4.23x10-5) and SPI1/PI.1 (P=1.17x10-7). Top predicted chemical drug regulators included the flavonoid genistein (P=4.56x10-7) and the quinoline alkaloid camptothecin (P=5.14x10-5). These results contribute to our understanding of immuno-pathology associated with VL and response to SSG treatment. Further replication could identify novel therapeutic strategies that improve on SSG treatment and reduce the likelihood of progression to PKDL.
Project description:The debilitating disease kala-azar or visceral leishmaniasis (VL) is caused by the kinetoplastid protozoan parasite Leishmania donovani. The parasite is transmitted by the hematophagous sandfly vector of the genus Phlebotomus in the old world and Lutzomyia in the new world. The predominant Phlebotomine species associated with transmission of kala-azar are Phlebotomus papatasi and Phlebotomus argentipes. The infected female sandfly transmits the parasite when it takes a blood meal. Understanding the molecular interaction of the sand fly-Leishmania during the development of parasite within the gut of the sandfly is crucial to understanding parasite life cycle. The complete genome sequences of sandfly vectors (Phlebotomus and Lutzomyia) are currently not available and sequencing efforts are underway. Non-availability of genome sequence can hamper identification of proteins in the sandfly vector. In the present study we have carried out proteogenomic analysis of unsequenced sandfly vector P. paptasi cell line using high-resolution mass spectrometry and comparative homology-based searches using related dipteran protein data (mosquitoes and fruit fly). This study resulted in identification of 1,312 proteins from P. papatasi based on homology. Our study demonstrates the power of proteogenomic approaches in mapping the proteomes of unsequenced organisms.
Project description:Leishmania donovani is a kinetoplastid protozoan which causes Kala-azar or visceral leishmaniasis.Leishmania possess glycosomes that are unique and specialized subcellular microbody organelles. Glycosomes are known to harbor most peroxisomal enzymes and in addition they also possess glycolytic enzymes. In the present study, we carried out proteomic profiling of purified glycosomes isolated from L. donovani promastigotes using high resolution mass spectrometry. The majority of identified proteins are involved in metabolic processes such as carbohydrate, lipid and nucleic acid metabolism. Our present proteomic analysis is the most comprehensive study till date to map the proteome of L. donovaniglycosomes.
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:Leishmania donovani, an intracellular protozoan parasite, is the causative agent of visceral leishmaniasis or kala-azar, the most severe form of leishmaniasis in humans. To date, our understanding of the molecular mechanisms associated with the pathogenicity of Leishmania infection is still limited. RNA interference—collectively RNA silencing pathways—participates in the regulation of various biological processes in most eukaryotic cells. Complexes of Argonaute proteins with small RNAs are core components of the RNA interference system and play a key role in silencing gene expression. It is becoming increasingly clear that several intracellular pathogens target host cell RNA interference pathways to promote their survival. In this study, we investigated the potential role of host macrophage Argonautes in Leishmania pathogenesis. Western blot analysis showed that protein abundance of infected macrophage Argonaute 1 (Ago1) was selectively and significantly higher than that of non-infected control at 24 h post-infection, suggesting that Ago1 plays a role in pathogenicity. In fact, siRNA-mediated downregulation of Ago1 enhanced Leishmania clearance from infected host cells, linking macrophage Ago1 to Leishmania virulence. To investigate the mechanisms of host Ago1 in Leishmania pathogenesis, a stable isotope labeling by amino acids in cell culture (SILAC)-based whole proteome approach was employed, which showed that expression of several previously reported Leishmania pathogenesis-related proteins were dependent on the level of macrophage Ago1. Moreover, the proteomic-based detailed biochemical analysis showed that Leishmania modulated host RNA-induced silencing complex (RISC) composition during infection, strongly suggesting macrophage RISC targeting. Strikingly, Leishmania proteins were detected as part of host RISC in infected cells. Together, our results demonstrate that Leishmania targets host RNA interference machinery to promote its survival inside the host macrophage.