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.
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.
Project description:Leishmania donovani WHO reference strain MHOM/IN/80/DD8 and Leptomonas seymouri isolates Ld 2001 and Ld39 were used for proteome analysis which were originally isolated from clinical cases of kala azar patients with different inherent antimonial sensitivities. Ld 2001 was Sb-S and Ld 39 was Sb-R. The genome sequencing of these isolates had confirmed co-infection with Leptomonas.
2016-03-16 | MSV000079588 | MassIVE
Project description:Genome wide comparison of Leishmania donovani strains from Indian visceral leishmaniasis and para-kala-azar dermal leishmaniasis patients
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.
2015-03-25 | PXD000724 | Pride
Project description: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:Infection with antimony resistant (SbR) but not with sentitive (SbS) Leishmania donovani (LD) gives rise to aggressive pathology in mammalian hosts, the cause of which is far from clear. Some intracellular pathogens exploit autophagy for their own benefit. Here we show that induction of autophagy in normal macrophages (MF) by pharmacological mediators prior to infection with SbRLD (SbRLD-MF) enhanced their growth as compared to untreated MF, unlike SbSLD-MF. Autophagy was evident in SbRLD-MF from electron microscopical studies showing double membrane-bound compartment around amastigote. In SbRLD-MF there is induction of beclin 1, which forms the platform to recruit other interacting molecules to initiate autophagy. Knocking down the beclin 1 transcription factor Nrf2 and subsequent infection with SbRLD showed significantly lower organ parasites as compared to wild type BALB/c mice. Cessation of autophagy in SbRLD-MF at the later stage of infection is coupled with induction of miR-30a, whose binding to 3'UTR of beclin 1 leads to its post-transcriptional attenuation followed by rise in intracellular Ca++ and apoptosis. SbRLD mediated translocation of AP-1 transcription factor to the nucleus induce pri-miR-30a over-expression. Rise in Ca++ causes caspase 8 activtion leading to the cleavage of beclin 1 and initiation of apoptosis in SbRLD-MF. Apoptosis may favor parasite egress for cell to cell transmission. We also found that beclin 1 expression is present in splenocytes of kala-azar patients harbouring SbRLD but not SbSLD. Our results suggest that SbRLD has evolved a unique mechanism for its own benefit which explains, in part, the cause of aggressive pathology. Peritoneal exudate macrophages were isolated from mouse, grown in 60mm plates and infected with Leishmania donovani and total RNA was isolated from cells at 12, 18 and 24 hrs post infection. Leishmania infected macrophage miRNA expression signature was generated. Cells grown on 60mm plates and infected with Leishmania. The main objective of the microarray analysis of mmu-miRNA in antimony resistant and antimony sensitive Leishmania donovani infected macrophages are as follows: 1. To study how the expression of miRNA varies in either antimony resistant or antimony sensitive Leishmania infected macrophages as compared to the normal macrophages as a function of time. LPS was used as control. 2. To study the expression of those miRNAs which are differentially expressed in antimony resistant and antimony sensitive Leishmania infected macrophages at each time point post infection. 3. To identify those miRNAs which are responsible for degradation of autophagy initiating protein beclin 1 mRNA
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.