Project description:Leishmania (Viannia) braziliensis is the main etiological agent of cutaneous and mucocutaneous leishmaniasis in Latin America. Reports have described non-ulcerated atypical tegumentary leishmaniasis cases caused by L. braziliensis in several regions of the world, including in patients from the Xacriabá Indigenous reserve, in São João das Missões/Minas Gerais - Brazil. Parasites isolated from these atypical clinical lesions have previously been found to be resistant to antimony-based therapeutics. In the present study, proteins displaying differential abundance in 2 strains of L. braziliensis isolated from patients with atypical lesions compared with 4 strains isolated from patients with typical lesions were identified using a quantitative proteomics approach based on tandem mass tag labeling (TMT) and mass spectrometry. A total of 532 (p value <0.05) differentially abundant proteins were identified (298 up-regulated and 234 down-regulated) in strains from atypical lesions compared to strains from typical lesions. We observed a variety of proteins with differential abundance among the studied strains. Prominent positively regulated in atypical strains included proteins which may confer a greater survival inside the macrophage, proteins related to resistance to antimony and higher peroxidase activity. Also were identified proteins suggest as new drug and vaccines target. Our data contribute to characterization of these intriguing L. braziliensis strains, and sheds new light on ACL cases has been associated with therapeutic failures.
Project description:Leishmania (Viannia) braziliensis is a parasite prevalent in Brazil and associated with tegumentary leishmaniasis (TL), including cutaneous (CL) and mucosal (ML) forms. The mechanisms of pathogenesis of TL are not fully understood, including some factors related to the host and parasite interaction in response to infection, and especially about Leishmania RNA Virus 1 (LRV1), an endosymbiont virus parasitizing Leishmania species, particularly triggers ML. Molecular approaches are usually applied to compare situations and to understand these interactions. Here, microarray analysis identified 162 differentially expressed genes in LbLRV1+ vs. LbLRV1- infection, with 126 upregulated genes related to IFN signaling, OAS/RNAse L, vitamin D3, and RIG-I type receptors. Additionally, 36 down-regulated genes were observed. Then, two validation assays were performed to confirm these results (RT-qPCR and Cytometric Bead Array). The main results comprise the differential gene expression in cells infected with LbLRV1+ compared to LbLRV1- and control, with overexpression of various genes in LbLRV1+ cells. Cytokine levels showed no significant differences between LbLRV1+ and LbLRV1-. This study highlighted the activation of the OAS/RNase L signaling pathway and the non-genomic actions of vitamin D3 in LbLRV1+ infection compared to LbLRV1- and control. This research contributes to our understanding of the immune response and molecular pathways involved in Leishmania infections, particularly in the presence of LRV1. We used microarrays to detail the global gene expression program underlying infection of human mnocyte-derived macrophages with LbLRV1-, LbLRV1+ and identified distinct classes of genes upregulated during this process.
Project description:The genomic DNAs of strains JPCM5 and 263 of L. infantum, strains LV39 and Friedlin of L. major and strains Parrot-TarII and S125 of L. tarentolae were used in comparative genomic hybridizations to reveal the intra-species and inter-species gene content, and to validate L. tarentolae Parrot-TarII genome sequencing results. Leishmania (Sauroleishmania) tarentolae was first isolated in the lizard Tarentola mauritanica. This species is not known to be pathogenic to humans but is often used as a model organism for molecular analyses or protein overproduction. The Leishmania tarentolae Parrot-TarII strain genome sequence was resolved by high-throughput sequencing technologies. The L. tarentolae genome was first assembled de novo and then aligned against the reference L. major Friedlin genome to facilitate contig positioning and annotation, providing a 23-fold coverage of the genome. This is the first non-pathogenic to humans kinetoplastid protozoan genome to be described, and it provides an opportunity for comparison with the completed genomes of the pathogenic Leishmania species. A high synteny was observed in de novo assembled contigs between all sequenced Leishmania species. A number of limited chromosomal regions diverged between L. tarentolae and L. infantum, while remaining syntenic with L. major. Globally, over 90% of the L. tarentolae gene content was shared with the other Leishmania species. There were 250 L. major genes absent from L. tarentolae, and interestingly these missing genes were primarily expressed in the intracellular amastigote stage of the pathogenic parasites. This implies that L. tarentolae may have impaired ability to survive as an intracellular parasite. In contrast to other Leishmania genomes, two gene families were expanded in L. tarentolae, namely the leishmanolysin (GP63) and a gene related to the promastigote surface antigen (PSA31C). Overall, L. tarentolae appears to have a gene content more adapted to the insect stage rather than the mammalian one. This may partly explain its inability to replicate within mammalian macrophages and its suspected preferred life style as promastigote in the lizards.
Project description:The mRNA expression of antimony resistant strains of Leishmania donovani was compared to the expression of the sensitive Leishmania donovani.
2016-01-01 | GSE62468 | GEO
Project description:Genetic diversity and comparative genomics across Leishmania (Viannia) species