Project description:To determine the modulation of gene expression of Leishmania mexicana(M379)-inoculated BALB/c ears in the presence of promastigote secretory gel (PSG) A genome-wide transcriptional analysis was performed by comparing the gene expression profiles of Leishmania mexicana- inoculated BALB/c ears and Leishmania mexicana plus PSG BALB/c ears. Leishmania mexicana amastigotes were purified from mouse cutaneous lesions and transformed in vitro in metacycic promastigotes (MT). After 6, 24 and 48 hours, ears were collected and processed for RNA extraction. Three Biological replicates per condition were run.
Project description:Eosinophils exert antimicrobial, cytotoxic and immunoregulatory effects, but their function in cutaneous tissue still remains poorly understood. Here, we used a mouse model of chronic cutaneous leishmaniasis caused by the protozoan parasite Leishmania (L.) mexicana to investigate the functional role and transcriptomic signature of eosinophils in the skin. In C57BL/6 wild-type mice, L. mexicana induced local and systemic eosinophilia that was dependent on type 2 innate lymphoid cells and interleukin-5. Genetic and pharmacological depletion of eosinophils led to clinical resolution of disease, which was accompanied by a more pronounced Th1 and M1-like macrophage response. Bioinformatic analyses revealed a novel inflammatory and tissue-specific transcriptional trajectory in skin-infiltrating eosinophils. Skin-imprinted eosinophils strongly expressed the high-affinity glucose transporter 3 (Slc2a3), deprived the environment of glucose and directly impeded the function of Th1 cells. Together, our results demonstrate that the chronicity of L. mexicana infection is linked to inflammatory eosinophils and their metabolic signature
Project description:Eosinophils exert antimicrobial, cytotoxic and immunoregulatory effects, but their function in cutaneous tissue still remains poorly understood. Here, we used a mouse model of chronic cutaneous leishmaniasis caused by the protozoan parasite Leishmania (L.) mexicana to investigate the functional role and transcriptomic signature of eosinophils in the skin. In C57BL/6 wild-type mice, L. mexicana induced local and systemic eosinophilia that was dependent on type 2 innate lymphoid cells and interleukin-5. Genetic and pharmacological depletion of eosinophils led to clinical resolution of disease, which was accompanied by a more pronounced Th1 and M1-like macrophage response. Bioinformatic analyses revealed a novel inflammatory and tissue-specific transcriptional trajectory in skin-infiltrating eosinophils. Skin-imprinted eosinophils strongly expressed the high-affinity glucose transporter 3 (Slc2a3), deprived the environment of glucose and directly impeded the function of Th1 cells. Together, our results demonstrate that the chronicity of L. mexicana infection is linked to inflammatory eosinophils and their metabolic signature
Project description:To determine the modulation of gene expression of Leishmania mexicana(M379)-inoculated BALB/c ears in the presence of promastigote secretory gel (PSG)
Project description:We examined the Leishmania mexicana transcriptome to identify differentially regulated mRNAs using high-density whole-genome oligonucleotide microarrays designed from the genome data of a closely related species, Leishmania major. This experiment appears as Fig. 1 of the associated publication. Keywords: RNA expression profiling
Project description:Protozoa of the genus Leishmania are the causative agents of leishmaniasis in humans. These parasites cycle between promastigotes in the sand fly mid-gut and amastigotes in phagolysosome of mammalian macrophages. During infection, host up-regulate nitric oxide synthase and parasite induce host arginase expression, both of which use arginine as a substrate. These elevated activities deplete macrophage arginine pools, a situation that invading Leishmania must overcome since it is an essential amino acid. Leishmania donovani imports exogenous arginine via a mono-specific amino acid transporter (AAP3) and utilizes it primarily through the polyamine pathway to provide precursors for trypanothione biosynthesis. Here we report the discovery of a pathway whereby promastigote and amastigote forms of the Leishmania sense the lack of environmental arginine and respond with rapid up-regulation in AAP3 expression and activity, as well as several other transporters. Significantly, this arginine deprivation response is also activated in parasites during macrophage infection. Phosphoproteomic analyses of L. donovani promastigotes have implicated a Mitogen-Activated Protein Kinase 2 (MPK2)-mediated signaling cascade in this response and L. mexicana mutants lacking MPK2 are unable to respond to arginine deprivation. In this study, we established that Leishmania cells sense the absence of arginine in their environment; both in culture (axenic promastigotes and amastigotes) and in macrophages during infection (amastigotes). This study describes the first amino acid deprivation sensing mechanism and the pathway that transduce this response, and reveals a novel host-pathogen metabolic interplay.
Project description:Protozoa of the genus Leishmania are the causative agents of leishmaniasis in humans. These parasites cycle between promastigotes in the sand fly mid-gut and amastigotes in phagolysosome of mammalian macrophages. During infection, host up-regulate nitric oxide synthase and parasite induce host arginase expression, both of which use arginine as a substrate. These elevated activities deplete macrophage arginine pools, a situation that invading Leishmania must overcome since it is an essential amino acid. Leishmania donovani imports exogenous arginine via a mono-specific amino acid transporter (AAP3) and utilizes it primarily through the polyamine pathway to provide precursors for trypanothione biosynthesis. Here we report the discovery of a pathway whereby promastigote and amastigote forms of the Leishmania sense the lack of environmental arginine and respond with rapid up-regulation in AAP3 expression and activity, as well as several other transporters. Significantly, this arginine deprivation response is also activated in parasites during macrophage infection. Phosphoproteomic analyses of L. donovani promastigotes have implicated a Mitogen-Activated Protein Kinase 2 (MPK2)-mediated signaling cascade in this response and L. mexicana mutants lacking MPK2 are unable to respond to arginine deprivation. In this study, we established that Leishmania cells sense the absence of arginine in their environment; both in culture (axenic promastigotes and amastigotes) and in macrophages during infection (amastigotes). This study describes the first amino acid deprivation sensing mechanism and the pathway that transduce this response, and reveals a novel host-pathogen metabolic interplay. Total RNA from Ten Leishmania donovani samples were analyzed using RNA-Seq. Cells from two life stages (promastigotes and amastigotes) were grown in axenic culture in the presence and absense of arginine. For each condition two biological replicates were grown and analyzed. In addition two macrophage grown amastigotes were analyzed.
