Distinct Transcriptional Signatures of Bone Marrow-Derived C57BL/6 and DBA/2 Dendritic Leucocytes Hosting Live Leishmania amazonensis Amastigotes
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ABSTRACT: To determine the modulation of gene expression of C57BL/6 and DBA/2 BMDLs in the presence of living intracellular Leishmania amazonensis amastigotes
Project description:To determine the modulation of gene expression of C57BL/6 and DBA/2 BMDLs in the presence of living intracellular Leishmania amazonensis amastigotes A genome-wide transcriptional analysis was performed by comparing the gene expression profiles of control DLs and live amastigote-hosting DLs from both mouse strains. Dendritic Leucocytes were generated in vitro from bone marrow progenitors (C57Bl/6 and DBA/2 mice). Leishmania amazonensis amastigotes were purified from mouse cutaneous lesions and were added to DL cultures. After 24h, and following a sorting procedure, only BMDls housing living amastigotes were selected for total RNA extraction. Three Biological replicates per condition were run.
Project description:In mammals, resident dermal macrophages (MΦs) are subverted by Leishmania (L.) amazonensis amastigotes as host cells permissive for parasite multiplication. These Leishmania are living within a communal parasitophorous vacuole (PV) and are expected to trigger unique MΦ transcriptional signatures. We performed a transcription profiling of mouse MΦs harboring amastigotes to get insights into their reprogramming as host cells for parasite multiplication. BALB/c mouse bone marrow-derived MΦs were either loaded or not with four amastigotes on average. Twenty four hours later, when amastigotes multiply, total RNA from MΦ cultures was prepared, amplified and hybridized onto Affymetrix Mouse430_2 GeneChips®. The outcome recorded a total of 1,248 probe-sets showing significant differential expression. Comparable fold-change values for a handful of genes were obtained between Affymetrix technology and the more sensitive RTqPCR method. Ingenuity Pathway Analysis software® pinpointed the up-regulation of the sterol biosynthesis pathway (P-value = 1.31e-02) involving several genes (1.95 to 4.30 fold-change values), and the modulation of various genes involved in polyamine synthesis and in pro/counter-inflammatory signaling. Our findings suggest that amastigotes exploit the MΦ lipid and polyamine pathways to multiply efficiently, and induce a counter-inflammatory environment to expand their dermis niche.
Project description:In mammals, resident dermal macrophages (MΦs) are subverted by Leishmania (L.) amazonensis amastigotes as host cells permissive for parasite multiplication. These Leishmania are living within a communal parasitophorous vacuole (PV) and are expected to trigger unique MΦ transcriptional signatures. We performed a transcription profiling of mouse MΦs harboring amastigotes to get insights into their reprogramming as host cells for parasite multiplication. BALB/c mouse bone marrow-derived MΦs were either loaded or not with four amastigotes on average. Twenty four hours later, when amastigotes multiply, total RNA from MΦ cultures was prepared, amplified and hybridized onto Affymetrix Mouse430_2 GeneChips®. The outcome recorded a total of 1,248 probe-sets showing significant differential expression. Comparable fold-change values for a handful of genes were obtained between Affymetrix technology and the more sensitive RTqPCR method. Ingenuity Pathway Analysis software® pinpointed the up-regulation of the sterol biosynthesis pathway (P-value = 1.31e-02) involving several genes (1.95 to 4.30 fold-change values), and the modulation of various genes involved in polyamine synthesis and in pro/counter-inflammatory signaling. Our findings suggest that amastigotes exploit the MΦ lipid and polyamine pathways to multiply efficiently, and induce a counter-inflammatory environment to expand their dermis niche. Experiment Overall Design: Mice, MΦs and amastigotes: Experiment Overall Design: Swiss nu/nu and BALB/c mice were used (following National Scientific Ethics Committee guidelines) for L. amazonensis (LV79 strain, MPRO/BR/1972/M1841) amastigote propagation and to prepare bone marrow-derived MΦs, respectively. Amastigotes were added at a multiplicity of 4 amastigotes per MΦ. Parasite-harboring MΦs (>98%; samples I1, I2 and I3) and parasite-free ones (samples UI1, UI2 and UI3) were cultured at 34°C (LV79 permissive temperature) for 24h. Experiment Overall Design: Real-time quantitative PCR: Experiment Overall Design: Total RNA from various biological samples including those used for hybridization experiments were reverse transcribed into cDNA using random hexamers (Roche Diagnostics) and Moloney Murine Leukemia Virus Reverse Transcriptase (Invitrogen Life Technologies). RTqPCR was performed using LightCycler-480 system (Roche) with primers designed with LightCycler Probe Design 1.0 software.Target genes primer sequences, amplicon melting temperatures and amplification efficiencies are available upon request. Gene expression analysis using qBase program allowed determining the normalized relative quantities between parasite-free and parasite-harboring MΦs.
Project description:To determine the modulation of gene expression of mouse BMDCs in the presence of living intracellular Leishmania amazonensis amastigotes Dendritic cells were generated in vitro from bone marrow progenitors. Leishmania amazonensis amastigotes were purified from mouse cutaneous lesions and were added to DC cultures. After 24h, and following a sorting procedure, only BMDCs housing living amastigotes were selected for total RNA extraction.
Project description:To determine the modulation of gene expression of mouse BMDCs in the presence of living intracellular Leishmania amazonensis amastigotes
Project description:Background/objectivesThe inoculation of a low number (10(4)) of L. amazonensis metacyclic promastigotes into the dermis of C57BL/6 and DBA/2 mouse ear pinna results in distinct outcome as assessed by the parasite load values and ear pinna macroscopic features monitored from days 4 to 22-phase 1 and from days 22 to 80/100-phase 2. While in C57BL/6 mice, the amastigote population size was increasing progressively, in DBA/2 mice, it was rapidly controlled. This latter rapid control did not prevent intracellular amastigotes to persist in the ear pinna and in the ear-draining lymph node/ear-DLN. The objectives of the present analysis was to compare the dendritic leukocytes-dependant immune processes that could account for the distinct outcome during the phase 1, namely, when phagocytic dendritic leucocytes of C57BL/6 and DBA/2 mice have been subverted as live amastigotes-hosting cells.Methodology/principal findingsBeing aware of the very low frequency of the tissues' dendritic leucocytes/DLs, bone marrow-derived C57BL/6 and DBA/2 DLs were first generated and exposed or not to live DsRed2 expressing L. amazonensis amastigotes. Once sorted from the four bone marrow cultures, the DLs were compared by Affymetrix-based transcriptomic analyses and flow cytometry. C57BL/6 and DBA/2 DLs cells hosting live L. amazonensis amastigotes do display distinct transcriptional signatures and markers that could contribute to the distinct features observed in C57BL/6 versus DBA/2 ear pinna and in the ear pinna-DLNs during the first phase post L. amazonensis inoculation.Conclusions/significanceThe distinct features captured in vitro from homogenous populations of C57BL/6 and DBA/2 DLs hosting live amastigotes do offer solid resources for further comparing, in vivo, in biologically sound conditions, functions that range from leukocyte mobilization within the ear pinna, the distinct emigration from the ear pinna to the DLN of live amastigotes-hosting DLs, and their unique signalling functions to either naive or primed T lymphocytes.
Project description:To determine the modulation of gene expression of mouse BMDCs in the presence of living intracellular Leishmania amazonensis amastigotes at 24 hr post infection.
Project description:In this study, we examined the transcriptome of Leishmania donovani promastigotes and axenic amastigotes to identify differentially regulated mRNAs utilizing the serial analysis of gene expression Keywords: stage differentiation; axenic amastigotes
Project description:We used Illumina sequencing of poly-A selected RNA of Leishmania mexicana (WHO strain MNYC/BZ/62/M379) culture-adapted promastigotes (PRO), axenic amastigotes (AXA) and intracellular amastigotes (AMA) in mouse bone marrow derived macrophages (BMDM), 24h after infection, to map 5' and 3' ends of Leishmania transcripts and determine transcript abundances. The AMA samples were prepared from total RNA of infected macrophages thus containing a mixture of leishmanial and murine RNA transcripts. We also sequenced poly-A selected RNA from uninfected BMDMs. Three biological replicates per sample.