Project description:Purpose:This study aimed to investigate the transcriptome-wide response of experimental cerebral malaria (ECM) and artesunate treated mice brain on 6 days post-infection. Methods: C57BL/6 mice were infected with Plasmodium berghei ANKA to construct a murine ECM in MB and AB group. AB group treated with artesunate (30mg/kg), while CB group treated with PBS for 4 days. Mice brain was tested by RNA-seq. Results: Gene ontology and KEGG pathway analyses of differentially expressed genes (DEGs) were performed. quantitative reverse transcription polymerase chain reaction (qPCR) verify DEGs such as Il6, Il1b, Il10, Tnf, Ifng, Il21, Icam1, which were up-regulated in MB vs. CB, while down-regulated in AB vs. MB. Conclusions:Our study revealed a transcriptome-wide profile in ECM and artesunate treated mice brain, and help to explore the underlying mechanism, as well as the further development of therapeutic strategies for clinical cerebral malaria.
Project description:RNA-seq analysis of the mouse brain reveals inflammatory genes associated with early artesunate treatment of experimental cerebral malaria
Project description:Cerebral malaria is a pathology involving inflammation in the brain. There are many immune cell types activated during this process, but there is little information on the contribution of microglia, the brain resident macrophages, to this severe complication. We have examined the responses of microglia in a model of experimental cerebral malaria (ECM), in which C57BL/6 mice are infected with Plasmodium berghei ANKA. Genome wide transcriptomic analysis of these cells revealed that thousands of transcripts were differentially expressed at two different time points during the infection. The analysis indicated that proliferation of microglia was a dominant feature before the onset of ECM, and supporting this, we observed an increase in numbers of these cells in the brain. When cerebral malaria symptoms were manifest, genes involved in immune responses and chemokine production were upregulated, which were possibly driven by Type I Interferon. Together, our data offer a unique insight into the responses of microglia in the brain during ECM.
Project description:Analysis of transcriptional response to Plasmodium berghei ANKA infection in cerebral malaria susceptible C57BL/6 mouse brains as well as cerebral malaria resistant BXH2 mice which carry a severe hypomorphic Irf8-R294C allele. Interferon Regulatory Factor 8 (IRF8) is required for development, maturation and expression of anti-microbial defenses of myeloid cells. BXH2 mice harbor a loss-of-function allele at Irf8 (Irf8-R294C) that causes susceptibility to infection with intracellular pathogens, including Mycobacterium tuberculosis. We report that XH2 are completely resistant to the development of cerebral malaria following Plasmodium berghei ANKA infection. Comparative transcriptional profiling of brain RNA as well as chromatin immunoprecipitation and high-throughput sequencing (ChIP-seq) was used to identify IRF8-regulated genes whose expression is associated with pathological acute neuroinflammation. Genes up-regulated by infection were strongly enriched for IRF8 binding sites, suggesting that IRF8 acts as a transcriptional activator in inflammatory programs. These lists were enriched for myeloid-specific pathways, including interferon responses, antigen presentation and Th1 polarizing cytokines. We show that inactivation of several of these downstream target genes confers protection against experimental cerebral malaria. We also report strong overlap between genes bound and regulated by IRF8 during cerebral malaria and genes regulated in the lungs of M. tuberculosis infected mice. This IRF8-dependent network contains several genes recently identified as risk factors in acute and chronic human inflammatory conditions. In summary, this work defines a common core of IRF8-bound genes forming a critical inflammatory host-response network. Comparison of whole brain transcript profiles for wildype C57BL/6 mice versus severely hypomorphic Irf8-R294C BXH2 mice following experimental infection with Plasmodium berghei ANKA (d7). Baseline (d0) profiles are also compared. Pleaes note that each sample record represents 2-4 replicates and sample data table contains mean, standard error of the mean (SEM), and quality for the replicates. The non_normalized data matrix contains raw data for each replicate (total 12 samples).
Project description:Plasmodium berghei ANKA infection in mice is used as a model for human cerebral malaria, the most severe complication of Plasmodium falciparum infection. The response of brain cells such as microglia has been little investigated, and may play a role in the pathogenesis or regulation of cerebral malaria. We showed previously that microglia are activated in P. berghei infections, and that Type 1 Interferon signaling is important for activation. This dataset contains the transcriptome of brain microglia of infected mice in the presence and absence of Type I interferon signaling, with the aim of identifying the genes involved in this pathway in microglia during experimental cerebral malaria. Refererence: Capuccini et al 2016, Scientific Reports, 6:39258 The global gene expression profiles from RNA of microglia isolated from uninfected and P berghei-infected wild-type C57BL/6 mice and and IFNA Receptor Knock-out mice using Illumina Beadarrays.
Project description:Gene expression patterns were investigated in well-defined genetically cerebral malaria-resistant (CM-R) and cerebral malaria-susceptible (CM-S) mouse strains. cDNA microarrays were used to search for differentially expressed genes in mouse brain. Four mouse strains, known to differ in susceptibility to cerebral malaria upon Plasmodium berghei ANKA infection, were compared: BALB/c and DBA/2 mice are CM-R, while C57BL/6 and CBA/J mice are CM-S.
Project description:Analysis of transcriptional response to Plasmodium berghei ANKA infection in cerebral malaria susceptible C57BL/6 mouse brains as well as cerebral malaria resistant BXH2 mice which carry a severe hypomorphic Irf8-R294C allele. Interferon Regulatory Factor 8 (IRF8) is required for development, maturation and expression of anti-microbial defenses of myeloid cells. BXH2 mice harbor a loss-of-function allele at Irf8 (Irf8-R294C) that causes susceptibility to infection with intracellular pathogens, including Mycobacterium tuberculosis. We report that XH2 are completely resistant to the development of cerebral malaria following Plasmodium berghei ANKA infection. Comparative transcriptional profiling of brain RNA as well as chromatin immunoprecipitation and high-throughput sequencing (ChIP-seq) was used to identify IRF8-regulated genes whose expression is associated with pathological acute neuroinflammation. Genes up-regulated by infection were strongly enriched for IRF8 binding sites, suggesting that IRF8 acts as a transcriptional activator in inflammatory programs. These lists were enriched for myeloid-specific pathways, including interferon responses, antigen presentation and Th1 polarizing cytokines. We show that inactivation of several of these downstream target genes confers protection against experimental cerebral malaria. We also report strong overlap between genes bound and regulated by IRF8 during cerebral malaria and genes regulated in the lungs of M. tuberculosis infected mice. This IRF8-dependent network contains several genes recently identified as risk factors in acute and chronic human inflammatory conditions. In summary, this work defines a common core of IRF8-bound genes forming a critical inflammatory host-response network.
Project description:Genes and pathways in which inactivation dampens tissue inflammation present new opportunities for understanding the pathogenesis of common human inflammatory diseases, including inflammatory bowel disease, rheumatoid arthritis and multiple sclerosis. We identified a mutation in the gene encoding the deubiquitination enzyme USP15 (Usp15L749R) that protected mice against both experimental cerebral malaria (ECM) induced by Plasmodium berghei and experimental autoimmune encephalomyelitis (EAE). Combining immunophenotyping and RNA sequencing in brain (ECM) and spinal cord (EAE) revealed that Usp15L749R-associated resistance to neuroinflammation was linked to dampened type I interferon responses in situ. In hematopoietic cells and in resident brain cells, USP15 was coexpressed with, and functionally acted together with the E3 ubiquitin ligase TRIM25 to positively regulate type I interferon responses and to promote pathogenesis during neuroinflammation. The USP15-TRIM25 dyad might be a potential target for intervention in acute or chronic states of neuroinflammation.
Project description:In malaria, T cells play a dual role by both restricting parasite growth and mediating immunopathology such as the deadly neuroinflammation called cerebral malaria. During experimental cerebral malaria (ECM), IFN produced by CD4 T cells promotes CD8 T cell sequestration in brain capillaries, resulting in endothelial damage, oedema and death. However the antigen-presenting cells controlling the development of CD4 T cell responses, as well as the antigens recognized by these CD4 T cells, are unknown. Here we used mass spectrometry to characterize the MHC II immunopeptidome presented by dendritic cells during blood stage malaria in C57BL/6 mice. We identified 14 MHC II ligands derived from 13 conserved Plasmodium berghei proteins that we validated in vivo. This work profiles the first MHC II immunopeptidome in a mouse model of blood stage malaria.
Project description:Microarray analyses allow the identification and assessment of molecular signatures in whole tissues undergoing pathological processes. To better understand cerebral malaria pathogenesis, we investigated intra-cerebral gene-expression profiles in well-defined genetically cerebral malaria-resistant (CM-R) and CM-susceptible (CM-S) mice, upon infection by Plasmodium berghei ANKA. We investigated mouse transcriptional responses prior to infection, and at early and late stages of infection by use of cDNA microarrays. Through a rigorous statistical approach with multiple testing corrections, we showed that P. berghei ANKA significantly altered brain gene expression in CM-R (BALB/c), and in CM-S (CBA/J and C57BL/6) mice, and that 327 genes discriminated between early and late infection stages, between mouse strains, and between CM-R and CM-S mice. We further identified 104, 56, 84 genes with significant differential expression between CM-R and CM-S mice on days 2, 5, and 7 respectively. The analysis of their functional annotation suggests that genes involved in metabolic energy pathways, the inflammatory response, and the neuroprotection/neurotoxicity balance play a major role in cerebral malaria pathogenesis. In particular, we evidenced the down-regulation of genes involved in oxidative phosphorylation and the Reln pathway, and the up-regulation of genes involved in the NF-kB signalling pathway in CM-S mice. In addition, our data suggest that cerebral malaria and Alzheimers disease may share some common mechanisms of pathogenesis, as illustrated by the accumulation of beta-amyloid proteins in brains of CM-S mice, but not of CM-R mice. Our results indicate that microarray analyses can provide new insights into the key events that govern malaria pathogenesis.