Project description:Cerebral Malaria (HCM) is a serious neurological complication caused by Plasmodium falciparum infection. Currently the only treatment for HCM is the provision of anti-malarial drugs; however, such treatment by itself often fails to prevent death or development of neurological sequelae. To identify new potential adjunct treatments for HCM, we performed a non-biased whole brain transcriptomic time-course analysis of anti-malarial drug chemotherapy of murine experimental CM (ECM).
Project description:Cerebral malaria (CM) is one of the most severe complications of malaria infection. There is evidence that repeated parasite exposure promotes resistance against CM, as indicated by the low incidence of CM in adults in malaria-endemic regions. However, the immunological basis of this infection-induced resistance remains poorly understood. Here, a microarray study done utilising the tractable Plasmodium berghei ANKA model of experimental cerebral malaria (ECM), we show that three rounds of infection and drug-cure protects against the development of ECM during a subsequent fourth infection.
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: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:<p>Malaria varies in severity, with complications ranging from uncomplicated to severe malaria. Severe malaria could be attributed to peripheral hyperparasitemia or cerebral malaria. The metabolic interactions between the host and <em>Plasmodium</em> species are yet to be understood during these infections of varied pathology and severity. An untargeted metabolomics approach utilizing the liquid chromatography-mass spectrometry platform has been used to identify the affected host metabolic pathways and associated metabolites in the serum of murine malaria models with uncomplicated malaria, hyperparasitemia and experimental cerebral malaria. We report that mice with malaria share similar metabolic attributes like higher levels of bile acids, bile pigments, and steroid hormones that have been reported for human malaria infections. Moreover, in severe malaria, upregulated levels of metabolites like phenylalanine, histidine, valine, pipecolate, ornithine and pantothenate, with decreased levels of arginine and hippurate, were observed. Metabolites of sphingolipid metabolism were upregulated in experimental cerebral malaria. Higher levels of 20-hydroxy-leukotriene B4 and epoxyoctadecamonoenoic acids were found in uncomplicated malaria, with lower levels observed for experimental cerebral malaria. Our study provides insights into host biology during different pathological stages of malaria disease and would be useful for the selection of animal models for evaluating diagnostic and therapeutic interventions against malaria.</p>
Project description:Cerebral malaria (CM) can be a fatal manifestation of Plasmodium falciparum infection. We examined global gene expression patterns by microarray during fatal murine CM (FMCM) and non-cerebral malaria (NCM). There was differential expression of a number of genes, including some not yet characterized in the pathogenesis of FMCM. Some gene induction was observed during Plasmodium infection regardless of the development of CM and there was a predominance of genes linked to IFN responses, even in NCM. However, upon real-time PCR validation and quantitation, these genes were much more highly expressed in FMCM than in NCM. The observed changes included genes belonging to pathways such as interferon (IFN) signaling, MHC processing and presentation, apoptosis, immunomodulatory and anti-microbial processes. We further characterized differentially expressed genes by examining the cellular source of their expression as well as their temporal expression patterns during the course of malaria infection. These data identify a number of novel genes that represent interesting candidates for further investigation in FMCM. Keywords: disease state analysis 5 individual mouse brains were collected for each group (Uninfected control, PbA(6), PbK(6), PbK(14). RNA was extracted from these mice and then pooled to create a single sample for hybridisation. Comparisons were made between the experimental groups (PbA(6), PbK(6), PbK(14)) and the reference group (Uninfected control).
Project description:Severe malaria encompasses a range of syndromes manifesting systemically or in diverse organs. These are believed to represent the end-stage processes of local parasite sequestration and inflammatory cascades. Classical anti-malarial drugs target parasites only. In treatment of severe disease, adjunctive therapies capable of controlling the inflammatory processes could be beneficial. Innate defense regulator (IDR) peptides display multiple immune modulatory activities. In this study, we assessed peptide IDR-1018, which shows promise as an anti-inflammatory drug, as a lead candidate for adjunctive host-directed therapy of established disease in the P. berghei ANKA model of experimental cerebral malaria (ECM). Intravenously administered IDR-1018 partially protected mice from ECM both prophylactically and in adjunctive treatment with classical anti-malarial drugs. We used transcriptional data from spleens and brains taken early in infection (day 3) of prophylactically treated mice to investigate the protective mechanisms. The microarrays compared spleens and brains from nine IDR-1018 i.v. treated, infected mice (IDR-1018-treated infected) with three saline i.v. treated infected mice (saline-treated infected) and three uninfected untreated control mice (controls). RNA samples were hybridized in randomized order to five Illumina WG-6 v2 BeadChips . No technical replicates were performed.
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.