Project description:The purpose of this research is to identify and evaluate the global gene expression of the rodent malaria parasites Plasmodium yoelii, Plasmodium berghei and Plasmodium chabaudi blood-stage parasites and specifically compare the blood stage gene expression profiles of samples derived from previous studies on Plasmodium falciparum, Plasmodium vivax and Plasmodium knowlesi
Project description:Analysis of blood samples taken throughout the acute phase of infection from mice infected with avirulent P. chabaudi AS strain or virulent CB strain The influence of parasite genetic factors on immune responses and development of severe pathology of malaria is largely unknown. In this study, we performed genome-wide transcriptomic profiling of whole blood during blood-stage infections of two strains of the rodent malaria parasite Plasmodium chabaudi that differ in virulence. We identified several transcriptomic signatures associated with the virulent infection, including signatures for lung inflammation, stronger and prolonged anemia and platelet aggregation. The latter two signatures were detected prior to pathology. The anemia signature indicated deregulation of host erythropoiesis, and the lung inflammation signature was linked to increased neutrophil infiltration, more cell death and greater parasite sequestration in the lungs. This comparative whole-blood transcriptomics profiling of virulent and avirulent malaria infections shows the validity of this approach to inform severity of malarial infection and provide insight into pathogenic mechanisms.
Project description:Recent advances in high throughput sequencing methodologies allow the opportunity to probe in depth the transcriptomes of organisms including important human pathogens. In this project, we are using Illumina sequencing technology to analyze the transcriptome (RNA-Seq) of experimentally accessible stages of the mouse malaria parasite, P. chabaudi AS. The aim is to analyse cir gene expression during Plasmodium chabaudi infection and determine whether host genetic background can influence cir expression. This data is part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/. Abstract: Transcriptome sequencing of blood stage P. chabaudi AS parasites grown under different host genetic backgrounds.
Project description:The spleen is considered as the major lymphoid organ involved in generating immune responses to the erythrocytic stages of the malaria parasite, Plasmodium, but access to human spleens is not practical and most studies rely on peripheral blood for assessing immune responses. However, the suitability of peripheral blood as a proxy for splenic immune responses is unknown. Here, we have analysed transcriptome activity for whole spleens over 12 days of erythrocytic stage Plasmodium chabaudi infection in C57BL/6 mice. These data will be compared with comparable data taken from whole blood: and previously published: GSE93631
Project description:The pir genes comprise the largest multi-gene family in Plasmodium, with members found in P. vivax, P. knowlesi and the rodent malaria species. Despite comprising up to 5% of the parasite genome, little is known about the functions of the proteins encoded by pir genes. P. chabaudi causes chronic infection in mice, which may be due antigenic variation. In this model, pir genes are called cirs and may be involved in this mechanism allowing evasion of host immune responses. We have annotated the cir repertoire and performed detailed bioinformatic characterization of the encoded CIR proteins. Two major sub-families were identified: A and B, which display different amino acid motifs, and are thus predicted to have undergone functional divergence. The expression of all cirs was analyzed via RNA sequencing and microarray. Up to 40% of cir genes were expressed in the parasite population during infection, including members of both sub-families. Dominant cir transcripts could also be identified. Finally, specific cir genes were expressed at different time points during the blood stages of infection. Together our data characterizing the cir genes and their expression throughout the intra-erythrocytic cycle of development indicate that CIR proteins are likely to be important for parasite survival in the host. P. chabaudi AS is a highly synchronous parasite for which development in the blood follows its hostM-bM-^@M-^Ys circadian rhythm. Twelve time-points were then collected; one every two hours, to cover the entire 24 h cycle of blood stage development. At the peak of parasitaemia, one mouse was sacrificed at each time point and thin blood films were made and stained with Giemsa for optical microscopy. The pan-rodent microarray was designed using the OligoRankPick program as previously described: Liew, K et al.2010, Defining species specific genome differences in malaria parasites. BMC genomics 11,128. The RNA preparation, Cy-dye coupling to cDNA, hybridization and slide scanning were performed as described by Bozdech and colleagues Bozdech, Z et al 2003, The transcriptome of the intraerythrocytic developmental cycle of Plasmodium falciparum. PLoS Biol 1, E5.
