Project description:Salivary glands are the only mosquito tissue invaded by Plasmodium sporozoites being a key stage for the effective parasite transmission and maturation, making knowledge regarding Anopheles sialome highly relevant to understand this process. In this study, we report for the first time a transcriptomic analysis using RNA-seq of An. gambiae infected by P. berghei.
Project description:Systemic injection of salivary glands P. berghei ANKA GFP-sporozoites into IFNAR-/- mice or salivary glands extracts from non-infected mosquitoes into wild-type C57BL/6 mice. Data obtained were compared with part of hybridizations from experiment E-TABM-839
Project description:Using in vitro models, total RNA was extracted from Plasmodium berghei infected hepatocytes at different time points (6,12,18,24 hours post-infection) and hybridized with Affymetrix microarrays. These genes are candidate for functional analysis, and we aim to use different tools to manipulate their expression and assess their impact in the infection.
Project description:Many eukaryotic developmental and cell fate decisions are effected post-transcriptionally that mechanistically involve RNA binding proteins as regulators of translation of key mRNAs. In the unicellular eukaryote malaria parasite, Plasmodium, one of the most dramatic changes in cell morphology and function occurs during transmission between mosquito and human host. In the mosquito salivary glands, Plasmodium sporozoites are slender, motile and remain infectious for several weeks; only after transmission and liver cell invasion, does the parasite rapidly transform into a round, non-motile exo-erythrocytic form (EEF) that gives rise to thousands of infectious merozoites to be released into the blood stream. Here we demonstrate a Plasmodium homolog of the RNA binding protein, Pumilio, as a key regulator of the sporozoite to EEF transformation. In the absence of Pumilio-2 (Puf2) Plasmodium berghei sporozoites initiate early stage EEF development inside mosquito salivary glands with characteristic morphological changes; puf2- salivary gland sporozoites lose gliding motility, cell traversal ability and are less infective. Global expression profiling confirmed that transgenic parasites exhibit genome-wide transcriptional adaptations typical for Plasmodium intra-hepatic development. The data demonstrate that Puf2 is a key player in regulating developmental control, and imply that transformation of salivary gland-resident sporozoites into early liver stage parasites is regulated by a post-translational mechanism.
Project description:Salivary gland proteins of Anopheles mosquitoes offer attractive targets to understand interactions with sporozoites, blood feeding behavior, homeostasis and immunological evaluation of malaria vectors and parasite interactions. To date limited studies have been carried out to elucidate salivary proteins of An. stephensi salivary glands. The aim of the present study was to provide detailed analytical attributives of functional salivary gland proteins of urban malaria vector An. stephensi. A proteomic approach combining one-dimensional electrophoresis (1DE), ion trap liquid chromatography mass spectrometry (LC/MS/MS) and computational bioinformatic analysis was adopted to provide the first direct insight into identification and functional characterization of known salivary proteins and novel salivary proteins of An. stephensi. Computational studies by online servers namely, Mascot and OMSSA algorithms identified a total of 36 known salivary proteins and 123 novel proteins analysed by LC/MS/MS. This first report describes a baseline proteomic catalogue of 159 salivary proteins belonging to various categories of signal transduction, regulation of blood coagulation cascade, and various immune and energy pathways of An. stephensi sialo-transcriptome by mass spectrometry. Our results may serve as basis to provide a putative functional role of proteins into concept of blood feeding, biting behavior and other aspects of vector-parasite host interactions for parasite development in anopheline mosquitoes.
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:Identification of innate immune responses in the livers of mice infected with liver-stage arresting, transgenic, Plasmodium yoelii parasites. Whole liver samples from mock and P. yoelli fabb/f- infected C57BL/6 and BALB/cJ mice. Samples were taken 3 days post infection
Project description:P. berghei ANKA parasites were collected from the blood at 74h after infection of wild-type and TCRδ-/- mice with 2x10^4 sporozoites (samples were pooled from 3 mice/ group) and mRNA was sequenced by RNA-seq.
Project description:We took advantage of a novel highly sensitive timsTOF PRO mass spectrometer, based on trapped ion mobility spectrometry with parallel accumulation-serial fragmentation. Combined with three alternative methods for sporozoite purification, this approach allowed us to identify the deep proteome of P. berghei sporozoites using low numbers of parasites. This study provides a reference proteome for P. berghei sporozoites, identifying a core set of proteins expressed accross species, and illustrates how the unprecedented sensitivity of the timsTOF PRO system enables deep proteomic analysis from limited sample amounts.
Project description:In addressing R. microplus - A. marginale interactions, we propose and test three linked hypotheses. The first is that the tick gene response is organ specific: the midgut gene regulation is unique during feeding and during acquisition of A. marginale as compared to the salivary gland. This distinction is relevant as the two organs serve very different roles in the transmission biology of A. marginale with early survival and replication within the midgut epithelium, composed of highly phagocytic cells, required for initial colonization while a second round of replication in the salivary gland acini, composed of highly secretory cells, is required for transmission of an infectious dose in the saliva. Importantly, both the midgut epithelium and salivary glands have been identified as separate and distinct barriers for transmission of A. marginale and thus represent two potential sites where transmission could be blocked. The second hypothesis to be tested is that the salivary gland transcriptome is temporally dynamic. Initiation of tick attachment and feeding involves secretion of a virtual pharmacopeia including lytic enzymes, anticoagulants, and inhibitors of the mammalian innate immune and nocioceptive systems. Concomitantly, the acini provide an environment where A. marginale replicates >100 fold and are secreted into the saliva. Prior studies show that duration of feeding is a critical component of transmission efficiency, with increased efficiency positively correlated with time of tick feeding. The third hypothesis to be tested is that A. marginale colonization does not significantly modulate the tick midgut and salivary gland transcriptome. This hypothesis is based on observations by ourselves and others that tick infection does not impart a significant fitness cost on the vector. This is in contrast to other bacterial and protozoal pathogens that have dramatic effects on success of tick attachment, engorgement, and survival. A. marginale, similar to other tick-borne pathogens in the Family Anaplasmataceeae, is believed to have evolved from an arthropod-specific bacterium with relatively late adaptation to specific niches in mammalian hosts. Consequently, we predict that A. marginale is well adapted to its tick vector and utilizes the normal signaling pathways of the feeding tick with few, if any, effects on the midgut and salivary gland transcriptome. In this manuscript, we report the testing of these three hypotheses and present the results in context of the vector-pathogen-mammalian host interaction at the time of transmission. A Roche NimbleGen high-density gene expression microarray was custom designed based on the expressed sequence tag (EST) database, B. microplus Gene Index Version 2 (BmiGI V2) for R. microplus. The expression level of 14,447 R. microplus genes was analyzed from total RNA extracted from 10 different tick tissue samples; 30 arrays were included since triplicates of each different sample were analyzed as follow: unfed (midgut and salivary glands), blood feeding (2 days midgut and 2, 6 and 9 days salivary glands), A. marginale-infected blood feeding (2 days midgut and 2, 6 and 9 days salivary glands).