Project description:After entering their mammalian host via the bite of an Anopheles mosquito, Plasmodium sporozoites migrate to the liver where they traverse several hepatocytes before invading the one inside which they will develop and multiply into thousands of merozoites. Although this constitutes an essential step in malaria infection, the requirements of Plasmodium parasites in liver cells and how they use the host cell for their own survival and development are poorly understood. To gain new insights into the molecular host-parasite interactions that take place during malaria liver infection, we have used high-throughput microarray technology to determine the transcriptional profile of P. yoelii-infected hepatocytes that were collected from P. yoelii-infected mice 24 and 40 h after infection. This in vivo microarray expression was compared with the microarray analysis of in vitro infected hepatoma cells infected with closely related rodent malaria parasite P. berghei. Differential expression patterns for host genes identify genes and pathways involved in the host response to rodent Plasmodium parasites. Keywords: gene expression
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:Using genome-wide expression profiles from persons either experimentally challenged with malaria-infected mosquitoes or naturally-infected with Plasmodium falciparum malaria, we present details of the transcriptional changes that occur with infection and that are either commonly shared between subjects with pre-symptomatic and clinically apparent malaria or that distinguish these two groups. Our findings confirm and extend aspects of the earliest responses to malaria infection at the molecular level and which may be informative in elucidating how innate and adaptive immune responses may be modulated in different stages of infection. Keywords: Human PBMC samples from natural and experimentally (clinical trial) induced malaria
Project description:The objective of this study is to characterize the overall transcriptome of P. falciparum NF54 derived from a controlled-human malaria infection (CHMI) study. Healthy, immunologically naïve human volunteers were infected intradermally or intravenously with different dosages of Plasmodium falciparum sporozoites (Sanaria® PfSPZ Challenge). Parasites were isolated from these volunteers and subjected to a range of in vitro culture generation prior to RNA collection.
Project description:Transmission of malaria is dependent on the successful completion of the Plasmodium lifecycle in the Anopheles vector. Major obstacles are encountered in the midgut tissue, where most parasites are killed by the mosquito’s immune system. In the present study, DNA microarray analyses have been used to compare Anopheles gambiae responses to invasion of the midgut epithelium by the ookinete stage of the human pathogen Plasmodium falciparum and the rodent experimental model pathogen P. berghei. Invasion by P. berghei had a more profound impact on the mosquito transcriptome, including a variety of functional gene classes, while P. falciparum elicited a broader immune response at the gene transcript level. Ingestion of human malaria-infected blood lacking invasive ookinetes also induced a variety of immune genes, including several anti-Plasmodium factors. Keywords: Anopheles gambiae, Plasmodium falciparum, ookinete, invasion, innate immunity
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:CD4+ T cells are critical for defense against the Plasmodium parasites that cause malaria. To better understand CD4+ T cell effector mechanisms during malaria, we performed microarray analysis of CD4+ T cells from naïve and infected mice. Comparison of activated (CD44 hi CD62L lo) CD4+ T cells from infected mice to bulk CD4+ T cells from naïve mice revealed a subset of genes that were upregulated by infection with Plasmodium chabaudi. These results help generate a more complete picture of CD4+ T cell function in malaria.
Project description:Transmission of malaria is dependent on the successful completion of the Plasmodium lifecycle in the Anopheles vector. Major obstacles are encountered in the midgut tissue, where most parasites are killed by the mosquito’s immune system. In the present study, DNA microarray analyses have been used to compare Anopheles gambiae responses to invasion of the midgut epithelium by the ookinete stage of the human pathogen Plasmodium falciparum and the rodent experimental model pathogen P. berghei. Invasion by P. berghei had a more profound impact on the mosquito transcriptome, including a variety of functional gene classes, while P. falciparum elicited a broader immune response at the gene transcript level. Ingestion of human malaria-infected blood lacking invasive ookinetes also induced a variety of immune genes, including several anti-Plasmodium factors. By comparing gene expression patterns between carcassess or guts of mosquitoes that fed on a P. falciparum or P. berghei wt and mosquitoes that fed on invasion incapable strains we gain information on the A. gambiae transcriptional responses to the invading ookinete at 24 hours after feeding. By comparing gene expression patterns between carcassess or guts of mosquitoes that fed on a P. falciparum ookinete invasion incapable strain and mosquitoes that fed on non-infected blood we gain information on the A. gambiae transcriptional responses to malaria infected blood in absence of ookinete invasion at 24 hours after feeding. By comparing gene expression patterns between mosquitoes at 4 hours after being injected with either E. coli or S. aureus and mosquitoes injected with sterile PBS we gain information on the mosquito's transcriptional response to these bacterial challenges.
Project description:After entering their mammalian host via the bite of an Anopheles mosquito, Plasmodium sporozoites migrate to the liver where they traverse several hepatocytes before invading the one inside which they will develop and multiply into thousands of merozoites. Although this constitutes an essential step in malaria infection, the requirements of Plasmodium parasites in liver cells and how they use the host cell for their own survival and development are poorly understood. To gain new insights into the molecular host-parasite interactions that take place during malaria liver infection, we have used high-throughput microarray technology to determine the transcriptional profile of P. yoelii-infected hepatocytes that were collected from P. yoelii-infected mice 24 and 40 h after infection. This in vivo microarray expression was compared with the microarray analysis of in vitro infected hepatoma cells infected with closely related rodent malaria parasite P. berghei. Differential expression patterns for host genes identify genes and pathways involved in the host response to rodent Plasmodium parasites. Keywords: gene expression Total RNA from sorted liver stage (LS) infected hepatocytes were isolated from PyGFP-infected BALB/c mice as described in Tarun et al (2008). RNA from LS-infected hepatocytes were isolated at two time points post-infection (pi): 24 hr pi (LS24) and 40 hr pi (LS40). As control, RNA from hepatocytes isolated from mock-infected mice (infected with salivary gland extract) at the same time points was also isolated following the same procedure. Total RNA was then subjected to two rounds of linear amplification using the Amino Allyl Message Amp II aRNA Amplification Kit (Ambion) according to manufaturerâs directions. The quality of total and amplified RNAs were examined with the Agilent 2100 BioanalyzerTM (Agilent Technologies) and the quantity of the RNA samples was assessed using a Nanodrop ND-1000 spectrophotometer prior to microarray hybridization. For each timepoint two independent biological replicates were obtained.
Project description:The pathogenesis of severe malaria is complex and involves several pathways that influence host inflammation and endothelial function. The human malaria parasite Plasmodium falciparum is responsible for the majority of mortality and morbidity caused by malaria infection and differs from other human malaria species in the degree of accumulation of parasite-infected red blood cells in the microvasculature, known as cytoadherence or sequestration. In P. falciparum, cytoadherence is mediated by a protein called PfEMP1 which, due to its exposure to the host immune system, undergoes antigenic variation resulting in the expression of different PfEMP1 variants on the infected erythrocyte membrane. These PfEMP1s contain various combinations of adhesive domains, which allow for the differential engagement of a repertoire of endothelial receptors on the host microvasculature, with specific receptor usage associated with severe disease. Cytoadherence results in perturbation of the micro-circulation as well as direct effects on endothelial cells promoted by receptor-mediated signalling. We used a co-culture model of cytoadherence incubating human brain microvascular endothelial cells with erythrocytes infected with two parasite lines expressing different PfEMP1s; IT4var14 (long-form; ups B) that binds strongly to human brain microvascular endothelial cells mainly via ICAM-1, and IT4var 37 (short-form; ups C) that does not bind brain endothelium but shows high levels of binding to human dermal microvascular endothelial cells via CD36. We determined the transcriptional profile of the endothelial cells following different incubation periods with infected erythrocytes, identifying different transcriptional profiles of pathways involved in the pathology of severe malaria, such as inflammation, apoptosis and barrier integrity, induced by the two PfEMP1 variants.