Transcription profiling of Strongyloides ratti response to environmental factors ex vivo
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ABSTRACT: Strongyloides ratti is a parasitic nematode of rats and a laboratory model for nematode infection more generally. The aim of this experiment was to determine the gene expression response of parasitic females to abiotic factors in its environment ex vivo that may be relevant to its natural environment in the gut in vivo. Thus, we used cDNA arrays to assay transcriptional responses to high and low salt, to RPMI versus PBS media and to 37C versus 40C. A moderate number of gene expression changes were observed.
Project description:This experiment exploits the life-cycle of Strongyloides ratti, which is a parasitic nematode of brown rats that exhibits three adult stages within its life-cycle - parasitic females, freeliving females and free-living males. We use a cDNA microarray to examine patterns of (i) gender-biased gene expression by contrasting free-living females against free-living males, and (ii) parasitic-biased expression by contrasting parasitic females against free-living females. Of the 3688 distinct transcripts represented on our array, 20% exhibited male-biased expression 19% exhibit female-biased expression, 11% exhibit parasitic-biased expression and 8% exhibit free-living-biased expression. Among the top responding genes, an orthologue of major sperm protein is upregulated in males, distinct aspartic protease orthologues are upregulated in either parasitic or in free-living females, and orthologues of hsp-17 chaperone are upregulated in parasitic females. Upon a global analysis of gene expression, we find that female-biased expression is associated with genes involved in reproductive processes and larval development, that male-biased expression is associated with genes involved in metabolism, and that free-living biased expression is associated with genes involved in regulation of body fluids and response to external stimulus. The association of gene ontology with parasite-biased expression is less clear. Our results provide an initial gene expression analysis of gender- and parasite-biased expression in S. ratti, may be more generally applicable to other parasitic nematodes, and may help to refine the search for novel drug or vaccine targets against parasitic nematodes.
Project description:Strongyloides ratti is a parasitic nematode of rats and a laboratory model for nematode infection more generally. Selected lines were generated over the course of 20 - 30 generations such that eggs were harvested either at the beginning or towards the end of an infection, termed 'fast' and 'slow' lines, respectively. Phenotypic differences in these lines in their fecundity and response to host immunity were observed. The gene expression response of these lines in both permissive and restrictive immune environments were assayed using cDNA microarrays. Large numbers of responding genes were found (but with modest fold changes) and clusters of co-expressed genes identified. Genes exhibiting female-biased expression responded to host immunity, consistent with increased investment into transmission in restrictive immune environments.
Project description:Strongyloides ratti is a parasitic nematode of rats and a laboratory model for nematode infection more generally. The response of two lines of S. ratti were compared in contrasting immunological environments: (i) day 5 post infection (p.i.) in naive rats; (ii) day 12 p.i. in naive rats; day 5 p.i. in rats previously immunised with 10 iL3s; and day 12 p.i. in rats previously immunised with 10 iL3s. The gene expression response of parasitic females were assayed using cDNA microarrays. Large numbers of responding genes were found (but with modest fold changes) and clusters of co-expressed genes identified with differences observed between worms taken from naive and previously exposed hosts and from the two time points.
Project description:Nematode derived substances are known to down regulate host immune responses in order to survive in the human host. Brugia malayi is a parasitic nematode responsible for long lasting and disabling infection known as lymphatic filariasis in humans. The therapeutic benefit of a controlled parasitic nematode infection on the course of inflammatory bowel disease (IBD) has been demonstrated in both animal and human models. However the inability of individual purified nematode proteins to recreate this beneficial effect has limited the application of component immunotherapy to human disease. This experiment addresses the hypothesis that the genes regulated by IL8 and recombinant Brugia malayi AsnRS (rBmAsnRS) are different even though it is known that both molecules interact with IL-8 receptors. Furthermore, we theorize that the signal transduction pathways activated by IL-8 and rBmAsnRS are different because it is known that the extracellular G protein loops utilized by IL-8 and rBmAsnRS to activate IL8 receptors, are different. These results obtained with a single recombinant nematode protein, rBmAsnRS, share immunological features with those observed in a whole nematode infection and include desirable features for treatment of idiopathic inflammatory diseases, such as IBD. The immune reaction of human host in response to most abundant nematode expressed protein Asparaginyl t RNA Synthetase was compared with reaction of human immature dendritic cells to IL-8 stimulation or no stimulation.
Project description:Angiostrongylus costaricensis is a relatively uncharacterized nematode that causes abdominal angiostrongyliasis in Latin America, a human parasitic disease. Currently, no effective pharmacological treatment for angiostrongyliasis exists. Peptidases are known to be druggable targets for a variety of diseases and are essential for several biological processes in parasites. Therefore, this study aimed to systematically characterize the peptidase activity of A. costaricensis in different developmental stages of this parasitic nematode.
Project description:This investigation was designed to follow the parasitic fungus Monacrosporium haptotylum during infection of the nematode Caenorhabditis elegans. M. haptotylum traps nematodes using a spherical structure called knob, which develops on the apex of a hyphal branch. The advantage of using this species is that the unicellular knobs can be separated from the mycelium that has been grown in liquid culture. The isolated knobs retain the function as infection structures. The cDNA microarray contained 2,778 M. haptotylum and 588 C. elegans gene reporters. The experiments was designed as a time course study including infected and non-infected tissue, over 24 hours which involves stages of adhesion, penetration and digestion of the infected nematodes.
Project description:Illumina sequencing of small RNAs from Brugia pahangi and Haemonchus contortus 4 samples examined, larval stage 3 and mixed sex adults from two parasitic nematode species.
Project description:A. simplex s.s. (parasitic nematode) under the in vitro treatment with different concentrations of lipopolysaccharide (LPS) of Escherichia coli. Complete TMT10plex labeling. LC-MS/MS analysis.
Project description:Nematode derived substances are known to down regulate host immune responses in order to survive in the human host. Brugia malayi is a parasitic nematode responsible for long lasting and disabling infection known as lymphatic filariasis in humans. The therapeutic benefit of a controlled parasitic nematode infection on the course of inflammatory bowel disease (IBD) has been demonstrated in both animal and human models. However the inability of individual purified nematode proteins to recreate this beneficial effect has limited the application of component immunotherapy to human disease. This experiment addresses the hypothesis that the genes regulated by IL8 and recombinant Brugia malayi AsnRS (rBmAsnRS) are different even though it is known that both molecules interact with IL-8 receptors. Furthermore, we theorize that the signal transduction pathways activated by IL-8 and rBmAsnRS are different because it is known that the extracellular G protein loops utilized by IL-8 and rBmAsnRS to activate IL8 receptors, are different. These results obtained with a single recombinant nematode protein, rBmAsnRS, share immunological features with those observed in a whole nematode infection and include desirable features for treatment of idiopathic inflammatory diseases, such as IBD.