Project description:C57BL/6 mice were infected with the GS strain of G. duodenalis and total RNA prepared from the duodenum on day 10. Age matched controls were compared using Affy chips to determine changes in gene expression induced by infection. The majority of induced transcripts are invlved in antibody production. Genes exhibiting the greatest increase in expression are all mast cell transcripts.
Project description:Despite of Giardia duodenalis being one of the most commonly found intestinal pathogens in humans and animals, little is known of the host-parasite interactions in natural hosts. Therefore, the objective of this study was to investigate the intestinal response in calves following a G. duodenalis infection, using a bovine high-density oligo microarray to analyze global gene expression in the small intestine. The resulting microarray data suggested a decrease in inflammation, immune response and immune cell migration in infected animals, which was examined in more detail by quantitative real-time PCR on a panel of cytokines combined with histological analyses. The cytokine transcription levels showed a trend of down regulated expression in infected animals compared to the negative controls, best seen in jejunum for IL-6 and IL-8 and statistically significant for IL-17, IL-13 and IFN-?. No increased immune cell recruitment could be seen after infection, as well as no intestinal pathologies, such as villus shortening or increased levels of apoptosis. Key regulators in this intestinal response seem to be the nuclear peroxisome proliferator-activated receptors alpha (PPARA) and gamma (PPARG), for which an up-regulated expression was seen on microarray and qRT-PCR data. The activation of PPARs can exert an anti-inflammatory effect with inhibition of pro-inflammatory cytokines and a decrease in cell recruitment. . How the PPARs are activated during a Giardia infection still needs to be further elucidated. Eight male Holstein calves aged two to four weeks old were used for the trial. Prior to arrival, all animals were screened for the presence of Giardia cysts in their faecal samples. After confirming their negative status for all these pathogens, four of the animals were randomly chosen and placed in a G. duodenalis contaminated environment, whereas the four remaining animals were kept as negative controls in separate G. duodenalis-free stables. All calves in the study received the same commercial milk replacer. After three weeks, the presence or absence of a G. duodenalis infection was confirmed by IFA on faecal samples after which the animals were euthanized. Changes in gene expression profiles induced by Giardia duodenalis infection were compared using a high-density 60mer bovine oligo microarray.
Project description:C57BL/6 mice were infected with the GS strain of G. duodenalis and total RNA prepared from the duodenum on day 10. Age matched controls were compared using Affy chips to determine changes in gene expression induced by infection. The majority of induced transcripts are invlved in antibody production. Genes exhibiting the greatest increase in expression are all mast cell transcripts. This is a 4X4 comparison, 4 infected mice and 4 uninfected mice
Project description:Despite Giardia duodenalis being one of the most commonly found intestinal pathogens in humans and animals, little is known about the host-parasite interactions in its natural hosts. Therefore, the objective of this study was to investigate the intestinal response in calves following a G. duodenalis infection, using a bovine high-density oligo microarray to analyze global gene expression in the small intestine. The resulting microarray data suggested a decrease in inflammation, immune response, and immune cell migration in infected animals. These findings were examined in more detail by histological analyses combined with quantitative real-time PCR on a panel of cytokines. The transcription levels of IL-6, IL-8, IL-13, IL-17, and IFN-γ showed a trend of being downregulated in the jejunum of infected animals compared to the negative controls. No immune cell recruitment could be seen after infection, and no intestinal pathologies, such as villus shortening or increased levels of apoptosis. Possible regulators of this intestinal response are the nuclear peroxisome proliferator-activated receptors alpha (PPARα), and gamma (PPARγ) and the enzyme adenosine deaminase (ADA), all for which an upregulated expression was found in the microarray and qRT-PCR analyses.
Project description:Giardiasis, caused by the protozoan parasite Giardia duodenalis, is an intestinal diarrheal disease affecting almost one billion people worldwide. A small endosymbiotic dsRNA viruses, G. lamblia virus (GLV), genus Giardiavirus, family Totiviridae, might inhabit human and animal isolates of G. duodenalis. Three GLV genomes have been sequenced so far, and only one was intensively studied, moreover a positive correlation between GLV and parasite virulence is yet to be proved. To understand the biological significance of GLV infection in Giardia, the characterization of several GLV strains from naturally infected G. duodenalis isolates is necessary. In the contest of high-throughput sequencing of four GLVs strains, from Giardia isolates of human and animal origin, we report on a new, unclassified viral sequence (designed GdRV-2), unrelated to Giardiavirus, encoding and expressing for a single large protein with a RdRp domain homologous to Totiviridae and Botybirnaviridae. We have analyzed the sequence of the GLV capsid protein (CP) and RNA-dependent RNA polymerase (RdRp) by LC-MS/MS analysis using different enzymatic strategies.
Project description:To investigate the transcriptional responses of intestinal epithelial cells and Giardia intestinalis, assemblage A isolate WB-C6, trophozoites during infection, we infected human enteroids with preconditioned trophozoites for 1h and 3h. Giardia intestinalis trophozoites were preconditioned before the infection with either DMEM/F-12 or DMEM/F-12 supplemented with 10% FBS to modify the trophozoites’ fitness.
Project description:Giardia duodenalis a species-complex of common gastrointestinal protists of major medical and veterinary importance. This complex is currently subclassifed as ‘Assemblages’, with Assemblage A and B infective to humans. To date, post-genomic proteomics are derived exclusively from Assemblage A, biasing understanding of these parasites’ biology. This bias is particularly notable, as Assemble B is the more prevalent cause of human infections. To address this gap, we quantitatively analysed proteomes of the intestinal ‘trophozoite’ stage of three Assemblage B isolates, including the genome reference (GS/M) and two clinical isolates (BRIS/91/HEPU/1279 and BRIS/92/HEPU/1487), during in vitro axenic culture. We used spectrum-to-peptide matching metrics to infer currently unknown intra-assemblage variation. We identified and quantified over 3000 proteins in the GS isolate, but demonstrated significant isolate-dependent losses in peptide and protein identifications in non-reference isolates, suggesting significant intra-assemblage variation. We also explore differential protein expression between in vitro cultured subpopulations enriched for dividing relative to feeding cells. This data is an important proteomic baseline for Assemblage B, and highlights unique differences heretofore avoided in post-genomic Giardia proteomics.
Project description:Giardia duodenalis is the protozoan agent responsible for the majority of parasitic gastroenteritis in humans worldwide. Disease pathology includes malabsorption and maldigestion, cell apoptosis and small intestinal barrier dysfunction, which occurs in absence of known toxins, cell invasion and overt inflammation. To understand pathogenesis, host-parasite in vitro interaction models provide global insights into disease induction and virulence. Hence, we performed the first proteomic analysis of G. duodenalis trophozoites interacted with intestinal epithelial cells (IECs, HT-29) for 6 hours, and compared it to trophozoites exposed to cell-free fractions of host-soluble signals. This has allowed us to demonstrate that distinct and independent protein cascades are induced by host attachment compared to host soluble signals. We utilised a tandem mass tag (TMT) approach and evaluated it as quantitative proteomics for the first time in Giardia.
Project description:The impact of high fat diet on secreted milk small RNA transcriptome was studied by isolating total RNA from milk fat fraction collected on lactation day 10 from control diet fed (C; n=5; 10% fat; 7% sucrose; Research Diets #D12450J, Brunswick, NJ) and high fat diet fed (HF; n=4; Research Diets #D12492, 60% of total kcal energy is fat and match 7% of total kcal is sucrose; Brunswick, NJ) mice.
Project description:The impact of high fat diet on secreted milk small RNA transcriptome was studied by isolating total RNA from milk fat fraction collected on lactation day 10 from control diet fed (C; n=5; 10% fat; 7% sucrose; Research Diets #D12450J, Brunswick, NJ) and high fat diet fed (HF; n=4; Research Diets #D12492, 60% of total kcal energy is fat and match 7% of total kcal is sucrose; Brunswick, NJ) mice.