Analysis diferential gene expression of skeletal muscular cells from a primary culture infected with tackyzoites of toxoplasma gondii.
The microarray technique is a powerful tool to analyze the changes in gene expression occurring during an infectious process caused by a pathogen. This work aims to study the biological process of interaction between a host cell and an intracellular parasite, Toxoplasma gondii, at a transcriptional level, using a high density microarray (Genechip®) Samples were collected from 30 minutes, 4 hours and 24 hours of infection, using mice skeletal muscular cells from a primaryculture infected with tackyzoites of Toxoplasma gondii, strain RH. We have selected 22 candidate genes modulated in the infectious process, by using two different analysis methods (Li-Wong and gcRMA). An analysis based on gene ontology (GO) has provided several biological processes that are affected during the infection. A comparative analysis with the work ofBLADER et al. showed a good correlation between both datasets. In our results, we have obtained 42 differentially expressed genes in 30 minutes, 95 in 4 hours and 631 in 24 hours, after a selection based in statistical (5% FDR) and fold change (gt;=1.75) criteria. It was seen that 435 outof 631 genes had annotation of biological processes, with 120 genes (27.6%) involved on nucleotide and amino acid metabolism, 78 genes (17.9%) involved on transcriptional regulation, 77 genes (17.7%) involved on cellular signaling, 44 genes (10.1%) involved on lipids and carbohydrates metabolism, 29 genes (6.7%) involved on cell cycle, 28 genes (6.4%) involved on cellular adhesion and cytoskeleton, 24 genes (5.5%) involved on protein synthesis and degradation, 22 genes (5.1%) involved on apoptosis and 8 genes (1.8%) involved oninflammatory processes. In a next step, we have used the Ingenuity Pathways Analysis 3.1 software, aiming to construct gene interaction and regulation network, being able to select themain networks modulated during the infection. Our work has identified many changes in the expression of several genes involved on the fusion of vesicles and the vesicle mediatedtransport, including the Rabs proteins, besides other accessories proteins from the complex; inflammatory response genes, apoptosis genes, cell cycle genes, among many others, which will be used as future research goals, to provide a deeper biological description of the infection process of Toxoplasma gondii.
Advisor:Christian Macagnan Probst; Marco Aurélio Krieger
School:Faculdades Oswaldo Cruz
Source Type:Master's Thesis
Date of Publication:06/14/2006