Wednesday, July 17, 2013

Transcriptome Analysis of Mouse Brain Infected with Toxoplasma gondii

2013 Jul 15. [Epub ahead of print]

Transcriptome Analysis of Mouse Brain Infected with Toxoplasma gondii


National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.


Toxoplasma gondii is an obligate intracellular parasite that invades a wide range of vertebrate host cells. Chronic infections with T. gondii become established in the tissues of the central nervous system where the parasites may directly or indirectly modulate neuronal function. However, the mechanisms underlying parasite-induced neuronal disorder in the brain remain unclear. This study evaluated host gene expression in mouse brain following infection with T. gondii. BALB/c mice were infected with the PLK strain, and after 32 days of infection, histopathological lesions in the frontal lobe were found to be more severe than in other areas of the brain. Total RNA extracted from infected and uninfected mouse brain samples was subjected to transcriptome analysis using RNA sequencing (RNA-seq). In the T. gondii-infected mice, 935 mouse brain genes were up-regulated, whereas 12 genes were down-regulated. GOstat analysis predicted that the up-regulated genes were primarily involved in host immune responses and cell activation. Positive correlations were found between the number of parasites in the infected mouse brains and the expression levels of genes involved in host immune responses. In contrast, genes that had a negative correlation with parasite numbers were predicted to be involved in neurological function such as small GTPase-mediated signal transduction and vesicle-mediated transport. Furthermore, differential gene expression was observed between mice exhibiting the clinical signs of toxoplasmosis and those that did not. Our findings may provide insights into the mechanisms underlying neurological changes during T. gondii infection.
[PubMed - as supplied by publisher]

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