The outcome of infections with Toxoplasma gondii in humans is dependent in part on the genetic makeup of the infecting organism. Recent studies have indicated that most infecting Toxoplasma organisms fall into 1 of 3 canonical lineages. Previous studies have investigated the effects of Toxoplasma on its host cell transcriptome. Little is known, however, about the effects of three canonical lineages on brain cells, the principal site of parasite lifelong persistence. In this study, we examined the transcriptional profile of human neuroepithelioma cells in response to T. gondii infection using microarray analysis to characterize the strain-specific host cell response to 3 canonical T. gondii strains. We found that the extent of the expression changes varied considerably among the three strains. Neuroepithelial cells infected with type I exhibited the most differential gene expression, whereas type II infected cells had a substantially smaller number of genes which were differentially expressed. Cells infected with type III exhibited intermediate effects on gene expression. The three strains also differed in the individual genes and gene pathways which were altered following cellular infection. For example, gene ontology (GO) analysis indicated that type I infection largely affects genes related to central nervous system while type III infection largely alters genes which affect nucleotide metabolism; type II infection does not alter expression of a clearly defined set of genes. Moreover, Ingenuity pathway analysis (IPA) revealed the sophistication of different strain in its interactions with the host. These differences may explain some of the variation in the neurobiological effects of different strains of Toxoplasma on infected individuals.
Differential effects of three canonical Toxoplasma strains on gene expression in human neuroepithelial cells.
Cell line
View SamplesMania is a serious neuropsychiatric condition associated with significant morbidity and mortality. Previous studies have suggested that environmental exposures can contribute to mania pathogenesis. We measured dietary exposures in a cohort of individuals with mania and other psychiatric disorders as well as in control individual without a psychiatric disorder. We found that a history of eating nitrated dry cured meat, but not other meat or fish products, was strongly and independently associated with current mania (adjusted odds ratio 3.49, 95% confidence interval (CI) 2.24-5.45, p<8.97x 10-8). Lower odds of association were found between eating nitrated dry cured meat and other psychiatric disorders. We further found that the feeding of meat preparations with added nitrate to rats resulted in alterations in behavior and changes in intestinal microbiota. Rats fed diets with added nitrate also showed alterations of brain pathways dysregulated in mania. These findings may lead to new methods for preventing mania and for developing novel therapeutic interventions
Nitrated meat products are associated with mania in humans and altered behavior and brain gene expression in rats.
Sex, Specimen part
View SamplesHuman mucosal surfaces contain a wide range of microorganisms. The biological effects of these organisms are largely unknown. Large-scale metagenomic sequencing is emerging as a method to identify novel microbes. Unexpectedly, we identified DNA sequences homologous to virus ATCV-1, an algal virus not previously known to infect humans, in oropharyngeal samples obtained from healthy adults. The presence of ATCV-1 was associated with a modest but measurable decrease in cognitive functioning. A relationship between ATCV-1 and cognitive functioning was confirmed in a mouse model, which also indicated that exposure to ATCV-1 resulted in changes in gene expression within the brain. Our study indicates that viruses in the environment not thought to infect humans can have biological effects.
Chlorovirus ATCV-1 is part of the human oropharyngeal virome and is associated with changes in cognitive functions in humans and mice.
Treatment
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