Gene expression profiling in cardiac tissue of mice chronically infected with Toxoplasma gondii: implications for immune response pathways

Toxoplasma gondii is a common and opportunistic protozoan in vertebrates. Most cases of infection are asymptomatic, but in individuals with an immune system deficiency, it can cause severe complications. The parasite has the ability to form cysts in the host's heart, brain, and other tissues. Heart tissue damage during toxoplasmosis infection is associated with many complications, such as myocarditis, pericarditis, arrhythmia and heart failure. The parasite can survive and create a chronic form of infection by changing the expression of genes effective in the immune system. Therefore, the present study aims to investigate expression dynamics of candidate genes in the heart tissue of mice infected with the chronic T. gondii strain of Tehran and the pathways involved. After causing toxoplasmosis infection in mice and confirming the infection by MAT, RNA was extracted from the heart tissue of mice and converted into cDNA. Then, real-time PCR was performed to check the expression changes based on the designed primers of the target genes, and pathway analysis was performed. The results of real-time PCR analysis showed that all candidate genes have a higher expression in infected heart tissue compared to non-infected heart tissue. In addition, gene ontology and pathway analysis revealed that the cytosolic DNA-sensing pathway and autoimmune thyroid illness had the most gene participation.