Comparison of splenocyte microRNA expression profiles of pigs during acute and chronic toxoplasmosis

Abstract

BackgroundToxoplasma gondii is an obligate intracellular parasite that infects humans and other warm-blooded animals. Previous quantitative proteomic analyses of infected host cells revealed that the expression of many host proteins is modulated by T. gondii infection. However, at present limited data are available on the differentially expressed miRNAs (DEMs) associated with the pathology and host immune responses induced by acute and chronic infection with T. gondii in pigs in vivo. In this study, high-throughput sequencing was used to investigate expression profiles of spleen miRNAs at 10, 25 and 50 days post-infection (DPI) in pigs infected with Chinese I genotype strain T. gondii isolated from a dead pig.ResultsWhen compared to the control group, 34, 6 and 86 DEMs were found in spleens of infected pigs at 10, 25 and 50 DPI, respectively. Gene Ontology (GO) enrichment analysis of the target genes of DEMs showed that no GO terms were enriched at 25 DPI, whereas 28 and 241 GO terms, of which two and 215 were sample-specific, were significantly enriched at 10 and 50 DPI, respectively. The top 20 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of the target genes of DEMs included signal transduction, immune system, metabolism and diseases. miRNA–gene network analysis revealed that the DEMs played important roles in the host immune response to T. gondii infection by modulating expression levels of cellular immunity-related cytokines and immune-related C-type lectins.ConclusionOur results not only showed that host miRNA expression is altered by T. gondii but also revealed differences in the regulation of key biological processes and pathways involved in host responses to acute versus chronic T. gondii infection. This will aid future research into miRNA-target interactions during T. gondii infection in pigs and the development of novel therapies against T. gondii.Electronic supplementary materialThe online version of this article (10.1186/s12864-019-5458-y) contains supplementary material, which is available to authorized users.

MicroRNAs: Biological Regulators in Pathogen–Host Interactions

“…On the other hand, infection with the Me49 strain upregulated the expression of this miRNA. In addition, when porcine splenocytes were infected with YZ-1, miR-17 was upregulated after 25 dpi [154]. However, PAMs also presented changes in the miRNAs that regulate TNFα, indicating a predictive link between some novel miRNAs.…”

Global Transcriptome Profiling of Multiple Porcine Organs Reveals Toxoplasma gondii-Induced Transcriptional Landscapes

“…Previous studies have provided beneficial but limited insights into the porcine response to T. gondii through using methods such as high-throughput sequencing to identify the mRNA and miRNA profiles (19–22), and microarrays (23). Recent research showed that T. gondii loads vary across different porcine tissues, with high parasite loads detected in the heart and lungs during acute infection, and in the heart and brain during chronic infection, regardless of the strain of the parasite (24).…”

The Role of microRNAs in the Infection by T. gondii in Humans

“…Toxoplasma gondii (T. gondii), the etiological agent for toxoplasmosis, is an intracellular parasite that infects nucleated cells from all warm-blooded animals (Li et al, 2019;Hou et al, 2019). It has three infectious stages known as tachyzoite, bradyzoite, and sporozoites (within oocysts) (Dubey et al, 1998).…”

“…The microRNA blockade of mRNA is fundamental for protection against pathogenic virus and bacteria in plants, insects and animals (Hou et al, 2019). microRNAs interact mainly with the 3' untranslated region of their target mRNAs, controlling the translation or affecting the transcript stability favouring mRNA degradation (Hou et al, 2019). Some studies have shown that Apicomplexan parasites affect the host microRNA expression profile (Deng et al, 2004;McDonald et al, 2013;Hou et al, 2019).…”