Differential proteomic analysis in a host–parasite interaction of host cells infected with Toxoplasma gondii

Toxoplasma gondii, a representative model organism of the phylum Apicomplexa, can infect almost all warm-blooded organisms including humans. Invasion of host cells in a host–parasite interaction is the key step necessary for T. gondii to complete its life cycle. Here, we investigate global proteomic changes based on TMT analysis in both the host cells (human foreskin fibroblasts, HFFs) and T. gondii during intracellular infection. A total of 3477 and 1434 proteins were quantified, of which 378 and 1100 proteins were differentially expressed (p-value<0.05 and ≥1.5-fold change)in Homo sapiens and T. gondii proteins, respectively. In HFF cells, Gene Ontology (GO) and KEGG pathway analyses revealed a large number of differentially expressed proteins (DEPs) enriched in metabolic processes and immune-associated signaling pathways, such as NF-κB, cAMP, and Rap1 signaling pathways. T. gondii DEPs involved in pathway analysis and GO annotations included cellular protein metabolic process, peptide metabolic process, and peptide biosynthetic processes and indicated that cell biosynthesis and metabolism were increased during T. gondii infection. These findings reveal new proteomic differences in the parasite–host interaction during T. gondii infection.