Exosomes derived from Toxoplasma gondii stimulate an inflammatory response through JNK signaling pathway.

Aim: Exosomes are nanoscale membranous vesicles secreted by most cell types able to transfer bioactive molecules among cells, which play crucial roles in intercellular communication. We characterized the exosomes derived from Toxoplasma gondii and detected the immune response in macrophages.

Methods: We used transmission electron microscopy, nanotracking analysis and western blotting to identify T. gondii exosomes. Functional experiments were performed in RAW264.7 cells for the induction of cytokines, MAPKs (p38 MAPK, ERK 1/2 and c-Jun N-terminal kinase [JNK]), mRNAs and nuclear translocation of phosphorylated JNK protein.

Results: JNK pathway was activated by T. gondii exosomes, and the production of IL-12, IFN-γ and TNF-α was significantly increased in macrophages.

Conclusion: Our findings demonstrated that T. gondii exosomes elicit innate immune through JNK activation, which could provide new insight into the essential regulators of host-pathogen interactions.