Molecular Mechanisms of the Host Immune Response to Toxoplasma gondii Infection

Toxoplasmosis is still a worldwide problem, causing severe disease in humans and animals. T. gondii virulence was originally defined based on murine infections. Previous studies focused mainly on three genotypes, the canonical T. gondii strains that are commonly found in Europe and North America, but new parasite strains with unexpected virulence even in humans have been discovered in other parts of the world. The great diversity in the T. gondii population structure worldwide suggests our understanding of parasite virulence will evolve significantly by studying these non-canonical strains in more detail. T. gondii virulence is mediated, in part, by secretion of effector molecules into the host cell cytosol during and after invasion. However, susceptibility to infection varies significantly between the host range, with laboratory mice eventually dying in the acute phase of infection and wild-derived mice being fully refractory, demonstrating that not only parasite effectors but also host cell molecules determine parasite virulence. Considering the broad host range of T. gondii, the impact of specific parasite effectors in other species is unpredictable due to possible variations between rodents and other intermediate hosts. Emerging evidence suggests that the host gut microbiota plays an immunomodulatory role in T. gondii colonization, and probiotics have been proven to be effective against Toxoplasma infection. New omics techniques have also been used to screen key molecules in hosts infected with T. gondii. Posttranslational modification (PTM) of proteins can strictly regulate various cell biological processes, and more than 400 PTMs related to cellular functions and diseases have been explored with the development of mass spectrometry technology. Phosphorylation, crotonylation and acetylation have been shown to regulate host immune responses after infection with T. gondii, and some modification sites may play an important role. Further research is necessary to unravel the intricate interactions between parasite and host cell molecules and their impact on the outcome of infection to develop effective treatments against this prevalent parasitic infection.

This Research Topic aims to further understand the molecular mechanisms of the host immune response towards the establishment of T. gondii infection by studying the interaction between the host and the parasite, thus explore new strategies to intervene with T. gondii infection. We are delighted to welcome reviews and original articles. The scope of this article collection includes, but is not limited to the following topics:

-Signaling mechanisms of host innate immune response in Toxoplasma gondii infection.

-Mechanisms of Toxoplasma gondii to escape the host immune response.

-Impact of gut microbiota on host-parasite interactions.

-Identification of potential molecular targets for diagnosis and treatment of the host infected with Toxoplasma gondii by new omics analysis (note: multi-omics analysis is also worth considering).