Schistosomal extracellular vesicle-enclosed miRNAs modulate host T helper cell differentiation

ABSTRACT: During the chronic stage of Schistosoma infection, the female lays fertile eggs, triggering a strong anti-parasitic Type 2 helper T cell (Th2) immune response. It is unclear how this Th2 response gradually declines even though the worms live for years and continue to produce eggs. Here, we show that S. mansoni downregulates Th2 differentiation in an antigen presenting cell-independent manner, by modulating the Th2-specific transcriptional program. Adult schistosomes secrete miRNA-harboring extracellular vesicles that are internalized by Th cells in-vitro. Schistosomal-miRNAs are found also in T helper cells isolated from Peyer's patches and mesenteric lymph nodes of infected mice. In T helper cells, the schistosomal miR-10 targets MAP3K7 and consequently down-modulates NF-kB activity, a critical transcription factor for Th2 differentiation and function. Our results explain, at least partially, how schistosomes tune down the Th2 response, and provide further insight into the reciprocal geographical distribution between high prevalence of parasitic infections and immune disorders such as allergy. Furthermore, this worm-host crosstalk mechanism can be harnessed to develop diagnostic and therapeutic approaches for human schistosomiasis and Th2-associated diseases.

SUBMITTER: Dr. Tal Meningher 

PROVIDER: S-SCDT-EMBOR-2019-47882V1 | biostudies-other |

REPOSITORIES: biostudies-other