Intestinal nematode infections affect about 24% of the world population. In most areas these infections are co-endemic with protozoan infections like malaria and toxoplasmosis, as well as with bacterial infections like tuberculosis. The seroprevalence of Toxoplasma infections, especially in tropical regions, is almost 70%. Toxoplasma gondii induces a strong Th1 immune response in contrast to nematodes inducing Th2 responses and we are currently investigating such co-infections.
Our findings have shown that a previous T. gondii infection leads to a significantly increased worm fecundity, which is associated with a massive suppression of H. polygyrus-specific Th2 responses. The numbers of IL-4, IL-5 and IL-13-producing GATA-3+ Th2 cells and eosinophils, as well as the expression of the effector molecule RELM-b in the intestinal tissues of co-infected mice is massively reduced by a preceding T. gondii infection (Ahmed et al, Frontiers in Cellular and Infection Microbiology, 2017).
Ahmed, N., T. French, S. Rausch, A. A. Kühl, K. Hemminger, I. R. Dunay, S. Steinfelder, S. Hartmann. 2017. Toxoplasma co-infection prevents Th2 differentiation and leads to a helminth-specific Th1 response. Frontiers in Cellular and Infection Microbiology, doi:10.3389/fcimb.2017.00341.
Associated scientists: Dr. Svenja Steinfelder, Norus Ahmed.
Third-party funds: DFG GK 2046, Project B4.