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).

Publication:

• 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.