Schistosoma mansoni egg-induced inflammation inhibits γ-herpesvirus replication

Geographically, S. mansoni overlaps with human γ-herpesvirus infections such as Kaposi’s sarcoma-associated herpesvirus. The strongly regulated Th2-type immune response generated during infection by S. mansoni may jeopardize or improve the host’s ability to generate effective immunity against co-infecting pathogens, such as viruses. Here, we have trialled two approaches using murine herpesvirus-4 (MuHV-4). The first used a S. mansoni egg model to induce lung granulomas followed by intranasal infection with the MuHV-4-luc+ recombinant virus. Alternatively, we naturally infected mice with S. mansoni cercariae to induce a systemic Th2-type response and granulomas in the liver and intestine before intranasal MuHV-4-luc+ infection. We observed in both models a significant reduction of MuHV-4 replication in the lungs at day 5 and 7 pi associated with reduced weight loss caused by MuHV-4 infection. These results indicate that helminth induce Th2-type responses could inhibit and protect against viral infection