- Mice coinfected with T. spiralis or H. polygyrus and with mouse Norovirus (MNV) had increased viral loads and reduced amounts of specific CD4+ T cells expressing IFN-γ and TNF-alpha when compared to the mice infected with Norovirus alone- Conclusion: Parasite infection alters the immune response creating favorable environment for the parasite at the expense of antiviral immunity. This evidence concerns the gene IFNG and biological process involved in symbiotic interaction.