CD1D and infection: While infection of both CD1d−/− and Jα18−/− mice with the IAV strain A/Puerto Rico/8/34 (PR8) lead to a more severe phenotype and a greater expansion of CD1d- and CD40-expressing MDSCs in the lungs of Jα18−/− and CD1d−/− mice as compared to PR8-infected wild-type mice, only adoptive transfer of iNKT cells into Jα18−/− mice ameliorated the disease course and reduced MDSC numbers whereas CD1d−/− mice remained hypersusceptible and depicted unchanged numbers of MDSCs.