We also tested another Type II T. gondii isolate, DEG (T. gondii DEG), which had been implicated in reduced IL-1β secretion following in vitro infection of macrophages24 but, similar to inoculation with T. gondii ME49 ASP5-deficient parasites, inoculation with T. gondii DEG did not lead to reduced levels of serum IL-18 and NK cell-produced IFN-γ in this model (Fig. 5c,d). This evidence concerns the gene IL1B and infection.