TNF and infection: Next, we assessed whether all these alterations in the immune response: robust increase in GITR expression in several cells from the immune system, together with the increase in IFN-γ, TNF-α, and IL-6 production and a decreased IL-10/ IFN-γ at sites of parasite replication in the acute stage of infection, would lead to an increased parasite killing in the chronic stage of the disease.