In summary, the results of our experiments in differentiated DC indicate that (1) whereas IL-6 production and low level of maturation characterize the DC response to Ei under resting conditions, selective inhibition of IL-12 production characterizes the response to infection under activating conditions; (2) Exposition of DC to Ei spores, results in both infected cells and non-infected “bystanders,” that exhibit segregated levels of maturation; (3) whereas mature bystanders DC promote, immature infected DC inhibit IFNγ secretion by naïve T cells. Here, IFNG is linked to infection.