IL10 and infection: We then measured cell frequencies and cytokine production at day 4 post infection (p.i.)in the spleen, when Th1 cell responses peak in this tissue in this model (Supplemental Figure 4), and found a decrease in the proportion of splenic PbTIIΔSting cells producing IL-10 and an increase in those producing IFN-γ relative to control PbTIIWT cells (Figure 5B and Supplemental Figure 5, A and B).