IL10 and infection: This population increased in frequency ∼50 fold, comprising 0.1±0.02% of CD3ε+CD4+ cells in naïve mice and 5.0±0.9% at day 28 of infection (p<0.001), equating to a ∼170 fold expansion in the total number of splenic T cells capable of simultaneous production of IFNγ and IL-10 (7.6±1.2×103 vs 1.3×106±1.7×105 in naïve and day 28 infected mice, respectively; p<0.001).