BCG-immunization protects <i>Socs3^fl/fl</i> and <i>Socs3^fl/fl lck cre</i> mice equally well against <i>M. tuberculosis</i> challenge.

<p><i>M. tuberculosis</i>-infected <i>Socs3^fl/fl lck cre</i> and <i>Socs3^fl/fl</i> mice were sacrificed 4 weeks after infection and the total RNA was extracted from lungs. The accumulation of <i>Ifn-γ</i> (A) or <i>Hprt</i> transcripts was measured by real time PCR. The mean fold cytokine mRNA increase ± SEM in lungs from infected mice (n≥5 per group) was calculated. One out of two independent experiments is depicted. Differences with controls are significant (*p&lt;0.05, **p&lt;0.01 Student t test). <i>Socs3^fl/fl lck cre</i> and <i>Socs3^fl/fl</i> mice were sacrificed 2.5 weeks after infection with <i>M. tuberculosis</i>. Lung cell suspensions were stimulated with 20 µg/ml PPD and concentrations of IFN-γ (B) in supernatants after 48 h were measured by cytokine bead assay (CBA). The mean cytokine concentration ± SEM (n≥6 animals per group) is depicted. Differences in cytokine concentrations are significant (***p&lt;0.001 ANOVA with Bonferroni correction). Total RNA was extracted from lungs of <i>Socs3^fl/fl lck cre</i> and <i>Socs3^fl/fl</i> mice 6 weeks after BCG infection. Levels of <i>Il-17a</i> (C) mRNA expression was determined by real time PCR (n = 6 mice per group). <i>Socs3^fl/fl lck cre</i> and <i>Socs3^fl/fl</i> mice were immunized s.c. with 5×10⁶ heat-killed BCG and boosted after 2 weeks with 2.5×10⁶ heat-killed BCG. Mice were sacrificed four weeks after the priming, and spleen cell suspensions from immunized or non-immunized control mice were co-incubated with 15 µg/ml PPD for 72 h. The concentration of IL-17 (D) and IFN-γ (E) in the culture supernatants was determined by ELISA. The mean cytokine concentration ± SEM (n = 6 animals per group) is depicted. <i>Socs3^fl/fl lck cre</i> and <i>Socs3^fl/fl</i> mice were sacrificed 6 weeks after i. v. infection with 10⁶ BCG, and the CFU per lung, spleen and liver were quantified. The individual and median CFU per group (n≥6) are depicted (F). <i>Socs3^fl/fl lck cre</i> and <i>Socs3^fl/fl</i> mice were infected with 10⁶ BCG i.v. and were challenged with <i>M. tuberculosis</i> 10 weeks post BCG infection. Four weeks after <i>M. tuberculosis</i> infection, mice were sacrificed and the CFU in the lungs were quantified. The individual and median CFU per group (n≥6) are shown (G). Differences in CFU are significant (**p&lt;0.05, ***p&lt;0.001 Mann Whitney U test). Wild type mice were either infected with 10⁶ BCG i.v. (I, J) or via aerosol with <i>M. tuberculosis</i> Harlingen (H, J). The total RNA was isolated from lungs or pulmonary CD90+ T cells at the indicated time points. The mean fold <i>Socs3</i> mRNA increase ± SEM (n = 5 per group) was determined by real-time PCR (H–J). Differences with between groups are significant (*p&lt;0.05 Student t test).