SOCS3-deficient BMM show diminished TNF secretion after infection with <i>M. tuberculosis</i>.

<p><i>Socs3^fl/fl LysM cre</i> and <i>Socs3^fl/fl</i> mice were infected with <i>M. tuberculosis</i> Harlingen via the aerosol route. Animals were sacrificed at the indicated time points after infection and the total RNA was extracted from lungs. The accumulation of <i>Il-6</i> and <i>Hprt</i> transcripts was measured by real time PCR. The mean fold <i>Il-6</i> mRNA increase ± SEM in lungs from infected mice (n≥5 per group) was calculated (*p&lt;0.05 Student t test)(A). The levels of <i>Il-6</i> mRNA in <i>Socs3^fl/fl</i> and <i>Socs3^fl/fl LysM cre</i> (B) or <i>gp130^F/F</i> and WT (D) BMM infected with <i>M. tuberculosis</i> were determined by real time PCR. The mean fold increase of mRNA level ± SEM in triplicate independent cultures per condition compared to non-infected cultures in one out of two independent experiments is depicted (*p&lt;0.05 Student t test). The mean IL-6 concentration ± SEM in supernatants of <i>M. tuberculosis</i>-infected <i>Socs3^fl/fl</i> and <i>Socs3^fl/fl LysM cre</i> pulmonary macrophages as determined by ELISA is depicted. IL-6 secretion by BCG-infected <i>Socs3^fl/fl</i> and <i>Socs3^fl/fl LysM cre</i> peritoneal macrophages is shown (C). The concentration of TNF was measured in supernatants of <i>M. tuberculosis</i>-infected <i>Socs3^fl/fl</i> and <i>Socs3^fl/fl LysM cre</i> BMM co-incubated with or without 50 ng/ml of recombinant IL-6 (E). The levels of <i>Tnf</i> mRNA in <i>Socs3^fl/fl</i> and <i>Socs3^fl/fl LysM cre</i> (F) or <i>gp130^F/F</i>, <i>gp130^F/F Il-6^−/−</i> and WT (G) BMM infected with <i>M. tuberculosis</i> were determined by real time PCR. The mean fold increase of mRNA level ± SEM in triplicate independent cultures per condition compared to non-infected cultures of one of two independent experiments is depicted (*p&lt;0.05, **p&lt;0.01, ***p&lt;0.001 Student t test).