TNF and infection: To ascertain whether LsfA would impact cytokine production in vivo, thus potentially decreasing the immune system activation and neutrophil recruitment to the infection site, the TNF-α and IFN-γ levels in the lungs of infected animals were determined by ELISA at 24 hours p.i. The wild-type strain induced local immunosuppression, with TNF-α and IFN-γ release similar to that observed in the control mice (Fig. 4C).