TNF and infection: It is generally accepted that macrophage activation by cytokines, such as IFN-γ and TNF-α, is important for eradication of Salmonella in experimental infection (Stoycheva and Murdjeva, 2005) as these cytokines stimulate NK cells and macrophage effector mechanisms and later ensure T-cell response for pathogen clearance (de Jong et al., 2012).