Figure 1

Natural killer cell function during bacterial infection is modulated by the balance of factors into a complex environment. Accessory cells (AC), such as dendritic cells, monocytes or others, provide activating signals that trigger synergistic activation of natural killer (NK) cells together with pathogen-associated molecular patterns (PAMPs) to produce cytokines. On the other hand, activated T regulatory cells (Tregs) can counterbalance this by providing suppressive cytokines (for example, transforming growth factor (TGF)-β and IL-10) to abolish NK cell activation. GM-CSF, granulocyte-macrophage colony-stimulating factor; IFN, interferon.