NK-DC Crosstalk in Immunity to Microbial Infection

Figure 1

Bidirectional activation of NK cells and DCs for optimal immune response to microbial infection. DCs recognize pathogen-associated molecular patterns (PAMPs) found on the surface of pathogen through the expression of pattern recognition receptor (PRR). Following recognition of pathogen, DCs release cytokines such as IL-12, IL-15, IL-18, and IFN-α/β. These cytokines produced by DCs as well as the interactions of DC with NK cell activation receptors promote NK cell activation, proliferation, and cytotoxicity. Reciprocally, NK cells release IFN-γ to promote DC maturation and release of IL-12. IL-12 produced by DC further promotes CD8⁺ T cell and/or CD4⁺ T cell activation depending upon the nature of pathogen. IL-2 produced by CD4⁺ T cell can also stimulate NK cell activation for optimal immune response.