Fig. 1

Comparison between the immune-related molecules expressed on murine pre-mNK cells and human CD56^bright HLA-DR⁺ NK cells. Murine pre-mNK cells classically express CD11c^loCD49bB220NK1.1 and are GR-1^neg in C57BL6/mice, but lack NK1.1 in other strains. Pre-mNK cells also express NKG2D and respond to the chemokine CCL2 due to expression of CCR2, making them apt for migrating to tumor sites. Upon licensing by tumor cells, pre-mNK cells express class II and other immune related molecules. The Id-2 transcription factor is prevalent in pre-mNK cells showing that they are more NK cell-like than DC. Both murine and human CD56^brightHLA-DR⁺ NK cells express the IL-2/IL-15Rβγ, making them responsive to these cytokines in different contexts. Human CD56^brightHLA-DR⁺ NK cells express CD56 at high levels, HLA-DR, and CD94/NKG2 receptors, and low to no amounts CD16. They are CXCR3 expressing cells making them able to migrate to secondary lymphatic tissues or places of inflammation. Both murine and humans cells may also express PD-L1 in different environmental conditions, and both can make IFN-γ and IL-10 in varying amounts, again depending on their environment. By no means are these molecules listed complete or absolute and further research is needed to clarify the roles of each on these cells