Figure 3.

Described murine phenotypes of pre-mNK cells. This figure illustrates the different described phenotypes of pre-mNK cells. The top left image represents pre-mNK cells which have the capacity to present antigens to both CD4⁺ and CD8⁺ T cells. Antigen-presenting pre-mNK cells express CD11b and CD206, a mannose receptor implicated in the uptake of antigens. The top right image depicts cytotoxic pre-mNK cells obtained through the trans-presentation of IL-15. IL-15 promotes pre-mNK cells to actively transcribe several genes, thus enhancing IFN-γ production, cytolytic potential, and upregulating the expression of chemokines receptors on pre-mNK cells which facilitates the recruitment at tumor sites. The bottom left image portrays ex vivo isolated primary pre-mNK cells, which express high levels of Ly108 and low levels of CD43. Primary pre-mNK cells acquire an mNK cell phenotype upon in vivo transfer. The bottom right image illustrates that bone-marrow pre-mNK cells can be recruited to the tumor environment by an unidentified mechanism. Upon killing of a tumor cell, these bone-marrow pre-mNK cells are licensed to cross-present tumor antigens to T cells, initiating the adaptive immune response.