NK Cell and CD4+FoxP3+ Regulatory T Cell Based Therapies for Hematopoietic Stem Cell Engraftment

Figure 1

Role of NK cells during allogeneic HSC rejection. Donor allogeneic HSCs express MHC class I molecules that are not recognized by the inhibitory receptors of licensed NK cells resulting in HSC lysis, whereas there can be unlicensed NK cell subsets that express inhibitory receptors capable of recognizing the MHCI of allogeneic BMC. On the contrary, donor NK cells share MHCI expression with donor BMC and thus are less likely to play a role in allogeneic BMC rejection. In allogeneic HCT settings, the presence of host licensed NK cells at the time of transplantation can influence the donor engraftment outcome.