Natural killer group 2 member D(NKG2D)is a type II transmembrane receptor.NKG2D is present on NK cells in both mice and humans,whereas it is constitutively expressed on CD8+T cells in humans but only expressed upon T-...Natural killer group 2 member D(NKG2D)is a type II transmembrane receptor.NKG2D is present on NK cells in both mice and humans,whereas it is constitutively expressed on CD8+T cells in humans but only expressed upon T-cell activation in mice.NKG2D is a promiscuous receptor that recognizes stress-induced surface ligands.In NK cells,NKG2D signaling is sufficient to unleash the killing response;in CD8+T cells,this requires concurrent activation of the T-cell receptor(TCR).In this case,the function of NKG2D is to authenticate the recognition of a stressed target and enhance TCR signaling.CD28 has been established as an archetype provider of costimulation during T-cell priming.It has become apparent,however,that signals from other costimulatory receptors,such as NKG2D,are required for optimal T-cell function outside the priming phase.This review will focus on the similarities and differences between NKG2D and CD28;less well-described characteristics of NKG2D,such as the potential role of NKG2D in CD8+T-cell memory formation,cancer immunity and autoimmunity;and the opportunities for targeting NKG2D in immunotherapy.展开更多
文摘Natural killer group 2 member D(NKG2D)is a type II transmembrane receptor.NKG2D is present on NK cells in both mice and humans,whereas it is constitutively expressed on CD8+T cells in humans but only expressed upon T-cell activation in mice.NKG2D is a promiscuous receptor that recognizes stress-induced surface ligands.In NK cells,NKG2D signaling is sufficient to unleash the killing response;in CD8+T cells,this requires concurrent activation of the T-cell receptor(TCR).In this case,the function of NKG2D is to authenticate the recognition of a stressed target and enhance TCR signaling.CD28 has been established as an archetype provider of costimulation during T-cell priming.It has become apparent,however,that signals from other costimulatory receptors,such as NKG2D,are required for optimal T-cell function outside the priming phase.This review will focus on the similarities and differences between NKG2D and CD28;less well-described characteristics of NKG2D,such as the potential role of NKG2D in CD8+T-cell memory formation,cancer immunity and autoimmunity;and the opportunities for targeting NKG2D in immunotherapy.
