Figure 5.

Schematic representation of receptors involved in NKCE mechanisms. NKCEs activate NK cells by targeting various receptors, including CD16a, NKp46, NKp30, NKG2C, and NKG2D. Structurally, CD16a, NKp46, and NKp30 are monomeric and classified as natural cytotoxicity receptors, whereas NKG2C and NKG2D are dimeric and categorized as C-type lectin receptors. NKG2C forms a heterodimeric structure with CD94, while NKG2D has a symmetric homodimeric configuration. Signal transduction is initiated through a signaling cascade starting with ITAM (immunoreceptor tyrosine-based activation motif) autophosphorylation. For CD16a, NKp46, and NKp30, ITAM function is mediated by CD3ζ/Fc-εRI-γ, whereas for NKG2C and NKG2D, it is mediated by DAP12 and DAP10, respectively.