Figure 5. Model for MHC-I selective inhibition.

(A) Trans-associated inhibitory receptors to MHC-I molecules are always inhibitory for effector cells. (B) and (C) Cis-associated inhibitory receptor/MHC-I selectively inhibits activating receptor signaling. It is proposed that LIRL receptors which bind to α3-β2m domains, and KIR or CD94-NKG2 receptors which bind to α1–α2 domains on MHC-I molecules [31] could participate in these interactions (shown as unknown receptors).