Functional properties of MHC-I receptors on iIELs. (A) MIP-1α production by CD8αα iIELs from B6 mice was determined after in vitro stimulation with plate-bound anti-CD3 mAb plus anti-NKG2A mAb (clone 16a11; ) or an isotype control mAb (■). MIP-1α production by CD94/NKG2A single-positive CD8αα iIELs relative to the subpopulation expressing no inhibitory MHC-I receptors is shown as mean ± SEM (n = 6). *Significant difference (P < .05) between isotype control and anti-NKG2A mAb (Mann-Whitney). (B) iIELs from B6 mice were stimulated with plate-bound anti-CD3 mAb plus anti-Ly49A mAb clone JR9–318 (), anti-Ly49A mAb clone A1 (□), or an isotype control mAb (■). MIP-1α production by Ly49A single-positive CD8αα iIELs relative to the subpopulation expressing no inhibitory MHC-I receptors is shown as mean ± SEM (n = 4). There was no significant difference (NS) in MIP-1α production in the presence of plate-bound anti-Ly49A mAb versus isotype control (Mann-Whitney). (C) iIELs from B6 mice were stimulated with plate-bound anti-CD3 mAb plus anti-Ly49G2 mAb clone 4D11 () or an isotype control mAb (■). MIP-1α production by Ly49G2 single-positive CD8αα iIELs relative to the subpopulation expressing no inhibitory MHC-I receptors is shown as mean ± SEM (n = 3). There was no significant difference (NS) in MIP-1α production in the presence of plate-bound anti-Ly49G2 mAb versus isotype control (Mann-Whitney).