The Ly49A receptor of TCR-αβ CD8αα iIELs interacts with MHC-I in cis. (A) iIELs isolated from B6 or B6 D^d mice were acid-treated or nontreated, and stained with D^d multimer. The percentage and the mean fluorescence intensity (MFI) of D^d multimer-binding by TCR-αβ CD8αα iIELs are shown as mean ± SEM (n = 3 for B6, n = 4 for B6 D^d). The extent of receptor masking was estimated by dividing the MFI of multimer staining after acid stripping (multimer, strip) by the MFI before acid stripping (multimer, no strip) and is presented as mean ± SEM. (B) Spleen cells from B6 or B6 D^d mice were acid-treated or nontreated, and stained with CD3, NK1.1, and D^d multimer. The percentage and the MFI of D^d multimer-binding NK cells (CD3⁻NK1.1⁺) are shown as mean ± SEM (n = 5). (A-B) *Significant difference (P < .05) in the MFI between nontreated versus acid-treated cells. **Significant difference (P < .05) in receptor masking between cells isolated from B6 versus B6 D^d mice (Mann-Whitney). (C) Representative histograms show D^d multimer staining of gated TCR-αβ CD8αα iIELs (left panels) and CD3⁻NK1.1⁺ spleen NK cells (right panels) from B6 or B6 D^d mice, as indicated.