Fetal liver- and thymus-derived NK1.1+ cells do not express known Ly- 49 receptors. Despite the absence of Ly-49 inhibitory receptors, fetal and neonatal NK1.1+Ly-49- cells can distinguish between class I(high) and class I(low) target cells, suggesting the existence of other class I-specific inhibitory receptors. We demonstrate that fetal NK1.1+Ly-49- cell lysates contain CD94 protein and that a significant proportion of fetal NK cells are bound by Qa1b tetramers. Fetal and adult NK cells efficiently lyse lymphoblasts from K(b-/-)D(b-/-) mice. Qa1b-specific peptides Qdm and HLA- CW4 leader peptide specifically inhibited the lysis of these blasts by adult and fetal NK cells. Qdm peptide also inhibited the lysis of Qa1b-transfected human 721.221 cells by fetal NK cells. Taken together, these results suggest that the CD94/NKG2A receptor complex is the major known inhibitory receptor for class I (Qa1b) molecules on developing fetal NK cells.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of Immunology|
|State||Published - Jun 15 1999|
ASJC Scopus subject areas
- Immunology and Allergy