Recognition of H-2K(b) by Ly49Q suggests a role for class Ia MHC regulation of plasmacytoid dendritic cell function.

Ly49Q is a member of the polymorphic Ly49 family of NK cell receptors that displays both a high degree of conservation and a unique expression pattern restricted to myeloid lineage cells, including plasmacytoid dendritic cells (pDC). The function and ligand specificity of Ly49Q are unknown. Here, we use reporter cell analysis to demonstrate that a high-affinity ligand for Ly49Q is present on H-2(b), but not H-2(d), H-2(k), H-2(q), or H-2(a)-derived tumor cells and normal cells ex vivo.