Natural killer cell receptors in the horse: evidence for the existence of multiple transcribed LY49 genes. Academic Article uri icon


  • In rodents, the Ly49 family encodes natural killer (NK) receptors interacting with classical MHC class I molecules, whereas the corresponding receptors in primates are members of the killer cell immunoglobulin-like receptor (KIR) family. Recent evidence indicates that the cattle, domestic cat, dog, and pig have a single LY49 and multiple KIR genes, suggesting that predominant NK receptors in most non-rodent mammals might be KIR. Here, we show that the horse has at least six LY49 genes, five with an immunoreceptor tyrosine-based inhibition motif (ITIM) and one with arginine in the transmembrane region. Interestingly, none of the horse KIR-like cDNA clones isolated by library screening encoded molecules likely to function asNK receptors; four types of clones were KIR-Ig-like transcript (KIR-ILT) hybrids and contained premature stop codons and/or frameshift mutations, and two putative allelic sequences predicting KIR3DL molecules had mutated ITIM. To our knowledge, this is the first report suggesting that non-rodent mammals may use LY49 as NK receptors for classical MHC class I. We also show that horse spleen expresses ILT-like genes with unique domain organizations. Radiation hybrid mapping and fluorescence in situ hybridization localized horse LY49 and KIR/ILT genes to chromosomes 6q13 and 10p12, respectively.

published proceedings

  • Eur J Immunol

author list (cited authors)

  • Takahashi, T., Yawata, M., Raudsepp, T., Lear, T. L., Chowdhary, B. P., Antczak, D. F., & Kasahara, M.

citation count

  • 53

complete list of authors

  • Takahashi, Tomoko||Yawata, Makoto||Raudsepp, Terje||Lear, Teri L||Chowdhary, Bhanu P||Antczak, Douglas F||Kasahara, Masanori

publication date

  • March 2004