Two major groups of rat NKR-P1 receptors can be distinguished based on chromosomal localization, phylogenetic analysis and Clr ligand binding

Eur J Immunol. 2009 Feb;39(2):541-51. doi: 10.1002/eji.200838891.


A major subset of non-alloreactive NK cells in PVG strain rats is generally low in Ly49 receptors, but expresses the rat NKR-P1B(PVG) receptor (previously termed NKR-P1C). The NKR-P1B(+) NK subset is inhibited by a non-polymorphic target cell ligand, which we have shown here to be a C-type lectin-related molecule (Clr). Clr11 ligates two divergent NKR-P1B alleles as judged by an NFAT-driven reporter assay, and inhibits NK-cell cytotoxicity of NKR-P1B(+) NK cells. Clr11 also interacts with the prototypic NKR-P1A receptor and exerts a stimulatory influence on NK lysis. NKR-P1A and B are encoded by adjacent genes in the proximal part of the NK gene complex and show close sequence homology in their extracellular region. They diverge from another pair, NKR-P1F and -G, which is encoded by a second, distal Nkrp1 gene cluster. NKR-P1F and -G bind an overlapping panel of Clr ligands, but not Clr11. Rat Clr molecules appear to be constitutively expressed by hematopoietic cells; expression in tumor cell lines is more variable. The data show the existence of two phylogenetic groups of NKR-P1 molecules, which demonstrate conservation of ligand-binding properties independent of signaling function.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • CHO Cells
  • Cell Line, Tumor
  • Cricetinae
  • Cricetulus
  • Cytotoxicity, Immunologic
  • Killer Cells, Natural / immunology*
  • Killer Cells, Natural / metabolism
  • Lectins, C-Type / immunology
  • Ligands
  • Molecular Sequence Data
  • NK Cell Lectin-Like Receptor Subfamily B / classification*
  • NK Cell Lectin-Like Receptor Subfamily B / genetics*
  • NK Cell Lectin-Like Receptor Subfamily B / immunology
  • Phylogeny
  • Rats
  • Sequence Alignment


  • Lectins, C-Type
  • Ligands
  • NK Cell Lectin-Like Receptor Subfamily B