Two major groups of rat NKR-P1 receptors can be distinguished based on chromosomal localization, phylogenetic analysis and Clr ligand binding.
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.
Kveberg
Lise
L
Institute of Immunology, IMMI, Rikshospitalet University Hospital and University of Oslo, Oslo, Norway.
Dai
Ke-Zheng
KZ
Westgaard
Ingunn H
IH
Daws
Michael R
MR
Fossum
Sigbjørn
S
Naper
Christian
C
Vaage
John T
JT
D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D045744:Cell Line, Tumor; D006224:Cricetinae; D003412:Cricetulus; D003602:Cytotoxicity, Immunologic; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism; D037181:Lectins, C-Type / Q000276:immunology; D008024:Ligands; D008969:Molecular Sequence Data; D055651:NK Cell Lectin-Like Receptor Subfamily B / Q000145:classification* / Q000235:genetics* / Q000276:immunology; D010802:Phylogeny; D051381:Rats; D016415:Sequence Alignment
D037181:Lectins, C-Type; D008024:Ligands; D055651:NK Cell Lectin-Like Receptor Subfamily B