Abstracts (complete list) - Wissenschaft Online

Philip Kruse, Cornelia Rosner, Lutz Walter
Molecular characterisation of the killer cell immunoglobulinlike
receptors (KIR) of the rhesus macaque (Macaca mulatta)
The killer cell immunoglobulin-like receptors (KIR) belong to the immunoglobulin
superfamily and are expressed mainly on the surface of natural killer (NK) cells. These
receptors interact with the major histocompatibility complex (MHC) class I molecules
and can mediate either an activating or an inhibitory signal to the NK cell. In contrast to
the activating receptors almost all ligands of the inhibitory receptors are known in
humans.
We have started to analyse KIR genes and their function in the rhesus macaque
(Macaca mulatta), a frequently used primate model for the study of infection diseases,
organ transplantation and in development of vaccines. A cDNA library of enriched NK
cells from 30 rhesus macaques has been established. Up to now, more then 15 new KIR
cDNA clones could be isolated. Phylogenetic analysis with already known rhesus
macaque KIR sequences confirms rapid evolution of KIR genes in primates. Further
analyses indicate the occurrence of two different activating KIR gene lineages in rhesus
macaques, which have developed independently from each other and both differ from
the lineage of human activating KIR genes.
The main differences of the rhesus macaque activating KIRs and the KIRs in hominoid
primates can be found in the transmembran region. Rhesus macaque activating KIRs
contain an arginin instead of a lysine in humans in the transmembran region. Usually,
this lysine residue interacts with the DAP12 adaptor molecule, which mediates
activating signals to the NK cell. Therefore, it is still open which adaptor molecule
interact with the activating KIRs of the rhesus macaque. Currently we are investigating
whether these activating KIRs do interact with adaptor molecules other than DAP12.