Searching for this unknown receptor, we discovered a new family of receptors (KLRI1 and KLRI2) (2005) and demonstrated that KLRE1 forms heterodimeric receptor complexes with KLRI1 and -2 that either inhibit (KLRE/I1) or activate (KLRE/I2) NK cell cytotoxicity (2008).
We identified KIR receptors in mouse and rat, selectively expressed by NK cells (2003). This disproved a long-standing dogma that this important NK receptor family evolved at the level of primates.
We identified a multigene family of KIR receptors in cattle (2003), containing both activating and inhibitory receptors, and defined the NK cell subset in cattle both functionally and phenotypically.
In collaboration with the NK-Cells group, we identified the APLEC gene complex, harboring a family of C-type lectin receptors expressed by antigen presenting cells (2004).
We cloned and identified rat NKp46 independent of its identification in the human, and demonstrated that this receptor activates NK cell cytotoxicity via the FcεRIγ/CD3ζ heterodimeric adaptor protein (2004). Moreover, we showed that NKp46 serves as the most NK-specific surface marker molecule in rats as well as in cattle (2004).
We identified the only human Ly49 receptor (Ly49L), a presumably nonfunctional receptor expressed by NK cells and localized within the human NK cell gene complex (1998).
We cloned and characterized the first non-human CD94 and NKG2 receptors, demonstrating a more ancient origin of the CD94/NKG2A, -C and –E receptors. Functional studies of the rat CD94/NKG2 receptors are still ongoing in the laboratory.
We mapped the Nka functional locus, determining the ability of NK cells to recognize target cells from MHC-disparate donors, to the Ly49 region of the rat NK gene complex. Moreover, we presented the first physical map of the NK gene complex in any species, based on a combination of linkage data and genomic pulsed-field gel electrophoresis mapping (1996). We identified striking differences between the cytoplasmic regions of rat Ly49 receptors, and postulated the existence of activating Ly49 receptors in addition to the previously known inhibitory members of the Ly49 family.