MHC class I-independent recognition of NK-activating receptor KIR2DS4.

Autor: Katz G; Lautenberg Center for General and Tumor Immunology, Hadassah Medical School, Hebrew University, Jerusalem, Israel., Gazit R, Arnon TI, Gonen-Gross T, Tarcic G, Markel G, Gruda R, Achdout H, Drize O, Merims S, Mandelboim O
Jazyk: angličtina
Zdroj: Journal of immunology (Baltimore, Md. : 1950) [J Immunol] 2004 Aug 01; Vol. 173 (3), pp. 1819-25.
DOI: 10.4049/jimmunol.173.3.1819
Abstrakt: Natural killer cells are capable of killing tumor and virus-infected cells. This killing is mediated primarily via the natural cytotoxicity receptors, including NKp46, NKp44, NKp30, and by the NKG2D receptor. Killer cell Ig-like receptors (KIRs) are mainly involved in inhibiting NK killing (inhibitory KIRs) via interaction with MHC class I molecules. Some KIRs, however, have been found to enhance NK killing when interacting with MHC class I molecules (activating KIRs). We have previously demonstrated that KIR2DS4, an activating KIR, recognizes the HLA-Cw4 protein. The interaction observed was weak and highly restricted to HLA-Cw4 only. These findings prompted us to check whether KIR2DS4 might have additional ligand(s). In this study, we show that KIR2DS4 is able to also interact with a non-class I MHC protein expressed on melanoma cell lines and on a primary melanoma. This interaction is shown to be both specific and functional. Importantly, site-directed mutagenesis analysis reveals that the amino acid residues involved in the recognition of this novel ligand are different from those interacting with HLA-Cw4. These results may shed new light on the function of activating KIRs and their relevance in NK biology.
Databáze: MEDLINE