Abstract: The present invention relates to agents and methods that are capable of augmenting NK-mediated killing of target cells by reducing inhibitory KIR signalling without reducing the binding of KIR to HLA-C. As described herein, transduction of negative signaling via KIR, 5 upon binding of KIR to its HLA class I ligand, can involve a ligand-binding induced, conformational reorientation of the KIR molecules allowing interactions to form between adjacent KIRs in specific domains, leading to accelerated clustering. Methods and agents such as mono-clonal antibodies for reducing KIR-mediated inhibition of NK cell cytotoxicity without reducing or blocking HLA-binding by, e.g., reducing or blocking dimerization of KIR, are provided.

Abstract: The present invention relates to novel compositions and methods for regulating an immune response in a subject. More particularly, the invention relates to specific antibodies that regulate the activity of NK cells and allow a potentiation of NK cell cytotoxicity in mammalian subjects. The invention also relates to fragments and derivatives of such antibodies, as well as pharmaceutical compositions comprising the same and their uses, particularly in therapy, to increase NK cell activity or cytotoxicity in subjects.

Abstract: The present invention relates to novel compositions and methods for regulating an immune response in a subject. More particularly, the invention relates to specific antibodies that regulate the activity of NK cells and allow a potentiation of NK cell cytotoxicity in mammalian subjects. The invention also relates to fragments and derivatives of such antibodies, as well as pharmaceutical compositions comprising the same and their uses, particularly in therapy, to increase NK cell activity or cytotoxicity in subjects.