Target cell recognition by NK cells
Natural killer (NK) cells are a subset of leukocytes (white blood cells) with innate activity to seek out and kill diseased cells in the body. They also modulate the activity of other immune cells through the production of immunomodulatory cytokines. Like all immune cells, the activity of NK cells is regulated by an array of cell surface receptors. NK cells express receptors belonging to different receptor families, which can have activating or inhibitory functions. NK cells depend on interactions between these receptors and their ligands to distinguish between normal and diseased cells. The balance of activating and inhibitory signals determines the outcome of responses mediated by NK cells. Increased activating signals results in activation of NK cell to perform their effector functions (killing of target cells and production of cytokines), while increased inhibitory signals suppresses NK cells activation. We are interested in understanding the role of these receptors in regulating NK cell functions, and their contribution to immunity against cancers and virus infections.
The NKR-P1:Clr receptor:ligand family
The primary focus of the Rahim lab is to understand the role of receptors belonging to NKR-P1 receptor family in NK cell-mediated cancer immunosurveillance and cancer immunoevasion, and in immunity against cytomegalovirus infection. The NKR-P1:Clr family in mice consists of five NKR-P1 receptors and seven Clr ligands ecoded by genetically-linked nkrp1/klrb1 and clr/clec2 genes, respectively, in the NK gene complex (NKC). NKR-P1A, NKR-P1C, and NKR-P1F are activating while NKR-P1B and NKR-P1G are inhibitory receptors. The currently known receptor-ligand pairs for the mouse NKR-P1:Clr family include NKR-P1B:Clr-b; NKR-P1F:Clr-c,d,g; and NKR-P1G:Clr-d,f,g. NKR-P1:Clr interactions are proposed to play important roles in innate immune responses.