All of the following statements about NK cells are true except:
They are derived from large granular cells
They comprise about 5% of human peripheral lymphoid cells
They are MHC restricted cytotoxic cells
They express IgG Fc receptors
NK cells are innate immune cells They are functional without prior activation and do not express highly variable and clonally distributed receptors for antigens. NK cells have two types of receptors-- Inhibitory and Activating. They are capable of MHC - unrestricted direct cell lysis which is not mediated by an immune response.
Immunology