Linfocitos "natural killer"

Abstract

Natural killer (NK) cells are responsible for the defence against viral infections and the elimination of tumour cells. They are characterised by their potent cytolytic ability and their highly efficient system for inducing apoptosis in target cells. In addition, they are responsible for differentiating between autologous and heterologous or xenogeneic cells, the latter of which are partly responsible for transplant rejection. NK cells perform this process efficiently thanks to a collection of receptors which receptors have been classified into two major groups: activating receptors and inhibitory receptors. Inhibitory receptors have been identified for some time and are responsible for recognising that which belongs to the body by examining class I histocompatibility molecules. We are steadily learning more about the activating receptors; however, we still know little about their ligands, which are the current focus of interest to scientists. Changes in the number or function of NK cells are responsible for numerous diseases in the context of infections, tumours, autoimmunities and immunodeficiencies. Of significant importance is the cooperation between NK cells and other innate immune system cells, such as dendritic cells, or adaptive immune system cells, such as T Iymphocytes. In this monograph, we review the latest discoveries in the biology of NK cells, subtypes, the receptors they express, the cytotoxic mechanisms and their role in antiviral and antitumour defence.