Natural Killer cells in Innate Defense against Infective Pathogens

Infectious diseases cause over 300 million illnesses and more than 5 million deaths each year worldwide. Understanding how components of the host immune system function to control disease-causing pathogens is critically important to develop strategies for preventing and controlling these diseases. With the discovery of innate immune receptors, we are beginning to appreciate the important role of innate immunity in the defense against infectious diseases. NK cells are a critical cell population in innate immunity, providing first line of defense against a variety of pathogens. NK cells mediate protection by direct killing of infected target cells and producing cytokines (mainly IFN-γ and TNF) that shape innate and adaptive immune responses. Recent studies have focused on the mechanisms by which NK cells recognize and respond to viruses, bacteria and parasites, and also the role of NK cells in modulating adaptive immune responses. Natural Killer cells in Innate Defense against Infective Pathogens