Discuss the Importance of Natural Killer Cells in the Maintenance of a Successful Pregnancy

Introduction: Natural killer cells play an important role in the development of the placenta early in pregnancy. The mechanism of angiogenesis is partially controlled by the action of uterus natural killer cells (uNK) and its production of cytokines. The mechanisms and effects of uNK cells are examined and the importance of uNK cells reveals when examining conditions associated with dysfunctional NK cells. Peripheral natural killer cells: Natural killer (NK) cells are part of the innate immune system and are lymphocytes with different functions depending on their location.

Other cells involved in innate immunity are natural killer cells. Natural killer cells recognize the absence of self-assembling molecules (various viral infections and characteristics of specific cancer cells) and lyse these cells by releasing toxic substances. Natural killer cells are thought to be important in limiting the early stages of viral infection before certain immunity becomes effective and in attacking malignant autologous cells. Specific immunity is characterized by a higher specificity and lower rate than the innate immune response. Lymphocytes have receptor sites on their cell surface. The receptors on each cell are consistent with the unique small molecule shape or antigen on a particular intruder and thus react to only one intruder.

Natural killer cells: Natural killer cells (NK cells) that do not directly attack pathogens. In contrast, natural killer cells destroy infected host cells to prevent spread of infection. Infected or damaged host cells can be indicative of the destruction of natural killer cells by expression of specific receptors and antigen presentation. Dendritic cells: Dendritic cells are antigen presenting cells located in tissues and may be exposed to the external environment through the internal mucosal lining of the skin, nose, lung, stomach and intestine. Since dendritic cells are located in tissues common to the first infection, they can identify threats and act as messengers in the rest of the immune system through antigen presentation. Dendritic cells also function as a bridge between the innate immune system and the adaptive immune system.

Cells of the innate immune system including macrophages, mast cells and natural killer cells are located in synovium, but neutrophils are usually present in synovial fluid. In particular, macrophages are an important effector of synovitis acting via phagocytosis, antigen presentation, release of proinflammatory cytokines, active oxygen intermediates, prostaglandins and matrix degrading enzymes. Tolllike receptors (TLRs) on monocytes, macrophages, and dendritic cells act as inflammatory and immune responses when exposed to immunogenic stimuli such as microbial pathogens. Activation of TLR results in rapid expression of proinflammatory cytokines that mediate immune responses against concentrated granulocytes, monocytes and lymphocytes. In most cases, a combination of congenital and adaptive immune system responses will eliminate pathogens and stop the immune response.