What is a natural killer cell?
A natural killer or NK cell is a white blood cell, which acts as the first defense line of the immune system against foreign attackers such as tumors, bacteria and viruses. NK cells are known as "natural killers" because they do not have to respond to specific antigens, only must recognize that the cell is alien and does not belong. Because these cells are so strong, the body has a number of steps that are designed to prevent NK cells from running and accidentally attack their hosts.
In order to understand how natural killer cells work, a short raid to biology must be carried out. These cells look for proteins known as human leukocyte antigens (HLA), which are depicted on the surface of other cells. If a natural killer cell recognizes the proteins of HLA as a "self", ignores the cell and provided they belong. If, on the other hand, a foreign HLA appears, a natural killer cell releases toxins that kill a foreign cell.
HLA are expressed through the main histocompatible toOMPLEX, groups of genes placed on the sixth chromosome. The main complex of histocompatibility is the "main" because it plays a critical rule in the adoption or rejection of transplanted tissues. If the HLA does not match the organ, the body refuses it, with natural murderer cells moving to protect the body from a perceived attacker.
The natural killer cell has a number of receptors that uses information about the cells that come into contact with. Usually, at least one specific receptor for a natural murderer cell must be activated to act. Other cells of the immune system may also be involved in the reaction, while the immune system is swinging into action to deal with emerging health problems. The natural killer cell works by capturing into a suspicious cell and basically injecting cytotoxins, the cloth is designed to kill cells.
Sometimes a thingEven with natural murder cells spoils. For example, sometimes a woman carries a child with incompatible HLA and natural murderer cells think that the fetus is dangerous. In these cases, different medical treatment is used to allow a child to develop so that a woman can carry a child to take care of. Natural killer cells can also turn malignant, develop lymphoma, a type of cancer. Lymphom NK cells can be very difficult to treat.