A unit of weight equal to 2,000 pounds (0.907 metric ton or 907.18 kilograms). Also called net ton, short ton. 2. A unit of weight equal to 2,240 pounds (1.016 metric tons or 1,016.05 kilograms). Also called long ton.
Cellular immunity is a protective immune process that involves the activation of phagocytes, antigen-sensitized cytotoxic T cells and the release of cytokines and chemokines in response to antigen. Cellular immunity is most effective against cells infected with viruses, intracellular bacteria, fungi and protozoans, and cancerous cells.
Cellular Defenses. Natural killer cells and macrophages are examples of nonspecific cellular defenses. Natural killer cells are a class of lymphocytes that recognize abnormal cells (such as cancerous cells or virus-infected cells), attach to them, and release chemicals that destroy them.pecific immune responses can distinguish among different invaders. The response is different for each invader. With nonspecific defenses, the protection is always the same, no matter what the invader may be. Whereas only vertebrates have specific immune responses, all animals have some type of nonspecific defense.