THE CELLS OF THE IMMUNE SYSTEM
A number of different cells work together within the immune system to fight infections and disease. Each type of cell plays an important role in identifying, marking, and destroying harmful cells that enter or develop in the body.
B cells release antibodies to defend against harmful, invading cells. Each B cell is programmed to make one specific type of antibody—for instance, one B cell might be responsible for making antibodies that defend against the common cold virus. Tumor-reactive antibodies can bind to cancer cells, disrupting their activity as well as stimulating immune responses against them.
CD4+ helper T cells send “help” signals to other immune cells (such as the CD8+ killer T cells) to better direct their response and make sure that they destroy harmful cells as quickly and efficiently as possible. These cells also communicate with the B cells producing antibodies.
CD8+ killer T cells destroy thousands of virus-infected cells in the body every day. These cells can also directly target and destroy cancer cells.
Dendritic cells digest foreign or cancerous cells and present their proteins on their surfaces, where other immune cells can better recognize and then destroy the harmful cells.
Macrophages are known as the “big eaters” of the immune system. Macrophages engulf and destroy bacteria and other harmful cells. Like dendritic cells, they present antigens to other cells of the immune system for identification and detruction.
Regulatory T cells provide checks and balances to make sure that the immune system does not overreact. A chronic immune overreaction is known as an autoimmune disease.
David Ogden – Http://markethive.com/david-ogden