Ailments and Situations - Common Cold - Causes |
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Page 2 of 6 Causes: A cold is the result of your immune system's inability to fight off an invader -- in this case, a cold virus. What follows is a brief primer on how the immune system functions when dealing with a cold. There are two main types of immune system responses when dealing with an invader: non-specific and specific. In a non-specific response, special immune cells attach to foreign cells and help eliminate infection -- a process called phagocytosis. WBCs (granulocytes and macrophages) are mainly responsible for this activity, while interferon-gamma stimulates the destructive killing power of macrophages, the largest of the white blood cells. A specific response involves two types of specialized lymphocytes known as T cells and B cells. Your body has thousands of T cells and B cells floating around, where each one looks for a specific type of fungus, foreign protein, or other invader. Once the macrophages (from the non-specific response) prepare the foreign cell for the assault, the T cells become killer T cells and will either destroy the invader, alter it so it can be destroyed, or recruit other cells to destroy it. The B cells produce antibodies that are responsible for fighting off bacteria and viruses in body fluids. Over time, these various responses result in the elimination of a cold virus.
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