Immune Defense
The immune system uses the lethal effects of oxidants by making production of oxidizing species a central part of its mechanism of killing pathogens; with activated phagocytes producing both ROS and reactive nitrogen species. These include superoxide (•O2-), nitric oxide (•NO) and their particularly reactive product, peroxynitrite (ONOO-). Although the use of these highly reactive compounds in the cytotoxic response of phagocytes causes damage to host tissues, the non-specificity of these oxidants is an advantage since they will damage almost every part of their target cell. This prevents a pathogen from escaping this part of immune response by mutation of a single molecular target.
Read more about this topic: Oxidative Stress
Famous quotes containing the words immune and/or defense:
“The moral immune system of this country has been weakened and attacked, and the AIDS virus is the perfect metaphor for it. The malignant neglect of the last twelve years has led to breakdown of our country’s immune system, environmentally, culturally, politically, spiritually and physically.”
—Barbra Streisand (b. 1942)
“He said, truly, that the reason why such greatly superior numbers quailed before him was, as one of his prisoners confessed, because they lacked a cause,—a kind of armor which he and his party never lacked. When the time came, few men were found willing to lay down their lives in defense of what they knew to be wrong; they did not like that this should be their last act in this world.”
—Henry David Thoreau (1817–1862)