Manipulating immune function — enhancing it or suppressing it — will rest on our ability to control the two aspects of the immune system: innate immunity, mentioned above, and adaptive immunity.
The innate immune system: the first line of defense
The innate immune system is the first part of the body to detect invaders such as viruses, bacteria, parasites and toxins, or to sense wounds or trauma. Upon detection of these agents or events, the innate immune system activates cells to attack and destroy the outsider, or to initiate repair, while also informing and modulating the adaptive immune response that follows this first line of defense.
The adaptive immune system: the second, specific response
Adaptive immune cells are the second and specific line of defense, and they are called to action by the innate immune system. After recognizing the invader, the cells can multiply and combat it, leading to recovery from disease and protection against its return.