Figure 4. Inflammation Engages Both Defense and Dormancy Programs.
Dormancy programs are induced by resource scarcity. Resource scarcity is sensed by the hypothalamus and endocrine organs which then send signals that activate catabolic cellular and organismal programs associated with quiescence and stress-resistance. Defense programs are induced by environmental insults such as infectious agents. These are sensed by the immune system which then use inflammatory mediators to activate anabolic cellular and organismal programs associated with proliferation and biogenesis.
A. During the inflammatory response to infection, inflammatory mediators engage dormancy-associated programs. While the immune system is engaged in defense programs, other parts of the organism are engaged in dormancy programs, which confers stress resilience and tissue protection.
B. The host response to infection is divided into immune resistance and immune tolerance. Immune resistance is a defense life history program utilized by the immune system and utilizes corresponding anabolic metabolic programs. Immune tolerance is a dormancy life history program activated by the immune system and utilizes corresponding catabolic metabolic programs.