Final answer:
Elevated body temperature during an acute phase response is primarily attributed to the effects of the pro-inflammatory cytokines IL-1 and TNF-α, which act as endogenous pyrogens to induce fever as a defense mechanism.
Step-by-step explanation:
The elevated body temperature during the acute phase response is mainly due to the long-range effects of pro-inflammatory cytokines, such as interleukin 1 (IL-1) and tumor necrosis factor-alpha (TNF-α). These cytokines act as endogenous pyrogens that circulate to the hypothalamus in the brain and reset the body’s thermostat to a higher setting, resulting in fever.
Fever is a defense mechanism that increases the body’s temperature to inhibit pathogen replication and boost the immune response by increasing the activity of protective enzymes and cells, conserving iron to limit bacterial growth, and potentially directly killing the pathogen with heat.