How do cytokines function?

How do cytokines function?

• A. They directly lyse pathogens
• B. They activate other immune defense cells to travel to inflamed sites, activate a response by the liver, and induce fever to fight microbial infection; increase vascular permeability that leads to increased movement of immune cells and complement into the tissues
• C. They store energy for immune cells
• D. They form the cellular components of tissue

Answer: (B)

Cytokines act as signaling molecules that coordinate the immune response. They’re produced by immune cells and then act on other cells to regulate inflammation, cell activation, and movement. In infection, they promote inflammation by increasing vascular permeability so immune cells and plasma proteins can reach the infected tissue, and they attract neutrophils and other leukocytes to the site. They also kick off systemic responses: signaling the liver to produce acute-phase proteins like CRP, which help opsonize pathogens, and triggering fever through effects on the hypothalamus. All of this is about communication and regulation, not directly destroying pathogens. They don’t store energy or form the physical components of tissue either.

Cytokines act as signaling molecules that coordinate the immune response. They’re produced by immune cells and then act on other cells to regulate inflammation, cell activation, and movement. In infection, they promote inflammation by increasing vascular permeability so immune cells and plasma proteins can reach the infected tissue, and they attract neutrophils and other leukocytes to the site. They also kick off systemic responses: signaling the liver to produce acute-phase proteins like CRP, which help opsonize pathogens, and triggering fever through effects on the hypothalamus. All of this is about communication and regulation, not directly destroying pathogens. They don’t store energy or form the physical components of tissue either.