What role do cytokines play in immune response?

• A. They enhance physical barriers
• B. They mediate and regulate immune responses
• C. They act as antibodies
• D. They destroy pathogen cells directly

Answer: (B)

Cytokines are crucial signaling molecules in the immune system that mediate and regulate various immune responses. They are produced by a range of immune cells and play significant roles in cell communication, influencing the behavior of other immune cells. By acting as messengers, cytokines coordinate the response to pathogens, facilitating processes such as cell recruitment, activation, and differentiation.

For instance, when an infection occurs, cytokines can trigger the inflammatory response, which helps to recruit additional immune cells to the site of infection, enhancing the body's ability to fight off pathogens. They also regulate the development of immune cells like T-cells and B-cells, which are essential for adaptive immunity. This orchestration ensures that the immune system operates efficiently and effectively, responding appropriately to the presence of infections or other immune challenges.

Other options provided do not capture the full scope of cytokine functions; while they may be related to aspects of the immune response, they do not encompass the primary role of cytokines in regulating and mediating responses during immune challenges.