Which plays a pivotal role in the body's lymphocyte immune response?

• A. Cyclins
• B. Lymphokines
• C. Neutrophils
• D. Cluster Differentiation (CD) Proteins

Answer: (B)

Lymphocytes drive adaptive immunity by sending signals that coordinate the rest of the immune system. Lymphokines are those signals produced specifically by lymphocytes to regulate the activity of other immune cells—telling T cells to proliferate, helping B cells mature and differentiate, and attracting or activating macrophages and natural killer cells. This signaling function is what makes lymphokines central to the lymphocyte-driven immune response. In comparison, cyclins control cell division, neutrophils are part of the innate phagocytic response, and cluster differentiation proteins are surface markers used to identify cells rather than to mediate signaling. So the molecule that best explains the lymphocyte-centered response is lymphokines.