Cytokines

Definition

Cytokines are small proteins released by cells, especially those of the immune system, that have a specific effect on interactions and communications between cells. They play crucial roles in regulating immune responses and inflammation.

5 Must Know Facts For Your Next Test

1. Cytokines include interleukins, interferons, tumor necrosis factors, and chemokines.
2. They can be pro-inflammatory or anti-inflammatory, depending on their function and context.
3. Cytokines are essential for the activation and differentiation of T lymphocytes and B lymphocytes during adaptive immunity.
4. An overproduction of cytokines can lead to a 'cytokine storm,' a dangerous condition often seen in severe infections.
5. Cytokines act through specific receptors on target cells, initiating signaling pathways that alter cell behavior.

Review Questions

• What are the primary functions of cytokines in the immune system?
• Name at least three types of cytokines and their general roles.
• How do cytokines affect the behavior of T lymphocytes and B lymphocytes?

Related terms

Interleukins: A group of cytokines that were first seen to be expressed by white blood cells (leukocytes).

Chemokines: A subset of cytokines responsible for inducing chemotaxis in nearby responsive cells.

Tumor Necrosis Factor (TNF): A type of cytokine involved in systemic inflammation and stimulation of the acute phase reaction.