Interleukin

Overview of interleukins in the immune system

Interleukins are a group of cytokines that were first seen to be expressed by white blood cells (leukocytes). The term interleukin derives from "inter-" as a means of communication, and "-leukin" derived from the fact that many of these proteins are produced by leukocytes and act on leukocytes. Interleukins play a crucial role in the immune system by regulating the growth, differentiation, and activation of immune cells.

Function

Interleukins are involved in a wide array of immunological functions. They are primarily responsible for:

• Promoting the development and differentiation of T cells, B cells, and hematopoietic cells.
• Modulating inflammation and immune responses.
• Acting as mediators in the communication between cells of the immune system.

Each interleukin has a specific role, and they are often classified by their numeric designation, such as IL-1, IL-2, IL-6, etc. For example, Interleukin 2 (IL-2) is crucial for the growth and proliferation of T cells, while Interleukin 6 (IL-6) is involved in inflammation and the maturation of B cells.

Classification

Interleukins are classified into several families based on their structural features and receptor binding properties. Some of the major families include:

• The IL-1 family, which includes IL-1α, IL-1β, and IL-18, known for their role in inflammation.
• The IL-2 family, which includes IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21, primarily involved in lymphocyte proliferation.
• The IL-6 family, which includes IL-6, IL-11, and IL-27, known for their role in immune regulation and inflammation.

Clinical Significance

Interleukins have significant clinical implications. Dysregulation of interleukin production or signaling can lead to autoimmune diseases, inflammatory disorders, and cancer. For instance, overproduction of IL-6 is associated with chronic inflammatory diseases such as rheumatoid arthritis and Crohn's disease.

Therapeutic interventions targeting interleukins include:

• Monoclonal antibodies that inhibit specific interleukins, such as Tocilizumab, an IL-6 receptor antagonist used in rheumatoid arthritis.
• Recombinant interleukins used as drugs, such as IL-2 in the treatment of certain cancers.

Research

Ongoing research is focused on understanding the complex roles of interleukins in the immune system and their potential as therapeutic targets. Advances in biotechnology have enabled the development of novel interleukin-based therapies for a variety of diseases.

Also see

• Cytokine
• Immune system
• T cell
• B cell
• Autoimmune disease