T-cell growth factor

T-cell growth factor (also known as Interleukin 2 or IL-2) is a type of cytokine signaling molecule in the immune system. It is a protein that regulates the activities of white blood cells (leukocytes, often lymphocytes) that are responsible for immunity. IL-2 is part of the body's natural response to microbial infection, and in rare instances, IL-2 receptor deficiencies can lead to life-threatening immune deficiency.

Function

IL-2/ T-cell growth factor plays a central role in the adaptive immune response. It promotes the differentiation of T cells into effector and memory T cells after they have encountered their cognate antigen within the context of the major histocompatibility complex. This leads to T cell proliferation and hence clonal expansion of the adaptive immune response.

Structure

The IL-2 protein is a four α-helix bundle protein that is a member of the interleukin family. It is composed of four long, winding, parallel alpha helices, and it is classified as a long-chain cytokine.

Clinical significance

IL-2 has been used in clinical trials for the treatment of chronic viral infections and in immunotherapy for cancers. It is used as a therapeutic drug under the name Proleukin. It has been used to boost the immune response in diseases where it is deficient or compromised, such as HIV/AIDS and certain types of cancer.

See also

• Interleukin
• Cytokine
• Immune system
• T cell