Interleukin

Interleukin are a group of cytokines (secreted proteins and signaling molecules) that were first seen to be expressed by white blood cells (leukocytes).

The function of the immune system depends in a large part on interleukins, and rare deficiencies of a number of them have been described, all featuring autoimmune diseases or immune deficiency. The majority of interleukins are synthesized by helper CD4 T lymphocytes, as well as through monocytes, macrophages, and endothelial cells. They promote the development and differentiation of T and B lymphocytes, and hematopoietic cells.

Interleukin receptors on astrocytes in the hippocampus are also known to be involved in the development of spatial memories in mice.