5th February 2024

Cytokines

Cytokines are a group of proteins whose actions can be determined through etymology – ‘cyto’ and ‘kinesis,’ the Greek words for cell and movement. Cytokines are secreted by immune cells and act on other cells to direct their movement and action through the inflammatory cascade. Important cytokines to be aware of include interleukins, interferons, tumour necrosis factor, chemokines and transforming growth factor.

Interleukins are synthesised and released by leucocytes, mainly CD4 helper T lymphocytes. Interleukins regulate immune and inflammatory responses as well as haematopoiesis. There are over fifty different interleukins with pro- and anti-inflammatory functions.

Interferons are cytokines released by cells in response to viral infection. Tumour necrosis factor (TNF) is a pro-inflammatory cytokine. Macrophages and eosinophils secrete TNF-a to recruit T lymphocytes. Transforming growth factor (TGF) controls the repair of damaged tissue. It is released by platelets and signals white blood cells (including T lymphocytes) and fibroblasts to approach.