Summary
Small signalling proteins such as interleukins and interferons that coordinate immune cell behaviour.
In depth
Interleukins, interferons (antiviral), TNF (inflammation), chemokines (cell migration) and colony stimulating factors. Cytokine storms in sepsis and severe COVID-19 cause damage.
They act locally (paracrine) or systemically. Redundancy and pleiotropy complicate therapy. Cytokine inhibitors treat autoimmune disease; IL-2 boosts T cells in cancer therapy.
Example: TNF blockers such as infliximab treat Crohn's disease.
Cytokines act in autocrine, paracrine or endocrine ways through receptors that signal via JAK-STAT pathways. Redundancy and pleiotropy (one cytokine with many effects) make them complex. Interferons alpha and beta induce an antiviral state, gamma activates macrophages; IL-2 drives T cell growth; IL-10 is anti-inflammatory; TGF-beta is regulatory.
Therapies: anti-TNF antibodies (infliximab, adalimumab) for arthritis, tocilizumab against IL-6 receptor, interferon for hepatitis and MS, and JAK inhibitors. Cytokine release syndrome can complicate CAR-T therapy. Chemokines such as IL-8 direct leukocytes to sites of infection.
Remember: cytokines are short-range messengers of the immune system, working like a language between cells.
Frequently asked questions
What is Cytokines?
Small signalling proteins such as interleukins and interferons that coordinate immune cell behaviour.
Which area of biology covers Cytokines, and how advanced is it?
Cytokines is one of the 52 topics in Immunology & Disease. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Inflammation, Toll-Like Receptors, Autoimmune Disease.
Can you give an example of Cytokines?
Interferon alpha is used to treat hepatitis.
What should I learn before Cytokines?
Work through the Beginner topics in Immunology & Disease first, such as Immune System, Viruses, Innate Immunity, then return to Cytokines. Advanced topics assume the Intermediate vocabulary.
What topics are related to Cytokines?
The closest topics to Cytokines are Inflammation, Toll-Like Receptors, Autoimmune Disease, T Lymphocytes. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Cytokines?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Cytokines. To practise the whole of Immunology & Disease, use the Immunology & Disease quiz.
How is Cytokines different from Inflammation?
Cytokines: Small signalling proteins such as interleukins and interferons that coordinate immune cell behaviour. Inflammation: A response with redness, heat, swelling and pain that brings immune cells to damaged tissue. Read both side by side and note what each one explains.
How should I study Cytokines step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Inflammation and explain the difference aloud. Finally, take the Immunology & Disease quiz and come back to this page for any question you miss.