Cytokines include a number of different proteins that modulate the immune response; cytokines contribute to symptoms and their severity in autoimmune disease.
Cytokines are immune system proteins that modulate or influence the immune response. Cytokines are produced when the immune system encounters an immune stimulus. Once induced, cytokines help determine how the immune system should respond and to what degree.
Cytokines are produced by various immune system white blood cells, and they’re categorized by their major function: for instance cytokines may be pro-inflammatory compounds, anti-inflammatory compounds, or growth factors. Cytokines may also induce the production of effector molecules or various cell receptors, and they may cause the proliferation of various immune system cells that are needed to prolong the immune response.
Subtypes
Cytokines are a general class of proteins that are often referred to by their specific function or by the cells that produced them.
- Monokines--Cytokines produced by monocytes
- Lymphokines—Cytokines produced by lymphocytes
- Chemokines—Cytokines with chemotactic activities
- Interleukins—Cytokines made by certain leukocytes and acting on others
- Interferons—Cytokines that influence the function of immune system cells
Cytokine Activities
Cytokines contribute to the symptoms of autoimmune disorders by releasing toxic chemicals and damaging cells. In rheumatoid arthritis and other rheumatic disorders, cytokines contribute to joint destruction and synovitis. Cytokines, depending on their type and function, can also trigger and perpetuate inflammation and they can taper the immune system's response, helping disease flares resolve.
Cytokines act by binding to specific receptors or locks on cell surfaces. Cytokines can act on specific cells or they can have the property of pleiotropy, which allows them to react with various cell types. Cytokines can work together or synergistically or they can work antagonistically, working to reduce the activity of other cytokines.
Cytokine Properties
Cytokines have a short half-life, which means they break down fairly quickly, and they’re present in low concentrations. Cytokines can be further differentiated by their individual characteristics.
Individual Cytokines
This is a list of some of the more common cytokines and their role in the immune response.
- GM-CSF produced by Th cells; target progenitor cells; as a colony stimulating factor, cause growth and differentiation of monocytes and differentiated white blood cells
- Interleukins 1a and 1 b (IL-1a, IL-1b) produced by monocytes, macrophages, and B lymphocytes; target Th cells, B cells, NK cells; cause cell activation, maturation, proliferation and inflammation and other acute phase responses such as fever
- Interleukin 2 (IL-2) produced by Th1 cells; target T and B cells, NK cells, causing growth, proliferation and activation
- Interleukin 3 (IL-3) produced by Th and NK cells; target activated T and B lymphocytes; NK cells, stem cells and mast cells, causing cell growth and activation
- Interleukin-4 (IL-4) produced by Th2 cell; target activated B cells, macrophages and T cells, participating in allergic and autoimmune reactions
- Interleukin-5 (IL-5) ; produced by Th2 cells; target activated B cells
- Interleukin-6 (IL-6) produced by monocytes, macrophages, Th2 cells and stromal cells; target activated B cells, plasma and stem cells; aid in antibody secretion and acute phase responses
- Interleukin-10 (IL-10) produced by Th2 cells; target macrophages and B cells causing cytokine production and B cell activation
- Interferon-alpha (IFN- autoimmunedisease.suite101.com/blog.cfm/hla_antigens) produced by leukocytes; target various cells causing viral replication and MHC I autoimmunedisease.suite101.com/blog.cfm/hla_antigens expression
- Tumor necrosis factor alpha (TNF-α) produced by macrophages, mast cells, NK cells; targets macrophages and tumor cells, causing cell death and cytokine expression, inflammation
Importance of Cytokines to You
Cytokines are primarily of academic interest because they explain how the immune response can progress from a protective encounter to an autoimmune destructive reaction. Therapies today are increasingly being geared toward drugs that can halt the production of various cytokines. For instance, therapies that reduce the fibroblast growth factors that contribute to fibrosis offer future benefits in a number of different diseases including scleroderma.
More importantly, recent studies show that cytokines can be modulated by exercise and diet. Cytokines are important in the acute phase response to injury or infection, and they can help prolong flares or induce remissions in people with autoimmune diseases. Learning what steps you can take to help your immune system heal and reduce the production of harmful cytokines is the basis of holistic healing in autoimmune disease.
Resource;
Elaine Moore, Autoimmune Diseases and Their Environmental Triggers; Jefferson, NC: McFarland and Company, 2002.
