cytokine
(noun)
Any of various small regulatory proteins that regulate the cells of the immune system.
Examples of cytokine in the following topics:
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Cytokines and Chemokines
- Cytokines and chemokines are both small proteins secreted by cells of the immune system.
- Cytokines can be classified as proteins, peptides, or glycoproteins.
- As of 2008, the current terminology refers to cytokines as immunomodulating agents.
- These are a family of small cytokines, or proteins secreted by cells.
- However, these proteins have historically been known under several other names including the SIS family of cytokines, SIG family of cytokines, SCY family of cytokines, Platelet factor-4 superfamily or intercrines.
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Type IV (Delayed Cell-Mediated) Reactions
- Cell-mediated immunity is an immune response that does not involve antibodies, but rather involves the activation of phagocytes, natural killer cells (NK), antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen.
- Cytotoxic T cells cause death by apoptosis without using cytokines.
- Therefore in cell mediated immunity cytokines are not always present.
- 3. stimulating cells to secrete a variety of cytokines that influence the function of other cells involved in adaptive immune responses and innate immune responses
- CD4+ T cells secrete IL-2 and interferon gamma, further inducing the release of other Th1 cytokines, thus mediating the immune response.
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Superantigens
- Superantigens are a class of antigens that cause activation of T-cells and massive cytokine release.
- More importantly, the large number of activated T-cells secretes large amounts of cytokines, the most important of which is Interferon gamma.
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Phagocyte Migration and Phagocytosis
- In the tissues, they are activated by cytokines and arrive at the battle scene ready to kill.
- These chemical signals may include proteins from invading bacteria, clotting system peptides, complement products, and cytokines that have been given off by macrophages located in the tissue near the infection site.
- Another group of chemical attractants are cytokines that recruit neutrophils and monocytes from the blood.
- Chemotaxis is the process by which phagocytes follow the cytokine "scent" to the infected spot.
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Immunotherapy for Cancer
- These immune cells are either activated in vivo by administering certain cytokines such as interleukins, or they are isolated, enriched, and transfused back into the patient to fight against cancer.
- Certain members of a group of molecules known as cytokines, such as interleukin-2, also play a key role in modulating the immune response.
- Cytokines have been tested in conjunction with antibodies in order to generate an even more devastating immune response against the tumor.
- While the therapeutic administration of such cytokines may cause systemic inflammation, resulting in serious side effects and toxicity, there is a new generation of chimeric molecules consisting of an immune-stimulatory cytokine attached to an antibody that targets a tumor.
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Antimicrobial Peptides
- AMPs have been shown to be important in such diverse functions as angiogenesis, wound healing, cytokine release, chemotaxis, and regulation of the adaptive immune system.
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Classes of T Cells
- In response to antigenic stimulation, helper T cells (characterized by the expression of CD4 marker on their surface) secrete proteins called cytokines, whose function is to stimulate the proliferation and differentiation of the T cells themselves, as well as other cells, including B cells, macrophages, and other leukocytes.
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Dendritic Cells
- However, the cell-cell interaction can also take place at a distance via soluble factors such as cytokines.
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Adaptive Immunity and the Immunoglobulin Superfamily
- Members of the IgSF include cell surface antigen receptors, co-receptors, and co-stimulatory molecules of the immune system, molecules involved in antigen presentation to lymphocytes, cell adhesion molecules, certain cytokine receptors, and intracellular muscle proteins.
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Immunoassays for Disease
- The humoral component includes complement, lyzozyme, interferon, antibodies, and cytokines.