View source for Autocrine signalling

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'''Autocrine signaling''' is a form of signaling in which a cell secretes a hormone, or chemical messenger (called the autocrine agent) that binds to autocrine receptors on the same cell, leading to changes in the cell. This can be contrasted with [[paracrine signaling]], [[intracrine]] signaling, or classical endocrine signalling.

==Examples==
An example of an autocrine agent is the [[cytokine]] [[interleukin-1]] in [[monocytes]]. When this is produced in response to external stimuli, it can bind to cell-surface [[receptor (biochemistry)|receptors]] on the same cell that produced it.

Another example occurs in activated [[T cell]] [[lymphocytes]], i.e. when a T cell is induced to mature by binding to a [[peptide]]:[[MHC]] complex on a professional [[antigen presenting cell]] and by the [[B7 (protein)|B7]]:[[CD28]] costimulatory signal. Upon activation, "low affinity" [[Interleukin-2|IL-2]] receptors are replaced by "high affinity" IL-2 receptors consisting of α, β, and γ chains. The cell then releases IL-2 which binds to its own new IL-2 receptors, causing self-stimulation and ultimately a [[monoclonal]] population of T cells. These T cells can then go on to perform effector functions such as [[macrophage]] activation, [[B cell]] activation, and cell-mediated [[cytoxicity]].

==See also==
*[[Paracrine signaling]]
*[[Intracrine]]
*[[Endocrine system]]

==External links==
* {{GPnotebook|2140799033}}
* {{MeshName|Autocrine+signaling}}
* {{Dorlands|a_74|12170175}}
* [http://www.sysbio.org/research/bsi/cellsignal/ligand.stm "Autocrine versus juxtacrine signaling modes" - illustration at sysbio.org]

{{Cell signaling}}
[[Category:Signal transduction]]

[[es:Liberación autocrina]]
[[fr:Communication autocrine]]
[[it:Autocrino]]
[[pt:Autócrino]]
[[sv:Autokrin]]

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