Editing Cytokine (section)

== Cellular effects ==
Each cytokine has a matching [[cell-surface receptor]]. Subsequent [[biochemical cascade|cascades]] of intracellular signaling then alter cell functions. This may include the upregulation and/or downregulation of several [[genes]] and their [[transcription factors]], resulting in the production of other cytokines, an increase in the number of surface receptors for other molecules, or the suppression of their own effect by [[enzyme inhibitor|feedback inhibition]]. The effect of a particular cytokine on a given cell depends on the cytokine, its extracellular abundance, the presence and abundance of the complementary receptor on the cell surface, and downstream signals activated by receptor binding; these last two factors can vary by cell type. Cytokines are characterized by considerable redundancy, in that many cytokines appear to share similar functions. It seems to be a paradox that cytokines binding to [[antibody|antibodies]] have a stronger immune effect than the cytokine alone. This may lead to lower therapeutic doses.

It has been shown that inflammatory cytokines cause an IL-10-dependent inhibition of<ref name="Said2010">{{cite journal | vauthors = Said EA, Dupuy FP, Trautmann L, Zhang Y, Shi Y, El-Far M, Hill BJ, Noto A, Ancuta P, Peretz Y, Fonseca SG, Van Grevenynghe J, Boulassel MR, Bruneau J, Shoukry NH, Routy JP, Douek DC, Haddad EK, Sekaly RP | title = Programmed death-1-induced interleukin-10 production by monocytes impairs CD4+ T cell activation during HIV infection | journal = Nature Medicine | volume = 16 | issue = 4 | pages = 452–459 | date = April 2010 | pmid = 20208540 | pmc = 4229134 | doi = 10.1038/nm.2106 }}</ref> T-cell expansion and function by up-regulating [[programmed cell death 1|PD-1]] levels on monocytes, which leads to IL-10 production by monocytes after binding of PD-1 by PD-L.<ref name="Said2010" /> Adverse reactions to cytokines are characterized by local inflammation and/or ulceration at the injection sites. Occasionally such reactions are seen with more widespread [[papule|papular eruptions]].<ref name="Andrews">James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. {{ISBN|0-7216-2921-0}}.{{page needed|date=July 2013}}</ref>