Editing DNA vaccine (section)

=== Interferons ===

Both helper and cytotoxic T-cells can control viral infections by secreting interferons. Cytotoxic T cells usually kill virally infected cells. However, they can also be stimulated to secrete antiviral cytokines such as [[Interferon gamma|IFN-γ]] and [[Tumor necrosis factor alpha|TNF-α]], which do not kill the cell, but limit viral infection by down-regulating the expression of viral components.<ref name=Franco1997>{{cite journal | vauthors = Franco A, Guidotti LG, Hobbs MV, Pasquetto V, Chisari FV | title = Pathogenetic effector function of CD4-positive T helper 1 cells in hepatitis B virus transgenic mice | journal = Journal of Immunology | volume = 159 | issue = 4 | pages = 2001–2008 | date = August 1997 | doi = 10.4049/jimmunol.159.4.2001 | pmid = 9257867 | s2cid = 20528634 | url = http://www.jimmunol.org/cgi/content/abstract/159/4/2001 | doi-access = free }}</ref> DNA vaccinations can be used to curb viral infections by non-destructive IFN-mediated control. This was demonstrated for hepatitis B.<ref name=Mancini1996>{{cite journal | vauthors = Mancini M, Hadchouel M, Davis HL, Whalen RG, Tiollais P, Michel ML | title = DNA-mediated immunization in a transgenic mouse model of the hepatitis B surface antigen chronic carrier state | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 93 | issue = 22 | pages = 12496–12501 | date = October 1996 | pmid = 8901610 | pmc = 38020 | doi = 10.1073/pnas.93.22.12496 | doi-access = free | bibcode = 1996PNAS...9312496M }}</ref> IFN-γ is critically important in controlling malaria infections<ref name=Doolan1999>{{cite journal | vauthors = Doolan DL, Hoffman SL | title = IL-12 and NK cells are required for antigen-specific adaptive immunity against malaria initiated by CD8+ T cells in the Plasmodium yoelii model | journal = Journal of Immunology | volume = 163 | issue = 2 | pages = 884–892 | date = July 1999 | doi = 10.4049/jimmunol.163.2.884 | pmid = 10395683 | s2cid = 41651105 | url = http://www.jimmunol.org/cgi/content/abstract/163/2/884 | doi-access = free }}</ref> and is a consideration for anti-malarial DNA vaccines.