Human evolution; human DNA has an immune system (Introduction)

by David Turell , Monday, January 27, 2020, 18:03 (1762 days ago) @ David Turell

Other than the usual known cells and antibodies, in general is anti-viral:

https://www.the-scientist.com/news-opinion/novel-dna-sensing-pathway-found-in-human-cel...

"Triggered by an enzyme called DNA protein kinase (DNA-PK), the newly found pathway is independent of the cGAS-STING pathway—until now considered the main regulator of mammalian innate immune responses to DNA—and is missing or inactive in mouse cells.

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"First described in 2013, the cGAS-STING pathway plays a critical role in the cell’s innate immune reaction to viral infection. Upon detecting cytosolic DNA (usually a tell-tale sign of viral entry), the cGAS enzyme binds to the transmembrane protein STING to trigger the production of interferons and other antiviral responses.

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"It’s not the first time DNA-PK has been implicated in antiviral defenses. The University of Cambridge’s Geoffrey Smith and Brian Ferguson reported in 2012 that DNA-PK in mouse and human cells could promote interferon production in response to transfection with foreign DNA. That study, however, concluded that DNA-PK was likely triggering the response via STING, not independently of it.

“'It’s nice to see that another group has found an important role for DNA-PK in sensing foreign DNA,” Smith tells The Scientist, adding that the Washington team’s paper presents “some data supportive” of the conclusion that the new pathway is STING-independent.

"He notes that assays the team carried out using DNA-PK inhibitors seemed to influence antiviral responses differently depending on cell type—a result that Stetson says might have do with interactions between the DNA-PK and gCAS-STING pathways in the various cell lines the team used. In some cases, “the two pathways may antagonize each other,” Stetson writes in an email to The Scientist. “It is something we are interested in pursuing.”

"Examining other mammalian cell lines, Stetson’s team detected evidence of the novel DNA-PK pathway in non-human primate cells and in rat cells. But the researchers couldn’t find the pathway in mouse cells, where most preclinical research on cGAS-STING therapies has been conducted." (my bold)

Comment: Note my bold. It is interesting that this ability is widely available at the primate level, but also in rats, a known species with close to human physiology. Another complex immune system must have been designed.