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A Newly Discovered Memory in Our Bones

posted by Fnord666 on Tuesday March 17 2020, @12:47AM   
from the it's-in-the-blood dept.

upstart writes in with an IRC submission for AnonymousCoward:

Blood stem cells boost immunity by keeping a record of previous infections:

"The first exposure to LPS causes marks to be deposited on the DNA of the stem cells, right around genes that are important for an immune response. Much like bookmarks, the marks on the DNA ensure that these genes are easily found, accessible and activated for a rapid response if a second infection by a similar agent was to come."

The authors further explored how the memory was inscribed on the DNA, and found C/EBPb to be the major actor, describing a new function for this factor, which is also important for emergency immune responses. Together, these findings should lead to improvements in tuning the immune system or better vaccination strategies.

"The ability of the immune system to keep track of previous infections and respond more efficiently the second time they are encountered is the founding principle of vaccines. Now that we understand how blood stem cells book mark immune response circuits, we should be able to optimize immunization strategies to broaden the protection to infectious agents. It could also more generally lead to new ways to boost the immune response when it underperforms or turn it off when it overreacts", concluded Prof. Michael Sieweke.

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Original Submission

• Acronym hunting Acronym hunting (Score: 2) by hemocyanin on Tuesday March 17 2020, @01:41AM (1 child)

  by hemocyanin (186) on Tuesday March 17 2020, @01:41AM (#972073) Journal

  Commonly called “blood stem cells”, the hematopoietic stem cells (HSC) are nestled in the bone marrow.
  ...
  “We discovered that HSCs could drive a more rapid and efficient immune response if they had previously been exposed to LPS, a bacterial molecule that mimics infection”
  ...
  [quote in TFS]

  So what is "LPS"? I'm guessing this, but the topic is way outside my wheelhouse: https://en.wikipedia.org/wiki/Lipopolysaccharide [wikipedia.org]

  Anybody know for sure?

  Starting Score:	1		point
  Karma-Bonus Modifier		+1
  Total Score:		2

• Re:Acronym hunting (Score: 2) by takyon on Tuesday March 17 2020, @01:48AM

  by takyon (881) <takyonNO@SPAMsoylentnews.org> on Tuesday March 17 2020, @01:48AM (#972075) Journal

  Yes

  https://www.cell.com/cell-stem-cell/pdfExtended/S1934-5909(20)30017-5 [cell.com]

  Hematopoietic stem cells (HSCs) maintain life-long production of immune cells and can directly respond to infection, but sustained effects on the immune response remain unclear. We show that acute immune stimulation with lipopolysaccharide (LPS) induced only transient changes in HSC abundance, composition, progeny, and gene expression, but persistent alterations in accessibility of specific myeloid lineage enhancers occurred, which increased responsiveness of associated immune genes to secondary stimulation. Functionally, this was associated with increased myelopoiesis of pre-exposed HSC and improved innate immunity against the gram-negative bacterium P. aeruginosa. The accessible myeloid enhancers were enriched for C/EBPβ (targets, and C/EBPβ deletion erased the long-term inscription of LPS-induced epigenetic marks and gene expression. Thus, short-term immune signaling can induce C/EBPβ-dependent chromatin accessibility, resulting in HSC-trained immunity, during secondary infection. This establishes a mechanism for how infection history can be epigenetically inscribed in HSC as an integral memory function of innate immunity.

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