Science Advances: What robs older people of their immunity?

During the flu season, we usually get the flu vaccine to intervene to prevent it.
but the flu vaccine is not very effective for older people.
because aging can lead to severe immune dysfunction, which reduces the vaccine's ability to respond.
previously thought it was an irreversible flaw in the immune system.
a research team led by Cincinnati Children's Hospital, affiliated with the University of Cincinnati School of Medicine, published a research paper in Science Advances entitled "IL-10-producing Tfh cells with age and link with age with age-related immuneion" to overturn this conclusion.
study found that the immune system in older people did not weaken, but was inhibited by the activity of a group of immune cells.
researchers call it the Tfh 10, which produces leukin 10, and this inhibition is reversible.
that eliminating this immune system suppression can trigger a strong response to vaccination in older adults.
and by managing Tfh 10 cells to avoid destroying the cell's useful role in fighting other types of disease, it seems likely to enhance the vaccine's ability.
As mentioned earlier, aging was previously thought to lead to irreversible immune dysfunction, while aging also has persistent low immune activation (so-called "inflammation") characteristics, accompanied by high levels of white mesoterine 6 (IL-6).
However, the new study found that in addition to an increase in leukocytocular mesotoprene-6 (IL-6), serum IL-10 (an effective anti-inflammatory medium) increased in older individuals, and IL-10 limited the body's protective response to pathogens.
latest study, researchers conducted dozens of different experiments to try to determine the cause of the ill levels of IL-10, and eventually identified the "culprit", Tfh 10.
, the researchers first determined whether IL-10 levels in older mice actually increased.
They used a sensitive in vivo cytokine capture assay (IVCCA) to detect IL-10 in the serums of young and older mice, and found that IL-10 levels in older mice were two to three times higher than in younger mice.
showed elevated levels of IL-10 in older mice.
, the researchers determined which cells enhanced IL-10 production in aging mice.
They found that THE IL-10 produced by CD4 plus FoxP3 plus T cells (T cells that express CD4 and fork transcription factor P3) increased slightly with age, while the IL-10 produced by FoxP3 - CD4 plus T cells (T cells that express CD4 but do not express fork-shaped transcription factor P3) increased about 10 times with age.
have been tested in many experiments, and it is finally shown that CD4 and FoxP3 - T cells are the main source of IL-10.
, the researchers then needed to further explore which subset of CD4-FoxP3-T cells produced a large amount of IL-10.
they found a significant increase in the frequency and total number of IL-10-plus cells that simultaneously produce IL-21, which is usually produced by follicle-assisted T-cells (Tfh).
, the researchers finally determined that the CD4 and FoxP3-T cells that produced IL-10 in older mice were primarily Tfh cells.
most cells that produce IL-10 exhibit Tfh dedications and require Tfh cytokines IL-6 and IL-21 to produce, which the researchers call Tfh10 cells.
, the researchers tried to determine the physiological correlation between age-driven Tfh10 cell accumulation.
because vaccine responsiveness is a major problem in older adults and Tfh cells are key regulators of vaccine response, the ability of Tfh cells to produce IL-10 for vaccine responses was first studied.
researchers found that antigen-specific Tfh10 cells, the main population of T-cells that produce IL-10, appeared after vaccination in older mice.
results show that IL-10 limits Tfh-dependent vaccine responses in older mice.
the accumulation of Tfh10 cells in mice, the researchers then determined whether Tfh10 cells also accumulated in older adults.
because Tfh cells are primarily located in and function in secondary lymphatic organs, the researchers analyzed the proportion of Tfh cells in the spleen of young and elderly organ donors without immune conditions.
results showed that the group with the highest il-10 production was Tfh cells in older organs, which, in line with data from mice, accumulated in older people.
findings explain the reduced vaccine response in older adults.
, of course, these conclusions have been confirmed in mouse models and experiments with human cells.
to assess the ability of the immune system to respond to vaccines, more research is needed to prove that Tfh 10 cells can be safely managed in the body, " he said.
researchers say they are testing whether IL-10 blockers can restore vaccine response in larger mammals.
their vision is to improve the effectiveness of vaccinations for older people in the future.
meanwhile, aging begins at birth, and the more you know about the immunodeficiency response, the more you can find strategies to overcome these deficiencies to help children with primary immunodeficiency and other immune disorders.
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