A potential role for ibuprofen in older adults' immunity to RSV
Study in rats suggests drug restores cell functions slowed by aging
Date:
November 9, 2021
Source:
Ohio State University
Summary:
New research suggests there may someday be a role for ibuprofen in
providing older adults with lasting immunity against RSV, a virus
commonly associated with infants and young kids that also rivals
the flu as a dangerous wintertime infection for the elderly.
FULL STORY ==========================================================================
New research suggests there may someday be a role for ibuprofen in
providing older adults with lasting immunity against RSV, a virus
commonly associated with infants and young kids that also rivals the
flu as a dangerous wintertime infection for the elderly.
==========================================================================
RSV, or respiratory syncytial virus, accounts for an estimated 14,000
deaths and 177,000 hospitalizations annually among U.S. adults over
65. RSV is problematic for older people in part because an initial
infection isn't effective at inducing a long-term immune response to
the virus.
The study showed that geriatric cotton rats given ibuprofen for a week
before initial infection with RSV cleared the virus more quickly than
those that didn't receive ibuprofen. When researchers re-infected those ibuprofen-treated rats a month later, the elderly animals were completely protected from the virus.
In contrast, young adult cotton rats were able to clear the virus fairly effectively and mount a suitable immune response to re-infection a month
later -- but got no benefit from the ibuprofen.
With ibuprofen showing effectiveness only in geriatric animals, the
findings suggest that the drug improves the immune response by lowering aging-related inflammation. Though there is still a lot to learn, the
Ohio State University researchers speculate that the reduced inflammation restored the function of specific immune cells needed to clear the virus.
"For a long time, people have thought that certain immune cells get burned
out and can't function properly any longer. And then we started treating against inflammation, and suddenly the old cells can do their job like
young cells," said senior study author Stefan Niewiesk, professor of
veterinary biosciences at Ohio State.
==========================================================================
"It only works in old animals, and in older people we see a lot of
inflammation and related chronic disease. When we think about what the
pathways are to fix RSV infection in the elderly, this study opens a
door to the possibilities." The research appears in the November 2021
issue of the journal Virology.
Niewiesk and first author Olivia Harder, a veterinary biosciences research associate at Ohio State, cautioned that it's far too soon to consider
taking ibuprofen to prevent RSV infection. Long-term use of ibuprofen,
a nonsteroidal anti-inflammatory drug (NSAID), can damage the kidneys
and gastric lining and slows down blood clotting time.
In this study, the researchers compared the influence of ibuprofen pre- treatment on groups of sexually mature adult cotton rats, younger than
2 months old, and geriatric rats between 9 and 15 months old. Cotton
rats are a good model for the study of RSV because the virus grows well
in both the lungs and nose as it does in humans, but the rats don't
experience symptoms of illness.
The drug was added to their chow and drinking water for one week before
they were first infected with RSV. The estimated ibuprofen dose was
intended to resemble the 200 to 400 milligrams humans might take every
four to six hours.
========================================================================== Though ibuprofen was linked to more rapid viral clearance in old rats,
the scientists were particularly interested in the animals' response to
re- infection a month later.
"We wanted to see if they could mount an immune response," Harder
said. "In the geriatric cotton rats we had treated with ibuprofen, there
was no growth of the virus with the second infection." In examinations
of cells and tissue, Harder found that ibuprofen did not improve the
antibody response in the old rats or kill the virus. The analysis
identified a specific type of immune cell, called CD8+ (cytotoxic) T
cells, that were critical to the geriatric rats' ability to clear the
virus because they remove infected cells. When the team used a technique
to deplete CD8+ T cells in the old rats, it took the animals longer to
clear the virus and any positive effects of the ibuprofen were lost -- suggesting the ibuprofen had a restorative effect on those cells.
Previous research has suggested that other immune cells responsible
for stimulating T cell production get sluggish in old animals, and that inflammation-related molecules are behind their slowed reactivity.
"If you take those inflammatory molecules away with ibuprofen, these
immune cells would migrate normally and we'd have stimulated CD8+ T
cells. That's the idea, but we still haven't confirmed the mechanism,"
Niewiesk said. "We're also asking what part of the inflammatory cascade
does ibuprofen affect? How does inflammation look in these old animals --
is it always there and then increased with infection? That's where we're looking at the moment." RSV vaccines are in development, but there is
no treatment -- with the exception of an expensive prophylactic antibody available to prevent severe symptoms only in at-risk infants.
Niewiesk hopes to eventually identify a more targeted agent for the
aging population that could have a similar protective effect against
RSV without any risks.
"This isn't a case where someone should take ibuprofen daily for the
whole winter. There are too many side effects," he said. "But if there
was something to take post-infection, after you feel sick -- that would
be great." This work was supported in part by the National Institute
of Allergy and Infectious Diseases. Former graduate student Margaret
Martinez also worked on the study.
========================================================================== Story Source: Materials provided by Ohio_State_University. Original
written by Emily Caldwell. Note: Content may be edited for style and
length.
========================================================================== Journal Reference:
1. Olivia E. Harder, Margaret Martinez, Stefan Niewiesk. Nonsteroidal
anti-
inflammatory drugs restore immune function to respiratory syncytial
virus in geriatric cotton rats (Sigmodon hispidus). Virology,
2021; 563: 28 DOI: 10.1016/j.virol.2021.08.006 ==========================================================================
Link to news story:
https://www.sciencedaily.com/releases/2021/11/211109120349.htm
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