In news that may bring hope to asthma sufferers, scientists
discover a mechanism that provides a possible new target for
allergy treatments.
By observing the allergic response in mice with asthma,
scientists at the Francis Crick Institute found that white blood
cells that normally reduce the symptoms of asthma convert into
cells that make allergies worse. The research was funded by the
Medical Research Council and the Francis Crick Institute.
"If we can work out what makes the cells change, and how to stop
them changing, we might be able to find new ways of tackling
allergic responses that make conditions such as asthma worse," says
Mark Wilson, Group Leader at the Francis Crick Institute, who led
the research.
The findings, published in The Journal of Experimental Medicine,
also reveal that this cell-changing mechanism could boost immunity
to worms in the intestine, which affect nearly half of the world's
population, providing a new approach for vaccines.
"The conversion of immune-suppressing cells to immune-boosting
cells is beneficial for providing immunity against intestinal
worms, but can make allergies worse," explains Victoria Pelly,
first author of the paper, and researcher at the Francis Crick
Institute. "If we can find a way to target this mechanism, it will
be extremely useful in the clinic."
After infecting mice with intestinal worms, the team took their
white blood cells and injected them into non-infected mice, as a
sort of 'vaccine', before infecting these mice with intestinal
worms. Using a combination of genetic and imaging tools, the team
monitored the white blood cells and found that a large proportion
of immune-suppressing cells turned into immune-boosting cells to
help fight the infection.
To investigate whether the same cell conversion happened in
conditions beside worm infection, the team observed what happened
to immune-suppressing cells in the lungs of mice with asthma. They
found that up to 60% of these cells converted to immune-boosting
cells, worsening the symptoms of asthma.
"Even though we notice the same cell conversion in worm
infection and asthma, we think that the molecular mechanisms
underlying this process are different," says Mark.
The paper, 'Interleukin 4 promotes the development of ex-Foxp3
Th2 cells during immunity to intestinal helminths', is
published in The Journal of Experimental Medicine.