New research explains why some tumours undetected
LONDON, Nov 20 (Reuters) Researchers looking at immune systems in healthy people have discovered an interaction between two types of cells that may help explain why the body's natural defences fail to detect and fight tumours.
The findings could lead to better cancer treatments and new targets for drugs, said Leonie Taams, an immunologist at King's College London, who led the study published on Tuesday.
The study looked at regulatory T-cells, which keep the immune system stable and are key in controlling immune cells called macrophages that cause inflammation. Inflammation is one of the body's first responses when fighting infection.
Taams said the study showed that just as regulatory ''police officer'' T-cells can stop killer T-cells from attacking a tumour, they can also shut off macrophages, suppressing inflammation and keeping the body from detecting tumours.
''Before these police officers were never believed to speak to these macrophages. We have shown they can do it,'' Taams said in a telephone interview.
''The regulatory T-cells trick the immune system into thinking there is no problem.'' Scientists had known things like the presence of bacteria typically activated macrophages but understood less about what caused the cells to switch off.
Taams said the study -- in which researchers took macrophages from healthy people and cultured them in dishes either on their own, with normal T-cells or with regulatory T-cells -- answered that question for the first time.
Their findings, published in the Proceedings of the National Academy of Sciences, could lead to better ways to detect whether someone's immune system is fighting a tumour after treatment, she said.
It could also lead to more specific drugs aimed at removing or altering these non-inflammatory macrophages that suppress the immune system's response, Taams added.
''The
work
was
done
in
healthy
people
but
we
believe
it
has
implications
for
cancer,''
she
said.
''We
believe
that
the
regulatory
T-cells
are
doing
the
job
they
are
supposed
to
do
but
they
are
doing
it
at
the
wrong
place
and
the
wrong
time.''
''The
findings
provide
more
ammunition
for
the
idea
that
regulatory
T-cells
should
be
removed
from
tumours.''
REUTERS
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