ARLA/CLUSTER: O uso do Berílio na industria electronica movel provoca doença pulmonar mortal

[João Costa > CT1FBF]

Beware of Beryllium

We are all warned of the dangers of Beryllium, here is why!

>From EE Times Europe
Researchers discover how beryllium

July 04, 2014 | Jean-Pierre Joosting | 222906517

Beryllium is fairly common in the mobile industry and for many years
there has been a fair amount of controversy over its use in
electronics. Purportedly safe if handled correctly, researchers have
discovered the mechanism by which beryllium causes a deadly lung
disease. This could help manufacturers ensure their handling protocols
work, enable doctors to find a possible treatment strategy, and also,
possibly prompt a look at alternative

Using detailed maps of molecular shapes and the electrical charges
surrounding them, researchers at National Jewish Health have
discovered how the metal beryllium triggers a deadly immune response
in the lungs.

In the July 3, 2014, issue of the journal Cell John Kappler, PhD, and
his colleagues show how a genetic susceptibility to the disease
creates a molecular pocket in an immune system protein, which captures
beryllium ions and triggers an inflammatory response in the lungs. The
findings describe for the first time an immune response that lies
somewhere between classic forms of allergic hypersensitivity and
auto-immunity.

"The immune system does not actually 'see' beryllium," said Dr.
Kappler. "The beryllium changes the shape of otherwise innocuous
self-peptides so that T cells recognize them as foreign and
dangerous."

Beryllium is a relatively rare metal whose unique combination of
strength and lightness makes it invaluable for various industrial
uses, ranging from triggers for nuclear bombs to satellite components,
computers and cell phones. It can cause disease when people who work
with the metal inhale particles that become lodged in the lungs.
People who develop chronic beryllium disease can have varied courses
of disease, from stable with medications to progressive lung damage
and death.

Not everyone who works with the metal becomes ill. About 85 percent of
people who develop chronic beryllium disease have an immune system
protein known as HLA-DP2. Cells throughout the body use this molecule
to tell the immune system what is going on inside of them. HLA-DP2
sits on the cell surface holding small protein fragments taken from
the cell's interior. Immune system sentinels known as T cells bump
against HLA-DP2 and its displayed protein fragment. If the protein
fragment is derived from the body's own proteins, the T cell ignores
it; if it is a foreign peptide, say from a bacterium, virus or other
pathogen, the T cell sounds the alarm and triggers an immune response.

HLA-DP2 differs from most other peptide-presenting proteins by a
single amino acid. Dr. Kappler and his colleagues performed a series
of highly detailed genetic, x-ray diffraction, molecular binding and
electrostatic studies to show how this single amino acid can combine
with other amino acids from HLA-DP2 and some of its bound
self-peptides to create a unique molecular pocket that captures a
single beryllium ion along with a sodium ion.

The peptides that bind to HLA-DP2 come from the body's own tissues and
normally elicit no immune response. With the beryllium and sodium
firmly lodged in the molecular pocket, however, those peptides have a
very slightly altered shape and electrical charge, which roving T
cells recognize as foreign and dangerous. They initiate an immune
response that causes inflammation and scarring in the lungs.

"This response resembles allergic hypersensitivity in that a metal ion
causes an allergic reaction," said Dr. Kappler. "But it also resembles
autoimmunity in that the immune system is mounting an attack against a
self-peptide. It is a new form of immune response, and may lead to new
therapeutic strategies to treat and prevent the disease."

Our thanks to John, G8MM for spotting this item