The breakthrough

IT COULD be the key to unlocking the
mystery of the AIDS virus. Scientists at
the National Institute of Allergy and
Infectious Diseases (NIAID) in Maryland,
have found a protein that enables the
entry Of HIV, the AIDS virus, into human
immune system cells, signalling a deadly
cycle of destruction.

The virus first attacks a receptor
molecule known as CD-4, which lies
embedded in the surface of certain
cells. Scientists had long established that CD-4 was insufficient for infection. They
were looking for a protein on the
cells' surface that opens the door for the
virus. Now, they have discovered the
elusive 'co-factor' protein and named
it 'fusin', because it helps the coat of
the virus to fuse with the cell's outer
-membrane and inject its genetic
material into it. Anthony S Fauci, director, NIAID, described the finding as a
"tremendous advance". The discovery
could make it possible to study genetically engineered mice or rabbits that
are likely to be infected with HIV
and could be used to test new drugs
and vaccines.