TUESDAY, April 1 (HealthDay News) -- U.S. researchers say
they've discovered how HIV -- the virus that causes AIDS -- hides
in human cells to avoid being destroyed by the body's immune
cells.
They explained that when a normal virus, such as the common
cold, infects a person, the immune system responds and produces
cells that quickly eliminate the virus. However, HIV makes itself
appear as part of the normal trash in a cell, rather than being
clearly visible on the cell surface.
"HIV can make a protein called Nef, which helps the virus hide,"
researcher Dr. Kathleen Collins, an associate professor at the
University of Michigan, said in a prepared statement.
"Nef interferes with one important part of our defenses, which
helps our immune system recognize infected cells, by displaying
pieces of the infecting virus or bacteria on the cell surface,
forming a target for our bodies' killer cells. When HIV infects one
of our cells, the protein Nef binds to this helper system and
alters it in such a way that the cell believes it belongs in the
cellular trash bin rather than on the surface where our main
defenses can see it," she said.
Collins added that the Nef protein recruits other proteins
naturally made by cells to help HIV hide from immune cells. She and
her colleagues identified these natural proteins and developed
inhibitors that block their actions and reverse the activity of
Nef. This may help the immune system to detect and destroy HIV.
"We are currently screening a whole range of substances, looking
for small molecule inhibitors which could be developed into drugs
to provide better therapies for people with HIV and AIDS," Collins
said.
"We have discovered that Nef takes on notably different shapes
and structural forms in different contexts, which allows it to
reveal or obscure different traffic signals within the infected
cell as needed. Once we have a better understanding of the surfaces
and shapes involved in these interactions, we will be in a better
position to develop medicines which may someday help to combat
AIDS."
The research was to be presented April 1 at the Society for
General Microbiology annual meeting, in Edinburgh, Scotland.
More information
The U.S. Centers for Disease Control and Prevention has more
about
HIV/AIDS.
