|
|
|
WHAT IS AIDS & HIV?
|
AIDS (acquired immune deficiency syndrome)
is a condition caused by a virus called HIV.
This virus attacks the immune system, the
body's "security force" that fights off
infections. When the immune system breaks
down, you lose this protection and can
develop many serious, often deadly
infections and cancers. HIV is a virus, like
the flu or cold. A virus is really nothing
but a set of instructions for making new
viruses, wrapped up in some fat, protein and
sugar.
|
Without living cells, a virus can't do
anything - it's like a brain with no body.
In order to make more viruses (and to do all
of the other nasty things that viruses do),
a virus has to infect a cell. HIV mostly
infects T-cells, other wise called as CD4+
cells, or T-helper cells. These cells are
white blood cells that turn the immune
system on to fight disease. Once inside the
cell, HIV starts producing millions of
viruses, which eventually kill the cell and
then go out to infect other cells. These
viruses had their RNA in the DNA of the
cell, and then, when the cell tries to make
new proteins, it accidentally makes new
viruses as well. HIV mostly infects cells in
the immune system. |
Infection: Several different kinds of cells
have proteins on their surface that are
called CD4 receptors. HIV searches for cells
that have CD4 surface receptors, because
this particular protein enables the virus to
bind to the cell. Although HIV infects a
variety of cells, its main target is the
T4-lymphocyte (also called the "T-helper
cell"), a kind of white blood cell
responsible for warning your immune system
that there are invaders in the system. |
Replication: Once HIV binds to a cell, it
hides HIV RNA inside the cell's DNA: this
turns the cell into a sort of HIV factory. |
|
| |
|
 |
|
