How does HIV affects the immune system?
Your immune system has different kinds of cells that work together to fight infections. CD4 T-cells are one kind of immune cell. They are like little "factories" that make things that your body needs to fight germs and infections. These cells are found in your blood, lymph nodes, and other places in your body.
After HIV enters the body, it uses the CD4 T-cells to make more copies of itself. When this happens, the CD4 T-cells that have been taken over by HIV no longer help your body fight infections, and instead produce more HIV.
At first, the body is able to make enough CD4 T-cells to keep up with those lost due to HIV. Over time, as the virus copies itself over and over, there are fewer and fewer CD4 T-cells. Eventually, your immune system is weakened and your body is less able to fight germs.
well HIV virus binds to CD4 cells of the immune system..they are responsible for initiation and memory of immune response...it destroys them.when the CD4 cell count decreases too much body is not able to defend itself against the other minor infections...