The Life Cycle of HIV

Those interested in learning more about the basic lifecycle of HIV will find this article useful. It contains information on how the virus reproduces, replicates and how this has lead to it being so effective at continuing to evade our efforts to eradicate it.

How HIV reproduces and replicates

After entering the body of a new host the HIV responds to certain immune cells by binding to them. These immune cells, known as T-lymphocytes, would normally help to fight off infection as part of a more comprehensive immune response.

The HIV then seeks to integrate its DNA into the cell's own DNA. It does this via a complicated set of processes that both penetrate the cell and nucleus then integrate viral DNA into the cell genome.

Once the virus has achieved integration the cell's own activity will produce thousands of copies of the virus. This won't happen until the cell is activated in some way. These copies then use the cell membrane as an outer layer, budding off of the cell and going on to infect either a new host or other T-cells.

Why is HIV so difficult to cure?

Every time HIV replicates it does so with large amounts of variability. This prevents the body's natural defences from being able to mount an attack against a standard virus particle. It also means that medically there are few parts of the virus that can be targeted without them changing at some point in the near future.

The HIV drugs currently used are sometimes initially effective against a strain of the virus. If however some survive due to variations in their composition, these go on to reproduce leading the virus to gradually develop resistance to our HIV drugs over time.

HAART tries to combat this by using multiple antiretrovirals so that the HIV would need to develop resistance to all three to survive. Even with this method though the virus still manages to slowly gain resistance, meaning that the HAART combination used may have to be changed for a patient at a later date.

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