The HIV virus’s life cycle begins as it is born in a host cell. The virus exits the cell through its cell membrane, and searches for a new T-cell to infect. The virus can identify the cell it wishes to find, the CD4+ T-cell, because they have CD4 molecules on their surface. Once the virus reaches a victim, it attaches itself to the CD4 molecules that make up its surface, and the virus’s outer envelope merges with the cells and becomes one.

After getting inside the cell, HIV uses a chemical called reverse transcriptase to convert RNA into DNA. This is the form of nucleic acid which can be used to produce copies of the virus.

When the DNA enters the cells nucleus, the next stage of the process is complete. This is done with the help of a chemical known as integrase. Next, the HIV DNA is turned into RNA that can use the cells machinery. After this is complete, this “messenger” RNA moves out of the nucleus and into the cytoplasm of the cell to take control of it. It creates proteins needed for more viruses using the host cells parts. The last stage occurs when these proteins join together and create young viruses. These are not yet ready to infect other cells. A chemical called protease cleans up the proteins and enzymes in these immature HIV strains, and then they gather up in the cells membrane and burst out. It is this eruption of new viruses that destroys the host cell.

To see an excellent Flash animation of the HIV life cycle, click here.

Sources:

• "Stages of Infection." About HIV. Aaron Diamond AIDS Research Center. 15 Feb. 2004. <http://www.adarc.org/hiv/stages/>.

Pictoral Sources:

• All from <http://www.adarc.org/hiv/stages/>.