This is a picture of a HIV virus. The green particles are the HIV virus infecting the T helper cells. HIV virus infects the T Helper cell because it has the protein CD4 on its surface. HIV needs to use CD4 to enter cells it infects. This is why the T helper cell is referred to as a CD4 lymphocyte. Once inside a T helper cell, HIV takes over the cell and the virus then replicates. In this process (which takes around a couple of days) the infected cell dies. New virus then seeks out new T -helper cells to infect. More about the different stages of HIV infection can be found at http://www.avert.org/hivstages.htm.

This photo is part of a larger HIV and AIDS picture gallery. For more HIV and AIDS photos visit http://www.avert.org/historyi.htm

Please note, that this HIV virus picture is copyrighted. If you wish to use it or any part of it on your site, or in any other way, please ask permission from the copyright holder. The contact details of the copyright holders can be found here.

Photo credit: © Jeff Johnson, Biological & Medical Visual and Hybrid Medical Animation