This transmission electron micrograph shows HIV (Human Immunodeficiency Virus) particles budding from the surface of a host T-lymphocyte white blood cell (coloured orange-yellow). Discovered by 1983 by Robert Gallo and Luc Montagnier, HIV reproduces by inserting a DNA copy of its own genetic material into the DNA of its host cell. This causes the cell to produce new virus particles that assemble at the host cell membrane, as seen here. The host cells are damaged by this process and may die, weakening the body's immune system. This picture has been coloured to reveal the various social structures, and is magnified 360,000 times.