Retrovirus is a type of virus whose genetic material consists of RNA (ribonucleic acid). The genetic material of most viruses is made up of DNA (deoxyribonucleic acid), a molecule closely related to RNA. All viruses must infect a living host cell to reproduce.
After they enter a host cell, retroviruses use an enzyme called reverse transcriptase to make DNA copies of their RNA. This DNA is then inserted into the host cell’s DNA. There, the DNA begins the process of producing proteins that are used to make new copies of the retrovirus.
Several different kinds of retroviruses infect many organisms. One of the most important for humans is the human immunodeficiency virus (HIV), the virus that causes AIDS. HIV is part of a larger group of retroviruses called lentiviruses. Following infection, such viruses can remain in the body for a long time before causing symptoms of disease.
Scientists have developed medications called antiretroviral drugs to treat diseases caused by retroviruses, including HIV. Many of these drugs work by inhibiting (blocking) enzymes, such as reverse transcriptase or protease, that retroviruses need to reproduce inside a host cell.
