Replication and pathogenesis of human immunodeficiency virus

Human immunodeficiency virus (HIV) was identified in the early 1980s. It belongs to a group of retroviruses called lentiviruses (genus Lentivirus). Lentiviruses cause life-long chronic infections of a variety of animals. They are very host specific, often infect cells of the immune system and have the ability to productively infect nondividing cells. HIVs are very closely related to the simian immunodeficiency viruses (SIVs) that infect a number of species of nonhuman primate. The two types of HIV, HIV-1, and HIV-2 are most closely related to SIV chimpanzee and SIV sooty mangabey, respectively. HIV-1 is the more widely distributed. In 2012 the World Health Organization estimated over 35 million HIV-1 infections worldwide. This chapter discusses HIV cell and host tropism, functions of structural, regulatory, and auxiliary proteins and provides a general overview of pathogenesis, vaccine development, and treatments.