Lentivirus

Lentivirus (lenti-, Latin for "slow") is a genus of slow viruses of the Retroviridae family, characterized by a long incubation period. Human immunodeficiency virus (HIV), Simian immunodeficiency virus (SIV), and Feline immunodeficiency virus (FIV) are all examples of lentiviruses. The Lentivirus genus belongs to the Orthoretrovirinae subfamily of the Retroviridae family.

Phylogeny
Five serogroups of lentiviruses are recognized, reflecting the vertebrate hosts with which they are associated (primates, sheep and goats, cats, horses, and cattle). The primate lentiviruses are distinguished by the use of CD4 protein as receptor and the absence of dUTPase. Feline lentivirus gag antibodies cross react with SRLV gag antigens


 * Bovine lentivirus group
 * Bovine immunodeficiency virus
 * Equine lentivirus group
 * Equine infectious anaemia virus


 * Small-ruminant lentiviruses (SRLV)
 * Caprine arthritis encephalitis virus (CAEV)
 * ovine Visna/maedi virus (MVV)
 * Feline immunodeficiency virus
 * domestic cat FIV (FIVfca)
 * puma immunodeficiency virus (FIVpco)
 * African lion (Panthera leo) FIV infection (FIVple)


 * Primate lentivirus group
 * Human immunodeficiency virus 1
 * Human immunodeficiency virus 2
 * Simian immunodeficiency virus

All of the above viruses infect mammalian hosts that belong to the clade Boreoeutheria:

Laurasiatheria:
 * Artiodactyla
 * goats
 * sheep
 * cows
 * Pegasoferae:
 * Carnivora
 * cats
 * Perissodactyla
 * horses

Euarchontoglires:
 * Primates
 * mangabeys
 * macaques
 * monkeys
 * chimpanzees and
 * humans.

Open reading frames
The lentivirus genome codes for at least five structural proteins and at least three enzymes:


 * structural proteins:
 * env gene
 * surface envelope protein (SU) gp120
 * transmembrane envelope protein (TM) gp41
 * gag gene
 * capsid protein (CA) p24
 * capsid protein (NC)
 * matrix protein (MA) p17
 * enzymes:
 * pro gene
 * protease (PR)
 * integrase (IN)
 * pol gene
 * reverse transcriptase
 * rev gene
 * vif gene
 * tat/vpr gene