SIVagm

SIVagm, or Simian immunodeficiency virus of African green monkeys, is a lentivirus that infects African green monkeys (Chlorocebus aethiops) in sub-Saharan Africa. It is one of several naturally occurring SIVs that have co-evolved with their primate hosts and is frequently cited in studies of lentiviral biology and host–virus interactions.

Taxonomy and genome

Like other SIVs, SIVagm belongs to the genus Lentivirus within the Retroviridae family. The virus has the typical lentiviral genome, including gag, pol, and env genes, along with regulatory and accessory genes that vary among strains. Genetic diversity among SIVagm isolates reflects adaptation to different populations of African green monkeys and supports a long co-evolutionary history with its natural host.

Natural history and pathogenesis

In African green monkeys, SIVagm infection is generally nonpathogenic. Infected animals may carry high levels of viremia without progressive CD4+ T-cell depletion or overt disease, a pattern characteristic of many SIV-host relationships. Transmission occurs primarily through mucosal exposure during sexual activity and can also occur from mother to offspring. In contrast, experimental infections of non-natural hosts can lead to more pronounced disease, highlighting the influence of host factors on pathogenesis.

Research significance

SIVagm serves as a model to study viral persistence, immune control, and tolerance in a natural SIV-host pairing. It provides insights into why some lentiviral infections cause disease in some hosts but remain asymptomatic in others, informing broader understanding of immune responses and vaccine strategies against lentiviruses.

Epidemiology and evolution

Diverse SIVagm lineages have been identified across African green monkey populations, with phylogenetic analyses supporting deep evolutionary history and geographic structuring. This diversity underscores the dynamic co-evolution of the virus with its natural host.

Public health

SIVagm is not known to cause disease in humans, and while cross-species transmission has historical significance in lentivirus research, SIVagm is not considered a current zoonotic threat.