Isolation and partial characterization of a lentivirus from talapoin monkeys (Myopithecus talapoin)

Area of Science:

• Virology
• Primate Immunology
• Infectious Diseases

Background:

• Talapoin monkeys (Myopithecus talapoin) exhibit human immunodeficiency virus-1 cross-reactive antibodies.
• Previous research suggested the presence of lentiviruses in this primate species.

Purpose of the Study:

• To identify and characterize a novel lentivirus in talapoin monkeys.
• To investigate the transmission and pathogenicity of this new virus in various primate models.

Main Methods:

• Virus isolation from seropositive talapoin monkeys.
• Propagation in primate peripheral blood mononuclear cells.
• Experimental infection of talapoin, rhesus, and cynomolgus macaques.
• PCR amplification and DNA sequencing of viral polymerase gene fragments.
• Monitoring of CD4(+) cell counts in infected animals.

Main Results:

• A novel simian immunodeficiency virus, SIVtal, was isolated and identified in talapoin monkeys.
• SIVtal was transmissible between captive monkeys via unknown routes.
• The virus could be propagated in talapoin monkey cells but not human cell lines.
• Experimental infection of talapoin and macaque species resulted in seroconversion and viral reisolation.
• Chronically infected talapoin monkeys showed a decrease in CD4(+) cells, but no other immunodeficiency signs were observed.
• Genetic analysis indicated SIVtal is distinct from known lentiviruses, possibly related to SIV from Sykes monkeys.

Conclusions:

• SIVtal represents a novel lentivirus in talapoin monkeys with potential for interspecies transmission.
• While SIVtal causes CD4(+) cell reduction in chronically infected talapoins, its pathogenic potential appears limited in the short term.
• Further research is needed to understand the evolutionary relationships and full pathogenic spectrum of SIVtal.