Simian immunodeficiency virus from African green monkeys.

Area of Science:

• Virology
• Immunology
• Genetics

Background:

• Simian immunodeficiency virus (SIV) is a lentivirus that infects non-human primates.
• Understanding SIV diversity is crucial for insights into human immunodeficiency virus (HIV) evolution and pathogenesis.
• African green monkeys are a natural reservoir for SIV, known as SIVagm.

Purpose of the Study:

• To isolate and characterize novel SIVagm strains from Kenyan green monkeys.
• To determine the replication efficiency of these SIVagm isolates in various cell lines.
• To compare the genetic and antigenic properties of SIVagm with other primate lentiviruses like SIVmac and HIV.

Main Methods:

• Isolation of SIVagm from peripheral blood mononuclear cells and monocyte-macrophage populations.
• Continuous production and replication studies using cell lines (MOLT-4 clone 8, SupT1, MT-4, U937, Jurkat-T, HUT-78, H9, CEM).
• Antigenic cross-reactivity assessment using enzyme-linked immunosorbent assay and Western blotting.
• Viral DNA hybridization and nucleotide sequencing of the pol gene.

Main Results:

• SIVagm was successfully isolated and produced in the M4C18 cell line.
• SIVagm isolates replicated efficiently in specific CD4+ T-cell lines (M4C18, SupT1, MT-4, U937, Jurkat-T), differing from SIVmac.
• Antigenic cross-reactivity between SIVagm and SIVmac was reduced; major viral proteins identified.
• Nucleotide sequencing revealed SIVagm385 is related to but distinct from SIVmac, HIV-2, and HIV-1.

Conclusions:

• The isolated SIVagm strains possess unique replication characteristics and genetic profiles.
• These findings highlight the genetic diversity within SIVagm.
• Further genetic analysis of SIV isolates can enhance understanding of lentivirus evolution and the origins of HIV.