Virus load and sequence variation in simian retrovirus type 2 infection

Area of Science:

• Veterinary Virology
• Primate Immunology
• Retroviral Pathogenesis

Background:

• The natural history of simian retrovirus (SRV) infection, particularly type D SRV-2, remains poorly understood regarding viral dynamics and host immune responses.
• Characterizing SRV-2 infection is crucial for understanding retroviral infections in non-human primates and their implications for biomedical research.

Purpose of the Study:

• To investigate the natural history of SRV type 2 (SRV-2) infection in cynomolgus macaques.
• To characterize viral load, antibody status, and sequence variation of SRV-2 over an 8-month period in naturally infected macaques.

Main Methods:

• Longitudinal blood sampling from a cohort of naturally SRV-2-infected cynomolgus macaques over 8 months.
• Quantification of provirus and RNA virus loads.
• Screening for antibodies to SRV-2 and assaying neutralizing antibody titers.
• Sequence analysis of the env gene to assess intra- and inter-monkey variation.

Main Results:

• Individual macaques exhibited stable virus loads over the 8-month study period, despite significant variations among different animals.
• No substantial env sequence variation was detected within individual macaques over time.
• Antibody status and neutralizing antibody titers did not show a clear correlation with viral load or disease outcome.

Conclusions:

• SRV-2 infection dynamics in macaques are complex and distinct from lentiviral infections.
• Viral load and sequence variation within individuals appear stable over short periods, irrespective of initial levels.
• The relationship between SRV-2 infection variables and disease outcome requires further investigation.