In vitro selection of Junin virus antigenic variants

Area of Science:

• Virology
• Immunology
• Infectious Diseases

Background:

• Junin virus is the causative agent of Argentine hemorrhagic fever.
• Persistent Junin virus infections in the rodent Calomys musculinus lead to the emergence of viral antigenic variants.
• These variants are observed in both the brain and blood of infected animals.

Purpose of the Study:

• To investigate the emergence of Junin virus antigenic variants in vitro.
• To explore the role of selective pressure, specifically polyclonal antibodies, in variant emergence.
• To discuss the involvement of neutralizing antibodies and host cells in the in vivo appearance of viral variants.

Main Methods:

• Establishing experimental persistent Junin virus infections in Calomys musculinus.
• Isolating viral antigenic variants from infected animal tissues (brain and blood).
• Applying selective pressure using polyclonal antibodies in vitro to isolate variants from infected cell cultures (C. musculinus primary embryo fibroblasts).

Main Results:

• Antigenic variants of Junin virus were successfully isolated from experimentally infected C. musculinus.
• Viral variants were also isolated in vitro from long-term infected fibroblast cultures subjected to polyclonal antibody pressure.
• This demonstrates that in vitro conditions can mimic the emergence of viral variants seen in vivo.

Conclusions:

• The study confirms the emergence of Junin virus antigenic variants during persistent infection.
• In vitro experiments show that polyclonal antibodies can act as a selective pressure for variant emergence.
• The findings suggest a significant role for both neutralizing antibodies and host cells in the development of Junin virus variants within a living organism.