Subacute sclerosing panencephalitis (SSPE) agent in hamsters

Area of Science:

• Neurovirology
• Immunology
• Cell Biology

Background:

• Subacute Sclerosing Panencephalitis (SSPE) is a severe, slow neurological complication of measles virus infection.
• The pathogenesis of SSPE and other latent measles infections of the central nervous system (CNS) remains incompletely understood.
• Understanding the interplay between the virus and host immune response is crucial for deciphering disease progression.

Purpose of the Study:

• To investigate the in vivo and in vitro effects of host antibody response on a hamster-adapted SSPE agent.
• To characterize the changes in viral infectivity and cell association during infection.
• To explore potential parallels between the observed phenomena and human SSPE.

Main Methods:

• Infection of weanling hamsters with a hamster-adapted SSPE agent.
• Monitoring of serum measles antibodies and viral characteristics in brain tissue.
• In vitro culture of infected brain cells (Vero and primary hamster brain cultures).
• Analysis of viral infectivity, cell destruction, and antigen presence (HA & HL) in cell cultures.

Main Results:

• The SSPE agent initially caused productive infection, transitioning to cell-associated/defective infection upon antibody appearance.
• Pre-antibody agent was cell-free infectious, rapidly destroying cell cultures.
• Post-antibody agent was cell-associated, inefficiently destroying cells with intermittent extracellular virus release.
• Infected giant cells showed measles HA & HL antigens in cytoplasmic membranes.

Conclusions:

• Host antibody response in vivo induces a shift from productive to cell-associated SSPE agent infection.
• This conversion may represent early events in human SSPE and other latent CNS measles infections.
• The findings highlight the critical role of the immune system in modulating viral persistence and disease manifestation in the CNS.