Quantitative analysis of visna virus replication in vivo

Area of Science:

• Virology
• Immunology
• Molecular Biology

Background:

• Visna virus, a lentivirus, causes slow infections in sheep and goats.
• Viral persistence occurs despite host immune response, linked to blocked gene expression.
• A gene dosage hypothesis suggests reduced transcription causes decreased virus production.

Purpose of the Study:

• To investigate the gene dosage hypothesis for visna virus persistence in vivo.
• To develop and utilize a pulmonary model for analyzing viral life cycle molecular events.
• To examine gene expression restriction in alveolar macrophages during infection.

Main Methods:

• Development of a novel pulmonary model in infected animals.
• Quantitative in situ hybridization for analyzing gene expression.
• Longitudinal analysis of molecular events in the viral life cycle.

Main Results:

• Established feasibility of in vivo longitudinal analysis of viral infection.
• Documented restriction in visna virus gene expression in alveolar macrophages.
• Provided evidence against gene dosage as the sole explanation for expression restriction.

Conclusions:

• Gene dosage does not fully explain visna virus gene expression restriction.
• The developed pulmonary model is effective for in vivo viral infection studies.
• The approach is applicable to investigating other dynamic viral infections.