Exogenous Expression of Equine MHC Class I Molecules in Mice Increases Susceptibility to Equine Herpesvirus 1 Pulmonary Infection.

This research study explores how the introduction of horse genes related to immune response makes mice more susceptible to a horse-specific virus called Equine herpesvirus 1 (EHV-1).

Objective of the Study

• The research aimed to understand the role of the horse’s Major Histocompatibility complex class I (MHC class I) as an initial receptor for EHV-1 infection by introducing these genes in a mouse model.

Methodology

• The researchers created transgenic (Tg) mice that expressed the horse MHC class I gene, controlled by a CAG promoter.
• This gene was expressed in the liver, spleen, lung, and brain of the Tg mice, which was validated through a Western blot analysis.
• The MHC class I antigen, however, could only be seen in the bronchiolar epithelium, as shown using an immunofluorescence-based method.

Infection and Observation

• Both Tg and normal mice (wild-type or WT) were exposed to EHV-1 infection through the nose. Post three days of exposure, all mice developed pneumonia.
• However, the Tg mice showed more severe damage in their bronchiolar epithelial cells compared to the WT mice.

Results and Conclusion

• Moreover, the count of cells in the lungs with positive virus antigens was higher in the Tg mice compared to the WT mice.
• This lead to the conclusion that the introduction of horse MHC class I genes indeed made the mice more susceptible to the EHV-1 infection.

The study’s findings provided insightful details regarding the implications of cross-species gene expression and its potential effects on the susceptibility to infections.