Intranasal Infection of a Mouse with a Pathogenic Influenza Virus

Begin with an anesthetized mouse.
Take a suspension of pathogenic influenza virus, known to cause respiratory infections.
Administer the suspension in one nostril and allow the mouse to inhale it naturally.
Pause briefly to ensure steady respiration, then repeat the administration in the other nostril.
Place the mouse in a warm cage for recovery.
The administered virus enters the respiratory tract.
The virus binds to sialic acid molecules on the epithelial cell surface and undergoes endocytosis.
The internalized virus utilizes host cell machinery to produce new viral particles.
These newly formed virions exit the infected cell, damaging epithelial cells and disrupting the protective mucociliary barrier of the airways.
The infection activates multiple immune cells in the respiratory tract. Some of these cells migrate to the draining lymphoid tissues, where they interact with and activate T cells, initiating adaptive immune responses.
The mouse is now ready for further antiviral immune response analysis.

For PR8 virus inoculation of eight-week-old male C57 black 6 mice under biosafety level 2 conditions, thaw a minus 80-degree Celsius stored PR8 virus stock on ice. Vortex the virus to obtain a