Transgenic mice with intracellular immunity to influenza virus

Area of Science:

• Virology
• Immunology
• Genetics

Background:

• Influenza virus poses a significant global health threat.
• The Mx1 protein is a key intracellular antiviral factor induced by interferon.
• Understanding host-pathogen interactions is crucial for developing new antiviral strategies.

Purpose of the Study:

• To investigate the role of the Mx1 protein in influenza virus pathogenesis.
• To determine if "intracellular immunization" through transgenic expression of Mx1 can confer resistance to influenza.
• To explore the relationship between viral dose, Mx1 levels, and host survival.

Main Methods:

• Generation of transgenic mouse lines expressing Mx1 under an interferon-responsive promoter.
• Infection of transgenic mice with influenza virus at varying doses.
• Assessment of viral replication, spread, and host survival.
• Evaluation of Mx1 protein expression levels in response to viral infection and interferon treatment.

Main Results:

• High responder mice produced Mx1 protein, limited viral spread, and survived influenza infection.
• Low responder mice exhibited more extensive viral spread and required high virus doses or interferon treatment to survive.
• Influenza pathogenesis was shown to depend on the balance between viral dose and host Mx1 levels.
• Transgenic expression of Mx1 conferred resistance to virulent influenza infection.

Conclusions:

• The level of intracellular Mx1 protein is a critical determinant of resistance to influenza virus.
• Germline transformation leading to "intracellular immunization" is a viable strategy to confer resistance against virulent viral infections.
• This study highlights the potential of genetic engineering for developing novel antiviral therapies.