Influenza A-induced cystic fibrosis transmembrane conductance regulator dysfunction increases susceptibility to...

Area of Science:

• Pulmonology
• Virology
• Microbiology

Background:

• Influenza A virus (IAV) infections often lead to severe secondary bacterial infections, increasing patient mortality.
• IAV disrupts airway homeostasis, causing pathology similar to cystic fibrosis due to impaired cystic fibrosis transmembrane conductance regulator (CFTR) function.

Purpose of the Study:

• To investigate how IAV infection alters the airway microenvironment, increasing susceptibility to secondary Streptococcus pneumoniae (Spn) infection.
• To elucidate the roles of CFTR dysfunction and airway epithelial changes in IAV-induced secondary bacterial susceptibility.

Main Methods:

• Utilized human airway organotypic cultures to model IAV infection and subsequent Spn challenge.
• Analyzed transcriptional and proteomic changes in the airway epithelium and surface liquid following IAV infection.

Main Results:

• IAV-induced CFTR dysfunction and airway surface liquid acidification were identified as key factors increasing Spn susceptibility.
• IAV infection triggered significant transcriptional and proteomic alterations in the airway, affecting host defense pathways.
• Both CFTR-dependent and independent mechanisms contributed to the observed changes in airway epithelial function and defense.

Conclusions:

• CFTR function is crucial for maintaining airway defense against secondary bacterial infections following IAV.
• The lung epithelium plays a central role in host defense mechanisms during secondary bacterial infections post-IAV.
• Understanding these mechanisms can inform strategies to mitigate morbidity and mortality associated with complicated influenza infections.