Age-associated Changes in the Respiratory Epithelial Response to Influenza Infection [hNEC]

This study evaluates how aging impacts the interaction between influenza viruses and human respiratory epithelial cells. Our results indicate that aging is associated with a decrease in the gene expression of key antiviral mediators, IFITM1 and MX1, and a decrease in the expression of MHC-I and TAP mRNA and proteins responsible for antigen processing and presentation. Importantly however epithelial cells from older individuals produce similar, and in some cases greater, levels of chemokines as compared with hNECs from younger individuals. Taken together a defect in antigen processing and presentation could result in impaired clearance of infected epithelial cells allowing them to continue to produce inflammatory cytokines and chemokines resulting in prolonged inflammation and perhaps increased severity of disease. Primary human nasal epithelial cells (hNECs) were cultured, and differentiated at air-liquid-interface (ALI). hNECs were cultured from nasal epithelial biopsies obtained from two groups of healthy volunteers between the ages of 20-25 (Young; N=5) and over 50 years of age (Old; N=7). Cultures were infected with 10 TCID50/cell Influenza A H3N2 virus (Influenza A/Washington/897/90) or media alone (Mock) and maintained in culture for 24 hours.