Exercise reduces inflammatory responses to influenza virus infectoin in aged mice (43.12)

Abstract

Abstract In order to examine the extent to which exercise alters the inflammatory and clinical responses to respiratory infection in old mice, 19-month old male BALB/cJ mice were assigned to exercise (EX) and non-exercise (non-EX) groups. After 3 months of exercise or control treatment, mice were intranasally infected with influenza virus. Bronchoalveolar lavage (BAL) fluid was collected at 4 and 7 days post-infection (DPI) to assess viral titer and cytokines/chemokine profiles. Sera were collected for antibody measurement at 7 and 10 DPI. Lungs were collected for lesion scores at 10DPI. Weight loss and food intake were recorded daily. The results showed that the virus titer in EX mice at 4 DPI was significantly lower than non-EX mice. At 7DPI, 14% of the mice in EX had virus in lungs whereas 35% of non-EX had detectable virus. IL-12p70 & IL-1α in BAL were significantly lower in EX than in non-EX, with trends for reduced IP-10, MIP-1α and RANTES at 4 DPI. At 7 DPI, EX mice had less IL-12p70, IL-1β, and IFNγ in BAL as compared to non-EX mice, whereas IL-10 tended to be higher in EX mice. Anti-influenza IgG titer was significantly lower in EX compared to non-EX at 7 and 10 DPI. Lung lesion scores were significantly lower in EX compared to that in non-EX at 10 DPI. Non-EX lost more weight and ate less food than EX over time. In summary, exercise improved influenza viral clearance, improved clinical scores, and reduced lung inflammation in aged mice.