Effects of Exercise on Immune Function in Young, Adult, and Aged Mice: Increased Survival and a Decrease in Inflammation

We have previously shown that moderate exercise for 4 days during a mounting immune response significantly increases survival during influenza virus (A/PR/8/34) infection in mice. We hypothesized that this brief duration of exercise resulted in a decreased level of lung histopathology while altering the immune response from a Th1 (inflammatory) to a Th2 (Anti-inflammatory) response. Adult male Balb/cByJ mice (5-6mo) were inflected with 50uL of A/PR/8/34 influenza virus (40HAU) intranasally under light anesthesia (Isoflurane) and randomized to either an exercise (EX) or sedentary (SED) group. EX mice performed 20-3min of moderate exercise (8-12m/min) on a motorized treadmill 4hr post-infection and then exercised similarly for 4 consecutive days. SED mice were exposed to similar environmental conditions but did not exercise. Mice from both EX and SED groups were sacrificed 1, 3, or 5 days post-infection lungs, mediastinal lymph nodes and spleens were harvested. We found a profound reduction in IFN-gamma in lungs of EX mice when compared to SED mice 3 and 5 days post-infection. There was also a reduction in viral gene mRNA expression, although not at the level of statistical significance (p=0.241). While there were no statistically significant differences in percentage or absolute number of CED8+ cells in the lungs of infected mice, EX mice had significantly fewer cells compared with SED mice 5 days post-infection. Interestingly, we found no observable difference in lung histopathology between groups. These data suggest that moderate exercise shifts the immune response from a Th1 to a Th2 profile in mice infected with influenza virus. This exercise-induced shift in immune response may be responsible for improved survival after influenza virus infection.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Kinesiology and Community Health

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2006

Author dc:creator

• Lowder, Thomas W.

Contributors dc:contributor

• Jeff Woods

• Biology, Physiology

Language dc:language

eng

Identifier

(MiAaPQ)AAI3250283

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/86382