Meeting Abstract
The immune system is segmented into two general parts that defend against foreign pathogens: innate and acquired. Innate immunity is made of rapid, non-specified germ line-encoded responses that act as the first line of defense against pathogens. Acquired responses are usually slower and more specific responses that need to be activated to serve as a secondary line of defense. Both elements are energetically costly and may conflict with energy required for physical performance, resulting in a potential trade-off between the two systems. Though exercise has been shown to have a direct effect on the immune system, few studies have been able to tease apart the specific effects exercise has on different components of immunity. Different forms of exercise also lead to different energy expenditures; sprint performance is largely anaerobic and depends on muscle size, while endurance performance is aerobic and depends on efficient oxygen delivery to tissues. We predicted that endurance-trained lizards would have increased cellular immunity when compared to the lizards that were sprint trained due to the increased allocation of energy to increased muscle mass, leading to a lack of energetic resources available to devote to immunity. We measured immunocompetence in 3 treatments of lizards: endurance trained, sprint trained, and not trained. We then measured the swelling response to phytohemagglutinin (cell-mediated), antigenic response to sheep red blood cells (humoral), bacterial killing ability (innate), and wound healing (integrated). Results showed significant differences in immune function between treatment groups, as well as differential trade-offs among the different components of the immune system.
