Meeting Abstract
86.2 Friday, Jan. 7 Innate immune function in mice selectively breed for high voluntary wheel-running behavior DOWNS, C.J.*; SCHUTZ, H.; MEEK, T.H.; DLUGOSZ, E.M.; ACOSTA, W.; GARLAND, T. JR.; University of Nevada, Reno; University of California, Riverside; University of California, Riverside; University of California, Riverside; University of California, Riverside; University of California, Riverside cdowns@unr.edu
Mice from 4 lines selectively bred for high voluntary wheel running (HR lines) run approximately 3-fold more revolutions/day than those from non-selected control (C) lines. HR mice have higher circulating corticosterone levels and daily energy expenditure then C mice, both of which potentially reduce an individual’s ability to mount an immune response when challenged. Therefore, we hypothesized that immune function in HR mice is suppressed. A total of 138 female mice from generation 55 were split evenly among 3 treatment groups. One group was injected with LPS, a lipopolysaccharide found on the cell wall of gram-negative bacteria. The second group was injected with a saline sham, and the third were non-injected controls. After injection, behavior was recorded for 1.5 hours. Blood samples were collected 2 hours after injection for quantification of inflammatory cytokines. Mice were then exposed to running wheels for 48 hours, after which a second blood sample was collected and mice were euthanized for organ dissection and measurement. As expected, mice injected with LPS exhibited classic signs of an innate immune response, including sickness behavior, weight loss, reduced wheel running, enlarged organs, elevated hematocrit, and elevated inflammatory cytokines. However, we found no statistical difference in the responses of HR and C lines. These results are consistent with those from a nematode challenge conducted at generation 36 in males (Malisch et al. 2009 Zoology 112:316-324), and suggest that selection for high voluntary wheel running has not adversely affected immune function. NSF IOB-0543429 to TG. CD partially supported by NSF IOS-0344994.
