Meeting Abstract

P3.119  Sunday, Jan. 6  Effect of age and temperature on antibody production in a long-lived ectotherm ZIMMERMAN, L.M.*; VOGEL, L.A.; BOWDEN, R.M.; Il. St. Univ.; Il. St. Univ.; Il. St. Univ. lmzimme@ilstu.edu

Immunosenescence, a decrease in immune function with age, is a common finding in both endothermic and ectothermic vertebrates. However, because of the effect of temperature on basic biological processes of ectotherms, temperature can also influence the immune responses of ectotherms. In general, ectothermic vertebrates can mount immune responses over a wide range of temperatures, and often there is a species-specific temperature at which responses are strongest, with impaired responses above and below this threshold. Little is known, though, about how the long-term effects of age may influence the response to short-term temperature changes. This study examined humoral immune responses in a long-lived reptile, the red-eared slider turtle, Trachemys scripta. Sliders can produce both natural antibodies in the absence of antigen stimulation and specific antibodies in response to stimulation. Adult turtles were trapped and blood samples taken. Because sliders grow throughout their lifetime, plastron length was measured as a proxy for age. Leukocytes were isolated and their ability to produce antibodies at different temperatures was measured using an ELISpot assay. Cells were cultured in media alone to examine spontaneous antibody (Ab) production or in the presence of lipopolysaccharide (LPS) to examine stimulated Ab production. The assay was conducted at 27, 29, 33, and 37°C. We found a significant plastron by temperature interaction on spontaneous Ab production, and a similar trend for stimulated Ab production. Our results suggest that the negative effects of aging may only manifest themselves at higher temperatures, which could lead to differences in basking behavior for young and old individuals.