Meeting Abstract

131.1  Tuesday, Jan. 7 13:30  Effect of age and temperature on B cell function in a long-lived ectotherm ZIMMERMAN, L.M.*; CARTER, A.W.; VOGEL, L.A.; BOWDEN, R.M.; Illinois St. Univ.; Illinois St. Univ.; Illinois St. Univ.; Illinois St. Univ. lmzimme@ilstu.edu

Both endothermic and ectothermic vertebrates typically demonstrate a functional decrease in immune function with age. In ectotherms, temperature can also influence immune responses. Typically, ectothermic vertebrates can mount immune responses over a wide range of temperatures with a species-specific temperature at which responses are strongest, and impaired responses above and below this threshold. In long-lived ectotherms, aging could negatively influence the ability to respond to short-term temperature changes. This study examined the effects of this interaction on B cell function in a long-lived reptile, the red-eared slider turtle, Trachemys scripta. Sliders can produce both natural antibodies (Abs) in the absence of antigen stimulation and specific Abs in response to stimulation. Slider B cells are also capable of phagocytosis. Adult turtles were trapped and blood samples taken. Because sliders grow throughout their lifetime, plastron length was used as a proxy for age. Leukocytes were isolated and used in either an ELISpot assay to examine their ability to produce Abs spontaneously or when stimulated, or used in a phagocytic assay. The ELISpot was conducted at 27, 29, 33, and 37°C while the phagocytic assay was run at 25, 27, 29, 33, and 37°C. We found no interaction between age and temperature on any measure of B cell function. In all cases there was a significant effect of temperature, with impaired function at temperatures below 29°C and no impairment of function at higher temperatures. We also found little evidence of immunosenesce in any response. This study provides insight into the thermal preferences of sliders and provides an interesting connection between immunology, behavior, and ecology in this turtle.