TY - JOUR
T1 - Immunocompetence in a long-lived ectothermic vertebrate is temperature dependent but shows no decline in older adults
AU - Zimmerman, Laura M.
AU - Carter, Amanda Wilson
AU - Bowden, Rachel M.
AU - Vogel, Laura A.
N1 - Publisher Copyright:
© 2017 The Authors. Functional Ecology © 2017 British Ecological Society
PY - 2017/7
Y1 - 2017/7
N2 - Temperature affects nearly all aspects of the physiology of ectotherms, including their ability to mount an immune response. Typically, the ectothermic vertebrate immune system can respond over a wide range of temperatures, but there is a species-specific temperature at which responses are strongest, with impaired responses above and below this threshold. In long-lived ectotherms, ageing could also influence the ability to respond to temperature changes as immunosenecence, the functional decrease in immune function with age, is widely reported. This study examined the effects of the interaction between temperature and age on B-cell function in a long-lived reptile, the red-eared slider turtle, Trachemys scripta. B cells in this species have previously been shown to have two main functions, phagocytosis and antibody production. Adult turtles were trapped and blood samples taken. Because sliders grow throughout their lifetime, plastron length was used as a proxy for age. Leucocytes were isolated and used in either an ELISpot assay to examine their ability to produce antibodies spontaneously or when stimulated, or used in a phagocytic assay. The ELISpot and phagocytic assays were conducted over a range of biologically relevant temperatures. 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, but no impairment of function at higher temperatures. We also found little evidence of immunosenescence in any response. This study provides insight into the thermal biology of B-cell function in sliders and provides an interesting connection between immunology, behaviour and ecology in this long-lived turtle. A lay summary is available for this article.
AB - Temperature affects nearly all aspects of the physiology of ectotherms, including their ability to mount an immune response. Typically, the ectothermic vertebrate immune system can respond over a wide range of temperatures, but there is a species-specific temperature at which responses are strongest, with impaired responses above and below this threshold. In long-lived ectotherms, ageing could also influence the ability to respond to temperature changes as immunosenecence, the functional decrease in immune function with age, is widely reported. This study examined the effects of the interaction between temperature and age on B-cell function in a long-lived reptile, the red-eared slider turtle, Trachemys scripta. B cells in this species have previously been shown to have two main functions, phagocytosis and antibody production. Adult turtles were trapped and blood samples taken. Because sliders grow throughout their lifetime, plastron length was used as a proxy for age. Leucocytes were isolated and used in either an ELISpot assay to examine their ability to produce antibodies spontaneously or when stimulated, or used in a phagocytic assay. The ELISpot and phagocytic assays were conducted over a range of biologically relevant temperatures. 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, but no impairment of function at higher temperatures. We also found little evidence of immunosenescence in any response. This study provides insight into the thermal biology of B-cell function in sliders and provides an interesting connection between immunology, behaviour and ecology in this long-lived turtle. A lay summary is available for this article.
KW - immunosenescence
KW - reptile
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U2 - 10.1111/1365-2435.12867
DO - 10.1111/1365-2435.12867
M3 - Article
AN - SCOPUS:85017643813
SN - 0269-8463
VL - 31
SP - 1383
EP - 1389
JO - Functional Ecology
JF - Functional Ecology
IS - 7
ER -