TY - JOUR
T1 - The effect of hydration state and energy balance on innate immunity of a desert reptile
AU - Moeller, Karla T.
AU - Butler, Michael W.
AU - Denardo, Dale
N1 - Funding Information:
We thank Christian D. Wright and Marin L. Jackson for helping with collection of samples and Zachary R. Stahlschmidt for assisting with pilot assays. This work was partially supported by the ASU School of Life Sciences, donations to the ASU Foundation, and a JumpStart Research Grant provided by the Graduate and Professional Student Association at ASU. During portions of this study, MWB was partially supported by a Graduate College Dissertation Fellowship and KTM by a School of Life Sciences Graduate Research Scholarship at ASU. All research was conducted with approval from the ASU Institutional Animal Care and Use Committee (protocol 09-1044R). Laboratory animals were acquired from the Arizona Game and Fish Department (AGFD; permits #SP577864, SP684760) and field research was conducted with AGFD approval (permit #SP583995).
PY - 2013/5/4
Y1 - 2013/5/4
N2 - Introduction: Immune function is a vital physiological process that is often suppressed during times of resource scarcity due to investments in other physiological systems. While energy is the typical currency that has been examined in such trade-offs, limitations of other resources may similarly lead to trade-offs that affect immune function. Specifically, water is a critical resource with profound implications for organismal ecology, yet its availability can fluctuate at local, regional, and even global levels. Despite this, the effect of osmotic state on immune function has received little attention.Results: Using agglutination and lysis assays as measures of an organism's plasma concentration of natural antibodies and capacity for foreign cell destruction, respectively, we tested the independent effects of osmotic state, digestive state, and energy balance on innate immune function in free-ranging and laboratory populations of the Gila monster, Heloderma suspectum. This desert-dwelling lizard experiences dehydration and energy resource fluctuations on a seasonal basis. Dehydration was expected to decrease innate immune function, yet we found that dehydration increased lysis and agglutination abilities in both lab and field studies, a relationship that was not simply an effect of an increased concentration of immune molecules. Laboratory-based differences in digestive state were not associated with lysis or agglutination metrics, although in our field population, a loss of fat stores was correlated with an increase in lysis.Conclusions: Depending on the life history of an organism, osmotic state may have a greater influence on immune function than energy availability. Thus, consideration of osmotic state as a factor influencing immune function will likely improve our understanding of ecoimmunology and the disease dynamics of a wide range of species.
AB - Introduction: Immune function is a vital physiological process that is often suppressed during times of resource scarcity due to investments in other physiological systems. While energy is the typical currency that has been examined in such trade-offs, limitations of other resources may similarly lead to trade-offs that affect immune function. Specifically, water is a critical resource with profound implications for organismal ecology, yet its availability can fluctuate at local, regional, and even global levels. Despite this, the effect of osmotic state on immune function has received little attention.Results: Using agglutination and lysis assays as measures of an organism's plasma concentration of natural antibodies and capacity for foreign cell destruction, respectively, we tested the independent effects of osmotic state, digestive state, and energy balance on innate immune function in free-ranging and laboratory populations of the Gila monster, Heloderma suspectum. This desert-dwelling lizard experiences dehydration and energy resource fluctuations on a seasonal basis. Dehydration was expected to decrease innate immune function, yet we found that dehydration increased lysis and agglutination abilities in both lab and field studies, a relationship that was not simply an effect of an increased concentration of immune molecules. Laboratory-based differences in digestive state were not associated with lysis or agglutination metrics, although in our field population, a loss of fat stores was correlated with an increase in lysis.Conclusions: Depending on the life history of an organism, osmotic state may have a greater influence on immune function than energy availability. Thus, consideration of osmotic state as a factor influencing immune function will likely improve our understanding of ecoimmunology and the disease dynamics of a wide range of species.
KW - Dehydration
KW - Digestion
KW - Energy balance
KW - Hemagglutination
KW - Hemolysis
KW - Osmolality
KW - Water
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U2 - 10.1186/1742-9994-10-23
DO - 10.1186/1742-9994-10-23
M3 - Article
C2 - 23642164
AN - SCOPUS:84876976411
SN - 1742-9994
VL - 10
JO - Frontiers in Zoology
JF - Frontiers in Zoology
IS - 1
M1 - 23
ER -