Meeting Abstract
The performance of the immune system varies with the physiological state of the organism, with immune function often suppressed during periods of negative resource balance due to scarcity or heavy investment (e.g., reproductive activity). In contrast, recent studies have shown that immune function is enhanced when water, a fundamental resource, is limited naturally or experimentally. The purpose of this study was to understand the mechanisms responsible for the peculiar finding that dehydration, while deleterious to most major physiological systems, somehow improves innate immunity in multiple species of reptile. First, we used a combination of temperature and proteinase treatments on plasma samples to explore the potential involvement of small innate peptides. Next, we looked at RNA expression in liver samples between hydrated and experimentally dehydrated animals to identify immune-related proteins that are upregulated with dehydration. Finally, we will perform western blot analyses on stored plasma aliquots to verify upregulated proteins identified by RNA-seq analysis are elevated in the blood. We found that various components of the complement and non-complement pathways are upregulated in dehydrated animals. These results provide a molecular and cellular basis for immune modulation and provide a mechanistic understanding of biochemical and proteonomic changes involved in resource-based upregulation of innate immunity. Understanding how animals cope with resource restrictions will enable us to predict how they might be impacted by future climate change, where, in many regions, rainfall events are predicted to be less reliable, resulting in more frequent drought.
