Meeting Abstract
The goals of this study were to 1) understand how a measure of innate immune function, bacterial killing ability, responded to different immune challenges, 2) how environmental temperature and lizard thermoregulatory behavior influenced this immune response, and 3) how metabolic rate was altered during an immune response. To accomplish this, three separate experiments were performed. In the first experiment, lizard bacterial killing ability (BKA) was measured following a cutaneous wound, lipopolysaccharide (LPS), or phytohemagglutinin (PHA) challenge while lizards were allowed to thermoregulate. We found that the LPS challenge, but not PHA or a cutaneous wound, significantly increased BKA and that all lizard plasma, regardless of treatment, performed better at higher assay incubation temperatures. In the second experiment, lizard thermoregulatory behavior in response to an LPS challenge was monitored and quantified. We found that LPS challenged lizards spent more time in warm zones of the thermal gradients when compared to the control treatment. Finally, we measured immune function and metabolic rate of lizards in response to an LPS challenge when lizards were held at a constant temperature. In this experiment, we found that BKA was higher for lizards held at the warm temperature and that the LPS treatment groups for both temperatures had higher BKA compared to the control animals held at the same temperature. Metabolic rate increased following the LPS challenge but decreased or did not change for control animals. Together, these results demonstrate the importance of assessing the environmental context and individual variation when interpreting immune measures.
