Immune system function of bottlenose dolphins
By Jeff Stott, PhD, and Myra Blanchard, MSc,

Peripheral blood samples have been analyzed on a yearly basis beginning in earnest in 1999. An extensive array of classical and advanced approaches are being used in the analysis. These studies are not only establishing important immunologic baseline values for free-ranging bottlenose dolphins in Sarasota Bay, but are providing a sensitive tool for assessing the biological effects of environmental perturbations on animal health. White blood cell (leukocyte) subpopulations are being enumerated by flow cytometry and functional capacity determined by cell proliferation and gene expression assays. Measuring differential gene expression, specifically cytokine genes, in leukocytes with molecular biology is just beginning. Expression of cytokine genes is induced upon leukocyte activation and dictate the type of immune response that is elicited. Data generated on these potent modulators of the immune system are providing an additional level of analysis of the immune system that has previously not been possible.

To date, a tremendous amount of baseline data has been generated on free-ranging dolphins. Such baseline values have been determined to be influenced by animal age and sex. Though sample numbers are low, preliminary data suggest that baseline values may also be influenced by season (time of collection). As would be expected, outliers in immunologic phenotype and function have been identified. The implication of these findings, relative to animal health and survival, will become evident as the study proceeds.