Abstract
Earlier detection of changes in the health status of bottlenose dolphins (Tursiops truncatus) is expected to further improve their medical care. Cytokines and chemokines are critical mediators of the cellular immune response, and studies have suggested that these molecules may serve as important biomarkers of alterations in the health status of mammals. While much is known regarding the immune system of humans and mice, less is known about the immune system of most veterinary species. This is especially true for marine mammals, including cetaceans. In order to better understand modifications of immune markers in marine mammals, there is a need to develop immune reagent tool kits that recognize species-specific molecules. Therefore, an objective of our research is to develop specific enzyme-linked immunosorbent assays (ELISAs) to measure the levels of cytokines and chemokines in bottlenose dolphin samples. Development of the proposed assays will allow for the evaluation of functional changes in the T. truncatus immune system in response to environmental insults/stressors, infectious diseases, and/or vaccination. To date, ELISAs have been developed for bottlenose dolphin interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-2, IL-4, IL-8, IL-17A, and chemokine CXCL10 and these are commercially available (http://www.kingfisherbiotech.com). In the current study, we have examined expression of dolphin TNF-α and IFN-γ in serial serum samples and in culture supernatants from mitogen-stimulated peripheral blood mononuclear cells (PBMCs) collected from the same individual animals over a period of several months. In general, 48 hour stimulation of PBMCs with 1 µg/mL ConA induced the highest secretion of TNFα, whereas stimulation with 1 µg/mL PHA produced the highest levels of secreted IFNγ in all animals. Serum levels of TNF-α and IFN-γ remained relatively constant for each animal over the time period examined. These assays will be of substantial benefit in monitoring overall bottlenose dolphin health as an adjunct to currently available diagnostic tests.
Acknowledgements
The authors wish to thank Theresa Waters and Tracy Porter, National Animal Disease Center for excellent technical assistance. The authors thank the Office of Naval Research for financial support of this project under ONR Award N00014IP0019 (R.E. Sacco), as well as the management, training, and animal care staff of the U.S. Navy Marine Mammal Program, Space and Naval Warfare Systems Center Pacific for their support of this study.
* Presenting author