Investigation of epidermal immunity in wild bottlenose dolphins, Tursiops truncatus.

Meagan A.M. Mollenhauer¹, Patricia A. Fair², Gregory D. Bossart³, Margie Peden-Adams¹, Tracy Romano⁴, and Gary S. Gilkeson^1,5   

¹ Marine Biomedicine and Environmental Sciences Center, Medical University of South Carolina, Charleston, SC

² National Ocean Service, Center for Coastal Environmental Health and Biomolecular Research, NOAA, Charleston, SC

³ Harbor Branch Oceanographic Institution, Ft. Pierce, FL

⁴ Mystic Aquarium, Mystic, CT

⁵ Department of Medicine, Division Rheumatology, Medical University of South Carolina, Charleston, SC

The status and health of marine mammal populations has been the topic of research for many years; still, relatively little is known about the defense mechanisms marine mammals use to cope with living in such a unique environment.  This project proposes to investigate the means by which these animals survive in an aquatic environment where they are constantly bombarded by potential pathogens.  It will determine the necessary components and characteristics of the cetacean skin immune system that enables cetaceans to be relatively free of infection.  We hypothesize that any alterations from the normal cellular and molecular physiology of skin greatly reduce its immune capabilities.  Therefore, both the cellular and molecular components of normal, healthy bottlenose dolphin skin will be significantly altered in diseased skin.  We will determine to what extent the major cellular components and protein expression patterns are significantly altered in diseased skin, by investigating three specific aims.  First, it will identify keratinocyte, dendritic cell, monocyte and macrophage densities and morphology in both normal and diseased tissue.  Secondly, this project will determine typical cell cycle progression and protein secretion of cultured primary keratinocytes originating from healthy and diseased skin samples.  Finally, it will determine approximate expression levels of select and possibly novel antimicrobial peptides, complement associated proteins and cytokines in both normal and diseased epidermal tissue.  This project will utilize current in vitro cell culture, pathological and proteomic methodologies including confocal microscopy, immunohistochemistry, western blot and ELISA assays.  Skin biopsy samples will be acquired through the bottlenose dolphin health and risk assessment project currently being conducted by NOAA’s National Ocean Service and the Harbor Branch Oceanographic Institution.  Results from this study will provide valuable information about the cetacean skin immune system; it will also provide information for better evaluating the health of wild dolphins and may prove useful in developing a novel, relatively non-invasive sampling method for future health assessment.