In-vitro lymphocyte response of bottlenose dolphins ( Tursiops truncatus): Mitogen-induced proliferation

Abstract

Stranded bottlenose dolphins, Tursiops truncatus, exhibit infections suggestive of immune dysfunction. Concurrent high levels of immunotoxic pollutants indicate that one possible cause of death is pollutant-induced immune dysfunction. In this study, immunological assays were adapted to assess immune function of healthy dolphins. Peripheral blood from 23 dolphins was obtained by capture/release near Sarasota, Florida. Blood was shipped at ambient temperature by overnight mail in vacutainers containing either sodium heparin or EDTA. Mononuclear cells were separated by centrifugation in Ficoll and cultured in RPMI1640 containing 10% fetal calf serum. 2-ME, and antibiotics. Lymphocytes were stimulated with a panel of mitogens across a broad dose-response range in order to determine the kinetics of proliferative responses (i.e. 3H-thymidine uptake). Responses to Con A, PHA, and PWM were maximal at 6, 5 and 2 days of culture, respectively. No significant response to LPS was observed. We conclude that culture and shipment conditions for human lymphocyte assays are appropriate for assessment of dolphin immune function. Further studies will examine the use of both mitogenic and non-mitogenic stimuli to evaluate immune function in both normal and at risk dolphin populations.