This Major Research Instrumentation award to Mississippi State University funds the acquisition of a fluorescence activated cell sorting system to enhance the scientific response to the Deep Horizons Oil Spill and its effects on coastal ecosystems. The overarching goal is to better understand how exposed fish populations will be affected by the Deepwater Horizon oil spill. Quantitative assessment of leukocyte cell populations in sampled fish will be used as an indicator of immune status, as will functional assays conducted with the sorted cells. Correlations of immune status assay results with environmental exposure data will help to establish both baseline values for fish health and direct assessment of the spill impacts. An expected result of this NSF-RAPID award is timely and critical information to inform policy and remediation efforts in response to the oil spill. Results from the studies and education efforts will be disseminated in peer-reviewed journal publications, though participation at regional and national scientific meetings, and through a range of public outreach efforts.
This project was designed to determine if fish in the Gulf of Mexico that were exposed to oil after the Deewater Horizon spill showed signs of immunosuppression that would make them more susceptible to infection. This was an equipment grant, and we used it to purchase a FACSAria III, which is a device that rapidly analyzes up to 17 different characteristics of cells at a rate of about 25,000/second. It also can sort cells from a complicated mixture (like blood) into separate purified cells. The instrument cost $350,000 and we used the $200,000 provided by NSF and $150,000 from Mississippi State University to purchase it. One of our investigators was granted a place on a NOAA research ship to collect sample from the Gulf of Mexico. They were prepared on site and returned to MSU for analysis. Also, live samples of one of the more numerous species (spotted sea trout) were brough to MSU and housed in aquariums. These were maintained for at least two weeks in oil-free water and used as controls. The gulf fish had significantly higher levels of an enzyme that increases upon exposure to hydrocarbons like those in oil. Assessment of immunolgical status of these fish is in progress, but initial tissue section suggest increased melanomacrophage clusters which indicates a stress or inflammatory response. We also did controlled exposures of alligator gar to oil (supplied by BP) in tanks here at MSU. Hydrocarbons were idrectly measured and persisted to some degree for more than a week. Two different cell types were identified with FACSAria III that changed in percentage depending on the dose of the oil. This is the first time these cells in the immune system were characterized in alligator gar. These quantitative results can be used in future spills to determine when fish will be at risk for immunological alterations (by measuring oil in the water and comparing to results in our tanks). Additional immunological characterization is in progress using cells purified by the FACSAria III.
