title: Sublethal red tide toxin exposure in free-ranging manatees (Trichechus manatus) affects the immune system through reduced lymphocyte proliferation responses, inflammation, and oxidative stress.
abstract: The health of many Florida manatees (Trichechus manatus latirostris) is adversely affected by exposure to blooms of the toxic dinoflagellate, Karenia brevis. K. brevis blooms are common in manatee habitats of Florida's southwestern coast and produce a group of cyclic polyether toxins collectively referred to as red tide toxins, or brevetoxins. Although a large number of manatees exposed to significant levels of red tide toxins die, several manatees are rescued from sublethal exposure and are successfully treated and returned to the wild. Sublethal brevetoxin exposure may potentially impact the manatee immune system. Lymphocyte proliferative responses and a suite of immune function parameters in the plasma were used to evaluate effects of brevetoxin exposure on health of manatees rescued from natural exposure to red tide toxins in their habitat. Blood samples were collected from rescued manatees at Lowry Park Zoo in Tampa, FL and from healthy, unexposed manatees in Crystal River, FL. Peripheral blood leukocytes (PBL) isolated from whole blood were stimulated with T-cell mitogens, ConA and PHA. A suite of plasma parameters, including plasma protein electrophoresis profiles, lysozyme activity, superoxide dismutase (SOD) activity, and reactive oxygen/nitrogen (ROS/RNS) species, was also used to assess manatee health. Significant decreases (p<0.05) in lymphocyte proliferation were observed in ConA and PHA stimulated lymphocytes from rescued animals compared to non-exposed animals. Significant correlations were observed between oxidative stress markers (SOD, ROS/RNS) and plasma brevetoxin concentrations. Sublethal exposure to brevetoxins in the wild impacts some immune function components, and thus, overall health, in the Florida manatee.
authors: Marine Immunology Program, Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL 34236, USA. Electronic address: cjwalsh@mote.org.
authors: Catherine J
authors: CJ
authors: Walsh
authors: Marine Immunology Program, Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL 34236, USA. Electronic address: mattbutawan@outlook.com.
authors: Matthew
authors: M
authors: Butawan
authors: Marine Immunology Program, Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL 34236, USA. Electronic address: jennifer.e.balmer@gmail.com.
authors: Jennifer
authors: J
authors: Yordy
authors: Lowry Park Zoo, 1101 W Sligh Ave, Tampa, FL 33604, USA. Electronic address: Ray.Ball@lowryparkzoo.com.
authors: Ray
authors: R
authors: Ball
authors: Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, 100 8th Ave SE, St. Petersburg, FL 33701, USA. Electronic address: Leanne.Flewelling@MyFWC.com.
authors: Leanne
authors: L
authors: Flewelling
authors: Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, 100 8th Ave SE, St. Petersburg, FL 33701, USA. Electronic address: Martine.deWit@MyFWC.com.
authors: Martine
authors: M
authors: de Wit
authors: U.S. Geological Survey, Sirenia Project, 7920 NE 71st Street, Gainesville, FL 32653, USA. Electronic address: rbonde@usgs.gov.
authors: Robert K
authors: RK
authors: Bonde
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D004141:Dinoflagellida / Q000737:chemistry; D005431:Florida; D007107:Immune System / Q000187:drug effects*; D007249:Inflammation / Q000139:chemically induced; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects*; D008387:Marine Toxins / Q000097:blood / Q000633:toxicity*; D018384:Oxidative Stress / Q000187:drug effects*; D035964:Oxocins / Q000097:blood / Q000633:toxicity*; D020455:Trichechus / Q000502:physiology*; D020457:Trichechus manatus / Q000276:immunology*; D014874:Water Pollutants, Chemical / Q000633:toxicity; D000095702:Polyether Toxins
chemical_list: D015415:Biomarkers; D008387:Marine Toxins; D035964:Oxocins; D014874:Water Pollutants, Chemical; C053342:brevetoxin; D000095702:Polyether Toxins
keywords: Brevetoxin; Florida manatee; Immune function; Oxidative stress; Red tide