Immunotoxicity Assessment

Co-PI: Sylvain De Guise (UConn)

Key Collaborators: Milton Levin (UConn) and Guillermo Risatti (UConn)

Exposure to Deepwater Horizon (DWH )oil led to increased infection rates in laboratory experiments with fish (Bayha et al., 2017). In both field studies of common bottlenose dolphins (CBNDs) in Barataria Bay, LA (heavily oiled during the DWH oil spill) and in post-mortem analyses of dead, stranded CBNDs, pathologists documented an increased prevalence of infections, especially in lung tissues. Preliminary results from immune studies of CBNDs in Barataria Bay showed that oil exposure may have affected animals’ ability to appropriately mount an immune response to infectious agents (De Guise et al., 2017). The CARMMHA Immune Assessment Project will address this question more directly.

Scientists at the University of Connecticut will develop state-of-the-art laboratory assays to measure immune cell activity and proliferation in response to stimuli, and to measure the amounts of cytokines (immune signaling molecules) in CBND blood. Once the methods are developed in the laboratory, the researchers will be able to analyze samples from the CARMMHA field projects and archived samples from the Gulf of Mexico. If DWH oil exposure caused a reduction in the number or activity of immune cells, or a change in the signaling mechanisms orchestrating immune responses, wild CBNDs would likely suffer increased infections and adverse health effects.

In addition to advancing our ability to understand the health of wild animals in the Gulf of Mexico, the University of Connecticut will perform controlled laboratory experiments exposing cell lines and mice to DWH oil. By carefully comparing the potential immunological effects to increasing doses of DWH oil, the team will be able to more critically investigate the cause-effect relationship between DWH oil and immunotoxicity.

Progress Summary

September 5th, 2019 – The University of Connecticut continues to refine the statistical approach to the analysis of dolphin immune cell activity and proliferation as well as serum cytokines results from health assessment captures. Efforts are also underway to coordinate serum cytokines analysis with reproductive success.  The team has begun laboratory exposure experiments with mice to investigate the cause and effect relationships among oil exposure, Treg cell function, reproductive success, and adverse effects in offspring. The team also began in vitro exposure of dolphin lymphocytes to oil to understand the direct effects at the cell and molecular level.