Grantee Research Project Results
1997 Progress Report: Biomarkers for Organochlorine-Associated Immunosuppression in Birds: Field Investigations in the Great Lakes and Laboratory Studies
EPA Grant Number: R825216Title: Biomarkers for Organochlorine-Associated Immunosuppression in Birds: Field Investigations in the Great Lakes and Laboratory Studies
Investigators: Grasman, Keith A.
Institution: Wright State University - Main Campus
EPA Project Officer: Hahn, Intaek
Project Period: December 1, 1997 through November 30, 2001
Project Period Covered by this Report: December 1, 1997 through November 30, 1998
Project Amount: $488,000
RFA: Exploratory Research - Early Career Awards (1996) RFA Text | Recipients Lists
Research Category: Environmental Justice , Early Career Awards
Objective:
1) To elucidate recently documented associations between environmental contaminants and immunosuppression in fish-eating birds of the Great Lakes by conducting field and laboratory studies that evaluate new immunological biomarkers and the interactive effects of PCB congeners; 2) to investigate the occurrence of infectious diseases in fish-eating birds of the Great Lakes; 3) to elucidate the relevance of immunological biomarkers by simultaneously measuring suppression of these biomarkers and susceptibility to infections; and 4) to investigate population-level effects associated with contaminants in Great Lake fish-eating birds by continuing long-term reproduction and banding studies.Progress Summary:
Fish-eating birds are effective "sentinel species" for assessing toxic effects of contaminants on the health of the Great Lakes ecosystem. Organochlorines are associated with reproductive, developmental, and population-level problems in these species. PCBs and TCDD cause immunosuppression and increase susceptibility to infections. Our previous studies revealed associations between PCBs and suppression of T-cell- mediated immunity in herring gull and Caspian tern chicks at highly contaminated sites in the Great Lakes.In 1997, herring gull and Caspian tern chicks were studied at high and low contamination sites in the Great Lakes and Atlantic Ocean. In both species, the phytohemagglutinin (PHA) skin test revealed significant suppression of T cell-mediated immunity at all highly contaminated sites. In terns, there was a strong negative association between plasma PCB concentrations and T cell function (PHA skin response) in individual birds. Our results in 1997 were consistent with our previous studies. The sheep red blood cell antibody assay was used to measure competence of humoral immunity. White blood cells were frozen for in vitro immune function tests (mitogen- stimulated proliferation, cytotoxic T-lymphocyte activity, natural killer (NK) cell activity). Tissues were collected for measurement of additional immunological and physiological biomarkers in herring gull embryos and chicks, including organochlorine contamination; liver EROD activity; immune organ masses; lymphoid cell counts in thymus and bursa of Fabricius; TdT (terminal deoxynucleotidal transferase) activity in the thymus; histopathological analysis of gonads and thyroids for endocrine effects.
A series of experiments were conducted to evaluate the effects of coplanar PCBs on the developing avian immune system. Most previous investigations on the immunotoxic effects of PCBs and TCDD in developing avian embryos have exposed embryos only during the later half of incubation. To simulate exposure in wild embryos, chicken eggs were injected with PCB 126 into the air cell before initiation of incubation. PCB 126 decreased the masses of the thymus and bursa of Fabricius and the number of developing lymphocytes in these organs. Doses necessary to reduce the number of lymphoid cells in the thymus and bursa were at least 1 order of magnitude lower when administered at the beginning of incubation as compared to exposure only during late incubation in previously published studies. Using pipping chicken embryos, we have developed several flow cytometry protocols to study the mechanism by which PCBs induce apoptosis in thymus and contribute to deficits in function of mature T lymphocytes. We have developed flow cytometry techniques for identifying thymocytes that express CD4 and CD8 proteins and a and e T cell receptors on their cell membranes. These are important markers for thymocyte development and differentiation, identifying which thymocyte subpopulations are most affected by PCBs. Two experiments with PCB-injected chicken embryos have employed these apoptosis and cell surface marker methods.
Future Activities:
Additional field studies will continue to investigate the effects of organochlorines on immune function in Great Lakes gulls and terns. Lab experiments with embryos and older chickens will examine the interactions of planar PCBs with other organochlorines and the consequences of in ovo exposure on immune function after hatch. Similar immunological biomarkers will be measured in chickens and Great Lakes birds. The last phase of the project will calibrate specific levels of suppression of immunological tests to decreased resistance to infections in laboratory and wild birds.Journal Articles:
No journal articles submitted with this report: View all 42 publications for this projectSupplemental Keywords:
dioxin, indicators, monitoring, aquatic, avian, endocrine disruptors, immunotoxicology., Health, RFA, Scientific Discipline, Ecosystem Protection/Environmental Exposure & Risk, Geographic Area, Toxics, Ecological Indicators, International, Health Risk Assessment, pesticides, State, Ecosystem Protection, Immunology, Ecosystem/Assessment/Indicators, Epidemiology, exploratory research environmental biology, Endocrine Disruptors - Human Health, Environmental Microbiology, endocrine disruptors, Ecological Effects - Environmental Exposure & Risk, Biochemistry, Endocrine Disruptors - Environmental Exposure & Risk, Toxicology, avian development, immune system response, organochlorine compounds, toxicity, ecological effects, EDCs, bird habitat, aquatic ecosystem, bioindicator, dioxins, risk assessment, exposure studies, immunotoxicology, susceptibility to infections, PCB, Ohio (OH), endocrine disrupting chemicals, reproductive processes, ecological exposure, pathogen, PCBs, Canada, Michigan (MI), birds, animal models, biomarkersRelevant Websites:
http://biology.wright.edu/BioSite/Personnel/Faculty/Grasman.html
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.