CHEEC Seed Grants: FY 2004

Sensitivity and reliability of ELISPOT assays for detection of cellular immune responses under simulated field collection 
E. Field, Department of Internal Medicine, University of Iowa

Are Iowans Exposed to Wild Ducks, Geese, and Game Birds at Risk of Avian Influenza Infections? 
J. Gill, MD, University Hygienic Laboratory, G. Gray, Sharon Setterquist, College of Public Health, University of Iowa

Development of a Passive Air Sampler for Measuring PCBs in Air 
K. Hornbuckle, Department of Civil and Environmental Engineering, Hans-Joachim Lehmler, Department of Occupational and Environmental Health, University of Iowa

Plant-Assisted Bacterial Degradation of Perchlorate 
G. Parkin, J Schnoor, C Just, G Struckhoff, Department of Civil and Environmental Engineering, University of Iowa

New Approach to Environmental Immunotoxicant Biomonitoring in Humans: Deoxynivalenol (Vomitoxin) as Example 
S. Hendrich, C Landgren, Department of Food Science and Human Nutrition, Iowa State University

 


Sensitivity and reliability of ELISPOT assays for detection of cellular immune responses under simulated field collection
Investigator: E. Field, Department of Internal Medicine, University of Iowa 
There is a need for epidemiology studies examining the role of cellular immune response to environmental risk factors in autoimmunity. These studies will require the development of assays of cell-mediated immunity to assess exposure and immune response to candidate environmental pathogens/xenobiotics. Nearly all of the immune monitoring of field-collected samples consists of assay of humoral immune response. Assays of cellular immune response, of which the lymphocyte proliferation of T cell assay (LPT) is most utilized, have been difficult to adapt to the field. The ELISPOT (enzyme-linked immunosorbant spot) assay is an alternative method to examine T cell immune response in vitro. The proposal examines the hypothesis that the ELISPOT is a more sensitive and reliable assay for evaluating T cell immune response to environmental factors than the standard LPT assay. Furthermore, the proposal seeks to develop ELISPOT to detect cellular immune response to human heat shock protein for future epidemiological studies.

Are Iowans Exposed to Wild Ducks, Geese, and Game Birds at Risk of Avian Influenza Infections? 
Investigators: J. Gill, University Hygienic Laboratory, G. Gray, Sharon Setterquist, College of Public Health, University of Iowa 
The recent explosive epidemic of avian influenza in Asia has many public health officials concerned. Iowans have numerous occupational and recreational exposures to avian species that might cause them to be infected with avian influenza viruses, yet they have never been studied. We propose a pilot seroprevalence study of 250 Iowans with exposure to ducks, geese, and game birds to investigate such transmission. After informed consent is obtained, DNR workers, hunters, and others with game bird exposure will be asked to complete a risk factor questionnaire, and to permit the collection of at least one serum sample. We will also collect cloacal or tracheal samples from 390 of their birds. Human serological testing and bird viral cultures will be performed to document Iowans at high risk of avian influenza virus infection. Identifying high-risk individuals and their exposures is a first step towards developing public health interventions to protect against such future infections.

Publication:  Gill J, Webby R, Gilchrist M, Gray G; Avian influenza among waterfowl hunters and wildlife professionals. Emerg Infect Dis ; 2006; 12(8):1284-1286

Development of a Passive Air Sampler for Measuring PCBs in Air
Investigators: K. Hornbuckle, Department of Civil and Environmental Engineering, Hans-Joachim Lehmler, Department of Occupational and Environmental Health, University of Iowa 
Sampling PCBs in air using high volume air samples is expensive, time consuming, and difficult to implement over a region. This pilot project will build and deploy an inexpensive passive air sampling system for atmospheric PCBs. The major benefit to using passive air samplers is their cost and ease in deployment. The major disadvantage is the lack of quantitative results. Thus, the goal of this project is two fold. First, the concentration of PCBs will be compared using the passive sampler to the concentration of PCBs using high volume samplers side by side. The second goal of this project is to compare the congener distributions of PCBs in air as collected by the passive sampler and a high volume sampler. PCBs are a mixture of as many as 209 different compounds (congeners). The complexity of these mixtures is a result of either the original manufacturing process or of weathering of these compounds in the environment. Several metabolites can be formed from each congener in plants, animals and humans, thus increasing the number of potentially environmentally and biologically relevant PCB compounds that may be present in the environment. This study using the passive samplers will be a good way to examine differences in congener distributions cheaply and effectively.

Plant-Assisted Bacterial Degradation of Perchlorate 
Investigators: G. Parkin, J Schnoor, C Just, G Struckhoff, Department of Civil and Environmental Engineering, University of Iowa
Perchlorate has been linked with thyroid dysfunction in humans and thus represents a serious potential health risk. Prior research on perchlorate remediation has shown that (1) perchlorate-degrading bacteria are present in nature but are often electron donor limited; (2) plants release electron donors and carbon sources into soil; (3) perchlorate-degrading bacteria require low redox potential to reduce perchlorate; and (4) plants raise redox potential in the subsurface. These findings are somewhat contradictory and may impact perchlorate remediation schemes. We propose to study the relationship between plants and bacteria to determine whether the integrated effect of plants on bacteria is synergistic or antagonistic, whether the release of electron donor and carbon by plants is sufficient to overcome the inhibition to bacterial perchlorate reduction caused by the higher redox potential. Our focus is on higher concentrations of perchlorate (>25mg/L) because we believe it is important to control contamination at its source to effectively reduce health risks.

Publication:  Shrout JD, Struckhoff GC, Parkin GF, Schnoor JL; Stimulation and molecular characterization of bacterial perchlorate degradation by plant-produced electron donors.Environ Sci Technol. 2006; 40(1): 310-317

New Approach to Environmental Immunotoxicant Biomonitoring in Humans: Deoxynivalenol (Vomitoxin) as Example 
Investigators: S. Hendrich, C. Landgren, Department of Food Science and Human Nutrition, Iowa State University 
Deoxynivalenol (DON) is the most common fungal contaminant in the human food supply. DON contaminates staple grains (wheat, corn, barley, oats). DON's potential as an agent of biochemical terrorism (it is easy to produce; grain supplies are insecure) also make it a good model for developing environmental human biomonitoring assays. Preliminary data support that this toxin is immunotoxic in vivo and in vitro in concentrations relevant to typical dietary exposures. Research will utilize an assay the PIs have developed to model a simple screening test for environmental immunotoxicants, based on suppression of lymphocyte proliferation in a human cell line. To develop this model, the following unknown effects will be assessed: 1) major DON metabolites on DON immunotoxicity from human plasma samples by synthesizing and testing this metabolite in an assay, and 2) interindividual variation of in human plasma immunotoxic responses due to endogenous or other exogenous factors by assessing the effects of DON-free human plasma assay.

Publication:  Landgren CA, Hendrich S, Kohut ML; Low-level dietary deoxynivalenol and acute exercise stress result in immunotoxicity in BALB/c mice; J Immunotoxicol. 2006; 3(4):173-178