Document Type

Honors Thesis

Publication Date



The innate immune system recognizes self from non-self and is involved in pathogen clearance. Neutrophils are innate immune cells that quickly migrate to areas of infection or wounding. Neutrophils phagocytize pathogens and produce a respiratory burst that kills infectious agents. However, inappropriate presence and function of neutrophils contributes to many chronic inflammatory diseases. Environmental toxicants and other ingested compounds are known to impact innate immunity and neutrophil behavior. Two compounds of importance to the Maine population are arsenic and glucose, due to the presence of arsenic in Maine well water and the high rate of obesity and diabetes in Maine. Since many Mainers and people worldwide are exposed to arsenic from the environment or have elevated glucose levels, it is important to understand how these compounds impact our health. To test the effects of these compounds on neutrophil behavior, we used a transgenic zebrafish line that allows for observation of neutrophil behavior. Zebrafish embryos were immersed in arsenic- or glucose-containing media and an immune response was stimulated through tail fin amputation or Pseudomonas aeruginosa injection. The total number of neutrophils per embryo was counted and the percentage of neutrophils that migrated to the site of infection or wound in control, arsenic- or glucose-treated zebrafish was calculated. We find that 1% glucose has no effect on the total number of neutrophils or the migration of neutrophils to a wound. However, treatment with 130 ppb arsenic affects neutrophil migration to a wound, with significantly fewer neutrophils being present at wound sites in arsenic treated zebrafish compared to controls.

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