Host Immunity Against Gastrointestinal Helminth Eggs
Open Access
- Author:
- Lambert, Kristin Anne
- Area of Honors:
- Biology
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Isabella Cattadori, Thesis Supervisor
Dr. James Harold Marden, Thesis Honors Advisor - Keywords:
- gastrointestinal helminth
parasite
egg-specific immunity
antibodies
hatchability - Abstract:
- Host immunity comprises multiple defense systems that have evolved to clear unwanted pathogens, including gastrointestinal helminths. While immune mechanisms against larval and adult stages of worms have been broadly studied in the laboratory and in the field, immunity specific to the egg stage of the parasite has received less attention. For soil-transmitted parasites, eggs produced within the host are shed via host’s feces into the environment. In the environment, egg hatching and larval survival are strongly modulated by climatic conditions. Also possible, the host might influence the ability of eggs to hatch and survive. We hypothesize that prior to shedding eggs within the host may be targeted by humoral immunity, influencing their hatchability. We examined this hypothesis using two gastrointestinal helminths Trichostrongylus retortaeformis and Graphidium strigosum common to the European rabbit, Oryctolagus cuniculus. Changes in egg hatching rate and volume were examined in relation to egg-specific antibodies in the serum and bound to egg shells over a 15 week laboratory experiment. Hatching rate was consistently higher for T. retortaeformis over G. strigosum. Over the course of infection, egg volume increased for G. strigosum but decreased for T. retortaeformis. Evidence of egg-specific antibody responses was observed with fewer antibodies bound to eggs of T. retortaeformis compared to G. strigosum. Little to no associations were found between antibodies, hatchability or volume for both helminths, suggesting that host antibodies play a minor role in regulating egg hatchability in the environment for these helminths.