Immunophenotypes of Australian Sea Lion Pups (Neophoca cinerea) Developing in the Context of Hookworm Infection (Uncinaria sanguinis)
Access status:
Open Access
Type
ThesisThesis type
Masters by ResearchAuthor/s
Meza Cerda, Maria IgnaciaAbstract
Pinnipeds are exposed to anthropogenic and environmental stressors, including disease, and these can, in turn, affect their immune system, health, and viability. The endemic Australian sea lion (Neophoca cinerea) population was impacted severely by commercial sealing in the 18th ...
See morePinnipeds are exposed to anthropogenic and environmental stressors, including disease, and these can, in turn, affect their immune system, health, and viability. The endemic Australian sea lion (Neophoca cinerea) population was impacted severely by commercial sealing in the 18th and 19th centuries and is now threatened by high pup mortality, such that hookworm disease (Uncinaria sanguinis) in pups has been identified as likely contributor to a declining population. To understand how the immune system functions, protects wild hosts from disease or causes immunopathology, it is crucial to bring our immunological toolbox into wild populations to measure immune phenotypes in the context of disease and other potential sources of heterogeneity, such as age. The immune profiles of Australian sea lion pups were assessed using serial blood samples collected from N. cinerea pups from two colonies located in South Australia, i.e. Seal Bay (n = 38) and Dangerous Reef (n = 34). One cohort of pups from Dangerous Reef was treated with ivermectin to provide a hookworm-negative cohort, allowing evaluation of the impact of this endemic infection and significant disease on immunophenotype. We measured indicators of health involved in innate and Th1/Th2 responses (IL-6, TNFα, IFNγ, IL-4, IL-10, lysozyme, acute-phase proteins and IgG) controlling for demographic factors such as development and colony or hookworm intensity season. Preliminary attempts to measure IL-4 and IFNγ in Australian sea lion pups blood samples revealed very low copy numbers using qPCR and digital droplet PCR methods, suggesting further investigations of these profiles. We found immunophenotypic differences associated with age, colony and disease status, highlighting some potentially promising indicators of health in the Australian sea lion.
See less
See morePinnipeds are exposed to anthropogenic and environmental stressors, including disease, and these can, in turn, affect their immune system, health, and viability. The endemic Australian sea lion (Neophoca cinerea) population was impacted severely by commercial sealing in the 18th and 19th centuries and is now threatened by high pup mortality, such that hookworm disease (Uncinaria sanguinis) in pups has been identified as likely contributor to a declining population. To understand how the immune system functions, protects wild hosts from disease or causes immunopathology, it is crucial to bring our immunological toolbox into wild populations to measure immune phenotypes in the context of disease and other potential sources of heterogeneity, such as age. The immune profiles of Australian sea lion pups were assessed using serial blood samples collected from N. cinerea pups from two colonies located in South Australia, i.e. Seal Bay (n = 38) and Dangerous Reef (n = 34). One cohort of pups from Dangerous Reef was treated with ivermectin to provide a hookworm-negative cohort, allowing evaluation of the impact of this endemic infection and significant disease on immunophenotype. We measured indicators of health involved in innate and Th1/Th2 responses (IL-6, TNFα, IFNγ, IL-4, IL-10, lysozyme, acute-phase proteins and IgG) controlling for demographic factors such as development and colony or hookworm intensity season. Preliminary attempts to measure IL-4 and IFNγ in Australian sea lion pups blood samples revealed very low copy numbers using qPCR and digital droplet PCR methods, suggesting further investigations of these profiles. We found immunophenotypic differences associated with age, colony and disease status, highlighting some potentially promising indicators of health in the Australian sea lion.
See less
Date
2021Rights statement
The author retains copyright of this thesis. It may only be used for the purposes of research and study. It must not be used for any other purposes and may not be transmitted or shared with others without prior permission.Faculty/School
Faculty of Science, Sydney Institute of Veterinary ScienceAwarding institution
The University of SydneyShare