Sexual immune dimorphism in ecological context : the impact of estrogen on human immune function and development of bacteria killing assay.

Sexual immune dimorphism refers to differences in immune function between males and females, shaped by hormonal, genetic, behavioral, and evolutionary factors. This dissertation examines these differences through an ecological and evolutionary lens, focusing on the role of estrogen in immune modulation and the development of a bacteria killing assay to assess innate immunity in human saliva. Females generally exhibit stronger immune responses than males, providing advantages in pathogen defense but increasing the risk of autoimmune diseases. Males, in contrast, have higher susceptibility to infections, influenced by the immunosuppressive effects of testosterone. These patterns align with life history theory, which suggests that reproductive investment and immune function are shaped by trade-offs between survival and reproduction. A systematic review and meta-analysis of studies on exogenous estrogen exposure reveal that estrogen enhances inflammation, regulates cytokine production, and influences both innate and adaptive immunity. This hormonal modulation is critical for understanding sex differences in disease susceptibility and immune resilience. Empirical data from the Waco COVID Survey further explore sex differences in immune responses, behavioral adaptations, and vaccine hesitancy. Another study on unrealistic optimism in disease risk perception highlights how sex-based differences in immunity influence health behaviors. To advance methodological approaches, this dissertation introduces a bacteria killing assay using human saliva, providing a non-invasive tool to measure innate immune function. This method facilitates assessments of immune variability across reproductive stages, hormonal profiles, and environmental conditions. Findings underscore the importance of integrating sex-specific approaches in immunological research, clinical medicine, and public health. By combining evolutionary theory, hormonal analysis, epidemiological data, and methodological innovation, this research advances understanding of immune variability and its implications for human health. These insights reinforce the need for interdisciplinary approaches in studying immune function, considering biological, environmental, and evolutionary influences.

Author dc:creator

• Nowak, Tomasz J. (Tomasz Jaroslaw), 1990-

Contributors dc:contributor

• Muehlenbein, Michael P., 1976-

• Sexual immune dimorphism.
• Estrogen modulation.
• Bacteria killing assay.
• Life history theory.
• Th1/Th2 cytokine ratio.
• Estrogen.
• COVID-19 risk perception.
• Reproductive trade-offs.
• Evolutionary immunology.

Statement dc:rights

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Language dc:language

en

Handle dc:identifier.uri

https://hdl.handle.net/2104/13761

OAI identifier oai:identifier

oai:tdl-ir.tdl.org:2104/13761