Date of Award
Spring 2026
Document Type
Open Access Dissertation
Department
Biomedical Science
First Advisor
Jason L. Kubinak
Abstract
Flow cytometry is a rapid, high-throughput method used to measure the physical and biochemical properties of individual cells. It combines fluidics, optics, and electronic signal processing to enumerate and characterize thousands of cells per second. Due to immune tissues’ highly heterogeneous cell populations, flow cytometry has become one of the most widely used tools for parsing immune cell subsets and tracking how these populations change during infection, in response to genotypic differences, and during metabolic perturbation.
In this dissertation, flow cytometry is used as a central method to investigate how immune cell populations respond to microbial challenges and physiological stress. In a murine fecal suspension test model of acute polymicrobial sepsis, high- dimensional flow cytometry was used to characterize circulating and tissue- resident leukocyte populations during the acute phase of disease. These measurements revealed a rapid shift in immune composition marked by expansion of immature myeloid populations consistent with emergency myelopoiesis. When integrated with plasma cytokine measurements and 16S-based characterization of microbial DNA in the bloodstream, these data provide a systems-level view of the immune response to an acute septic challenge.
Flow cytometry was also used to examine how major histocompatibility complex class II polymorphism shapes immune cell organization in the gut. Comparative phenotyping across multiple secondary lymphoid tissues demonstrated that Peyer’s patches exhibit the greatest interindividual variation in immune composition in response to MHCII polymorphism. Detailed flow analysis of GC B cell populations reveals that MHC heterozygosity is associated with a more balanced distribution of dark zone and light zone germinal center cells and increases IgA binding to small-intestinal bacteria. These phenotypic differences were strongly influenced by the microbiota, as antibiotic treatment eliminated many of the observed differences between mouse MHC genotypes.
Finally, flow cytometry analysis of intestinal immune populations was used to examine the effects of a recombinant GDSL (rGDSL) lipase derived from Nepenthes pitcher plants. These experiments suggest that treatment with the enzyme alters immune populations associated with lipid antigen presentation while also improving intestinal lipid absorption in mice. Together, these studies demonstrate how high-dimensional flow cytometry can be applied to resolve immune heterogeneity across infection models, homeostatic mucosal immunity, and metabolic physiology.
Rights
© 2026, Tori E. Peacock
Recommended Citation
Peacock, T. E.(2026). Biomedical Insights Derived From Applications of Next Generation Flow Cytometry. (Doctoral dissertation). Retrieved from https://scholarcommons.sc.edu/etd/8727