Theses and Dissertations

ORCID

https://orcid.org/0009-0005-1515-0292

Advisor

Ross, Matthew

Committee Member

Kaplan, Barbara

Committee Member

Howell, George

Committee Member

Pharr, Gregory

Date of Degree

5-15-2026

Original embargo terms

Immediate Worldwide Access

Document Type

Dissertation - Open Access

Major

Veterinary & Biomedical Science (Veterinary Medical Research)

Degree Name

Doctor of Philosophy (Ph.D.)

College

College of Veterinary Medicine

Department

College of Veterinary Medicine

Abstract

Macrophages originate from hematopoietic progenitors they are immune cells, part of innate immunity. They patrol tissues to identify damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs) from microorganisms. Macrophage pattern recognition receptors (PRRs) detect these signals, and respond by secreting lipid mediators, cytokines, and chemokines, thereby initiating the inflammatory response. Carboxylesterases (CES) belong to the α/β-hydrolase fold family of proteins and catalyze the hydrolysis of ester-containing substrates into alcohols and carboxylic acids. CES1 is one of the six CES identified in the human genome. They are localized in the endoplasmic reticulum lumen and cytosol of cells, primarily expressed in the liver and lung, and to a lesser extent in the kidney, intestine, monocyte, and macrophages. This research focused on understanding the role of CES1 in macrophage metabolism and its impact on their phenotypic functions. First, the role of CES1 in triacylglycerol (TAG) metabolism was explored by knocking down the expression of CES1 (CES1 knockdown, KD) by transduction with a lentiviral CES1 shRNA. In contrast, a Control was generated by transduction with a lentivirus with scrambled mRNA. CES1-deficient THP-1 macrophages acquired more intracellular TAG than Control THP-1 macrophages, with more than 80% being polyunsaturated fatty acids. CES1KD macrophages expressed more cytokine genes, such as TNF-α, IL-1β, and IL-6, without prior PAMP or DAMP stimulation, with an enhanced response when stimulated with lipopolysaccharide (LPS) or LPS/IFNγ. Additionally, CES1KD cells exhibited a transcriptomic profile similar to that of Control cells treated with LPS/IFNγ. A core metabolism study revealed the disruption of the citric acid cycle (TCA), increased secretion of citrate and lactate, and enhanced glycolytic capacity in CES1KD cells. To investigate the mechanism responsible for CES1 action, this study revealed that the expression of components of the TLR-NFβ signaling pathway was higher in CES1KD. Additionally, HIF1α was more highly expressed and directly regulated the secretion of IL-1 in CES1KD macrophages. Finally, NLRP3 priming, and activation were higher in CES1KD than in Control. Overall, this study demonstrates that CES’s crucial role in maintaining the tight regulation of inflammation and can be a potential therapeutic target by enhancing its activity to manage chronic inflammation.

Sponsorship (Optional)

NIH R15HL157818, Mass spectrometry infrastructure was supported in part by P20GM103646 (Center for Biomedical Research Excellence in Pathogen Host Interactions) and 2P20GM103476 (MS INBRE)

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