Author ORCID Identifier

https://orcid.org/0000-0001-6636-5967

Date of Award

10-2026

Document Type

Thesis (Ph.D.)

Department or Program

Microbiology and Immunology

First Advisor

Edward Usherwood

Second Advisor

Pamela Rosato

Third Advisor

Yina Huang

Abstract

Metabolism is critical to CD8 T cell differentiation and response to intracellular infections and cancer. Mitochondrial NAD is a key component of cellular metabolism; however, the biology of this metabolite in CD8 T cells is poorly understood due to limitations of existing NAD analysis techniques. In this thesis, we develop the mitochondrial NAD redox index and capacity analysis (RICA) assay, a powerful flow-cytometry based technique for assessing mitochondrial NAD content and redox state in living cells. We use this assay to profile mitochondrial NAD dynamics across the course of CD8 T cell differentiation and in multiple in vitro and ex vivo contexts. Our results reveal that mitochondrial NAD changes dramatically across T cell subsets and conditions, emphasizing the importance of this metabolite in T cell responses. We also identify a deficit in mitochondrial NAD concentration within exhausted CD8 T cells infiltrating the tumor, and propose a mechanism for depletion of mitochondrial NAD within these cells. This knowledge could be used in the context of CD8 T cell-based cancer immunotherapies in order to enhance treatment efficacy and patient health outcomes. In conclusion, the RICA assay represents a powerful new tool for deepening our understanding of CD8 T cell metabolism in human health and disease.

Original Citation

Bostwick-Galaviz AM, Usherwood EJ. Redox index and capacity analysis (RICA) reveals NAD biology changes in T cell responses in vitro and ex vivo. J Immunol. 2026 Apr 15;215(4):vkag035. doi: 10.1093/jimmun/vkag035. PMID: 42019959; PMCID: PMC13108513.

Download

Share

COinS