Abstract #0894

Intracellular Oximetry Using in vivo Fluorine-19 MRI as Biomarker of Immunotherapeutic Response of Cytotoxic T Cells in Mouse Glioma

Jia Zhong¹,², Masashi Sakaki³, Hideho Okada³,⁴, Eric T. Ahrens¹,²

¹Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA, United States; ²The Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, Pittsburgh, PA, United States; ³Brain Tumor Program, Cancer Institute, University of Pittsburgh, Pittsburgh, PA, United States; ⁴Department of Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States

Immunotherapy using live cells is opening up new avenues for brain tumor treatment with minimal damage to healthy tissue. Noninvasive biomarkers of therapeutic efficacy is of great importance for the evaluation of emerging immunotherapies. In this study, we report the use of intracellular perfluorocarbon (PFC) labeling of glioma cells, combined with 19F T1 measurements, to assay glioma oximetry. We show that glioma oxygen level responds sensitively to the influx of therapeutic cytotoxic CD8+ T cells into mouse glioma. We also show that intracellular oximetry can detect the presence of sparse CD8+ T cell numbers, even in the absence of significant tumor shrinkage.