Immune Effects of Cryoablation in Woodchuck Hepatocellular Carcinoma

Michal Mauda-Havakuk; Natalie M Hawken; Joshua W Owen; Andrew S Mikhail; Matthew F Starost; Baktiar Karim; Paul G Wakim; Olga L Franco-Mahecha; Andrew L Lewis; William F Pritchard; John W Karanian; Bradford J Wood

doi:10.2147/JHC.S426442

Immune Effects of Cryoablation in Woodchuck Hepatocellular Carcinoma

J Hepatocell Carcinoma. 2023 Nov 6:10:1973-1990. doi: 10.2147/JHC.S426442. eCollection 2023.

Authors

Affiliations

¹ Center for Interventional Oncology, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA.
² Interventional Radiology, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel.
³ Division of Veterinary Resources, National Institutes of Health, Bethesda, MD, USA.
⁴ National Cancer Institute, National Institutes of Health, Frederick, MD, USA.
⁵ Biostatistics and Clinical Epidemiology Service, National Institutes of Health Clinical Center, Bethesda, MD, USA.
⁶ Alchemed Bioscience Consulting Ltd, Stable Cottage, Monkton Lane, Farnham, Surrey, UK.
⁷ Center for Interventional Oncology, Radiology and Imaging Sciences, Clinical Center, National Institute of Biomedical Imaging and Bioengineering and National Cancer Institute Center for Cancer Research; National Institutes of Health, Bethesda, MD, USA.

Abstract

Objectives: Local and systemic immune responses evoked by locoregional therapies such as cryoablation are incompletely understood. The aim of this study was to characterize cryoablation-related immune response and the capacity of immune drugs to augment immunity upon cryoablation for the treatment of hepatocellular carcinoma (HCC) using a woodchuck hepatocellular carcinoma model.

Materials and methods: Twelve woodchucks chronically infected with woodchuck hepatitis virus and with hepatocellular carcinoma underwent imaging with contrast-enhanced CT. Partial cryoablation of tumors in three woodchucks was performed. Fourteen days after cryoablation, liver tissues were harvested and stained with H&E and TUNEL, and immune infiltrates were quantified. Peripheral blood mononuclear cells (PBMC) were collected from ablated and nonablated woodchucks, labeled with carboxyfluorescein succinimidyl ester (CFSE) and cultured with immune-modulating drugs, including a small PD-L1 antagonist molecule (BMS-202) and three TLR7/8 agonists (DSR 6434, GS-9620, gardiquimod). After incubation, cell replication and immune cell populations were analyzed by flow cytometry.

Results: Local immune response in tumors was characterized by an increased number of CD3+ T lymphocytes and natural killer cells in the cryolesion margin compared to other tumor regions. T regulatory cells were found in higher numbers in distant tumors within the liver compared to untreated or control tumors. Cryoablation also augmented the systemic immune response as demonstrated by higher numbers of PBMC responses upon immune drug stimulation in the cryoablation group.

Conclusions: Partial cryoablation augmented immune effects in both treated and remote untreated tumor microenvironments, as well as systemically, in woodchucks with HCC. Characterization of these mechanisms may enhance development of novel drug-device combinations for treatment of HCC.

Keywords: cryoablation; hepatitis B virus; hepatocellular carcinoma; immune effect; tumor microenvironment; woodchuck.