Oxygen-carrying nanoemulsions and respiratory hyperoxia eliminate tumor hypoxia–induced immunosuppression
Katarina Halpin-Veszeleiova, … , Bruce D. Spiess, Stephen M. Hatfield
Katarina Halpin-Veszeleiova, … , Bruce D. Spiess, Stephen M. Hatfield
Published March 24, 2025
Citation Information: JCI Insight. 2025;10(6):e174675. https://doi.org/10.1172/jci.insight.174675.
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Research Article Immunology Oncology

Oxygen-carrying nanoemulsions and respiratory hyperoxia eliminate tumor hypoxia–induced immunosuppression

Abstract

Hypoxia/hypoxia-inducible factor 1α–driven immunosuppressive transcription and cAMP-elevating signaling through A2A adenosine receptors (A2ARs) represent a major tumor-protecting pathway that enables immune evasion. Recent promising clinical outcomes due to the blockade of the adenosine-generating enzyme CD73 and A2AR in patients refractory to all other therapies have confirmed the importance of targeting hypoxia-adenosinergic signaling. We report a feasible approach to target the upstream stage of hypoxia-adenosinergic immunosuppression using an oxygen-carrying nanoemulsion (perfluorocarbon blood substitute). We show that oxygenation agent therapy (a) eliminates tumor hypoxia, (b) improves efficacy of endogenously developed and adoptively transferred T cells, and thereby (c) promotes regression of tumors in different anatomical locations. We show that both T cells and NK cells avoid hypoxic tumor areas and that reversal of hypoxia by oxygenation agent therapy increases intratumoral infiltration of activated T cells and NK cells due to reprogramming of the tumor microenvironment (TME). Thus, repurposing oxygenation agents in combination with supplemental oxygen may improve current cancer immunotherapies by preventing hypoxia-adenosinergic suppression, promoting immune cell infiltration and enhancing effector responses. These data also suggest that pretreating patients with oxygenation agent therapy may reprogram the TME from immunosuppressive to immune-permissive prior to adoptive cell therapy, or other forms of immunotherapy.

Authors

Katarina Halpin-Veszeleiova, Michael P. Mallouh, Lucy M. Williamson, Ashley C. Apro, Nuria R. Botticello-Romero, Camille Bahr, Maureen Shin, Kelly M. Ward, Laura Rosenberg, Vladimir B. Ritov, Michail V. Sitkovsky, Edwin K. Jackson, Bruce D. Spiess, Stephen M. Hatfield

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Figure 1

Exposure of PFC nanoemulsion to 100% O2 prior to in vivo administration maximizes levels of dissolved oxygen.

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Exposure of PFC nanoemulsion to 100% O2 prior to in vivo administration ...
(A) Schematic representation of the rationale to use PFC to reverse tumor hypoxia and target hypoxia-adenosinergic signaling. The hypoxia/HIF1A-driven increase in adenosine-generating ectoenzymes CD39 and CD73 leads to the accumulation of extracellular adenosine in the TME that triggers immunosuppressive A2AR → cAMP → PKA signaling. PFCs target the upstream stage of the hypoxia-adenosinergic axis of immunosuppression by increasing tumor oxygen tension and eliminating hypoxia/HIF1A- and A2AR-mediated signaling. Tumor oxygenation weakens all known stages of the hypoxia-adenosinergic signaling axis to prevent inhibition of antitumor cytotoxic killer cells and promote tumor regression (28, 29). HRE, hypoxia response element; CRE, cAMP response element; PKA, protein kinase A; CREB, cAMP response element binding protein; HIF1A, hypoxia-inducible factor 1α; VHL, von Hippel-Lindau; PFC, perfluorocarbon; TCR, T cell receptor. Created with BioRender.com. (B) Illustration depicting Perflubron, a PFC-based nanoemulsion consisting of 60% (w/v) perfluorooctylbromide (PFOB) and perfluorodecylbromide (PFDB) in water stabilized with egg yolk phospholipids (EYPs). After homogenization, the nanoemulsion consists of particles that are less than 200 nm in size. The amount of dissolved oxygen (O2) in Perflubron is proportional to the partial pressure of O2 in the environment. (C) Left: Illustration depicting the strategy to maximize oxygen-carrying capacity of Perflubron by saturation with 100% O2 for 7 minutes. Unsaturated samples were maintained at 21% O2. Right: One mL of unsaturated (21% O2) or saturated (100% O2) PFC or PBS as control was placed into an H35 HEPA Hypoxystation (Don-Whitley) maintained at 1% O2, 5% CO2, and 37°C. Dissolved oxygen concentration was measured continuously by the Presens oxygen monitoring system and Presens in vitro oxygen probes.