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

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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