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posted on 2023-04-04, 02:04 authored by Rosanne E. Veerman, Gözde Güclüler Akpinar, Annemarijn Offens, Loïc Steiner, Pia Larssen, Andreas Lundqvist, Mikael C.I. Karlsson, Susanne Gabrielsson Upregulation of functional markers on DCs after in vitro exposure to EVs.
Funding
Vetenskapsrådet (VR)
Cancerfonden (Swedish Cancer Society)
Radiumhemmets Forskningsfonder (Cancer Research Foundations of Radiumhemmet)
Stockholm läns landsting (Stockholm County Council)
Hjärt-Lungfonden (Swedish Heart-Lung Foundation)
Karolinska Institutet (KI)
History
ARTICLE ABSTRACT
Extracellular vesicles (EV) are important mediators of intercellular communication and are potential candidates for cancer immunotherapy. Immune checkpoint blockade, specifically targeting the programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) axis, mitigates T-cell exhaustion, but is only effective in a subset of patients with cancer. Reasons for therapy resistance include low primary T-cell activation to cancer antigens, poor antigen presentation, and reduced T-cell infiltration into the tumor. Therefore, combination strategies have been extensively explored. Here, we investigated whether EV therapy could induce susceptibility to anti–PD-1 or anti–PD-L1 therapy in a checkpoint-refractory B16 melanoma model. Injection of dendritic cell–derived EVs, but not checkpoint blockade, induced a potent antigen-specific T-cell response and reduced tumor growth in tumor-bearing mice. Combination therapy of EVs and anti–PD-1 or anti–PD-L1 potentiated immune responses to ovalbumin- and α-galactosylceramide–loaded EVs in the therapeutic model. Moreover, combination therapy resulted in increased survival in a prophylactic tumor model. This demonstrates that EVs can induce potent antitumor immune responses in checkpoint refractory cancer and induce anti–PD-1 or anti–PD-L1 responses in a previously nonresponsive tumor model.
