Abstract
The cluster of differentiation 47 (CD47) protein is abundantly expressed on various malignant cells and suppresses the phagocytic function of macrophages and dendritic cells. High CD47 expression levels are correlated with poor cancer survival. Antagonizing CD47 antibodies with potent antitumor effects have been developed in clinical trials, but have critical side effects, inducing anemia and thrombocytopenia. To develop a safe and potent CD47 blockade, we designed extracellular vesicles (EVs) harboring signal regulatory protein alpha (SIPRα)—EV-SIRPα (EVs that express SIPRα). EV-SIRPα showed minimal toxic effects on hematologic parameters and utilized RBCs as delivery vehicles to tumors rather than inducing anemia. EV-SIRPα inhibited ligation of residual CD47 molecules, which attribute to the EV-endocytosis-mediated CD47 depletion and steric hindrance of EV. In an immunologically cold tumor model, EV-SIRPα induced tumor-specific T-cell-mediated antitumor effects. When directly administered to the accessible lesions, EV-SIRPα monotherapy elicited an abscopal effect in the B16F10 tumor model by increasing immune cell infiltration and CD8+-mediated immunity against non-treated tumors. The combinational approach by loading doxorubicin into the EV-SIRPα dramatically reduced the tumor burden and led to 80% complete remission rate. Thus, a potent EV-based CD47 blockade that is hematologically safe, has efficient signaling blocking efficacy, and has systemic antitumor immunity against cancer is recommended.
Original language | English |
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Pages (from-to) | 727-738 |
Number of pages | 12 |
Journal | Journal of Controlled Release |
Volume | 351 |
DOIs | |
Publication status | Published - 2022 Nov |
Bibliographical note
Funding Information:This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government [NRF-2017R1A3B1023418 and NRF-2018H1A2A1062948]; the National R&D Program for Cancer Control, Ministry of Health and Welfare , Republic of Korea; the KIST Institutional Program; the KU-KIST Graduate School of Converging Science and Technology Program.
Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government [NRF-2017R1A3B1023418 and NRF-2018H1A2A1062948]; the National R&D Program for Cancer Control, Ministry of Health and Welfare, Republic of Korea; the KIST Institutional Program; the KU-KIST Graduate School of Converging Science and Technology Program.
Publisher Copyright:
© 2022 The Authors
Keywords
- CD47
- Cancer immunotherapy
- Extracellular vesicle
- SIRPα
ASJC Scopus subject areas
- Pharmaceutical Science