2. Academic Validation
  3. Delivery of CD47-SIRPα checkpoint blocker by BCMA-directed UCAR-T cells enhances antitumor efficacy in multiple myeloma

Delivery of CD47-SIRPα checkpoint blocker by BCMA-directed UCAR-T cells enhances antitumor efficacy in multiple myeloma

  • Cancer Lett. 2024 Jan 22:216660. doi: 10.1016/j.canlet.2024.216660.
Qizhong Lu 1,  Donghui Yang 2,  Hexian Li 1,  Zhixiong Zhu 1,  Zongliang Zhang 1,  Yongdong Chen 1,  Nian Yang 1,  Jia Li 1,  Zeng Wang 1,  Ting Niu 3,  Aiping Tong 4
Affiliations

Affiliations

  • 1 State Key Laboratory of Biotherapy and Cancer Center, Research Unit of Gene and Immunotherapy, Chinese Academy of Medical Sciences, Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China.
  • 2 College of Veterinary Medicine, Shaanxi Center of Stem Cells Engineering and Technology, Northwest A&F University, Yangling, 712100, China.
  • 3 Department of Hematology, State Key Laboratory of Biotherapy and Cancer Center, Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China. Electronic address: [email protected].
  • 4 State Key Laboratory of Biotherapy and Cancer Center, Research Unit of Gene and Immunotherapy, Chinese Academy of Medical Sciences, Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China. Electronic address: [email protected].
PMID: 38266806 DOI: 10.1016/j.canlet.2024.216660
Abstract

In the treatment of relapsed or refractory multiple myeloma patients, BCMA-directed autologous CAR-T cells have showed excellent anti-tumor activity. However, their widespread application is limited due to the arguably cost and time-consuming. Multiple myeloma cells highly expressed CD47 molecule and interact with the SIRPα ligand on the surface of macrophages, in which evade the clearance of macrophages through the activation of "don't eat me" signal. In this study, a BCMA-directed universal CAR-T cells, BC404-UCART, secreting a CD47-SIRPα blocker was developed using CRISPR/Cas9 gene-editing system. BC404-UCART cells significantly inhibited tumor growth and prolonged the survival of mice in the xenograft model. The anti-tumor activity of BC404-UCART cells was achieved via two mechanisms, on the one hand, the UCAR-T cells directly killed tumor cells, on the other hand, the BC404-UCART cells enhanced the phagocytosis of macrophages by secreting anti-CD47 nanobody hu404-hfc fusion that blocked the "don't eat me" signal between macrophages and tumor cells, which provides a potential strategy for the development of novel "off-the-shelf" cellular immunotherapies for the treatment of multiple myeloma.

Keywords

Chimeric antigen receptor; Immunotherapy; Macrophages; Multiple myeloma; Nanobody.

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