Format

Send to

Choose Destination
Proc Natl Acad Sci U S A. 2019 Jun 11;116(24):11978-11987. doi: 10.1073/pnas.1819992116. Epub 2019 May 28.

Gene-edited stem cells enable CD33-directed immune therapy for myeloid malignancies.

Author information

1
Irving Cancer Research Center, Columbia University Medical Center, Columbia University, New York, NY 10032; fb2311@cumc.columbia.edu ama2241@columbia.edu sm3252@cumc.columbia.edu.
2
Humanized Mouse Core, Columbia Center for Translational Immunology, Columbia University Medical Center, Columbia University, New York, NY 10032.
3
Irving Cancer Research Center, Columbia University Medical Center, Columbia University, New York, NY 10032.
4
Myelodysplastic Syndromes Center, Columbia University Medical Center, Columbia University, New York, NY 10032.

Abstract

Antigen-directed immunotherapies for acute myeloid leukemia (AML), such as chimeric antigen receptor T cells (CAR-Ts) or antibody-drug conjugates (ADCs), are associated with severe toxicities due to the lack of unique targetable antigens that can distinguish leukemic cells from normal myeloid cells or myeloid progenitors. Here, we present an approach to treat AML by targeting the lineage-specific myeloid antigen CD33. Our approach combines CD33-targeted CAR-T cells, or the ADC Gemtuzumab Ozogamicin with the transplantation of hematopoietic stem cells that have been engineered to ablate CD33 expression using genomic engineering methods. We show highly efficient genetic ablation of CD33 antigen using CRISPR/Cas9 technology in human stem/progenitor cells (HSPC) and provide evidence that the deletion of CD33 in HSPC doesn't impair their ability to engraft and to repopulate a functional multilineage hematopoietic system in vivo. Whole-genome sequencing and RNA sequencing analysis revealed no detectable off-target mutagenesis and no loss of functional p53 pathways. Using a human AML cell line (HL-60), we modeled a postremission marrow with minimal residual disease and showed that the transplantation of CD33-ablated HSPCs with CD33-targeted immunotherapy leads to leukemia clearance, without myelosuppression, as demonstrated by the engraftment and recovery of multilineage descendants of CD33-ablated HSPCs. Our study thus contributes to the advancement of targeted immunotherapy and could be replicated in other malignancies.

KEYWORDS:

CD33; CRISPR/Cas9; acute myeloid leukemia; chimeric antigen receptor; transplantation

Conflict of interest statement

Conflict of interest statement: This study was funded by a grant from Vor Biopharma and PureTech Health, which has launched a company called Vor Biopharma. Columbia University owns equity in Vor Biopharma and has licensed technology that is the subject of this study to Vor Biopharma. F.B., A.M.A., and S.M. are coinventors on issued and pending patent applications licensed to Vor Biopharma. S.M. has equity ownership and is on the Scientific Advisory Board of Vor Biopharma. A.R. received funding from PureTech Health.

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center