Surface Proteomics Reveals CD72 as a Target for In Vitro-Evolved Nanobody-Based CAR-T Cells in KMT2A/MLL1-Rearranged B-ALL

Cancer Discov. 2021 Aug;11(8):2032-2049. doi: 10.1158/2159-8290.CD-20-0242. Epub 2021 Mar 16.


Alternative strategies are needed for patients with B-cell malignancy relapsing after CD19-targeted immunotherapy. Here, cell surface proteomics revealed CD72 as an optimal target for poor-prognosis KMT2A/MLL1-rearranged (MLLr) B-cell acute lymphoblastic leukemia (B-ALL), which we further found to be expressed in other B-cell malignancies. Using a recently described, fully in vitro system, we selected synthetic CD72-specific nanobodies, incorporated them into chimeric antigen receptors (CAR), and demonstrated robust activity against B-cell malignancy models, including CD19 loss. Taking advantage of the role of CD72 in inhibiting B-cell receptor signaling, we found that SHIP1 inhibition increased CD72 surface density. We establish that CD72-nanobody CAR-T cells are a promising therapy for MLLr B-ALL. SIGNIFICANCE: Patients with MLLr B-ALL have poor prognoses despite recent immunotherapy advances. Here, surface proteomics identifies CD72 as being enriched on MLLr B-ALL but also widely expressed across B-cell cancers. We show that a recently described, fully in vitro nanobody platform generates binders highly active in CAR-T cells and demonstrate its broad applicability for immunotherapy development.This article is highlighted in the In This Issue feature, p. 1861.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD / immunology*
  • Antigens, CD19 / immunology*
  • Antigens, Differentiation, B-Lymphocyte / immunology*
  • Humans
  • Immunotherapy, Adoptive
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / immunology
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / therapy*
  • Proteomics
  • Receptors, Chimeric Antigen / immunology*


  • Antigens, CD
  • Antigens, CD19
  • Antigens, Differentiation, B-Lymphocyte
  • CD72 protein, human
  • Receptors, Chimeric Antigen