Format

Send to

Choose Destination
See comment in PubMed Commons below
J Mol Biol. 2010 Jun 11;399(3):436-49. doi: 10.1016/j.jmb.2010.04.001. Epub 2010 Apr 9.

Effector cell recruitment with novel Fv-based dual-affinity re-targeting protein leads to potent tumor cytolysis and in vivo B-cell depletion.

Author information

1
MacroGenics, Inc., 1500 East Gude Drive, Rockville, MD 20850, USA. johnsons@macrogenics.com

Abstract

Bispecific antibodies capable of redirecting the lytic potential of immune effector cells to kill tumor targets have long been recognized as a potentially potent biological therapeutic intervention. Unfortunately, efforts to produce such molecules have been limited owing to inefficient production and poor stability properties. Here, we describe a novel Fv-derived strategy based on a covalently linked bispecific diabody structure that we term dual-affinity re-targeting (DART). As a model system, we linked an Fv specific for human CD16 (FcgammaRIII) on effector cells to an Fv specific for mouse or human CD32B (FcgammaRIIB), a normal B-cell and tumor target antigen. DART proteins were produced at high levels in mammalian cells, retained the binding activity of the respective parental Fv domains as well as bispecific binding, and showed extended storage and serum stability. Functionally, the DART molecules demonstrated extremely potent, dose-dependent cytotoxicity in retargeting human PBMC against B-lymphoma cell lines as well as in mediating autologous B-cell depletion in culture. In vivo studies in mice demonstrated effective B-cell depletion that was dependent on the transgenic expression of both CD16A on the effector cells and CD32B on the B-cell targets. Furthermore, DART proteins showed potent in vivo protective activity in a human Burkitt's lymphoma cell xenograft model. Thus, DART represents a biologically potent format that provides a versatile platform for generating bispecific antibody fragments for redirected killing and, with the selection of appropriate binding partners, applications outside of tumor cell cytotoxicity.

PMID:
20382161
DOI:
10.1016/j.jmb.2010.04.001
[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center