Structural design of disialoganglioside GD2 and CD3-bispecific antibodies to redirect T cells for tumor therapy.

Abstract

Antibody-based immunotherapy has proven efficacy for patients with high-risk neuroblastoma. However, despite being the most efficient tumoricidal effectors, T cells are underutilized because they lack Fc receptors. Using a monovalent single-chain fragment (ScFv) platform, we engineered tandem scFv bispecific antibodies (BsAbs) that specifically target disialoganglioside (GD2) on tumor cells and CD3 on T cells. Structural variants of BsAbs were constructed and ranked based on binding to GD2, and on competency in inducing T-cell-mediated tumor cytotoxicity. In vitro thermal stability and binding measurements were used to characterize each of the constructs, and in silico molecular modeling was used to show how the orientation of the variable region heavy (VH) and light (VL) chains of the anti-GD2 ScFv could alter the conformations of key residues responsible for high affinity binding. We showed that the VH-VL orientation, the (GGGGS)3 linker, disulfide bond stabilization of scFv, when combined with an affinity matured mutation provided the most efficient BsAb to direct T cells to lyse GD2-positive tumor cells. In vivo, the optimized BsAb could efficiently inhibit melanoma and neuroblastoma xenograft growth. These findings provide preclinical validation of a structure-based method to assist in designing BsAb for T-cell-mediated therapy.

• Authors: Ming Cheng, Mahiuddin Ahmed, Hong Xu, Nai-Kong V Cheung
• Journal: International journal of cancer (Int J Cancer) Vol. 136 Issue 2 Pg. 476-86 (Jan 15 2015) ISSN: 1097-0215 [Electronic] United States
• PMID: 24895182 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: © 2014 UICC.

Chemical References

• Antibodies, Bispecific
• Antibodies, Monoclonal
• CD3 Complex
• Gangliosides
• Single-Chain Antibodies
• ganglioside, GD2

Topics

• Animals
• Antibodies, Bispecific (chemistry, immunology, therapeutic use)
• Antibodies, Monoclonal (immunology, therapeutic use)
• Blotting, Western
• CD3 Complex (immunology)
• Cell Proliferation
• Enzyme-Linked Immunosorbent Assay
• Flow Cytometry
• Gangliosides (immunology)
• Humans
• Immunotherapy
• Lymphocyte Activation
• Melanoma (immunology, therapy)
• Mice
• Mice, Inbred BALB C
• Mice, Nude
• Models, Molecular
• Neuroblastoma (immunology, therapy)
• Single-Chain Antibodies (immunology)
• T-Lymphocytes (immunology, transplantation)
• Tumor Cells, Cultured