Humanization of an anti-CCR4 antibody that kills cutaneous T-cell lymphoma cells and abrogates suppression by T-regulatory cells.

Abstract

Cutaneous T-cell lymphoma (CTCL) is a heterogeneous group of neoplastic disorders characterized by clonally derived and skin-homing malignant T cells that express high level of chemokine receptor CCR4, which is associated with their skin-homing capacity. CCR4 is also highly expressed on T-regulatory cells (Tregs) that can migrate to several different types of chemotactic ligand CCL17- and CCL22-secreting tumors to facilitate tumor cell evasion from immune surveillance. Thus, its high-level expression on CTCL cells and Tregs makes CCR4 a potential ideal target for antibody-based immunotherapy for CTCL and other types of solid tumors. Here, we conducted humanization and affinity optimization of a murine anti-CCR4 monoclonal antibody (mAb), mAb1567, that recognizes both the N-terminal and extracellular domains of CCR4 with high affinity and inhibits chemotaxis of CCR4(+) CTCL cells. In a mouse CTCL tumor model, mAb1567 exhibited a potent antitumor effect and in vitro mechanistic studies showed that both complement-dependent cytotoxicity (CDC) and neutrophil-mediated antibody-dependent cellular cytotoxicity (ADCC) likely mediated this effect. mAb1567 also exerts human NK cell-mediated ADCC activity in vitro. Moreover, mAb1567 also effectively inhibits chemotaxis of CD4(+)CD25(high) Tregs via CCL22 and abrogates Treg suppression activity in vitro. An affinity-optimized variant of humanized mAb1567, mAb2-3, was selected for further preclinical development based on its higher binding affinity and more potent ADCC and CDC activities. Taken together, this high-affinity humanized mAb2-3 with potent antitumor effect and a broad range of mechanisms of action may provide a novel immunotherapy for CTCL and other solid tumors.

• Authors: De-Kuan Chang, Jianhua Sui, Shusheng Geng, Asli Muvaffak, Mei Bai, Robert C Fuhlbrigge, Agnes Lo, Anuradha Yammanuru, Luke Hubbard, Jared Sheehan, James J Campbell, Quan Zhu, Thomas S Kupper, Wayne A Marasco
• Journal: Molecular cancer therapeutics (Mol Cancer Ther) Vol. 11 Issue 11 Pg. 2451-61 (Nov 2012) ISSN: 1538-8514 [Electronic] United States
• PMID: 22869555 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: ©2012 AACR.

Chemical References

• Antibodies, Monoclonal
• Mutant Proteins
• Receptors, CCR4
• Complement System Proteins

Topics

• Amino Acid Sequence
• Animals
• Antibodies, Monoclonal (chemistry, immunology, pharmacology, therapeutic use)
• Antibody-Dependent Cell Cytotoxicity (drug effects)
• Cell Line, Tumor
• Chemotaxis (drug effects)
• Cloning, Molecular
• Complement System Proteins (immunology)
• Humans
• Lymphoma, T-Cell, Cutaneous (drug therapy, pathology)
• Mice
• Mice, SCID
• Molecular Sequence Data
• Mutant Proteins (chemistry, metabolism)
• Neutrophils (drug effects, immunology)
• Protein Binding (drug effects)
• Receptors, CCR4 (immunology)
• T-Lymphocytes, Regulatory (drug effects, immunology)