TCR-like human antibodies expressed on human CTLs mediate antibody affinity-dependent cytolytic activity.

Abstract

The permanent genetic programming via gene transfer of autologous T cells with cell surface receptors directed toward tumor-related Ags holds great promise for the development of more-specific tumor therapies. In this study we have explored the use of Abs directed to MHC-peptide complexes (or TCR-like Abs) to engraft CTLs with exquisite specificity for cancer cells. First, we affinity matured in vitro a previously selected TCR-like Ab, Fab-G8, which is highly specific for the peptide melanoma-associated Ag-A1 presented by the HLA-A1 molecule. A combination of L chain shuffling, H chain-targeted mutagenesis, and in vitro selection of phage display libraries yielded a Fab-G8 Ab derivative, Fab-Hyb3, with an 18-fold improved affinity yet identical peptide fine specificity. Fab-G8 and Fab-Hyb3 were expressed on primary human T lymphocytes as cell surface-anchored Fab, demonstrating that T cells expressing the high-affinity Fab-Hyb3 molecule eradicate tumor cells much more effectively. Furthermore, the gain in ligand-binding affinity resulted in a 2-log improvement in the detection of peptide/MHC complexes on melanoma-associated Ag-A1 peptide-loaded cells. In summary, an affinity-matured Ab specifically recognizing a cancer-related peptide/MHC complex was generated and used to improve the tumor cell killing capacity of human T cells. This strategy, based on engraftment of T cells with in vitro engineered Abs, is an attractive alternative to the laborious, and in many cases unsuccessful, generation of highly potent tumor-specific T lymphocytes.

• Authors: Patrick Chames, Ralph A Willemsen, Gertrudis Rojas, Detlef Dieckmann, Louise Rem, Gerold Schuler, Reinder L Bolhuis, Hennie R Hoogenboom
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 169 Issue 2 Pg. 1110-8 (Jul 15 2002) ISSN: 0022-1767 [Print] United States
• PMID: 12097420 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antigens, Neoplasm
• HLA-A1 Antigen
• Immunodominant Epitopes
• Immunoglobulin Fab Fragments
• Immunoglobulin Heavy Chains
• Immunoglobulin Light Chains
• Melanoma-Specific Antigens
• Neoplasm Proteins
• Receptors, Antigen, T-Cell
• Receptors, Antigen, T-Cell, gamma-delta

Topics

• Antibody Affinity (genetics)
• Antibody Specificity
• Antigen Presentation (genetics)
• Antigens, Neoplasm
• Cloning, Molecular
• Cytotoxicity, Immunologic (genetics)
• Gene Targeting
• Genetic Vectors (chemical synthesis)
• HLA-A1 Antigen (immunology)
• Humans
• Immunodominant Epitopes (immunology, metabolism)
• Immunoglobulin Fab Fragments (biosynthesis, genetics, metabolism, physiology)
• Immunoglobulin Heavy Chains (biosynthesis, chemistry, metabolism)
• Immunoglobulin Light Chains (biosynthesis, chemistry, metabolism)
• Melanoma-Specific Antigens
• Neoplasm Proteins (immunology)
• Protein Binding (genetics, immunology)
• Receptors, Antigen, T-Cell (biosynthesis, genetics, metabolism, physiology)
• Receptors, Antigen, T-Cell, gamma-delta (biosynthesis, genetics, metabolism)
• T-Lymphocytes, Cytotoxic (immunology, metabolism)