1
|
Holland CJ, Crean RM, Pentier JM, de Wet B, Lloyd A, Srikannathasan V, Lissin N, Lloyd KA, Blicher TH, Conroy PJ, Hock M, Pengelly RJ, Spinner TE, Cameron B, Potter EA, Jeyanthan A, Molloy PE, Sami M, Aleksic M, Liddy N, Robinson RA, Harper S, Lepore M, Pudney CR, van der Kamp MW, Rizkallah PJ, Jakobsen BK, Vuidepot A, Cole DK. Specificity of bispecific T cell receptors and antibodies targeting peptide-HLA. J Clin Invest 2021; 130:2673-2688. [PMID: 32310221 DOI: 10.1172/jci130562] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 02/11/2020] [Indexed: 01/09/2023] Open
Abstract
Tumor-associated peptide-human leukocyte antigen complexes (pHLAs) represent the largest pool of cell surface-expressed cancer-specific epitopes, making them attractive targets for cancer therapies. Soluble bispecific molecules that incorporate an anti-CD3 effector function are being developed to redirect T cells against these targets using 2 different approaches. The first achieves pHLA recognition via affinity-enhanced versions of natural TCRs (e.g., immune-mobilizing monoclonal T cell receptors against cancer [ImmTAC] molecules), whereas the second harnesses an antibody-based format (TCR-mimic antibodies). For both classes of reagent, target specificity is vital, considering the vast universe of potential pHLA molecules that can be presented on healthy cells. Here, we made use of structural, biochemical, and computational approaches to investigate the molecular rules underpinning the reactivity patterns of pHLA-targeting bispecifics. We demonstrate that affinity-enhanced TCRs engage pHLA using a comparatively broad and balanced energetic footprint, with interactions distributed over several HLA and peptide side chains. As ImmTAC molecules, these TCRs also retained a greater degree of pHLA selectivity, with less off-target activity in cellular assays. Conversely, TCR-mimic antibodies tended to exhibit binding modes focused more toward hot spots on the HLA surface and exhibited a greater degree of crossreactivity. Our findings extend our understanding of the basic principles that underpin pHLA selectivity and exemplify a number of molecular approaches that can be used to probe the specificity of pHLA-targeting molecules, aiding the development of future reagents.
Collapse
Affiliation(s)
| | - Rory M Crean
- Department of Biology and Biochemistry and.,Doctoral Training Centre in Sustainable Chemical Technologies, University of Bath, Bath, United Kingdom
| | | | - Ben de Wet
- Immunocore Ltd., Milton Park, Abingdon, United Kingdom
| | | | | | | | - Katy A Lloyd
- Immunocore Ltd., Milton Park, Abingdon, United Kingdom
| | | | - Paul J Conroy
- Immunocore Ltd., Milton Park, Abingdon, United Kingdom
| | - Miriam Hock
- Immunocore Ltd., Milton Park, Abingdon, United Kingdom
| | | | | | - Brian Cameron
- Immunocore Ltd., Milton Park, Abingdon, United Kingdom
| | | | | | | | - Malkit Sami
- Immunocore Ltd., Milton Park, Abingdon, United Kingdom
| | - Milos Aleksic
- Immunocore Ltd., Milton Park, Abingdon, United Kingdom
| | | | | | | | - Marco Lepore
- Immunocore Ltd., Milton Park, Abingdon, United Kingdom
| | | | | | - Pierre J Rizkallah
- Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| | | | | | - David K Cole
- Immunocore Ltd., Milton Park, Abingdon, United Kingdom.,Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom
| |
Collapse
|