Related Experiment Videos
Engineering a humanized bispecific F(ab')2 fragment for improved binding to T cells
M L Rodrigues1, M R Shalaby, W Werther
1Department of Protein Engineering, Genentech Inc., South San Francisco, CA 94080.
International Journal of Cancer. Supplement = Journal International Du Cancer. Supplement
|January 1, 1992
Summary
Researchers improved a bispecific antibody (BsF(ab)2v9) for cancer therapy. This enhanced antibody targets HER2-expressing tumors and T cells more effectively, representing a key step in developing new treatments.
Area of Science:
- Immunology
- Oncology
- Biotechnology
Background:
- Bispecific antibodies are engineered proteins that can bind to two different targets simultaneously.
- Humanized antibodies aim to reduce immunogenicity while retaining therapeutic efficacy.
- Targeting HER2-overexpressing cancers with T-cell redirecting antibodies is a promising therapeutic strategy.
Purpose of the Study:
- To improve the T-cell binding efficiency of a humanized bispecific antibody (BsF(ab)2v1) targeting CD3 and HER2.
- To develop a more effective therapeutic agent for HER2-positive breast cancers.
Main Methods:
- Construction of a humanized bispecific antibody (BsF(ab)2v1) via chemical coupling of Fab' arms.
- Engineering variant anti-CD3 arms with specific amino acid substitutions.
- Evaluation of T-cell binding efficiency using Jurkat cells.
Main Results:
- BsF(ab)2v1 demonstrated retargeting of cytotoxic T-cell activity against HER2-positive breast cancer cells (SK-BR-3).
- The initial humanized anti-CD3 arm showed reduced T-cell binding compared to a chimeric version.
- A variant, BsF(ab)2v9, with 6 amino acid replacements in the anti-CD3 heavy chain variable domain, exhibited significantly improved T-cell binding.
Conclusions:
- Minimalistic humanization can be successful for antigen-binding arms but may require optimization for T-cell engagement.
- BsF(ab)2v9 shows enhanced T-cell binding, making it a promising candidate for further development as a cancer therapeutic.
- This improved humanized bispecific antibody represents a significant advancement in T-cell-based cancer immunotherapy.