Related Experiment Videos
Bacterial expression and characterization of recombinant biologically active anti-tyrosine kinase receptor antibody
1Department of Pathology & Laboratory Medicine, University of Pennsylvania, Philadelphia 19104, USA.
Abstract:
Homomeric and heteromeric interactions among cell-surface tyrosine kinase receptors belonging to the ErbB family lead to intracellular signaling cascades which are involved in cell activation, cytoskeletal interactions, and cellular transformation leading to neoplasia. Monoclonal antibodies which specifically bind to p185neu or epidermal growth factor receptor (EGFR), such as 7.16.4 and 225, respectively, can elicit tumor growth-inhibitory effects on transformed cells which overexpress either or both of these receptors. In order to better understand these receptor-receptor and receptor-antibody interactions and to gain insights that may be useful in the production and design of an antibody-based anticancer therapeutic, novel small recombinant 7.16.4 and 225 single-chain Fv fragments (scFv) were constructed, expressed, and characterized. We showed that these recombinant antibody fragments, which retain binding affinity, can be produced and purified from bacterial cell lysates. Our analyses further demonstrate that fusion of a 61 amino-acid dimerization domain with 7.16.4 and 225 scFv (7.16.4hth and 225hth) is sufficient to restore biological activity to these recombinant proteins.
Insights
Researchers created small antibody fragments targeting cancer-related receptors. Fusing these fragments with a dimerization domain restored their biological activity, offering potential for new antibody-based cancer therapies.
Area of Science:
- Molecular biology
- Immunology
- Oncology
Background:
- Cell-surface tyrosine kinase receptors, like ErbB family members, mediate signaling involved in cell growth and cancer.
- Monoclonal antibodies targeting these receptors, such as anti-p185neu (7.16.4) and anti-epidermal growth factor receptor (EGFR) (225), show anti-tumor effects.
- Understanding receptor-antibody interactions is crucial for developing antibody-based cancer therapeutics.
Purpose of the Study:
- To construct and characterize novel single-chain variable fragment (scFv) antibody fragments against p185neu and EGFR.
- To investigate the potential of these recombinant antibody fragments for therapeutic applications.
- To explore methods for restoring biological activity to engineered antibody fragments.
Main Methods:
- Construction and expression of recombinant 7.16.4 and 225 single-chain Fv fragments (scFv) in bacterial systems.
- Purification of scFv fragments from bacterial cell lysates.
- Fusion of a 61 amino-acid dimerization domain to scFv fragments to create 7.16.4hth and 225hth.
Main Results:
- Recombinant scFv fragments (7.16.4 and 225) were successfully produced and purified, retaining binding affinity.
- The engineered scFv fragments could be produced in bacterial cell lysates.
- Fusion with a dimerization domain restored biological activity to the recombinant antibody fragments.
Conclusions:
- Small recombinant antibody fragments targeting ErbB receptors can be efficiently produced.
- Engineered antibody fragments can be biologically reactivated through domain fusion.
- These findings support the development of novel antibody-based therapeutics for cancers involving ErbB receptor overexpression.