Related Experiment Video
Updated: Aug 17, 2026
Validated Immunochemical Assay for Comprehensive Determination of the Human Epidermal Growth Factor Receptor 2 Released from and Bound to Cells
Published on: May 9, 2025
Biological properties of a human compact anti-ErbB2 antibody
Claudia De Lorenzo1, Rosanna Cozzolino, Andrea Carpentieri
1Department of Structural and Functional Biology, University of Naples Federico II, Naples, Italy.
Abstract:
ErbB2 is a prognostic factor and target of therapy for many carcinomas. In contrast with the other ErbB receptors, ErbB2 lacks a soluble direct ligand, but it is the preferred co-receptor for the ErbB family members, forming heterodimers with more potent and prolonged signalling activity than that of homodimers. We recently produced a new anti-ErbB2 antibody, Erb-hcAb, by fusion of Erbicin, a human, anti-ErbB2 scFv, selectively cytotoxic to ErbB2-positive cells, and a human Fc domain. This fully human antitumour antibody represents a compact version of an IgG1, with the cytotoxicity of the scFv moiety on target cells, combined with the ability of the Fc moiety to induce both antibody- and complement-dependent cytotoxicity. Here, we describe the main properties of Erb-hcAb, using as a reference Herceptin, an anti-ErbB2 humanized monoclonal currently employed in clinical immunotherapy. We found that both bivalent Erb-hcAb and Herceptin increase receptor phosphorylation and downregulation, whereas monovalent Erbicin does not. These results correlate with the finding that Erb-hcAb is capable of inducing apoptosis and inhibiting cell cycle progression in ErbB2-positive cells. Its powerful in vitro antitumour action matched that observed in vivo in experiments with human ErbB2-positive tumour xenografts established in athymic mice. Finally, Erb-hcAb displays a glycosylation profile virtually superimposable to that of a human IgG. These findings suggest that Erb-hcAb is a very promising new agent for the immunotherapy of carcinomas that overexpress the ErbB2 receptor.
Insights
A novel anti-ErbB2 antibody, Erb-hcAb, demonstrates potent anti-tumor activity by inducing apoptosis and inhibiting cell cycle progression. This promising agent shows efficacy in vitro and in vivo for ErbB2-overexpressing carcinomas.
Area of Science:
- Oncology
- Immunotherapy
- Molecular Biology
Background:
- ErbB2 is a key prognostic factor and therapeutic target in various carcinomas.
- ErbB2 functions as a preferred co-receptor, enhancing signaling through heterodimerization.
- Existing therapies like Herceptin target ErbB2, but novel agents are needed.
Purpose of the Study:
- To characterize a new fully human anti-ErbB2 antibody, Erb-hcAb.
- To evaluate the anti-tumor properties of Erb-hcAb in comparison to Herceptin.
- To assess the therapeutic potential of Erb-hcAb for ErbB2-overexpressing carcinomas.
Main Methods:
- Production of Erb-hcAb by fusing an anti-ErbB2 scFv (Erbicin) with a human Fc domain.
- Assessment of receptor phosphorylation and downregulation in response to Erb-hcAb and Herceptin.
- Evaluation of Erb-hcAb's in vitro cytotoxicity, apoptosis induction, and cell cycle inhibition.
- In vivo efficacy studies using human ErbB2-positive tumor xenografts in athymic mice.
- Analysis of Erb-hcAb glycosylation profile.
Main Results:
- Erb-hcAb, like Herceptin, induced ErbB2 phosphorylation and downregulation, unlike monovalent Erbicin.
- Erb-hcAb demonstrated significant in vitro induction of apoptosis and inhibition of cell cycle progression in ErbB2-positive cells.
- In vivo studies showed potent anti-tumor activity of Erb-hcAb against xenografts.
- Erb-hcAb exhibited a glycosylation profile similar to human IgG.
Conclusions:
- Erb-hcAb is a potent anti-tumor agent with dual cytotoxic mechanisms (antibody- and complement-dependent).
- Its efficacy in vitro and in vivo suggests significant therapeutic potential for ErbB2-overexpressing carcinomas.
- Erb-hcAb represents a promising new candidate for immunotherapy in relevant cancer types.
Related Concept Videos
01:10Antibody Structure
Antibodies, also known as immunoglobulins (Ig), are essential players of the adaptive immune system. These antigen-binding proteins are produced by B cells and make up 20 percent of the total blood plasma by weight. In mammals, antibodies fall into five different classes, which each elicits a different biological response upon antigen binding.
The Y-Shaped Structure of Antibodies Consists of Four Polypeptide Chains
Antibodies consist of four polypeptide chains: two identical heavy...
01:10Antibody Structure
Antibodies, also known as immunoglobulins (Ig), are essential players of the adaptive immune system. These antigen-binding proteins are produced by B cells and make up 20 percent of the total blood plasma by weight. In mammals, antibodies fall into five different classes, which each elicits a different biological response upon antigen binding.
The Y-Shaped Structure of Antibodies Consists of Four Polypeptide Chains
Antibodies consist of four polypeptide chains: two identical heavy...
02:38Mitogens and the Cell Cycle
01:25Antibody Structure and Classes
The basic structure of an antibody consists of four protein chains: two identical heavy chains and two identical light chains. These chains are held together by disulfide bonds and other non-covalent interactions, forming a Y-shaped structure.
00:42Cross-reactivity