How to make bispecific antibodies

Area of Science:

• Biotechnology
• Immunology
• Protein Engineering

Background:

• Bispecific antibodies (BsAbs) offer enhanced therapeutic potential by engaging multiple targets simultaneously.
• Current methods for BsAb production can be complex and yield heterogeneous products.
• Developing efficient and reproducible protocols for BsAb generation is crucial for advancing antibody-based therapies.

Purpose of the Study:

• To describe a robust protocol for the production of bispecific F(ab′)2 antibody derivatives (BsAbs).
• To utilize the bifunctional crosslinker o-phenylenedimaleimide (o-PDM) for linking Fab′ fragments via their hinge region SH groups.
• To provide a method for generating homogeneous BsAbs with potential applications in targeted therapies.

Main Methods:

• Digestion of parent IgG antibodies to generate F(ab′)2 fragments.
• Preparation of Fab′ fragments by reduction of F(ab′)2, exposing hinge region SH groups.
• Alkylation of one Fab′ species (Fab′-A) with o-PDM, followed by conjugation with a second reduced Fab′ species (Fab′-B).
• Purification of the bispecific F(ab′)2 product using gel filtration chromatography and quality control via HPLC.

Main Results:

• Successful production of bispecific F(ab′)2 antibody derivatives (BsAbs) through the described o-PDM crosslinking method.
• Demonstration that controlled stoichiometry yields the desired bispecific product, while excess Fab′-A can lead to F(ab′)3 formation.
• Validation of each step using HPLC, ensuring the purity and integrity of the BsAb product.

Conclusions:

• The described protocol provides an effective method for generating bispecific F(ab′)2 antibody derivatives.
• This technique allows for the controlled production of BsAbs, minimizing heterogeneity.
• The generated BsAbs hold promise for various applications, including targeted drug delivery and immunotherapy.