Affinity maturation refers to the process of improving antibody affinity and binding interactions to target antigens. This is done naturally in vivo by somatic hypermutation and clonal selection in mammalian B cells, but it can also be done in the lab in vitro by mutagenesis and selection for therapeutic applications.
In vivo
When a host is repeatedly exposed to the same antigen, the antibodies produced by their immune response will have increasingly greater affinity, avidity, and anti-pathogen activity. This occurs due to somatic hypermutation in the variable CDRs (complementarity-determining regions) of immunoglobulin genes in B cells, and takes place in germinal centers (structures within secondary lymphoid tissues). Clonal selection takes place when follicular dendritic cells of the germinal centers present antigens to the B cells, with only the most competitive B cells surviving to stably conjugate with follicular B helper T cells. After several rounds of selection, high-affinity antibodies will be produced.1
In vitro
Similar to the in vivo process, in vitro affinity maturation is used to optimize antibodies, antibody fragments, or other peptides by diversifying the antibody base sequence and isolating higher-affinity binders.
FCMES-AM™ (Full Coverage Mammalian Expression System for Affinity Maturation) is Biointron's proprietary platform for affinity maturation. Each amino acid in the CDR region will be mutated to the other 17 amino acids (except Cysteine and Methionine) with equal ratios. The clones will be expressed in a mammalian system, and an ELISA binding assay will be conducted as an initial test. This will be followed by SPR (surface plasmon resonance) or FACS (fluorescence-activated cell sorting) for further affinity measurements.The process is as follows:
Site-directed saturated mutation
High-throughput mammalian cell expression
ELISA and sequencing to identify hot spots
Combinatorial mutation design and characterization
At Biointron, we are dedicated to accelerating antibody discovery, optimization, and production. Our advantages in affinity maturation include:
No-bias Site Saturation Mutagenesis in CDR Regions
Guaranteed at least 5-fold Affinity Improvement
Our team of experts can provide customized solutions that meet your specific research needs. Contact us to learn more about our services and how we can help accelerate your research and drug development projects.
References:
Doria-Rose, N. A., & Joyce, M. G. (2015). Strategies to guide the antibody affinity maturation process. Current Opinion in Virology, 11, 137. https://doi.org/10.1016/j.coviro.2015.04.002
In vitro display technologies are a group of methods used to display diverse antibody libraries on the surface of solid supports or particles like phage, yeast, ribosomes, and bacteria. They are powerful tools for the discovery and engineering of novel antibodies with desired binding properties and were first explored for antibody selection over 30 years ago.
Chimeric antibodies, formed by combining the variable regions of one species with the constant domains of another, are essential for various research fields, especially in vivo and in vitro studies. These hybrid antibodies maintain their antigen-binding specificity while offering flexibility in different research settings. This flexibility makes them highly valuable for biotherapeutic research, immunoassays, and diagnostic applications.
Biointron’s AbDrop & Cyagen’s HUGO-Ab is a high-throughput fully human antibody discovery platform that combines microdroplet-based single B cell screening with transgenic mice. This combination accelerates the discovery and development of fully human antibodies, reducing the time from target identification to therapeutic candidate to just three months.
The development of chimeric antibodies was a significant turning point in antibody engineering. To engineer more human-like antibodies, researchers combined the variable regions of antibodies from one species with the constant regions of another, resulting in increased antigen specificity with reduced immunogenicity. This was a key advance in making antibodies more suitable for therapeutic applications in humans.
