Parameters and determinants of responses to selection in antibody libraries

Area of Science:

• Immunology
• Molecular Biology
• Evolutionary Biology

Background:

• Antibody diversity is crucial for immune response.
• Scaffolds are often overlooked compared to hypervariable regions.
• Understanding scaffold impact is key for antibody engineering.

Purpose of the Study:

• To quantify the impact of antibody scaffolds on binding affinity and specificity.
• To compare the selective potential of germline versus affinity-matured scaffolds.
• To investigate the evolutionary potential of antibody scaffolds.

Main Methods:

• Quantitative phage display experiments were performed.
• Three antibody libraries with distinct scaffolds and identical randomized diversity were used.
• Response to selection for binding to four different targets was measured.

Main Results:

• Antibody library response to selection can be characterized by two parameters.
• One parameter correlates with the scaffold's affinity maturation.
• Libraries with germline scaffolds exhibited a higher response to selection than those with matured scaffolds.

Conclusions:

• Germline antibody scaffolds possess greater selective potential than affinity-matured ones.
• This suggests long-term evolutionary selection for scaffold potential.
• Results offer insights into quantifying the evolutionary potential of biomolecules.