01
Antibody Libraries
Antibodies can be created from natural B lymphocytes found in the blood of donors. They can also be generated synthetically via cloning. However, cloning inherently limits heavy-and light-chain pairing, thus limiting diversity in an engineered-antibody library.
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To maximize diversity in our library deliverables, Specifica builds antibody libraries from natural antibody genes isolated from human donors. We use a unique in vivo recombination technology that generates maximum diversity from all possible combinations of the available heavy- and light-chain variable regions. This results in phage antibody libraries that are far more diverse than other available libraries.
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The figure below shows the introduction of two different scFvs, by infection into a bacterium in which Cre recombinase is expressed, which results in the generation of four scFvs: the two original and two new ones arising from the recombination of the two VH and VL genes.
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This technique enables as many as twenty different scFvs to enter a single bacterium, yielding up to four hundred different antibodies from a single bacterium.
LIBRARIES BEFORE RECOMBINATION
VLA
VHA
VLB
VHB
LIBRARIES AFTER RECOMBINATION
VLA
VHA
VLB
VHB
VLA
VHA
VLB
VHB
02
Antibody Discovery
Specifica's antibody discovery process employs three powerful coordinating technologies to select the antibodies with the most desirable binding properties.
First, we generate an initial pool of potential antibody leads from our proprietary phage antibody display libraries.
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Next, we use yeast display to isolate a population in which all antibodies bind with the target.
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Finally, we use generation sequencing to rank the antibodies according to selected
properties of interest, such as affinity or specificity.
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The complementary properties of phage and yeast display are illustrated in the table below.
COMPLEMENTARY PROPERTIES OF PHAGE AND YEAST DISPLAY
PHAGE
YEAST
PROS:
​- Larger primary libraries.
- Selection from naïve libraries.
- Relatively straightforward.
PROS:
- Precise selection calibration.
- Direct characterization on
yeast without antibody
purification: Affinity; epitopes.
- Repertoires sampled more
completely.
03
Humanization & Affinity Maturation
Humanization is a method to transform a murine monoclonal antibody with desired binding activity into a human antibody that can be used in therapy. When humanizing monoclonals, Specifica usually incorporates an affinity maturation to improve binding affinity and/or specificity.
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Affinity maturation is the process of increasing the affinity of an antibody. The higher the affinity, the better an antibody binds to its target. Specifica uses a number of different diversification approaches including light chain shuffling, error prone PCR and targeted mutations prior to selecting higher affinity antibody variants by yeast display.