Modelling the human immune response: performance of a 1011 human antibody repertoire against a broad panel of therapeutically relevant antigens

Abstract

A large 1.29 x 10(11) antibody fragment library, based upon variable (V) genes isolated from human B-cells from 160 donors has been constructed and its performance measured against a panel of 28 different clinically relevant antigens. Over 5000 different target-specific antibodies were isolated to the 28 antigens with 3340 identified as modulating the biological function (e.g. antagonism, agonism) of the target antigen. This represents an average of approximately 120 different functionally active antibodies per target. Analysis of a sample of >800 antibodies from the unselected library indicates V gene usage is representative of the human immune system with no strong bias towards any particular V(H)-V(L) pairing. Germline diversity is broad with 45/49 functional V(H) germlines and 28/30 V(lambda) and 30/35 V(kappa) light-chain germlines represented in the sample. The number of functional V(H) germlines and V(kappa) light-chain germlines present is increased to 48/49 and 31/35, respectively, when selected V gene usage is included in the analysis. However, following selection on the antigen panel, V(H)1-V(lambda)1 germline family pairings are preferentially enriched and represent a remarkable 25% of the antigen-specific selected repertoire.

In vitro potency, pharmacokinetic profiles and pharmacological activity of optimized anti-IL-21R antibodies in a mouse model of lupus

“…The scFv parental clone 18A5 (accession number GP230882) was obtained from the CS human scFv library (Cambridge Antibody Technology) 28 by standard phage display methods, 29,30 using BaF3 cells expressing human IL-21R as a target in rounds 1 and 3 and biotinylated IL-21R-Fc fusion protein as a target in round 2. It was identified on the basis of its ability to compete with MuF, an anti-IL-21R antibody previously identified in the same screen, for binding to biotinylated hIL-21R-Fc in ELISA.…”

Phage display and hybridoma generation of antibodies to human CXCR2 yields antibodies with distinct mechanisms and epitopes

“…In parallel to the hybridoma approach, anti-human CXCR2 antibodies were isolated from naive phage display libraries 52,53 using CXCR2 magnetic proteoliposomes to enrich for CXCR2 specific scFv. Multiple rounds of selection were performed using the proteoliposomes, resulting in the isolation of 1373 scFv that Fig.…”

“…52,53 Paramagnetic proteoliposomes containing CXCR2 were prepared as described by Mirzabekov et al 46 and the expression of human CXCR2 confirmed by flow cytometry using commercially available anti human CXCR2 antibodies (BD Biosciences clone 6C6 and R&D Systems #MAB331). The proteoliposomes were used as the antigen for multiple rounds of soluble selections.…”

Sequencing antibody repertoires

“…16 Diversification strategies have been mainly based on the amplification and random association of naturally rearranged heavy and light chain variable genes or the introduction of synthetic diversity into the CDRs of selected antibody frameworks. 17,18 A crucial characteristic of a library is its size and diversity as they correlate with the number and affinity of target specific antibodies that can be isolated. 19 Diversity is limited by the number of transformants obtained at the bacterial or yeast transformation stage or by the number of molecules present and how additional mechanisms further introduce diversity to fine-tune the interaction with an antigen.…”