Inhibition of Cancer Cell Adhesion, Migration and Proliferation by a Bispecific Antibody that Targets two Distinct Epitopes on αv Integrins

Beyond Natural Immune Repertoires: Synthetic Antibodies

Synthetic antibody libraries, in which the antigen-binding sites are precisely designed, offer unparalleled precision in antibody engineering, exceeding the potential of natural immune repertoires and constituting a novel generation of research tools and therapeutics. Recent advances in artificial intelligence-driven technologies and their integration into synthetic antibody discovery campaigns hold the promise to further streamline and effectively develop antibodies. Here, we provide an overview of synthetic antibodies. Our associated protocol describes how to develop highly diverse and functional synthetic antibody phage display libraries.

The rise of big data: deep sequencing-driven computational methods are transforming the landscape of synthetic antibody design

Synthetic antibodies (Abs) represent a category of artificial proteins capable of closely emulating the functions of natural Abs. Their in vitro production eliminates the need for an immunological response, streamlining the process of Ab discovery, engineering, and development. These artificially engineered Abs offer novel approaches to antigen recognition, paratope site manipulation, and biochemical/biophysical enhancements. As a result, synthetic Abs are fundamentally reshaping conventional methods of Ab production. This mirrors the revolution observed in molecular biology and genomics as a result of deep sequencing, which allows for the swift and cost-effective sequencing of DNA and RNA molecules at scale. Within this framework, deep sequencing has enabled the exploration of whole genomes and transcriptomes, including particular gene segments of interest. Notably, the fusion of synthetic Ab discovery with advanced deep sequencing technologies is redefining the current approaches to Ab design and development. Such combination offers opportunity to exhaustively explore Ab repertoires, fast-tracking the Ab discovery process, and enhancing synthetic Ab engineering. Moreover, advanced computational algorithms have the capacity to effectively mine big data, helping to identify Ab sequence patterns/features hidden within deep sequencing Ab datasets. In this context, these methods can be utilized to predict novel sequence features thereby enabling the successful generation of de novo Ab molecules. Hence, the merging of synthetic Ab design, deep sequencing technologies, and advanced computational models heralds a new chapter in Ab discovery, broadening our comprehension of immunology and streamlining the advancement of biological therapeutics.

USP10 Promotes Fibronectin Recycling, Secretion, and Organization

Purpose

Integrins play a central role in myofibroblast pathological adhesion, over-contraction, and TGFβ activation. Previously, we demonstrated that after corneal wounding, αv integrins are protected from intracellular degradation by upregulation of the deubiquitinase USP10, leading to cell-surface integrin accumulation. Because integrins bind to and internalize extracellular matrix (ECM), we tested whether extracellular fibronectin (FN) accumulation can result from an increase in integrin and matrix recycling in primary human corneal fibroblasts (HCFs).

Methods

Primary HCFs were isolated from cadaver eyes. HCFs were transfected with either USP10 cDNA or control cDNA by nucleofection. Internalized FN was quantified with a FN ELISA. Recycled extracellular integrin and FN were detected with streptavidin-488 by live cell confocal microscopy (Zeiss LSM 780). Endogenous FN extra domain A was detected by immunocytochemistry. Cell size and removal of FN from the cell surface was determined by flow cytometry.

Results

USP10 overexpression increased α5β1 (1.9-fold; P < 0.001) and αv (1.7-fold; P < 0.05) integrin recycling, with a concomitant increase in biotinylated FN internalization (2.1-fold; P < 0.05) and recycling over 4 days (1.7–2.2-fold; P < 0.05). The dependence of FN recycling on integrins was demonstrated by α5β1 and αv integrin blocking antibodies, which, compared with control IgG, decreased biotinylated FN recycling (62% and 84%, respectively; P < 0.05). Overall, we established that extracellular FN was composed of approximately 1/3 recycled biotinylated FN and 2/3 endogenously secreted FN.

Conclusions

Our data suggest that reduced integrin degradation with a subsequent increase in integrin/FN recycling after wounding may be a newly identified mechanism for the characteristic accumulation of ECM in corneal scar tissue.