Transcutaneous penetration of a single-chain variable fragment (scFv) compared to a full-size antibody: potential tool for atopic dermatitis (AD) treatment

Abstract

Currently, several biologics are used for the treatment of cutaneous pathologies such as atopic dermatitis (AD), psoriasis or skin cancers. The main administration routes are subcutaneous and intravenous injections. However, little is known about antibody penetration through the skin. The aim was to study the transcutaneous penetration of a reduced-size antibody as a single-chain variable fragment (scFv) compared to a whole antibody (Ab) and to determine its capacity to neutralize an inflammatory cytokine involved in AD such as human interleukin-4 (hIL-4). Transcutaneous penetration was evaluated by ex vivo studies on tape-stripped pig ear skin. ScFv and Ab visualization through the skin was measured by Raman microspectroscopy. In addition, hIL-4 neutralization was studied in vitro using HEK-Blue™ IL-4/IL-13 cells and normal human keratinocytes (NHKs). After 24 h of application, analysis by Raman microspectroscopy showed that scFv penetrated into the upper dermis while Ab remained on the stratum corneum. In addition, the anti-hIL4 scFv showed very efficient and dose-dependent hIL-4 neutralization. Thus, scFv penetrates through to the upper papillary dermis while Ab mostly remains on the surface, the anti-hIL4 scFv also neutralizes its target effectively suggesting its potential use as topical therapy for AD.

Quenchbodies That Enable One-Pot Detection of Antigens: A Structural Perspective

“…In addition to these pre-selections, post-selections, such as FACS sorting and droplet microfluidic single-cell analysis, are suitable for increasing the sensitivity and response of the Q-body. Because it has antigen-binding properties and is smaller than IgG, scFv has relatively high cell-penetration ability [107][108][109]. When a large fluorescent probe, such as a fluorescent protein, is conjugated to an antibody or antibody fragment, the size of the fusion antibody increases, causing steric hindrance or obstructing the recognition of epitopes on the cell surface [110,111].…”

A Detailed Protocol for Constructing a Human Single-Chain Variable Fragment (scFv) Library and Downstream Screening via Phage Display

“…Antibodies sourced from immune libraries exhibit superior binding affinities scFv, first developed by Bird et al in 1988 [9], is a recombinant polypeptide where V H is joined to V L via a flexible linker composed of glycine and serine amino acids [10]. With a molecular weight of approximately 27 kDa, scFvs are much smaller than conventional whole Ig-based monoclonal antibodies (~150 kDa), enabling more effective tissue penetration and access to epitope crevices, while retaining high antigen-binding affinity [11]. Their rapid systemic clearance has led to widespread use in therapeutic and imaging applications in clinical settings.…”