Bacteroides fragilis toxin (BFT) detection and neutralization using phage display-derived synthetic hagfish VLRBs
5 affiliations
- 1Laboratory of Aquatic Animal Diseases, Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Jinju-si, Gyeongsangnam-do, Republic of Korea
- 2Institute of Chemistry, College of Arts and Sciences, University of the Philippines Los Baños, Laguna, Philippines
- 3Earwynbio Co., Ltd., Jinju-si, Gyeongsangnam-do, Republic of Korea
- 4Moredun Research Institute, Penicuik, Scotland, United Kingdom
- 5Department of Anatomy, Institute of Medical Sciences, College of Medicine, Gyeongsang National University, Jinju-si, Gyeongsangnam-do, Republic of Korea
Abstract
Enterotoxigenic Bacteroides fragilis (ETBF) weakens the intestinal epithelial barrier and promotes inflammatory signaling through secretion of B. fragilis toxin (BFT), a metalloprotease associated with chronic intestinal inflammation. By triggering the breakdown of the E-cadherin glycoprotein in cellular junctions, BFT compromises tissue integrity and affects pathways involved in tumor suppression and signal transduction. Despite growing evidence implicating BFT in colorectal carcinogenesis, its role remains ambiguous, in part due to limited availability of suitable tools for its detection and neutralization. Selective binding molecules targeting BFT are, therefore, critical for understanding the role of ETBF in these clinical pathologies. Here, we used phage display screening to develop hagfish VLRB-derived consensus scaffold, termed ccombodies, as alternative non-immunoglobulin molecules targeting BFT. Three candidate binders (B8-1, C2-6, and G8-5) were expressed and purified for characterization. Specificity analyses against a range of bacterial virulence factors confirmed the selective recognition of BFT. Binding affinity was determined by ELISA titration and biolayer interferometry (BLI) yielding apparent KD values in the nanomolar range. The ccombodies detected BFT at low nanogram levels by Western blot and exhibited high specificity and sensitivity in toxin recognition. Furthermore, treatment with ccombody attenuated BFT-induced cytotoxicity in Caco-2 and HT-29 epithelial cells. These findings establish ccombodies as a novel class of BFT-targeting molecules with potential applications in selective toxin detection, passive immunoprophylaxis, and antivirulence intervention.
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BibTeX
@article{rodelasangelia2026bacteroides,
title = {{Bacteroides fragilis toxin (BFT) detection and neutralization using phage display-derived synthetic hagfish VLRBs}},
author = {Abigail Joy D. Rodelas-Angelia and Mark Rickard N. Angelia and Young Rim Kim and Cheolung Yang and Hyeok Jang and Jihyun Mun and Baek San Chang and Seong Wook Shin and Kim D. Thompson and Sang Soo Kang and Tae Sung Jung},
journal = {PLOS One},
year = {2026},
month = nov,
doi = {10.1371/journal.pone.0361228},
url = {https://doi.org/10.1371/journal.pone.0361228},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Bacteroides fragilis toxin (BFT) detection and neutralization using phage display-derived synthetic hagfish VLRBs
AU - Abigail Joy D. Rodelas-Angelia
AU - Mark Rickard N. Angelia
AU - Young Rim Kim
AU - Cheolung Yang
AU - Hyeok Jang
AU - Jihyun Mun
AU - Baek San Chang
AU - Seong Wook Shin
AU - Kim D. Thompson
AU - Sang Soo Kang
AU - Tae Sung Jung
PY - 2026
DA - 2026/11/02
JO - PLOS One
DO - 10.1371/journal.pone.0361228
UR - https://doi.org/10.1371/journal.pone.0361228
AB - Enterotoxigenic Bacteroides fragilis (ETBF) weakens the intestinal epithelial barrier and promotes inflammatory signaling through secretion of B. fragilis toxin (BFT), a metalloprotease associated with chronic intestinal inflammation. By triggering the breakdown of the E-cadherin glycoprotein in cellular junctions, BFT compromises tissue integrity and affects pathways involved in tumor suppression and signal transduction. Despite growing evidence implicating BFT in colorectal carcinogenesis, its role remains ambiguous, in part due to limited availability of suitable tools for its detection and neutralization. Selective binding molecules targeting BFT are, therefore, critical for understanding the role of ETBF in these clinical pathologies. Here, we used phage display screening to develop hagfish VLRB-derived consensus scaffold, termed ccombodies, as alternative non-immunoglobulin molecules targeting BFT. Three candidate binders (B8-1, C2-6, and G8-5) were expressed and purified for characterization. Specificity analyses against a range of bacterial virulence factors confirmed the selective recognition of BFT. Binding affinity was determined by ELISA titration and biolayer interferometry (BLI) yielding apparent KD values in the nanomolar range. The ccombodies detected BFT at low nanogram levels by Western blot and exhibited high specificity and sensitivity in toxin recognition. Furthermore, treatment with ccombody attenuated BFT-induced cytotoxicity in Caco-2 and HT-29 epithelial cells. These findings establish ccombodies as a novel class of BFT-targeting molecules with potential applications in selective toxin detection, passive immunoprophylaxis, and antivirulence intervention.
SN - 1932-6203
ER -