Nanobody-Based EGFR-Targeting Immunotoxins for Colorectal Cancer Treatment

Javier Narbona; Luisa Hernández-Baraza; Rubén G Gordo; Laura Sanz; Javier Lacadena

doi:10.3390/biom13071042

Nanobody-Based EGFR-Targeting Immunotoxins for Colorectal Cancer Treatment

Biomolecules. 2023 Jun 26;13(7):1042. doi: 10.3390/biom13071042.

Authors

Javier Narbona¹, Luisa Hernández-Baraza^{1

2}, Rubén G Gordo¹, Laura Sanz³, Javier Lacadena¹

Affiliations

¹ Department of Biochemistry and Molecular Biology, Faculty of Chemical Sciences, Complutense University, 28040 Madrid, Spain.
² University Institute of Biomedical and Health Research (IUIBS), Las Palmas University, 35016 Las Palmas de Gran Canaria, Spain.
³ Molecular Immunology Unit, Biomedical Research Institute, Hospital Universitario Puerta de Hierro, Majadahonda, 28222 Madrid, Spain.

Abstract

Immunotoxins (ITXs) are chimeric molecules that combine the specificity of a targeting domain, usually derived from an antibody, and the cytotoxic potency of a toxin, leading to the selective death of tumor cells. However, several issues must be addressed and optimized in order to use ITXs as therapeutic tools, such as the selection of a suitable tumor-associated antigen (TAA), high tumor penetration and retention, low kidney elimination, or low immunogenicity of foreign proteins. To this end, we produced and characterized several ITX designs, using a nanobody against EGFR (V_HH 7D12) as the targeting domain. First, we generated a nanoITX, combining V_HH 7D12 and the fungal ribotoxin α-sarcin (αS) as the toxic moiety (V_HHEGFRαS). Then, we incorporated a trimerization domain (TIE^XVIII) into the construct, obtaining a trimeric nanoITX (TriV_HHEGFRαS). Finally, we designed and characterized a bispecific ITX, combining the V_HH 7D12 and the scFv against GPA33 as targeting domains, and a deimmunized (DI) variant of α-sarcin (BsITXαSDI). The results confirm the therapeutic potential of α-sarcin-based nanoITXs. The incorporation of nanobodies as target domains improves their therapeutic use due to their lower molecular size and binding features. The enhanced avidity and toxic load in the trimeric nanoITX and the combination of two different target domains in the bispecific nanoITX allow for increased antitumor effectiveness.

Keywords: antibody engineering; antitumor efficacy; colorectal cancer; immunotoxin; nanobody; α-sarcin.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Antigens, Neoplasm
Colorectal Neoplasms* / drug therapy
ErbB Receptors
Humans
Immunotoxins* / chemistry
Single-Domain Antibodies* / pharmacology
Single-Domain Antibodies* / therapeutic use

Substances

Immunotoxins
Single-Domain Antibodies
Antigens, Neoplasm
ErbB Receptors
EGFR protein, human

Grants and funding

This research was funded by the Complutense University of Madrid (grant numbers PR75/18-21563 and PR87/19-22627), the PID2020-116692RB-I00 grant from the I+D+I Retos Investigación of the Spanish Ministry of Science and Innovation, and by a REACT-EU grant from the Comunidad de Madrid to the ANTICIPA-REACT project of Complutense University of Madrid. J.N. was supported by a predoctoral fellowship from the Spanish Ministry of Science and Innovation (FPU15/04121).