A C1qTNF3 collagen domain fusion chaperones diverse secreted proteins and anti-Aβ scFvs: Applications for gene therapies

• Authors: Brenda Dawn Moore, Emory University; Yong Ran, Emory University; Marshall S. Goodwin, University of Florida, Gainesville; Kavitha Komatineni, University of Florida, Gainesville; Karen N. McFarland, University of Florida, Gainesville; Kristy Dillon, University of Florida, Gainesville; Caleb Charles, University of Florida, Gainesville; Danny Ryu, Emory University; Xuefei Liu, Emory University; Stefan Prokop, University of Florida, Gainesville; Benoit I. Giasson, University of Florida, Gainesville; Todd Eliot Golde, Emory University; Yona Levites, Emory University
• Journal Title: Molecular Therapy - Methods & Clinical Development
• Volume: Volume 31
• Publisher: Elsevier | 2023-10-31, Pages 101146-None
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1016/j.omtm.2023.101146
• Subjects: Biology, Genetics; Engineering, Biomedical
• Keywords: collagen domain; C1qTNF3; scFv; amyloid-β; immunotherapy; adeno-associated viral vector; AAV; Alzheimer; antibody

Abstract

Enhancing production of protein cargoes delivered by gene therapies can improve efficacy by reducing the amount of vector or simply increasing transgene expression levels. We explored the utility of a 126-amino acid collagen domain (CD) derived from the C1qTNF3 protein as a fusion partner to chaperone secreted proteins, extracellular “decoy receptor” domains, and single-chain variable fragments (scFvs). Fusions to the CD domain result in multimerization and enhanced levels of secretion of numerous fusion proteins while maintaining functionality. Efficient creation of bifunctional proteins using the CD domain is also demonstrated. Recombinant adeno-associated viral vector delivery of the CD with a signal peptide resulted in high-level expression with minimal biological impact as assessed by whole-brain transcriptomics. As a proof-of-concept in vivo study, we evaluated three different anti-amyloid Aβ scFvs (anti-Aβ scFvs), alone or expressed as CD fusions, following viral delivery to neonatal CRND8 mice. The CD fusion increased half-life, expression levels, and improved efficacy for amyloid lowering of a weaker binding anti-Aβ scFv. These studies validate the potential utility of this small CD as a fusion partner for secretory cargoes delivered by gene therapy and demonstrate that it is feasible to use this CD fusion to create biotherapeutic molecules with enhanced avidity or bifunctionality.