Development and characterization of IB4-Fc (IgG) fusion proteins targeting Trypanosoma cruzi glycotopes for potential therapeutic and diagnostic applications in Chagas Disease 3770

Abstract Description Chagas disease (CD), caused by Trypanosoma cruzi, is a significant global health issue, particularly in Latin America, with no vaccines and limited treatment options for chronic stages. This study aimed to develop and evaluate IB4-Fc (IgG) fusion proteins targeting the parasite’s surface glycotopes, specifically Galα3LN. IB4, an α-galactose-specific lectin, was fused to murine IgG Fc regions to enhance immune-mediated mechanisms, such as phagocytosis and lysis. The fusion proteins were successfully expressed in CHO cells, purified, and confirmed to form monomers and dimers via Western blot. ELISA and inhibition assays demonstrated dose-dependent and high-affinity binding of IB4-Fc (IgG), especially the IgG2b variant, to synthetic Galα3LN and T. cruzi trypomastigotes. Fluorescence microscopy revealed targeted binding on the parasite’s surface, co-localizing with Galα3LN-rich regions. Functionally, IB4-Fc (IgG) significantly enhanced macrophage phagocytosis and induced parasite lysis in vitro. While anti-α-Gal antibodies exhibited broader epitope recognition, IB4-Fc (IgG) provided specific and robust targeting of Galα3LN. These findings suggest IB4-Fc (IgG) fusion proteins hold promise as diagnostic tools and therapeutic agents for CD. Further in vivo studies are necessary to evaluate their efficacy and safety, paving the way for novel approaches in managing Chagas Disease. Funding Sources This work was supported by NIH grant # U01AI129783. We are grateful to the following UTEP/BBRC Core Facilities: Biomolecule Analysis (BACF), Genomic Analysis (GACF) and Cellular Characterization and Biorepository (CCB). All three BBRC/UTEP Core Facilities are supported by a grant (2G12MD007592) from the National Institute on Minority Health and Health Disparities (NIMHD). Topic Categories Vaccines and Immunotherapy (VAC)