Soluplus® nanomicelles enhance IgG neutralizing properties against Shiga toxin type 2

Shiga toxin (Stx) is the main virulence factor of Stx-producing Escherichia coli, a pathogen responsible for developing Hemolytic Uremic Syndrome. Nowadays, no specific treatment exists for this disease, and nanomicelles may be an excellent platform for the delivery of specific compounds, including immunoglobulins (IgG), for therapeutic or diagnostic strategies. In this work, Soluplus® nanomicelles (NM) were associated with IgG against Stx type 2 (NM-IgG-Stx2). Physicochemical evaluation of NM-IgG-Stx2 was performed by Dynamic Light Scattering, Uv–Vis, Fluorescence, and Circular Dichroism spectroscopy. Morphology was analyzed by transmission electron microscopy. An in silico analysis of NM-IgG-Stx2 association was performed, and neutralization properties against purified Stx2 and Stx-derived supernatants were analyzed on Vero and HGEC cells. Our results suggest that IgG-Stx2 assemble with NM, and the interaction improves the Stx2 neutralization capacity of the antibody. These results suggest that NM may enhance IgG-Stx2 paratope availability and may be an excellent platform for the recognition and neutralization of Stx2.