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

GIRÓN DANIEL; GÓMEZ GABRIELA E; CASAL JUAN JOSÉ; DELFINO JOSÉ M; GOMEZ FERNANDO; IBARRA CRISTINA; AMARAL MARÍA MARTA; CHIAPPETTA DIEGO; MORETTON MARCELA; SACERDOTI FLAVIA

Mar del Plata

Congreso; LXVIII REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIÓN CLÍNICA; 2023

Shiga toxin type 2 (Stx2) is the main virulence factor of Shiga toxin producing Escherichia coli (STEC) and is responsible for the development of typical Hemolytic uremic syndrome (HUS). Nowadays, no specific treatment exists for this disease. The aim of this work was to develop Soluplus® nanomicelles (NM) associated to specific IgG (IgG-Stx2), characterize them, and evaluate their neutralizing capacity against Stx2 to propose them as a treatment for HUS. IgG-Stx2 or control (IgG-CT) were purified from bovine colostrum by affinity chromatography. NM-IgG association (NM-IgG-Stx2 or NMIgG-CT) was achieved by the magnetic stirring method. Characterization of NM-IgG was performed by dynamic light scattering (DLS), UV-Vis, fluorescence, and circular dichroism (CD) spectroscopies, while morphology was analyzed by transmission electron microscopy (TEM). Neutralization capacity of NM, NM-IgG-CT, NM-IgG-Stx2, IgG-CT or IgG Stx2 against Stx2 was evaluated on Vero cells and HGEC. Additionally, neutralization of supernatants (SN) from STEC strains containing Stx2 was also assayed on Vero cells. NM showed a monomodal size distribution with a hydrodynamic diameter (Dh) of 69.2 ± 0.3 nm, while IgG showed a major Dh peak of 19.3 ± 1.8 nm. NM-IgG showed a single peak with a Dh value of 75.1 ± 0.5 nm, significantly higher compared to NM alone (*p