DEVELOPMENT AND CHARACTERIZATION OF SOLUPLUS® NANOMICELLES ASSOCIATED WITH IgG AGAINST SHIGA TOXIN PRODUCING ESCHERICHIA COLI VIRULENCE FACTORS

GIRÓN DANIEL; GOMEZ FERNANDO; AMARAL MARÍA MARTA; CHIAPPETTA DIEGO; MORETTON MARCELA; SACERDOTI FLAVIA

Mar del Plata

Congreso; Reunión de Sociedades de Biociencias 2022; 2022

SAIC. SAFIS. SAI-FAIC.

Shiga toxin type 2 (Stx2) is the main virulence factor of Shiga toxin producing Escherichia coli (STEC), a foodborne pathogen responsible for the development of Hemolytic Uremic Syndrome (HUS). Several STEC virulence factors are involved in the colonization of the intestinal epithelia, including Intimin (Int) and EspB. We propose that specific antibodies (IgG) coupled to nanomicelles (NMs) can be used as a tool for the treatment of STEC infections and prevention of HUS. The aim of this work was to couple Soluplus® NMs with IgG against Stx2, Int and EspB, characterize them and evaluate their functionality against STEC. IgG-Stx2, IgG-Int, IgG-EspB were purified from hyperimmune bovine colostrum by affinity column. Soluplus® NMs were coupled with IgG (NM-IgG-Stx2, NM-IgG-Int, NM-IgG-EspB) by mixing 4 mg/ml of IgG with 1% NMs in PBS. The morphology and hydrodynamic diameter of the NMs with or without IgG were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). NM-IgG-Stx2 neutralization capacity was evaluated on HGEC and Vero cells. The capacity of NM-IgG/Stx2/Int/EspB to modify the growth behavior of STEC and the ability to inhibit bacterial adhesion to HCT-8 was evaluated. No significant differences between NMs hydrodynamic diameter and NM-IgG were observed (71.30 ± 2.10 and 92.38 ± 18.51 nm respectively, p>0.05). TEM analysis revealed circular particles with a diameter of approximately 100 nm for both NMs and NM-IgG. NM-IgG-Stx2 preserved the neutralization capacity of the toxin, in a dose dependent manner, compared to IgG (p>0.05). Finally, no inhibition of STEC growth nor inhibition of bacteria adhesion in vitro was observed with IgG nor NM-IgG/Stx2/Int/EspB. We proposed that IgG assemble efficiently on the corona of the NMs without a significant size, shape and IgG functionality change. These results suggest that the inhibitory strategy against STEC may be improved involving other adherence virulence factors.