Allergen immunotherapy with nanoparticles containing lipopolysaccharide from Brucella ovis.

Abstract

Background: Specific immunotherapy implies certain drawbacks which could be minimized by the use of good adjuvants, capable of amplifying the appropriate immune response with minimal adverse effects. Objective: To evaluate the adjuvant capacity of the association of the rough lipopolysaccharide of Brucella ovis with Gantrez® AN nanoparticles. Methods: Ovalbumin (allergen model)-containing Gantrez® AN nanoparticles with either encapsulated or coated lipopolysaccharide were prepared and administered intradermally to BALB/c mice in order to evaluate the immune response. Pre-sensitized BALB/c mice were also administered with the formulations and they were challenged with an intraperitoneal injection of ovalbumin. Anaphylactic symptoms, including mortality rates, were evaluated after the challenge. Results: The intradermal administration of mice with ovalbumin-containing nanoparticles elicited high and sustained specific IgG1 and IgG2a responses. However, the only treatment that totally protected the mice from death after the challenge of induced allergic mice to ovalbumin, required the co-administration of lipopolysaccharide entrapped inside the nanoparticles. Conclusion: Gantrez® AN nanoparticles with entrapped rough lipopolysaccharide of Brucella ovis protected ovalbumin pre-sensitized BALB/c mice from anaphylactic shock. Clinical Implications: These results are highly suggestive for the valuable use of Gantrez® nanoparticles combined with lipopolysaccharide of Brucella ovis in immunotherapy with allergens.