Inactivated alpha toxin from Clostridium novyi type B in nano-emulsion protect partially protects Swiss mice from lethal alpha toxin challenge

Mellanie Karoline C Felix,Eliane M Sobrinho,Igor V Brandi,Tullio T Deusdará,Raimundo Wagner S Aguiar,Luis André M Mariúba,Paulo A Nogueira,Roberto Franco T Corrêa,Lucas Samuel S Santos,Kelvinson F Viana,Kattyanne S Costa,Bergmann M Ribeiro,Alex Sander R Cangussu

doi:10.1038/s41598-019-50683-2

Abstract

Nano-emulsions are promising carriers for antigen delivery. Here, we evaluated the efficacy of a water-oil nano-emulsion containing concentrated, inactivated Clostridium novyi (C. novyi) type B supernatant culture (nano-iCnB) in protecting Swiss mice against a lethal dose of alpha toxin concentrated extract. Proteins were confirmed in the nano-iCnB and their stabilities were determined according physical parameters such as Zeta Potential (ZP). Biochemical, hematological parameters and morphological appearance of liver, spleen and thigh muscle alterations were examined to determine the safety of the compound. Partial protection against lethal doses was achieved in immunized mice despite low IgG titers. These data suggest that our nano-emulsion is a simple and efficient method of promoting antigen delivery for toxin-related diseases.

Highlights

Current vaccines are composed of multiple antigens adsorbed on aluminum hydroxide; their efficacies remain unsatisfying[4,7,8]
Alpha toxin-producing C. novyi type B has substantial economic importance because of the damage it generates in livestock production chains
We demonstrated partial protection in immunized Swiss mice using nano-iCnB, indicating its promising action as carriers for antigen delivery

Summary

Introduction

Current vaccines are composed of multiple antigens adsorbed on aluminum hydroxide; their efficacies remain unsatisfying[4,7,8]. Aqueous adjuvant induces short-term responses, besides the fact that costs with handling and revaccination make them more expensive[9,10]. Alternatives to reduce animal handling as well as elimination of interactions between antigens are necessary for vaccine development[10]. Antigens in nano-emulsions are promising alternatives to improve vaccine efficacy because they delay antigen delivery, generating good cellular and humoral responses for long periods[10,11]. We demonstrated that our formulation is a substantial improvement and advance in terms of adsorption of antigens for control of clostridiosis. Correspondence and requests for materials should be addressed to www.nature.com/scientificreports/

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