Oral immunization with attenuated Salmonella vaccine expressing Escherichia coli O157:H7 intimin gamma triggers both systemic and mucosal humoral immunity in mice

Author(s)

Oliveira, Aline Ferreira ^{[1, 2, 3]} ; Cardoso, Silvia Almeida ^{[1, 2]} ; dos Reis Almeida, Fausto Bruno ^[1] ; de Oliveira, Leandro Licursi ^[4] ; Pitondo-Silva, Andre ^[5] ; Soares, Sandro Gomes ^[2] ; Hanna, Ebert Seixas ^{[1, 2]}

Affiliation

^[1] Univ Sao Paulo, Dept Biol Celular & Mol Bioagentes Patogen, Fac Med Ribeirao Preto, BR-14049900 Ribeirao Preto, SP - Brazil

^[2] Invent Biotecnol Ltd, Business Incubator Supera, BR-14040900 Ribeirao Preto, SP - Brazil

^[3] Univ Estadual Campinas, Dept Genet Evolut & Bioagents, Inst Biol, BR-13083862 Campinas, SP - Brazil

^[4] Univ Fed Vicosa, Dept Gen Biol, BR-36570000 Vicosa, MG - Brazil

^[5] Univ Sao Paulo, Dept Clin Chem Toxicol & Bromatol, Fac Pharmaceut Sci Ribeirao Preto, BR-14040903 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: MICROBIOLOGY AND IMMUNOLOGY; v. 56, n. 8, p. 513-522, AUG 2012.
• Web of Science Citations: 18

Abstract

Human infections with EHEC such as O157:H7 have been a great concern for worldwide food-industry surveillance. This pathogen is commonly associated with bloody diarrhea that can evolve to the life-threatening hemolytic uremic syndrome. Animals are the natural reservoir where this pathogen remains asymptomatically, in steps of ingestion and colonization of the bowel. The bacterium is shed in the feces, contaminating the surroundings, including water and food that are directed for human consumption. A major player in this colonization process is intimin, an outer membrane adhesion molecule encoded by the E. coli attachment and effacement (eae) gene that has been shown to be essential for intimate bacterial attachment to eukaryotic host cells. In an attempt to reduce the colonization of animal reservoirs with EHEC O157:H7, we designed a vaccine model to induce an immune response against intimin gamma. The model is based on its recombinant expression in attenuated Salmonella, used as a suitable vaccine vector because of its recognized ability to deliver recombinant antigens and to elicit all forms of immunity: mucosal, systemic, and humoral responses. To test this model, mice were orally immunized with a S. enterica serovar Typhimurium strain carrying the pYA3137eaeA vector, and challenged with E. coli O157:H7. Here we show that immunization induced the production of high levels of specific IgG and IgA antibodies and promoted reduction in the fecal shedding of EHEC after challenge. The live recombinant vaccine reported herein may contribute to the efforts of reducing animal intestinal mucosa colonization. (AU)

• FAPESP's process: 05/04465-1 - Microencapsulation of IgY and its utilization in the inhibition of Salmonella enterica Typhimurium adhesion
• Grantee: Leandro Licursi de Oliveira
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE