Prevention and treatment of DNA vaccine encoding cockroach allergen Bla g 1 in a mouse model of allergic airway inflammation

To cite this article: Zhou B, Ensell M, Zhou Y, Nair U, Glickstein J, Kermany MH, Cai Q, Cai C, Liu W, Deng Y‐P, Kakigi A, Barbieri M, Mora M, Kanangat S, Yoo TJ. Prevention and treatment of DNA vaccine encoding cockroach allergen Bla g 1 in a mouse model of allergic airway inflammation. Allergy 2012; 67: 166–174. Background: One‐fourth of the US population is sensitized to the German cockroach. Primary German cockroach allergen Bla g 1 is detected in 63% of homes and 52% of childcare facilities in the United States. No effective treatment or vaccination strategies are yet available. Objectives: We evaluated the prophylactic and therapeutic efficacy of a plasmid DNA‐mediated vaccination using the Bla g 1 gene in a mouse model of allergic inflammatory airway disease. Methods: A plasmid DNA vector coding for the Bla g 1 allergen controlled by cytomegalovirus promoter was constructed. To estimate the protective efficacy, BALB/c mice were given three injections of plasmid DNA–Bla g 1 prior to sensitization with two priming doses of recombinant Bla g 1 (rBla g 1) antigens, followed by nebulized rBla g 1 challenge. In the therapeutic approach, sensitization was followed by administering Bla g 1 DNA vaccine. Results: Bla g 1 vaccination significantly reduced allergen‐induced airway inflammation, even after mice were presensitized and a Th2‐dominant response was established. The Bla g 1 vaccination significantly reduced total inflammatory cell infiltrate, eosinophilia, secretion of Th2 cytokines IL‐4 and IL‐5 in bronchoalveolar lavage fluid, allergen‐induced inflammatory infiltrates in the lungs, and Bla g 1‐specific IgE in serum upon challenge with rBla g 1. Importantly, Bla g 1 DNA vaccination was able to induce IL‐10‐secreting regulatory T cells that could suppress the allergen‐specific Th2 cells. Conclusion: DNA vaccination showed protective and therapeutic efficacy against a clinically relevant allergen Bla g 1.