Complex Bfr-O-Antigen of Francisella tularensis Outer Membranes: Production, Characteristics and Potential Use

Abstract

A method for the isolation of a complex antigen of protein-carbohydrate nature from outer membranes of the vaccine strain Francisella tularensis subsp. holarctica 15 NIIEG cells and its detailed characteristics have been described. A protein of bacterioferritin (Bfr) and O-antigen were identified in the antigenic complex. It was shown that the obtained complex antigen is non-toxic, harmless, has high immunogenic activity and protects white mice in the subcutaneous infection with a virulent strain of F. tularensis subsp. holarctica 503/840. This antigen was shown to occur in the tularemia microbe regardless of the subspecies and presence of a capsule. The high antigenic and immunobiological activity of the Bfr-O-antigen complex provides the prerequisites for its further use as a component in the development of preventive and diagnostic drugs against the tularemia infection. Francisella tularensis, antigens, outer membrane proteins, immunogenicity, lipopoly saccharide, O-antigen. Authors would like to thank to the staff of the Institute «Microbe»: laboratory of molecular diagnostics I.V. Terekhova for providing us with the monoclonal antibodies, laboratories for genomic and proteomic analysis N.V. Kotova for her excellent technical assistance.