Antigenic identity of immunodominant proteins of <i>Bacillus anthracis</i> genovariants

Abstract

Introduction. The main biological raw materials for the production of immunobiological preparations for identification of Bacillus anthracis are its specific antigens, the protective antigen and the EA1 protein. Purpose. To determine the antigenic identity of immunodominant proteins of different genovariants of B. anthracis isolated by gel chromatography and electrophoresis. Materials and methods. Culture filtrates of isogenic variants of B. anthracis strain 575/122 (pXO1+, pXO2+): R01 (pXO1+, pXO2); R00 (pXO1, pXO2) were used in the study. Gel chromatographic fractionation and electrophoretic separation were carried out according to standard methods. The antigenic properties of proteins isolated by gel chromatography and electrophoresis were studied by immunodiffusion with polyclonal monospecific sera against the protective antigen and the EA1 protein of the S-layer. Results. Gel chromatographic separation of B. anthracis 575/122 culture filtrates R01 (pXO1+, pXO2) and R00 (pXO1, pXO2)yielded fractions 1 and 5. Sera against EA1 protein and antigens of fraction 1 of strains B. anthracis 575/122 R00 and B. anthracis 575/122 R01 culture filtrates identified the identical antigens. Serum against antigens of fraction 5 of B. anthracis 575/122 R01 contained antibodies to numerous proteins, including the protective antigen isolated by electrophoresis. Discussion. The antigenic identity of immunodominant proteins isolated by gel chromatography and electrophoresis was identified. Conclusion. EA1 and PA proteins isolated by electrophoresis and gel chromatography can be used for production of monoclonal and polyclonal monospecific antibodies suitable for the design of diagnostic preparations.