Effect of Antigens Obtained from the Recombinant Strain Bacillus anthracis 55ΔTPA-1Spo- on Organs and Tissues of Immunized Animals.

The recombinant B. anthracis strain 55ΔTPA-1Spo- was used for the development and trial of a method for the simultaneous production of immunogenic anthrax antigens, a protective antigen, and the EA1 protein of the S layer, which are components of a prototype anthrax vaccine. The proposed method includes inoculum preparation, cultivation in liquid medium without antibiotics, sterilizing filtration, concentration, diafiltration, and chromatographic purification on various carriers. This method provides for a high yield of both target products. The purified antigens (alone or in combination with each other) were shown to have no toxic effect on organs and tissues of vaccinated laboratory animals in amounts that were several times higher than immunizing doses. The minor changes revealed by histological examination reflect the adaptation-compensatory reactions of the macroorganism and tend to normalize. The response of immune-competent organs corresponded to moderate development of immunogenesis. The addition of EA1 protein to the recombinant protective antigen resulted in an increase in the expression of the genes determining TLR of innate immunity. Immunization of laboratory animals with the combined preparation caused more pronounced immunobiological alterations in lymphoid organs than the use of only the protective antigen. [ABSTRACT FROM AUTHOR]