[Immunogenicity of protective antigen extracted from asporogenic recombinant strain Bacillus anthracis]

To study the ability of recombinant protective antigen (PA) to stimulate adaptive immune response in laboratory animals.

Vaccine, recombinant, and reference strains of Bacillus anthracis were used in the study. Laboratory animals were immunized subcutaneously with two doses of antigenic preparation or one dose of B. anthracis strain. After inoculation with reference strain of B. anthracis, measurement of LD50 as well as indexes of immunity was performed by specified methods.

It was revealed that asporogenic recombinant strain has stable biological characteristics during passages in vitro and is effective producer of PA. Using 2-stage chromatography, highly purified protein was obtained. Experiments on different biomodels--BALB/c mice, guinea pigs, and rabbits--demonstrated high protective activity of PA obtained from asporogenic producer. Increase of immunity index was noted when EA1 protein from S-layer was added to preparation for immunization.

Immunity indexes determined in experiments on laboratory animals point to high protective efficacy of recombinant PA. Further studies of its interaction with macroorganism's innate and adaptive immunity systems are promising.