The article presents the data on the influence of Yersinia pestis plasmid profile on subpopulation structure of mononuclear cells of peritoneal fluid of mice at the early stages of infectious process. It was showed that change of cellular composition of peritoneal fluid of the experimental animals depended on the plasmid profile of Yersinia pestis strains. The phase character in the changes of quantitative composition of the mast cells of peritoneal fluid of white mice infected with Y. pestis strains with different plasmid spectrum was determined.

Influence of Francisella tularensis lipopolysaccharide preparations on morphological changes in immunocompetent experimental animals was studied by subcutaneous introduction using survey microscopy and morphometric methods. Low expressed activation of Band T-dependent bands in immunocompetent organs was determined. Proliferation of antigen-presented cells at early stages of investigation indicates the cell immunity activation. Pathomorphological alterations caused by lipopolysaccharide inoculation are homogeneous and benignant.

Data of Yersinia pestis plasmid structure influence on its adhesive properties and phagocytic activity of peritoneal macrophages in vitro are represented. It is shown that Y. pestis strains of diverse subspecies differing by a plasmid profile, particularly by one of the plasmids (pYP, pYV) lacking, possess low adhesive activity and promote the increase of laboratory animal phagocyte absorbing capacity.

Influence of a cobalt-containing nanobiocomposite on basis of arabinogalactane on morphological changes in immunocompetent organs of the experimental animals at peroral and parenteral introduction was studied, by a computer program. «Morphometry». Comparative estimation, of morphological and. histological changes in spleen and. regional lymph, nodes of the outbred. white mice was performed.

Study of morphofunctional state of parenchymatous organs of the experimental animals infected with the brucellosis agent in L-form was carried out in the early periods of the infection. Immune reorganisation of macroorganism was estimated by the change of the structural components and cellular composition of spleen and of lymph nodes. Toxic action of Brucella I-6 (L-form) was evaluated by the change of neutrophil shift index and pathological granularity of peripheral blood neutrophils.

Influence of Yersinia pestis EV in combination with a phytogenous immunomodulator, arabinogalactane, on cellular structure of red bone marrow and thymus of white mice was studied. Quantitative estimation of the cellular composition both thymus cortical and medullary substance and red bone marrow was conducted using the computer program «Morphometry». The data obtained in experiments indicate high sensitivity of these bodies to arabinogalactane influence

Extract of Bacillus anthracisantigens was prepared. Its immunobiological properties and influence on immunophagocytic system were studied. It was established that the extract increases non-specific immune factors by stimulation of oxygen-dependent and nitric oxide-dependent bactericidal systems and results in tolerance of a live organism to Bacillus anthracis.

Immune response in spleen and lymph nodes of guinea pigs followed to inoculation of various Francisella tularensis subspecies was evaluated at light-optical level with the computer programs «Motic Images Plus» (Version 2) and «Morphometry». The findings can be prognostic for characterization of the infectious process