INVESTIGAISTION AND MODELING OF LEUKOCYTE RESPONSES IN THE BLOOD TO γ- IRRADIATION USING ENERGY PARAMETERS OF IMMUNE NETWORK CELLS

Abstract

Biophysical control of radiation exposure to humans in the areas of nuclear reactors, in space flight conditions, as well as during radiation therapy, is relevant today. In this regard, the following tasks were solved in this work: 1) study of the leukocytes reactions in the blood after a single exposure to 60Co γ-radiation on the blood in vitro; 2) mathematical modeling of the fast immune responses using energy indicators of cells. By use of the luminescent microscope, lymphocytes and neutrophils were recognized and examined in donor venous blood smears, vitally stained with a cationic probe 4-(n-dimethylaminostyril)-1-methylpyridinium (DSM). Cell energy activity (EA) in each population was characterized by the sum of transmembrane potentials (TMP) on the outer and mitochondrial membranes, which was assessed by DSM fluorescence intensity and color in cell mitochondria and nuclei. Dose-dependent γ-irradiation effects were evaluated on the basis of digital fluorescent images computer analysis. It was found in the experiments that the change in the TMP of after blood γ - irradiation in doses of 1Gy-5Gy depends on their initial EA. An S-shaped dose dependence was revealed for the irradiated lymphocytes energy activity. The greatest effect of cells energy decrease occurs after irradiation with 4 Gy dose. A model of T-dependent immune responses is proposed in the form a system of nonlinear differential equations before and after blood irradiation, where the concentrations for five cell populations are replaced by their fluorescent variables, which reflect the number of active mitochondria in each population. Such a model is also adequate for describing the rapid phase of the immune response after single-hit radiation exposure of the body.