Phenotypic heterogeneity of the neutrophilic granulocytes in terms of the pathogenesis of the late effects of the chronic radiation exposure. Review

One of the main tasks of the contemporary radiobiology is to study mechanisms of the late effects development and to prove that radiation exposure either stimulates or suppresses the systemic immunity that could modify considerably the risks of cancer and cardio-vascular disease development. According to the epidemiological data chronically exposed residents of the Techa riverside settlements demonstrate increased risks of mortality from malignant neoplasms including leukemia and circulatory system diseases in the long-term period after the onset of radiation exposure. The changes in the immune system in these people have been registered over the course of decades and are pro-inflammatory. In the long-term period impairment of the functional activity of phagocytes, one of the most important effector cells of the anti-tumor immunity and inflammation, in chronically exposed people could be viewed as one of the pathophysiologic mechanisms of the carcinogenesis and cardiovascular pathology under long-term low-dose-rate exposure with predominant damage to the bone marrow. The objective of the study is to summarize and analyze the currently important scientific data on the functional activity of the human peripheral blood neutrophilic granulocytes after ionizing radiation exposure including the chronic low dose rate exposure, and phenotypes of the main subpopulations of neutrophilic granulocytes that reflect the specific features of their functioning. The review presents topical information on the main functions of neutrophilic granulocytes, changes in their functional activity under ionizing radiation exposure, and contemporary view of the phenotypes of the main subpopulations of the neutrophilic granulocytes circulating in the peripheral blood.