Objectives. The CD56 differentiation cluster has been found on cells of neurogenic origin, muscle, natural killer cells, and on various populations of T lymphocytes, neutrophils, monocytes, epithelial and dendritic cells; this cluster sends signals to activate the secretion of chemokines, integrins, enzymes, cytokines, and other biologically active substances that are characteristic for this cell type. The CD16 third receptor for Fc immunoglobulins (FcγRIII) has been found on the membranes of granulocytes, mast cells, monocytes, macrophages, natural killers, and lymphocytes. The Fc fragment of antibodies provides the cytophilicity of immunoglobulins and frequently binds to IgM, IgA, and IgE. The aim of this study was to evaluate the effect of elevated concentrations of sCD56 and sCD16 on the secretory and cytotoxic activity of peripheral blood mononuclear cells in healthy people. Methods. An immunological examination was performed on 178 healthy people aged 21 to 55 years, including 112 women and 66 men, living in the Murmansk region and on the Spitsbergen (Svalbard) archipelago. The peripheral venous blood was analyzed; specifically, the hemogram, phagocytic activity of neutrophilic leukocytes, and contents of lymphocyte phenotypes (CD3+, CD4+, CD8+, CD10+, CD16+, CD56+, CD25+, CD71+, HLADRII, CD95+) were determined using an Epics XL instrument (Beckman Coulter, USA). The concentrations of free sCD16, sCD56, cytokines IL-1β, IL-6, TNF-α, IL-10, cGMP and cAMP, and circulating immune complexes (CICs) to IgA, IgM, and IgG were evaluated using an Evolis automatic analyzer (Bio-Rad, Germany). Results. Increases in the serum concentrations of sCD56 and sCD16 in healthy adults of working age are associated with an increase in the content of circulating mononuclear cells with the corresponding membrane clusters. An increase in sCD16 concentration is associated with a decrease in circulating leukocytes in the blood, and an increase in sCD56 concentration is associated with an increase in cytokines. Concentrations of CICs increase in parallel with increases in sCD16 and sCD56 concentrations. An increase in signal-sending activity with an increase in circulating CD16 + and CD56 + leukocytes and the shedding of these signaling molecules occur in parallel with decreases in the cAMP and cGMP concentrations. Conclusion. The increase in serum concentrations of sCD56 and sCD16 reflects the specificity and activity of the functions they perform. Membrane CD56 sends a signal that activates cell secretory activity, which results in increases in serum cytokine and immunoglobulin concentrations. In addition, membrane CD56 initiates cell interaction with immunoglobulins. The interaction of mCD16 and sCD16 with immunoglobulins causes a decrease in circulating lymphocytes in the blood and an increase in serum CIC concentration. The activation of signal transduction through CD56 and CD16 and their shedding occur in parallel with a twofold decrease in the extracellular cAMP and cGMP concentrations.

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The present article describes a comparative study on the cellular reactions in capillary and venous blood in northerners under general hypothermia in a climatic chamber during different photoperiods. The authors examined 108 relatively healthy people that lived in Archangelsk (80 women and 28 men aged 21 to 50 years old). It was established that total neutrophil count in venous blood was lower by 8.07±0.41%, monocyte count -by 51.32±1.03% and basophil count -by 50.21±1.24% than in capillary blood, but the lymphocyte count was higher by 25.23±0.41% due to smaller forms that are known to be recirculating. After a 5minute period in a climatic chamber ("USHZ-25N", Russia) at -25º,25 volunteers (27.53%)during a polar night and 16 volunteers during a polar day had elevated levels of neutrophils in the venous blood due to the increase in the levels of TNF-α in blood and decrease in noradrenaline, adrenaline, and irisin. During a summer period, the increase in monocyte count contributed to the reactions of neutrophils. The volunteers that reacted to short-term general hypothermia with an increase in the neutrophil count had the following peculiarities in the venous blood: general neutrophil count and their phagocytic activity, lymphocyte count, including CD71+, ATP in lymphocytes, adrenaline, TNF-α and irisin levels were higher in blood serum. The content of endothelin-1 did not change significantly.

The processes of apoptosis and necrosis are the mechanisms of programmed cell death, differing from each other in the mechanisms of their implementation. The implementation of these processes within the physiological norm is of interest in assessing their influence on the activity of immune responses. Purpose. To identify the nature of the relationship between the level of lymphocyte necrosis of peripheral blood and the expression of immune system reactions in practically healthy people. Materials and methods. The study examined 77 people. Leukograms were carried out using a XS-1000i hematology analyzer Sysmex XS-500i (Japan). Determination of cell death was carried out by flow cytometry Epics XL (Beckman Coulter, USA). Determination of cytokines, immunoglobulins (Bender MedSystems, Austria) and serotonin (DRG, Germany). The results of the study were processed using the Statistica 6 application package (StatSoft, USA). Results. It is established that the increased level the necrosis of lymphocytes is combined with increase in number the apoptosis of lymphocytes, T-helpers, lymphocytes of CD95, IgA, IgE, IgG against the background of reduction of the level CD23, HLADR, cytokines (IFN-γ, IL-6) and serotonin. Necrotic death is not associated with cellular cytolysis of cytotoxic T lymphocytes and natural killer content, but is inversely related to neutrophil phagocytosis response. Conclusion. Conclusion. The results of the study show that necrotic lymphocyte death within physiological boundaries as opposed to apoptosis increases immune response activity. Necrosis and apoptosis are subject to predominantly mature B cells with receptors to IgE and proteins of the main histocompatibility complex class II.

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