Modulation of cell life cycle during exposure to phenols

Aim. To evaluation the life cycle characteristics of cells under conditions of exposure to phenols. Methods. Examined were 128 people: the main group included 90 people with an occupational specialty «insulator», the control group included 39 people with no exposure to industrial hazards. Materials of working environment attestaion, the results of industial control, data of analytical chemical analysis on the content of substances (phenol) in the working area were used. Using a capillary gas chromatograph the content of organic compounds in the blood (phenol, o-cresol, m-cresol, p-cresol) was determined. Phenotyping of lymphocytes was performed by flow cytometry. Populations and subpopulations of lymphocytes (CD3+, CD4+, CD8+, CD19+, CD95+, CD3+CD16+CD56+, CD4+CD25+, CD4+CD25+127-) were determined by membrane immunofluorescence using a panel of labeled monoclonal antibodies. Registration of apoptosis of lymphocytes was performed by determining the expression of phosphatidylserine using annexin V conjugated with fluorescein isothiocyanate. Results. Among those who work in conditions of exposure to phenols (main group) noted were changes in the quantitative and qualitative composition of the cell-lymphocytic link of the immune system. Revealed were signs of activation of the immune system, which is expressed in a significant (p <0.05) increase in the expression of early activation antigens on the immune cells (11.33±0.33%) compared with the control values (7.82±0.39%). At the same time, the number of regulatory lymphocytes (0.81±0.05%) increased with statistical significance (p <0.05), providing suppressive effect on various types of immune cells with respect to the values obtained in the control group (0.55±0.06%). Registered was a significant reduction in the number of markers that characterize apoptotic cell death: the expression of a receptor for the tumor necrosis factor-alpha type I (1.39±0.11%), transcription factor p53 (1.44±0.11%) compared with such in the the control group (3.31±0.27% and 3.42±0.29% respectively, p <0.05). Analysis of the immunograms has demonstrated that those who work in conditions of phenol exposure have significantly (p <0.05) reduced levels of apoptotic (2.17±0.09%) and necrotic (7.69±0.25%) cells with respect to such numbers registered in the control group (apoptotic - 4.77±0.42%, necrotic - 13.06±1.17%). Noted was a statistically significant negative relationship between indicators that determine the activation-induced cell death and the content of phenol in the blood of the main group of examined individuals. Conclusion. Exposition of phenols leads to the development of immune disorders, in particular changes in the quantitative and qualitative composition of the cell-lymphocytic link of the immune system and can induce apoptotic death of immunocompetent cells.

occupational hazards, occupational hygiene, immunity, lymphocyte-cellular link, cell death, apoptosis, phenols