CIRCADIAN DISRUPTION AS A FACTOR OF IMPAIRED ADAPTIVE T-CELL IMMUNITY RESPONSE

The study was carried out with the aim to evaluate the effects of continuous lightning (CL) and subsequent circadian rhythm disruption on CD4+/CD8+ populations of adaptive cell immunity. For further understanding of underlying processes that affect CD4+/CD8+ proliferation and differentiation, the expression levels of CD3+ and CD95+ cell receptors were evaluated. Chinchilla rabbits were exposed to shift work simulation - 24 hours of CL. We organized 5 time-related groups: 2, 4, 6, 12 months of CL respectively. The 5th group – corresponding control. Thymus derived slides were examined using immunofluorescence assay. A decrease in the expression of CD3+ and CD8+ and an increase in the expression of CD4+ lymphocytes, which was accompanied by an increase in the ratio of CD4+/CD8+ were found after 2 months of the experiment. After 4 and 6 months of CL, there was an increase in CD3+ expression and a decrease in CD4+ and CD8+ expression. The lowest levels of CD3+, CD4+ and CD8+ were recorded after 12 months of the experiment, which is a manifestation of significant immunosuppression due to premature aging of the thymus. The level of CD95+ lymphocytes was higher in the group after 12 months of CL, indicating the activation of apoptosis in thymocytes caused by circadian rhythms disruption under the influence of chronic light stress.