Analysis of Vβ-Segment Diversity of T-Cell Receptor in Residents of the Techa Riverside Villages Chronically Exposed to Radiation in the Long-Term Period

Objective. To study the repertoire of the T-cell receptor in persons chronically exposed to radiation in the long-term period. Materials and methods. The study involved 48 people, who were divided into two groups: a group of exposed persons (31 individuals with the average accumulated dose to red bone marrow (RBM) of 981 ± 130 mGy) and a comparison group (17 individuals with the average accumulated dose to RBM of 25.3 ± 5.91 mGy). The study groups did not differ significantly in age, gender and ethnicity. The repertoire of Vβ-segments of the T-cell receptor of the peripheral blood T-lymphocytes of exposed persons was analyzed by flow cytometry method. 24 Vβ-segments of the T-cell receptor were studied. Statistical processing of the obtained data was carried out using the Wilcoxon signed-rank test, and a direct description of Vβ-segment repertoire of the T-cell receptor was performed using the Lorenz curve and the Gini-TCR index. Results. The study revealed a statistically significant increase in the number of Vβ3 and Vβ5.2 T-cell receptor segments in exposed individuals relative to the comparison group (p = 0.03 and p = 0.003, respectively). It was also shown that the distribution of the Vβ-segments of the T-cell receptor is uneven in both study groups. However, there was no significant difference between the repertoires of the T-cell receptor of the studied groups in the Gini-TCR index (p = 0.14).