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

Purpose: Study the repertoire of the T-cell receptor in persons chronically exposed to radiation in the long-term period. Material 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, the average accumulated dose to RBM was 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 by the Gini-TCR index (p=0.14).