Polymorphism of TP53 (rs1042522) gene and peculiarities of the immune profile in children exposed to airborne benzo(a)pyrene

Abstract

Examining peculiarities of an immune profile and genetic polymorphisms is especially relevant when identifying markers of effect and sensitivity to exposure to benzo(a)pyrene in northern areas. We examined 1253 children who lived in industrial centers and on conditionally clean territories in the north and south of Eastern Siberia. Levels of benzo(a)pyrene in ambient air and in children’s blood were determined by using HPLC. TP53 (rs1042522) polymorphism was examined by using real-time PCR; p53 levels were identified with flow cytofluorometry; IgG to benzo(a)pyrene, by the radioallergosorbent tests. Exposure of children in Northern Siberia to airborne benzo(a)pyrene at the dose of 7.11•10-3 µg/(kg•day) causes ben-zo(a)pyrene contamination in blood, activates apoptosis (p53) and stimulates occurrence of specific sensitization (IgG to benzo(a)pyrene) (p < 0.05). Similar disorders were established in children in Southern Siberia under exposure to airborne benzo(a)pyrene at the dose of 86.46•10-3 µg/(kg•day). The detected changes in immune profiles of children living in Northern Siberia are associated with G-allele and GG-genotype (rs1042522) of the TP53 gene (OR = 1.37–1.83, p < 0.05); children in Southern Siberia, С-allele and СС-genotype of the said gene (OR = 1.55–2.38, p < 0.05). Therefore, the immune profile of children exposed to airborne benzo(a)pyrene at the dose of 7.11•10-3 µg/(kg•day) in Northern Siberia bears some signs of activated apoptosis (p53) and specific sensitization (IgG to benzo(a)pyrene) associated with G-allele and GG-genotype of the TP53 gene (rs1042522) (OR = 1.37–1.83, p < 0.05). These identified changes in the immune profile are comparable with effects produced by exposure to airborne benzo(a)pyrene at the dose of 86.46•10-3 µg/(kg•day) in Southern Siberia, which are associated with С-allele and СС-genotype of the same gene (OR = 1.55–2.38, p < 0.05). This confirms a hypothesis that effects of technogenic chemical factors can be modulated by specific climatic conditions in northern areas and a contribution made by genetic predisposition. Their combined effect creates a serious risk of developing impairments in an immune profile (OR = 1.37–1.83, p < 0.05; RR = 1.17; 95 % CI: 1.07–1.27) even under low-dose exposure to airborne benzo(a)pyrene.