Expression of FOXP3 and RORγt in CD4+ thymocytes of children with congenital heart defects of different severity

Abstract

Expression of transcription factors FOXP3 and RORγt in CD4⁺ thymocytes of children with different severity of congenital heart disease (CHD) related with the level of hypoxia was studied. Expression of FOXP3 and RORγt was evaluated in 72-h culture of CD4⁺ thymocytes isolated from thymus fragments of children under twelve months with CHD of different severity (white defect, n = 7; blue malformation, n = 7) in the conditions of the specific induction of the formation of natural regulatory T lymphocytes (nTreg) and IL-17-producing T lymphocytes (Th17). It was found that in CD4⁺ thymocytes of children with blue type CHD the expression of both FOXP3 and RORγt was increased as compared to CD4⁺ thymocytes of the children with white type CHD. An increase in the Th17 level in the children with blue type CHD was accompanied by an increase in the intracellular expression and concentrations of IL-17A in supernatants of cultured CD4⁺ thymocytes. The results point to an important role of the severity of hypoxia in the regulation of the expression of FOXP3 and RORγt in CD4⁺ thymocytes of children, as well as in the formation of nTreg and Th17 in the thymus.