Activation Markers and Regulatory T cells in Children with Chronic Pyelonephritis Associated with Bacterial Uropathogens

Abstract

© 2019, Springer Science+Business Media, LLC, part of Springer Nature. The expression of activation markers on lymphocytes and a subpopulation of regulatory T cells (CD4+ CD25+ Hi) were evaluated in children with chronic pyelonephritis. We have distinguished the following clinical variants of pathology: dysmetabolic, obstructive, and mixed (obstructive dysmetabolic) chronic pyelonephritis. Flow cytofluorometry was used to evaluate the population and subpopulations of T lymphocytes expressing CD3+HLA-DR+ and CD8+HLA-DR+ class II histocompatibility antigens, CD95−СD3+CD95+ activation apoptosis marker, subpopulations expressing the homing receptor CD4+CD62L+ and CD4+CD62L−, and subpopulations of CD4+CD25+Hi regulatory T cells (Treg). In dysmetabolic variants of chronic pyelonephritis, an activation profile of lymphocytes is characterized mainly by positive activation and the subpopulation of CD4+ lymphocytes, forming an increase in the content of effectors/activated cells with enhanced migration into the target organ. In the case of obstructive variants of chronic pyelonephritis, antigen-mediated activation and an increase in the pool of activated cytotoxic T lymphocytes (CD8+HLA-DR+) result in activation-induced apoptosis and cell death, leading to leukopenia and lymphopenia. Expansion of regulatory T cells (CD4+CD25+ Hi) in obstructive variants of chronic pyelonephritis can be considered a factor regulating apoptosis in the process of long-term activation of T lymphocytes.