Skewing the balance of regulatory T-cells and T-helper 17 cells in breast cancer patients

Abstract

This study investigated the distribution of interleukin (IL)-17-producing CD4+ T-cells (T-helper [Th17] cells) in relation to CD4+CD25+CD127- cells (regulatory T-cells [Treg]) in tumour-infiltrating lymphocytes (TILs) and peripheral blood mononuclear cells (PBMCs) from breast cancer patients. The Th17 and Treg cells were evaluated by flow cytometry and reported as a percentage of total CD4+ cells. In TILs from early breast cancer patients (n = 12), the frequency of Th17 cells was significantly higher than in PBMCs (14.5 ± 7.2% versus 6.9 ± 2.1%). In TILs from patients with advanced breast cancer (n = 15), the frequency of Th17 cells was also significantly higher than that in PBMCs (9.1 ± 5.7% versus 3.2 ± 2.3%) but lower compared with early disease. The Th17/Treg ratio in TILs was markedly increased in early versus advanced disease. In conclusion, Th17 and Treg cell accumulation in the tumour microenvironment of breast cancer occurred in early disease; Th17 cell infiltration gradually decreased and Treg cells accumulated with disease progression. © 2011 Field House Publishing LLP.