The immunomodulatory effect of Oxidized-LDL and/or transforming growth factor-β on peripheral T cell-mediated immune responses in patients with stable angina

Abstract

Background: Atherosclerosis is a progressive inflammatory disease marked by the development of a plaque within the injured arterial wall in response to various harmful insults. Although regulatory T cells (Tregs) and Th-17 cells might be implicated in antagonistic functions, transforming growth factor β (TGF-β) could be required for the differentiation of these two T-cell subsets. Objective: The aim of our study was to investigate the immunomodulatory effect of ox-LDL and/or TGF-β in patients with stable angina and normal subjects. Methods: Peripheral blood mononuclear cells (PBMCs) from stable angina (SA) and normal coronary arteries (NCA) subjects were treated in vitro with ox-LDL, TGF-β alone or in combination. Under these conditions, the frequency of Treg cells was assessed after four days of incubation. Moreover; the release of the signature Treg cytokine, IL-10, as well as the Th17 related cytokines IL-17 were quantified in the supernatant of PBMC cultures from patients and controls. Results: Our results showed that only patients were vulnerable to an increase in IL17 levels after treatment with ox-LDL and TGF-β. However, there was no significant difference in the percentages of Treg cells and IL-10 secretion levels between NCA and SA groups. Conclusions: We suggest that the maintained peripheral cellular tolerance in patients suffering from a stable angina pectoris might be altered under the effect of specific cytokines and lipoproteins concentration that can exist in the cell culture media. This microenvironment is able to modulate the inflammatory or anti-inflammatory responses of the immune system.