Expansion of CD8+ T cells lacking the IL-6 receptor α chain in patients with coronary artery diseases (CAD)

Abstract Background and aims The pathogenesis of coronary artery disease (CAD) is closely associated with chronic inflammatory processes. CD8+ T cells are a key participant in the pathogenesis of atherosclerosis, the major cause of CAD; however, it remains unclear which CD8+ T-cell subset is responsible. We investigated the immunological features of CD8+ T cells expressing low and high levels of the IL-6 receptor α chain (IL-6Rα), a cytokine known to play a key role in cardiovascular diseases. Methods The expression of IL-6Rα on CD8+ T cells and its association with plasma levels of soluble components of the IL-6/IL-6Rs as well as with clinical parameters were analyzed using FACS analysis and ELISA of CAD patients and age-matched healthy controls (HCs). Immunological characteristics of CD8+ T cells expressing low and high levels of IL-6Rα (CD8+ IL-6Rαlow or high ) were examined by in vitro culture and intracellular FACS analysis. Results CAD patients had higher frequencies of circulating CD8+ IL-6Rαlow effector memory (EM) T cells compared with HCs (median frequency; 74.59% vs. 60.09%, p = 0.0158). Expanded CD8+ IL-6Rαlow T cells positively correlated with the frequency of senescent, cytotoxic CD8+ CD57+ T cells (r = 0.6655, p