Erschienen in:
01.11.2014 | Original Contribution
Altered CD31 expression and activity in helper T cells of acute coronary syndrome patients
verfasst von:
Davide Flego, Anna Severino, Francesco Trotta, Marco Previtero, Sara Ucci, Chiara Zara, Daniela Pedicino, Gianluca Massaro, Luigi M. Biasucci, Giovanna Liuzzo, Filippo Crea
Erschienen in:
Basic Research in Cardiology
|
Ausgabe 6/2014
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Abstract
In acute coronary syndrome (ACS), T cell abnormalities are associated to a worse outcome. Loss of inhibitory activity of CD31, an Ig-like adhesion molecule, on peripheral leukocytes has been found to enhance atherosclerosis in experimental models. In this study, we examined the expression of CD31 on T cells, and its role on TCR signaling in 35 patients with non-ST elevation ACS, in 35 patients with stable angina (SA), and in 35 controls. Furthermore, 10 ACS and 10 SA patients were re-analyzed at 1-year follow-up. Flow-cytometry analysis showed that in ACS patients, CD31 expression was reduced on total CD4+ and CD4+CD28null (P < 0.001, ACS vs. SA), on naïve (P < 0.001, ACS vs. SA) and on central-memory and effector-memory CD4+ T cells (P < 0.05, ACS vs. SA and controls). The immunomodulatory effect of CD31 on TCR signaling of CD4+ and CD4+CD28null T cells, was lower in ACS than SA patients (P < 0.05, for both comparisons). At 1-year follow-up, CD31 expression and function increased in ACS becoming similar to that found in SA. CD31 recruitment in the immunological synapse was lower in ACS than controls (P = 0.012). Moreover, CD31 modulated MAPK signaling and reduced the expression of T bet and Rorγ-t, necessary for Th1 and Th17 differentiation. Finally, we studied TCR signaling in CD31+ naïve and primed T cell subsets observing a different pattern of protein phosphorylation. A CD31-mediated regulatory pathway is enhanced in SA and temporarily downregulated in ACS. As CD31 modulates both T cell activation, by increasing the threshold for TCR stimulation, and T cell differentiation, it might represent a novel molecular target to treat T cell abnormalities in ACS.