Soluble Fas ligand is associated with natural killer cell dynamics in coronary artery disease.

Abstract

OBJECTIVE:

Apoptosis of natural killer (NK) cells is increased in patients with coronary artery disease (CAD) and may explain why NK cell levels are altered in these patients. Soluble forms of Fas and Fas ligand (L) are considered as markers of apoptosis. Here, we investigated whether plasma levels of Fas and FasL were associated with NK cell apoptosis and NK cell levels in CAD patients.

METHODS:

Fas and FasL in plasma were determined by ELISA in 2 cohorts of CAD patients; one longitudinal study measuring circulating NK cells and apoptotic NK cells by flow cytometry 1 day, 3 months and 12 months after a coronary event and one cross-sectional study measuring NK cell apoptosis ex vivo. Both studies included matched healthy controls. Fas and FasL were also determined in supernatants from NK cells undergoing cytokine-induced apoptosis in cell culture.

RESULTS:

In the 12-month longitudinal study, plasma FasL increased by 15% (p<0.001) and NK cell levels by 31% (p<0.05) while plasma Fas did not change. Plasma FasL and NK cell levels were significantly related at 3 months and 12 months, r=0.40, p<0.01. Furthermore, plasma FasL, but not plasma Fas, correlated with NK cell apoptosis ex vivo in CAD patients, r=0.54, p<0.05. In vitro, cytokine-induced apoptosis of NK cells resulted in abundant release of FasL.

CONCLUSION:

In CAD patients, FasL in plasma is associated with both apoptotic susceptibility of NK cells and dynamic changes in circulating NK cells. NK cells are also themselves a potential source of soluble FasL. Our findings link NK cell status to a soluble marker with possible atheroprotective effects thereby supporting a beneficial role of NK cells in CAD.

• Authors: Aleksander Szymanowski, Wei Li, Anna Lundberg, Chamilly Evaldsson, Lennart Nilsson, Karin Backteman, Jan Ernerudh, Lena Jonasson
• Journal: Atherosclerosis (Atherosclerosis) Vol. 233 Issue 2 Pg. 616-622 (Apr 2014) ISSN: 1879-1484 [Electronic] Ireland
• PMID: 24534457 (Publication Type: Journal Article)
• Copyright: Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Chemical References

• FAS protein, human
• FASLG protein, human
• Fas Ligand Protein
• IL6 protein, human
• Interleukin-15
• Interleukin-6
• fas Receptor
• Interleukin-12

Topics

• Aged
• Aged, 80 and over
• Apoptosis
• Cohort Studies
• Convalescence
• Coronary Artery Disease (blood, immunology, therapy)
• Cross-Sectional Studies
• Fas Ligand Protein (blood)
• Female
• Follow-Up Studies
• Humans
• Interleukin-12 (pharmacology)
• Interleukin-15 (pharmacology)
• Interleukin-6 (blood)
• Killer Cells, Natural (drug effects, metabolism, pathology)
• Lymphocyte Count
• Male
• Middle Aged
• Sweden
• T-Lymphocytes (drug effects, metabolism, pathology)
• fas Receptor (blood)