Microparticles from patients with systemic lupus erythematosus induce production of reactive oxygen species and degranulation of polymorphonuclear leukocytes

Line Kjær Winberg,Søren Jacobsen,Claus H Nielsen

doi:10.1186/s13075-017-1437-3

Line Kjær Winberg, Søren Jacobsen + Show 1 more

Open Access

https://doi.org/10.1186/s13075-017-1437-3

Copy DOI

Abstract

BackgroundThe interaction of circulating microparticles (MPs) with immune cells in systemic lupus erythematosus (SLE) is sparsely investigated. We examined the ability of MPs from SLE patients to induce production of reactive oxygen species (ROS) and degranulation of polymorphonuclear leukocytes (PMNs).MethodsPlasma MPs, leukocytes and sera isolated from 20 SLE patients and 10 healthy controls were mixed in different combinations, with or without lipopolysaccharide (LPS), and incubated for 30 min. Dihydrorhodamine 123 was used to measure ROS production by flow cytometry. The ability of immunoglobulin G (IgG) isolated from five SLE patients to increase MP-induced production of ROS by PMNs was tested. Cell supernatants were analysed for content of primary, secondary and tertiary granule components by Luminex assays.ResultsMPs from SLE patients promoted ROS production by PMNs, and enhanced LPS-induced ROS production and release of primary granules by PMNs, when added to samples of autologous leukocytes and serum. In a similar autologous setting, MPs from healthy controls enhanced LPS-induced ROS production by PMNs. When leukocytes from a healthy control were stimulated with autologous MPs in the presence of various sera, SLE patient serum promoted ROS production and release of primary and secondary granules by PMNs. A role for antibodies in this respect was indicated by the observation that supplementation of normal serum with IgG from SLE patients promoted MP-induced ROS production by healthy PMNs. Moreover, when various MPs were incubated with leukocytes and serum from a healthy control, patient-derived MPs induced more ROS production by PMNs than did healthy control-derived MPs.ConclusionsSLE patients display increased ROS production and degranulation by PMNs in response to MPs, which partly depends on serum components, including antibodies, MP properties and hyper-responsiveness of the PMNs per se.

Highlights

The interaction of circulating microparticles (MPs) with immune cells in systemic lupus erythematosus (SLE) is sparsely investigated
reactive oxygen species (ROS) production and degranulation of Polymorphonuclear leukocyte (PMN) stimulated with MPs and/or LPS We examined ROS production by PMNs in fresh leukocyte preparations by flow cytometry using dihydrorhodamine 123 as a probe
When PMNs were stimulated with LPS, co-stimulation with MPs increased the production of ROS significantly in PMNs from both SLE patients and healthy controls (Fig. 1e)

Summary

Introduction

The interaction of circulating microparticles (MPs) with immune cells in systemic lupus erythematosus (SLE) is sparsely investigated. Evidence of involvement of polymorphonuclear leukocytes (PMNs) in the pathogenesis of SLE has become increasingly established during the past decade: PMNs from SLE patients show enhanced apoptosis and production of neutrophil extracellular traps (NETosis) [7] and decreased production of reactive oxygen species (ROS) after stimulation with phorbol-12-myristate-13-acetate (PMA) [8], as well as with complement-opsonized immune complexes (ICs) [9]. This may be explained by a generalized hyper-reactivity of SLE PMNs [7, 10, 11] and death of the most reactive PMNs [8]. Antioxidant treatment has been shown to reduce both oxidative stress and symptom severity in SLE [13, 14]

Objectives

Methods

Results

Discussion

Conclusion