Volume 11 Supplement 2

Proceedings of 20th Pediatric Rheumatology European Society (PReS) Congress

Open Access

PReS-FINAL-2336: Induction of MDSCS in Muckle-Wells syndrome

  • N Rieber1,
  • A Brand1,
  • D Neri1,
  • T Hall1,
  • I Schäfer1,
  • S Hansmann1,
  • J Kümmerle-Deschner1 and
  • D Hartl1
Pediatric Rheumatology201311(Suppl 2):P326

https://doi.org/10.1186/1546-0096-11-S2-P326

Published: 5 December 2013

Introduction

Muckle-Wells syndrome (MWS) is caused by mutations in the NLRP3-gene encoding cryopyrin, leading to overproduction of IL-1β and other NLRP3 inflammasome products. Myeloid-derived suppressor cells (MDSCs) represent a novel innate immune cell subset, are generated in tumor, infective, and proinflammatory microenvironments and are capable of suppressing T cell responses. Consequently, MDSCs are considered a key intermediary in balancing innate and adaptive immune responses, particularly under chronic disease conditions.

Objectives

We hypothesized that NLRP3 inflammasome-dependent factors induce the generation of MDSCs in MWS.

Methods

We studied granulocytic MDSC numbers in 25 MWS patients under anti-IL-1 therapy with canakinumab and 20 healthy controls. After Ficoll density gradient sedimentation, granulocytic MDSCs were characterized as CD33highCD66bhighIL-4RainterHLA-DRlow neutrophilic cells in the PBMC fraction, according to previously established human MDSC analysis methods. The functionality of MACS-isolated MDSCs was assessed using polyclonal T cell proliferation and cytokine/chemokine secretion tests. Physician's global assessment of disease activity, CRP, ESR, and T helper cell subsets were determined at the same time points and correlated with MDSC levels. Serum samples of 22 MWS patients and 5 healthy controls were examined by multiplex technique for possible MDSC inducing factors.

Results

MWS patients under anti-IL-1 therapy displayed significantly elevated MDSC numbers (mean 1.65 ± 0.33%; range 0.16 - 5.17%) compared to healthy controls (mean 0.45 ± 0.05%; range 0.12 - 1.04%; p = 0.0025), although clinical MWS-disease activity was generally low at time of examination. MDSCs were functionally competent, as they suppressed polyclonal T cell proliferation, Th1, Th2, and Th17 responses. MDSCs correlated directly with Treg/Th17 and Treg/Th1 ratios indicating an influence on T helper cell subsets. Multiplex assays revealed the established MDSC-inducing growth factors GM-CSF and VEGF elevated in MWS sera even under anti-IL-1 therapy with canakinumab.

Conclusion

MWS patients under anti-IL-1 therapy display significantly elevated numbers of granulocytic MDSCs. Increased MDSCs in MWS might represent a novel autologous anti-inflammatory mechanism in autoinflammatory conditions and may serve as a future therapeutic target.

Disclosure of interest

N. Rieber Grant/Research Support from: NR, JKD, and DH obtained research grants from Novartis GmbH, Consultant for: NR and JKD took part in advisory boards for Novartis GmbH, A. Brand: None Declared, D. Neri: None Declared, T. Hall: None Declared, I. Schäfer: None Declared, S. Hansmann: None Declared, J. Kümmerle-Deschner: None Declared, D. Hartl: None Declared.

Authors’ Affiliations

(1)
Children's Hospital, Autoinflammation Reference Center, University of Tübingen

Copyright

© Rieber et al.; licensee BioMed Central Ltd. 2013

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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