Research article

Microparticle-induced release of B-lymphocyte regulators by rheumatoid synoviocytes

Laurent Messer^1,2 , Ghada Alsaleh^1,2 , Jean-Marie Freyssinet^3,4 , Fatiha Zobairi^3,4 , Isabelle Leray^1,2 , Jacques-Eric Gottenberg^1,2 , Jean Sibilia^1,2 , Florence Toti-Orfanoudakis^3,4 and Dominique Wachsmann^1,2

¹  Laboratoire Physiopathologie des Arthrites, Université de Strasbourg, UFR Sciences Pharmaceutiques, 74 route du Rhin, Illkirch 67401, France

²  Département de Rhumatologie, Hôpitaux Universitaires de Strasbourg, Avenue Molière, Strasbourg Hautepierre 67200, France

³  Laboratoire de Biologie Cellulaire et Vasculaire, Faculté de Médecine, 4 rue Kirschleger, Strasbourg 67085, France

⁴  Inserm U770 Hôpital Bicêtre (AP-HP), 78 rue du Général Leclerc, Le Kremlin-Bicêtre 94275, France

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Arthritis Research & Therapy 2009, 11:R40doi:10.1186/ar2648

Published:	16 March 2009

Abstract

Introduction

In the present study, we investigated the ability of microparticles isolated from synovial fluids from patients with rheumatoid arthritis or osteoarthritis to induce the synthesis and release of key cytokines of B-lymphocyte modulation such as B cell-activating factor, thymic stroma lymphopoietin, and secretory leukocyte protease inhibitor by rheumatoid fibroblast-like synoviocytes.

Methods

Microparticles were analyzed in synovial fluids from patients with rheumatoid arthritis, osteoarthritis, microcristalline arthritis, and reactive arthritis. In addition, microparticle release after activation from various cell lines (CEM lymphocyte and THP-1 cells) was assessed. Microparticles were isolated by differential centrifugation, and quantitative determinations were carried out by prothrombinase assay after capture on immobilized annexin V. B cell-activating factor, thymic stroma lymphopoietin, and secretory leukocyte protease inhibitor release was evaluated by enzyme-linked immunosorbent assay.

Results

Microparticles isolated from synovial fluids obtained from rheumatoid arthritis and osteoarthritis patients or microparticles derived from activated THP-1 cells were able to induce B cell-activating factor, thymic stroma lymphopoietin, and secretory leukocyte protease inhibitor release by rheumatoid arthritis fibroblast-like synoviocytes. Conversely, CEM-lymphocytes-derived microparticles generated by treatment with a combination of PHA, PMA and Adt-D did not promote the release of B cell-activating factor but favored the secretion of thymic stroma lymphopoietin and secretory leukocyte protease inhibitor by rheumatoid arthritis fibrobast-like synoviocytes. However, microparticles isolated from actinomycin D-treated CEM lymphocytes were not able to induce B cell-activating factor, thymic stroma lymphopoietin, or secretory leukocyte protease inhibitor release, indicating that microparticles derived from apoptotic T cells do not function as effectors in B-cell activation.

Conclusions

These results demonstrate that microparticles are signalling structures that may act as specific conveyors in the triggered induction and amplification of autoimmunity. This study also indicates that microparticles have differential effects in the crosstalk between B lymphocytes and target cells of autoimmunity regarding the parental cells from which they derive.