The exposure of autoantigens by microparticles underlies the formation of potent inflammatory components: the microparticle-associated immune complexes.
Bottom Line: Rather, mpICs display autoantigens vimentin and fibrinogen, and recognition of these targets by anti-citrullinated peptide antibodies contributes to the production of mpICs.Functionally, platelet mpICs are highly pro-inflammatory, eliciting leukotriene production by neutrophils.Taken together, our data suggest a unique role for platelet MPs as autoantigen-expressing elements capable of perpetuating formation of inflammatory ICs.
Affiliation: Faculté de Médecine de l'Université Laval, Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du Centre Hospitalier Universitaire de Québec, Québec, Québec, Canada.Show MeSH
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Mentions: After optimizing high sensitivity flow cytometry (hs-FCM) parameters to distinguish small particles (Fig 1A), we assessed size and quantity of MPs in RA. For comparison, the MPs present in psoriatic arthritis (PA) – a disease family not associated with intra-articular ICs and complement consumption – were also examined. Similarly to MPs, ICs can display dimensions ranging from 100 to 1000 nm (Gyorgy et al, 2011a). Further, since it is hypothesized that ICs can interact with multiple MPs to form larger components, we included all particles up to 3500 nm in diameter for our analyses. Interestingly, unlike MPs in PA SF, MPs in RA SF appear highly heterogeneous in size and include two major subpopulations, one exhibiting diameters ranging from ∼100 to ∼300 nm and a second one from ∼700 to ∼3000 nm (Fig 1B and C).
Affiliation: Faculté de Médecine de l'Université Laval, Centre de Recherche en Rhumatologie et Immunologie, Centre de Recherche du Centre Hospitalier Universitaire de Québec, Québec, Québec, Canada.