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The exposure of autoantigens by microparticles underlies the formation of potent inflammatory components: the microparticle-associated immune complexes.

Cloutier N, Tan S, Boudreau LH, Cramb C, Subbaiah R, Lahey L, Albert A, Shnayder R, Gobezie R, Nigrovic PA, Farndale RW, Robinson WH, Brisson A, Lee DM, Boilard E - EMBO Mol Med (2012)

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.

View Article: PubMed Central - PubMed

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.

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Platelet MPs in RA SF exhibit autoantigensA. Identification of the autoantibodies contained in CD41+ mpICs in RA SF. The binding specificity of the mpIC-eluted IgG to 40 antigens was determined on a Bio-Plex™ bead-based antigen array and only the antigens that presented significant binding are presented (n = 23 RA patients, identified 1–23). Colours denote amount of binding: undetectable (blue); progressively greater binding (green, yellow, red). Color scale is presented on right. The negative control (C) was obtained by incubating isotypic antibodies in SF. Cfc; cyclic citrullinated filaggrin, H2A/a; histone H2A/a.B–D. The presence of autoantigens was examined on in vitro platelet MPs (left) and platelet MPs from RA SF (right) by hs-FCM (n = 4). (B) MPs were incubated with anti-vimentin and the interaction was revealed using Alexa 647-conjugated secondary antibody. (C) MPs were incubated with exogenous Alexa 647-fluorescent fibrinogen and associations quantified by hs-FCM. (D) MPs were incubated with anti-fibrinogen and the interaction with endogenous fibrinogen was determined using Alexa 647-conjugated secondary antibody. The vertical lines were positioned according to the isotypic controls. Green: negative population; blue: positive population. The % of positive MPs is indicated on graphs.
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fig06: Platelet MPs in RA SF exhibit autoantigensA. Identification of the autoantibodies contained in CD41+ mpICs in RA SF. The binding specificity of the mpIC-eluted IgG to 40 antigens was determined on a Bio-Plex™ bead-based antigen array and only the antigens that presented significant binding are presented (n = 23 RA patients, identified 1–23). Colours denote amount of binding: undetectable (blue); progressively greater binding (green, yellow, red). Color scale is presented on right. The negative control (C) was obtained by incubating isotypic antibodies in SF. Cfc; cyclic citrullinated filaggrin, H2A/a; histone H2A/a.B–D. The presence of autoantigens was examined on in vitro platelet MPs (left) and platelet MPs from RA SF (right) by hs-FCM (n = 4). (B) MPs were incubated with anti-vimentin and the interaction was revealed using Alexa 647-conjugated secondary antibody. (C) MPs were incubated with exogenous Alexa 647-fluorescent fibrinogen and associations quantified by hs-FCM. (D) MPs were incubated with anti-fibrinogen and the interaction with endogenous fibrinogen was determined using Alexa 647-conjugated secondary antibody. The vertical lines were positioned according to the isotypic controls. Green: negative population; blue: positive population. The % of positive MPs is indicated on graphs.

Mentions: Proteomic analyses permit the identification of the antigens targeted by autoantibodies (Hueber et al, 2005; Monach et al, 2009; Zhao et al, 2008). To identify autoantigens expressed by platelet MPs, we isolated the CD41+ mpICs from RA SF using magnetic affinity columns. These CD41+-enriched preparations, composed of immunoglobulins and complement C3a (466.6 ± 193 pg C3a/µg protein, n = 23), were applied to protein G affinity columns and the IgG within mpICs were isolated. Using an autoantigen microarray (Hueber et al, 2005; Robinson et al, 2002), we demonstrate that the IgG from platelet mpICs associate with a broad series of recognized citrullinated autoantigens (Fig 6A).


The exposure of autoantigens by microparticles underlies the formation of potent inflammatory components: the microparticle-associated immune complexes.

Cloutier N, Tan S, Boudreau LH, Cramb C, Subbaiah R, Lahey L, Albert A, Shnayder R, Gobezie R, Nigrovic PA, Farndale RW, Robinson WH, Brisson A, Lee DM, Boilard E - EMBO Mol Med (2012)

Platelet MPs in RA SF exhibit autoantigensA. Identification of the autoantibodies contained in CD41+ mpICs in RA SF. The binding specificity of the mpIC-eluted IgG to 40 antigens was determined on a Bio-Plex™ bead-based antigen array and only the antigens that presented significant binding are presented (n = 23 RA patients, identified 1–23). Colours denote amount of binding: undetectable (blue); progressively greater binding (green, yellow, red). Color scale is presented on right. The negative control (C) was obtained by incubating isotypic antibodies in SF. Cfc; cyclic citrullinated filaggrin, H2A/a; histone H2A/a.B–D. The presence of autoantigens was examined on in vitro platelet MPs (left) and platelet MPs from RA SF (right) by hs-FCM (n = 4). (B) MPs were incubated with anti-vimentin and the interaction was revealed using Alexa 647-conjugated secondary antibody. (C) MPs were incubated with exogenous Alexa 647-fluorescent fibrinogen and associations quantified by hs-FCM. (D) MPs were incubated with anti-fibrinogen and the interaction with endogenous fibrinogen was determined using Alexa 647-conjugated secondary antibody. The vertical lines were positioned according to the isotypic controls. Green: negative population; blue: positive population. The % of positive MPs is indicated on graphs.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3569640&req=5

fig06: Platelet MPs in RA SF exhibit autoantigensA. Identification of the autoantibodies contained in CD41+ mpICs in RA SF. The binding specificity of the mpIC-eluted IgG to 40 antigens was determined on a Bio-Plex™ bead-based antigen array and only the antigens that presented significant binding are presented (n = 23 RA patients, identified 1–23). Colours denote amount of binding: undetectable (blue); progressively greater binding (green, yellow, red). Color scale is presented on right. The negative control (C) was obtained by incubating isotypic antibodies in SF. Cfc; cyclic citrullinated filaggrin, H2A/a; histone H2A/a.B–D. The presence of autoantigens was examined on in vitro platelet MPs (left) and platelet MPs from RA SF (right) by hs-FCM (n = 4). (B) MPs were incubated with anti-vimentin and the interaction was revealed using Alexa 647-conjugated secondary antibody. (C) MPs were incubated with exogenous Alexa 647-fluorescent fibrinogen and associations quantified by hs-FCM. (D) MPs were incubated with anti-fibrinogen and the interaction with endogenous fibrinogen was determined using Alexa 647-conjugated secondary antibody. The vertical lines were positioned according to the isotypic controls. Green: negative population; blue: positive population. The % of positive MPs is indicated on graphs.
Mentions: Proteomic analyses permit the identification of the antigens targeted by autoantibodies (Hueber et al, 2005; Monach et al, 2009; Zhao et al, 2008). To identify autoantigens expressed by platelet MPs, we isolated the CD41+ mpICs from RA SF using magnetic affinity columns. These CD41+-enriched preparations, composed of immunoglobulins and complement C3a (466.6 ± 193 pg C3a/µg protein, n = 23), were applied to protein G affinity columns and the IgG within mpICs were isolated. Using an autoantigen microarray (Hueber et al, 2005; Robinson et al, 2002), we demonstrate that the IgG from platelet mpICs associate with a broad series of recognized citrullinated autoantigens (Fig 6A).

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.

View Article: PubMed Central - PubMed

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
Related in: MedlinePlus