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CD55 deposited on synovial collagen fibers protects from immune complex-mediated arthritis.

Karpus ON, Kiener HP, Niederreiter B, Yilmaz-Elis AS, van der Kaa J, Ramaglia V, Arens R, Smolen JS, Botto M, Tak PP, Verbeek JS, Hamann J - Arthritis Res. Ther. (2015)

Bottom Line: Abundant CD55 expression seen in FLS of the intimal lining layer was associated with linearly oriented reticular fibers and was resistant to phospholipase C treatment.Expression of CD55 colocalized with collagen type I and III as well as with complement C3.A comparable distribution of CD55 was established in three-dimensional micromasses after ≥3 weeks of culture together with the ECM.

View Article: PubMed Central - PubMed

Affiliation: Departments of Experimental Immunology, Internal Medicine, and Genetics, Room K0-140, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands. o.karpus@amc.uva.nl.

ABSTRACT

Introduction: CD55, a glycosylphosphatidylinositol-anchored, complement-regulating protein (decay-accelerating factor), is expressed by fibroblast-like synoviocytes (FLS) with high local abundance in the intimal lining layer. We here explored the basis and consequences of this uncommon presence.

Methods: Synovial tissue, primary FLS cultures, and three-dimensional FLS micromasses were analyzed. CD55 expression was assessed by quantitative polymerase chain reaction (PCR), in situ hybridization, flow cytometry, and immunohistochemistry. Reticular fibers were visualized by Gomori staining and colocalization of CD55 with extracellular matrix (ECM) proteins by confocal microscopy. Membrane-bound CD55 was released from synovial tissue with phospholipase C. Functional consequences of CD55 expression were studied in the K/BxN serum transfer model of arthritis using mice that in addition to CD55 also lack FcγRIIB (CD32), increasing susceptibility for immune complex-mediated pathology.

Results: Abundant CD55 expression seen in FLS of the intimal lining layer was associated with linearly oriented reticular fibers and was resistant to phospholipase C treatment. Expression of CD55 colocalized with collagen type I and III as well as with complement C3. A comparable distribution of CD55 was established in three-dimensional micromasses after ≥3 weeks of culture together with the ECM. CD55 deficiency did not enhance K/BxN serum-induced arthritis, but further exaggerated disease activity in Fcgr2b (-/-) mice.

Conclusions: CD55 is produced by FLS and deposited on the local collagen fiber meshwork, where it protects the synovial tissue against immune complex-mediated arthritis.

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Related in: MedlinePlus

Expression pattern of CD55 and collagen III coincides with collagenous structures in rheumatoid arthritis (RA) synovial tissue. Sections of RA synovial tissue first were stained with (A) anti-collagen antibody or (C) anti-CD55 antibody and then processed to (B/D) Gomori silver impregnation. Red arrowheads indicate localization of CD55 to collagenous fibers. Shown are representative stainings derived by light microscopy; magnification 20 x.
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Fig2: Expression pattern of CD55 and collagen III coincides with collagenous structures in rheumatoid arthritis (RA) synovial tissue. Sections of RA synovial tissue first were stained with (A) anti-collagen antibody or (C) anti-CD55 antibody and then processed to (B/D) Gomori silver impregnation. Red arrowheads indicate localization of CD55 to collagenous fibers. Shown are representative stainings derived by light microscopy; magnification 20 x.

Mentions: Microscopy of synovial tissue revealed a distinct fibrillar staining pattern of CD55 (Figure 1A/B) indicating a possible extracellular distribution. To test this hypothesis, we stained paraffin sections of synovial tissue first with a CD55 or collagen III antibody and subsequently with Gomori’s silver technique, which visualizes reticular collagenous fibers [24,25]. The silver impregnation revealed a meshwork of fibers, a pattern closely matching the distribution of collagen III at both the intimal lining layer and the synovial sublining area (Figure 2A/B). At the intimal lining layer, CD55 staining coincided with these fibers (Figure 2C/D), suggesting localization of CD55 with collagenous fibers, specifically at the intima.Figure 2


CD55 deposited on synovial collagen fibers protects from immune complex-mediated arthritis.

Karpus ON, Kiener HP, Niederreiter B, Yilmaz-Elis AS, van der Kaa J, Ramaglia V, Arens R, Smolen JS, Botto M, Tak PP, Verbeek JS, Hamann J - Arthritis Res. Ther. (2015)

Expression pattern of CD55 and collagen III coincides with collagenous structures in rheumatoid arthritis (RA) synovial tissue. Sections of RA synovial tissue first were stained with (A) anti-collagen antibody or (C) anti-CD55 antibody and then processed to (B/D) Gomori silver impregnation. Red arrowheads indicate localization of CD55 to collagenous fibers. Shown are representative stainings derived by light microscopy; magnification 20 x.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4325944&req=5

Fig2: Expression pattern of CD55 and collagen III coincides with collagenous structures in rheumatoid arthritis (RA) synovial tissue. Sections of RA synovial tissue first were stained with (A) anti-collagen antibody or (C) anti-CD55 antibody and then processed to (B/D) Gomori silver impregnation. Red arrowheads indicate localization of CD55 to collagenous fibers. Shown are representative stainings derived by light microscopy; magnification 20 x.
Mentions: Microscopy of synovial tissue revealed a distinct fibrillar staining pattern of CD55 (Figure 1A/B) indicating a possible extracellular distribution. To test this hypothesis, we stained paraffin sections of synovial tissue first with a CD55 or collagen III antibody and subsequently with Gomori’s silver technique, which visualizes reticular collagenous fibers [24,25]. The silver impregnation revealed a meshwork of fibers, a pattern closely matching the distribution of collagen III at both the intimal lining layer and the synovial sublining area (Figure 2A/B). At the intimal lining layer, CD55 staining coincided with these fibers (Figure 2C/D), suggesting localization of CD55 with collagenous fibers, specifically at the intima.Figure 2

Bottom Line: Abundant CD55 expression seen in FLS of the intimal lining layer was associated with linearly oriented reticular fibers and was resistant to phospholipase C treatment.Expression of CD55 colocalized with collagen type I and III as well as with complement C3.A comparable distribution of CD55 was established in three-dimensional micromasses after ≥3 weeks of culture together with the ECM.

View Article: PubMed Central - PubMed

Affiliation: Departments of Experimental Immunology, Internal Medicine, and Genetics, Room K0-140, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands. o.karpus@amc.uva.nl.

ABSTRACT

Introduction: CD55, a glycosylphosphatidylinositol-anchored, complement-regulating protein (decay-accelerating factor), is expressed by fibroblast-like synoviocytes (FLS) with high local abundance in the intimal lining layer. We here explored the basis and consequences of this uncommon presence.

Methods: Synovial tissue, primary FLS cultures, and three-dimensional FLS micromasses were analyzed. CD55 expression was assessed by quantitative polymerase chain reaction (PCR), in situ hybridization, flow cytometry, and immunohistochemistry. Reticular fibers were visualized by Gomori staining and colocalization of CD55 with extracellular matrix (ECM) proteins by confocal microscopy. Membrane-bound CD55 was released from synovial tissue with phospholipase C. Functional consequences of CD55 expression were studied in the K/BxN serum transfer model of arthritis using mice that in addition to CD55 also lack FcγRIIB (CD32), increasing susceptibility for immune complex-mediated pathology.

Results: Abundant CD55 expression seen in FLS of the intimal lining layer was associated with linearly oriented reticular fibers and was resistant to phospholipase C treatment. Expression of CD55 colocalized with collagen type I and III as well as with complement C3. A comparable distribution of CD55 was established in three-dimensional micromasses after ≥3 weeks of culture together with the ECM. CD55 deficiency did not enhance K/BxN serum-induced arthritis, but further exaggerated disease activity in Fcgr2b (-/-) mice.

Conclusions: CD55 is produced by FLS and deposited on the local collagen fiber meshwork, where it protects the synovial tissue against immune complex-mediated arthritis.

Show MeSH
Related in: MedlinePlus