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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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CD55 either on immune or stromal cells protects from K/BxN serum transfer-induced arthritis in the absence of FcγRIIB (CD32). Mice were injected at day 0 with 12.5 μl/g K/BxN serum and followed for disease development. At day 10, animals were sacrificed for further analysis. (A) Collagen III staining in representative knee joint sections of non-diseased and arthritic Fcgr2b−/− mice. Magnification 20 x. (B) Development of arthritis evaluated by measuring clinical scores and ankle thickness. Depicted are mean ± standard error of the mean (SEM) of five animals per group. ***, P <0.001; **, P <0.01; *, P <0.05 (C) Histological evaluation of knee joints for proteoglycan loss (toluidine blue; above) and cell infiltration (hematoxylin and eosin; below). Photographs are representative of mice with no or highest disease activity in the experiment, respectively. Joint structures are labeled as F, femur; M, meniscus; S, synovium; T, tibia. Magnification 5 x. (D) Flow cytometry plots of isolated synovial tissue cells stained for CD11b+Gr1+ granulocytes, representative of mice with no or highest disease activity in the experiment, respectively. (E) Development of arthritis evaluated by measuring clinical scores and ankle thickness in bone marrow chimeric mice that lacked CD55 on stromal cells (Fcgr2b−/− x Cd55host−/−BM+/+, depicted as a dark green line), on immune cells (Fcgr2b−/− x Cd55host+/+BM−/−, depicted as a light green line), or on none of the two compartments (Fcgr2b−/− x Cd55host+/+BM+/+, depicted as a red line). Depicted are mean ± SEM values of five animals per group. (F) Flow cytometry plots of isolated synovial tissue cells stained for CD11b+Gr1+ granulocytes, representative of mice with no or highest disease activity in the experiment, respectively. Quantifications provided to the right in (C), (D), and (F) show individual mice (dots) with a horizontal line indicating the mean per group (n = 5).
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Fig5: CD55 either on immune or stromal cells protects from K/BxN serum transfer-induced arthritis in the absence of FcγRIIB (CD32). Mice were injected at day 0 with 12.5 μl/g K/BxN serum and followed for disease development. At day 10, animals were sacrificed for further analysis. (A) Collagen III staining in representative knee joint sections of non-diseased and arthritic Fcgr2b−/− mice. Magnification 20 x. (B) Development of arthritis evaluated by measuring clinical scores and ankle thickness. Depicted are mean ± standard error of the mean (SEM) of five animals per group. ***, P <0.001; **, P <0.01; *, P <0.05 (C) Histological evaluation of knee joints for proteoglycan loss (toluidine blue; above) and cell infiltration (hematoxylin and eosin; below). Photographs are representative of mice with no or highest disease activity in the experiment, respectively. Joint structures are labeled as F, femur; M, meniscus; S, synovium; T, tibia. Magnification 5 x. (D) Flow cytometry plots of isolated synovial tissue cells stained for CD11b+Gr1+ granulocytes, representative of mice with no or highest disease activity in the experiment, respectively. (E) Development of arthritis evaluated by measuring clinical scores and ankle thickness in bone marrow chimeric mice that lacked CD55 on stromal cells (Fcgr2b−/− x Cd55host−/−BM+/+, depicted as a dark green line), on immune cells (Fcgr2b−/− x Cd55host+/+BM−/−, depicted as a light green line), or on none of the two compartments (Fcgr2b−/− x Cd55host+/+BM+/+, depicted as a red line). Depicted are mean ± SEM values of five animals per group. (F) Flow cytometry plots of isolated synovial tissue cells stained for CD11b+Gr1+ granulocytes, representative of mice with no or highest disease activity in the experiment, respectively. Quantifications provided to the right in (C), (D), and (F) show individual mice (dots) with a horizontal line indicating the mean per group (n = 5).

Mentions: To address the possibility that CD55 protects the synovial tissue from complement-mediated immune activation in vivo, we studied the K/BxN serum transfer model of arthritis. The K/BxN model is driven by immune complexes and depends on complement, Fc receptors, and innate immune cells, mainly neutrophils [35-37]. In analogy with the situation seen in RA synovial tissue, we observed intensive collagen III staining in the intimal lining layer in arthritic mice (Figure 5A).Figure 5


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)

CD55 either on immune or stromal cells protects from K/BxN serum transfer-induced arthritis in the absence of FcγRIIB (CD32). Mice were injected at day 0 with 12.5 μl/g K/BxN serum and followed for disease development. At day 10, animals were sacrificed for further analysis. (A) Collagen III staining in representative knee joint sections of non-diseased and arthritic Fcgr2b−/− mice. Magnification 20 x. (B) Development of arthritis evaluated by measuring clinical scores and ankle thickness. Depicted are mean ± standard error of the mean (SEM) of five animals per group. ***, P <0.001; **, P <0.01; *, P <0.05 (C) Histological evaluation of knee joints for proteoglycan loss (toluidine blue; above) and cell infiltration (hematoxylin and eosin; below). Photographs are representative of mice with no or highest disease activity in the experiment, respectively. Joint structures are labeled as F, femur; M, meniscus; S, synovium; T, tibia. Magnification 5 x. (D) Flow cytometry plots of isolated synovial tissue cells stained for CD11b+Gr1+ granulocytes, representative of mice with no or highest disease activity in the experiment, respectively. (E) Development of arthritis evaluated by measuring clinical scores and ankle thickness in bone marrow chimeric mice that lacked CD55 on stromal cells (Fcgr2b−/− x Cd55host−/−BM+/+, depicted as a dark green line), on immune cells (Fcgr2b−/− x Cd55host+/+BM−/−, depicted as a light green line), or on none of the two compartments (Fcgr2b−/− x Cd55host+/+BM+/+, depicted as a red line). Depicted are mean ± SEM values of five animals per group. (F) Flow cytometry plots of isolated synovial tissue cells stained for CD11b+Gr1+ granulocytes, representative of mice with no or highest disease activity in the experiment, respectively. Quantifications provided to the right in (C), (D), and (F) show individual mice (dots) with a horizontal line indicating the mean per group (n = 5).
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Related In: Results  -  Collection

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Fig5: CD55 either on immune or stromal cells protects from K/BxN serum transfer-induced arthritis in the absence of FcγRIIB (CD32). Mice were injected at day 0 with 12.5 μl/g K/BxN serum and followed for disease development. At day 10, animals were sacrificed for further analysis. (A) Collagen III staining in representative knee joint sections of non-diseased and arthritic Fcgr2b−/− mice. Magnification 20 x. (B) Development of arthritis evaluated by measuring clinical scores and ankle thickness. Depicted are mean ± standard error of the mean (SEM) of five animals per group. ***, P <0.001; **, P <0.01; *, P <0.05 (C) Histological evaluation of knee joints for proteoglycan loss (toluidine blue; above) and cell infiltration (hematoxylin and eosin; below). Photographs are representative of mice with no or highest disease activity in the experiment, respectively. Joint structures are labeled as F, femur; M, meniscus; S, synovium; T, tibia. Magnification 5 x. (D) Flow cytometry plots of isolated synovial tissue cells stained for CD11b+Gr1+ granulocytes, representative of mice with no or highest disease activity in the experiment, respectively. (E) Development of arthritis evaluated by measuring clinical scores and ankle thickness in bone marrow chimeric mice that lacked CD55 on stromal cells (Fcgr2b−/− x Cd55host−/−BM+/+, depicted as a dark green line), on immune cells (Fcgr2b−/− x Cd55host+/+BM−/−, depicted as a light green line), or on none of the two compartments (Fcgr2b−/− x Cd55host+/+BM+/+, depicted as a red line). Depicted are mean ± SEM values of five animals per group. (F) Flow cytometry plots of isolated synovial tissue cells stained for CD11b+Gr1+ granulocytes, representative of mice with no or highest disease activity in the experiment, respectively. Quantifications provided to the right in (C), (D), and (F) show individual mice (dots) with a horizontal line indicating the mean per group (n = 5).
Mentions: To address the possibility that CD55 protects the synovial tissue from complement-mediated immune activation in vivo, we studied the K/BxN serum transfer model of arthritis. The K/BxN model is driven by immune complexes and depends on complement, Fc receptors, and innate immune cells, mainly neutrophils [35-37]. In analogy with the situation seen in RA synovial tissue, we observed intensive collagen III staining in the intimal lining layer in arthritic mice (Figure 5A).Figure 5

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