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Biomedical subjects

J C Burrows

Publications and source records attributed to J C Burrows.

12 recordsLinked to original sources

In vitro cytokine modulation of intercellular adhesion molecule-1 expression on systemic sclerosis dermal fibroblasts.

Our objective was to study the regulation of intercellular adhesion molecule-1 (ICAM-1) expression by cytokines on cultured fibroblasts obtained from systemic sclerosis and normal skin. ICAM-1 expression on dermal fibroblasts obtained from diffuse systemic sclerosis patients with early disease (< or = 2 years) and normal dermal fibroblasts incubated with and without cytokines was measured by radioimmunoassay and flow cytometry. Systemic sclerosis dermal fibroblasts expressed lower basal levels of ICAM-1 than did normal dermal fibroblasts. Both the normal and systemic sclerosis dermal fibroblasts increased their cell surface expression of ICAM-1 in response to interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma) in a dose-dependent fashion. Systemic sclerosis dermal fibroblasts appeared to be hyperresponsive to IL-1 beta, TNF-alpha, and IFN-gamma. ICAM-1 expression in response to cytokine stimulation increased to a greater degree on systemic sclerosis compared to normal dermal fibroblasts. The enhanced ICAM-1 expression may play a role in the retention of leukocytes involved in systemic sclerosis skin lesions.

Adult↗

4A11, a monoclonal antibody recognizing a novel antigen expressed on aberrant vascular endothelium. Upregulation in an in vivo model of contact dermatitis.

We describe the production and characterization of a novel monoclonal antibody (MAb) that recognizes a human endothelial cell antigen expressed mainly in inflamed and malignant disease states. We have used immunohistochemistry to determine the spectrum of reactivity of this MAb compared with that of a MAb to factor VIII-related antigen (MAb FVIII). MAb 4A11 does not react with several myeloid or lymphoid cell lines or with peripheral blood cells. Unlike MAb FVIII, MAb 4A11 does not react with platelets. MAb 4A11 reacts with most vascular endothelial cells in lymphoid tissue but with few (< 10%) endothelial cells in thymus, spleen, liver, lung, adrenal gland, placenta, testes, and skin. MAb 4A11 detects endothelial cells in diseased tissues such as rheumatoid and osteoarthritic synovium and psoriatic skin. Vascular endothelial cells in both adrenal tumors and cutaneous Kaposi's sarcomas lesions are MAb 4A11 reactive. In vitro the 4A11 antigen is not detectable on cultured human umbilical vein endothelial cells and its expression is not induced on these cells by treatment with lipopolysaccharide, interferon-gamma, interleukin-1 and -6, or tumor necrosis factor-alpha. However, in an in vivo model of allergic contact dermatitis the 4A11 antigen is upregulated differentially from other endothelial markers such as E-selectin, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1. In this dermal model of inflammation, poison ivy extract is applied to the skin and biopsies taken at 0, 6, and 24 hours. In addition to focal keratinocyte expression, 4A11 antigen is found on 11% of dermal endothelial cells at time 0 and antigen expression increases with time until 24 hours, when 4A11 antigen is present on 63% of the endothelial cells. Using thin layer chromatography, MAb 4A11 reacts with the H-5-2 [Fuc alpha 2Gal beta 4GlcNAc beta 3Gal beta 4Glc beta 1Cer] and Lewis(y)-6 [Fuc alpha 2Gal beta 4(Fuc alpha 3)GlcNAc beta 3Gal beta 4-Glc beta 1Cer] blood group glycolipids. The presence of the novel 4A11 antigen in inflamed and malignant tissues containing many blood vessels and its differential upregulation in allergic contact dermatitis may signify an important function for this antigen in the inflammatory process.

Animals↗

Localization of the angiogenesis inhibitor thrombospondin in human synovial tissues.

Recently, we have shown that a macrophage subpopulation isolated from the synovial tissue of patients with rheumatoid arthritis was potently angiogenic and that a secreted inhibitor of angiogenesis, which is controlled by a tumor suppressor gene in hamster cells, was similar to thrombospondin. In order to investigate the potential role of thrombospondin in human arthritic disorders, we employed immunohistochemistry to examine frozen synovial tissue sections from normal controls (n = 3), patients with rheumatoid arthritis (n = 14) and with osteoarthritis (n = 5). The synovial tissues were stained with monoclonal antibody (mAb) A2.5, which reacts with the heparin-binding domain of thrombospondin, mAb A6.1, which reacts with the epidermal growth factor repeat motif of thrombospondin, and with mAb A4.1, which reacts with the properdin-repeat domain of thrombospondin. In rheumatoid synovial tissues the anti-thrombospondin mAbs reacted with vascular endothelial cells, and to a lesser extent with vascular smooth muscle. Pericytes were stained, particularly with mAb 6.1. Reactivity was also found with isolated macrophages and with the macrophage-derived synovial lining layer in over half the tissues. In osteoarthritis synovial tissues, mAb A2.5 stained fewer macrophages than in rheumatoid arthritis synovial tissues. Slightly fewer blood vessels reacted with mAb A2.5 in normal compared to diseased synovia. The mAbs reacted with capillaries, venules and arterioles in all synovial tissues. We conclude that mAbs to thrombospondin react primarily with blood vessels and macrophages in synovial tissues. Perhaps thrombospondin may function as an adhesive glycoprotein mediating cellular interactions, or it may serve to counteract the effects of the angiogenic factors produced by cells within diseased synovial tissues.

Antibodies, Monoclonal↗

Decreased monocyte-mediated angiogenesis in scleroderma.

Scleroderma is a disease characterized by proliferative vascular lesions in which monocytes/macrophages may play a key role. Monocytes were isolated from 14 scleroderma patients and 11 normal controls and cultured with or without lipopolysaccharide (LPS) (5 micrograms/ml). Monocyte-conditioned medium was assayed in the rat corneal bioassay for angiogenesis. Conditioned medium from normal monocytes was nonangiogenic, as was conditioned medium from scleroderma monocytes. While conditioned medium from LPS-activated normal monocytes was potently angiogenic in 11/13 corneas, conditioned medium from LPS-activated scleroderma monocytes was angiogenic in only 3/14 corneas. Levels of the angiogenic cytokine tumor necrosis factor-alpha (TNF-alpha) were measured in conditioned medium from scleroderma and normal monocytes. TNF-alpha levels were not significantly different in patient and control groups and thus do not account for the decreased angiogenic activity exhibited by scleroderma monocytes. As monocytes require activation to produce angiogenic activity, we determined the cell surface binding of monoclonal antibodies to activation-related (HLA-DR, 3D8, and 8D7) and other (Leu-M5) markers on monocytes by radioimmunoassay. Monocytes were cultured alone, with LPS (5 micrograms/ml), or with interferon-gamma (IFN) (200 units/ml). The usual increase in binding of anti-HLA-DR on stimulation of scleroderma monocytes with IFN was slightly less than that of controls. IFN-stimulated monocytes bound less anti-8D7 than controls. Anti-3D8 and anti-Leu-M5 binding was comparable in both groups. These results suggest that scleroderma monocytes do not produce normal levels of angiogenic activity with LPS stimulation, have some altered markers of activation on their cell surfaces, and may thus contribute to the aberrant vascular proliferation found in this disease.

Adult↗

Inhibition of production of monocyte/macrophage-derived angiogenic activity by oxygen free-radical scavengers.

We showed previously that thiol-containing compounds inhibited the production of macrophage-mediated angiogenic activity. Since thiol-containing compounds may act on macrophages by affecting activation and inhibiting the production of oxygen free-radicals, we studied the effects of oxygen free-radical scavengers on production of angiogenic activity by elicited mouse peritoneal macrophages and lipopolysaccharide stimulated normal human monocytes. Monocyte/macrophage conditioned media were potently angiogenic when assayed in rat corneas, while conditioned media, from oxygen free-radical scavenger-treated cells were not. The inhibitory effect of oxygen free-radical scavengers was due to a direct effect on monocyte/macrophage production of angiogenic activity but was not due solely to a decrease in the production of the macrophage-derived angiogenic cytokine tumor necrosis factor-alpha. We conclude that oxygen free-radical scavengers are potent inhibitors of the production of macrophage-mediated angiogenic activity.

Angiogenesis Inducing Agents↗

Monoclonal antibodies defining shared human macrophage-endothelial antigens.

We have selected several monoclonal antibodies (mAbs) producing using human rheumatoid arthritis (RA) synovial macrophages (m phi s) as immunogen. Of these, mAbs 8H2, 10G7 and 10G9 showed cross reactivity with endothelium, suggesting common antigens between these cell types. We have determined the spectrum of reactivity of these mAbs on hematopoietic cell lines, peripheral blood cells, and inflammatory and non-inflammatory tissues by immunohistochemistry. MAb 8H2 does not react with the myeloid cell lines HL60 (myelocytic), U937 (histiocytic lymphoma), and K562 (erythroleukemia), or with peripheral blood cells. In normal and inflamed tissue sections, mAb 8H2 reacts with m phi s and endothelial cells. In contrast, mAb 10G7 does not react with peripheral blood cells, but reacts with HL60, U937, and K562 cell lines, as well as with m phi s and endothelial cells in inflamed and noninflamed tissues. MAb 10G9 does not react with myeloid cell lines, but reacts with monocytes and platelets in peripheral blood. In both normal and inflamed tissues, mAb 10G9 reacts with m phi s and endothelial cells. The antigens identified by these three mAbs were characterized biochemically, by enzymatic digestion of RA synovial tissue m phi s followed by a cellular ELISA, as well as by reactivity of the mAbs with NIH-3T3 cells genetically engineered to express known myeloid antigens. These mAbs reacted with protein or glycoprotein antigens distinct from the known myeloid antigens CD13, CD14, CD33, CD34, CD36, and c-fms. These mAbs should prove to be a valuable tool for studying m phi s and endothelial cells and their shared antigenic determinants.

3T3 Cells↗

Synovial tissue macrophage as a source of the chemotactic cytokine IL-8.

Cells of the synovial microenvironment may recruit neutrophils (PMN) and lymphocytes into synovial fluid, as well as lymphocytes into the synovial tissues, of arthritic patients. We have investigated the production of the chemotactic cytokine IL-8 by using sera, synovial fluid, synovial tissue, and macrophages and fibroblasts isolated from synovial tissues from 75 arthritic patients. IL-8 levels were higher in synovial fluid from rheumatoid (RA) patients (mean +/- SE, 14.37 +/- 5.8 ng/ml), compared with synovial fluid from osteoarthritis patients (0.135 +/- 17 ng/ml) (p less than 0.05) or from patients with other arthritides (5.52 +/- 5.11 ng/ml). IL-8 from RA sera was 8.44 +/- 2.33 ng/ml, compared with nondetectable levels found in normal sera. IL-8 levels from RA sera and synovial fluid were strongly positively correlated (r = 0.96, p less than 0.05). Moreover, RA synovial fluid chemotactic activity for PMN in these fluids was inhibited 40 +/- 5% upon incubation with neutralizing polyclonal antibody to IL-8. Synovial tissue fibroblasts released only small amounts of constitutive IL-8 but could be induced to produce IL-8 by stimulation with either IL-1 beta, TNF-alpha, or LPS. In contrast, unlike normal PBMC or alveolar macrophages, macrophages isolated from RA synovial tissue constitutively expressed both IL-8 mRNA and antigenic IL-8. RA synovial macrophage IL-8 expression was not augmented by incubation with either LPS, TNF-alpha, or IL-1 beta. Immunohistochemical analysis of synovial tissue showed that a greater percentage of RA macrophages than osteoarthritis macrophages reacted with anti-IL-8. Whereas macrophages were the predominant cell for immunolocalization of IL-8, less than 5% of synovial tissue fibroblasts were positive for immunolocalized IL-8. These results suggest that macrophage-derived IL-8 may play an important role in the recruitment of PMN in synovial inflammation associated with RA.

Animals↗

Thiol-containing compounds inhibit the production of monocyte/macrophage-derived angiogenic activity.

Macrophage (M phi)-mediated angiogenesis is believed to play an important role in the pathogenesis of rheumatoid arthritis. Gold sodium thiomalate, which is used in the treatment of rheumatoid arthritis, is a potent inhibitor of the production of m phi-derived angiogenic activity. To determine the mechanism of this inhibition, we studied the effects of thiol containing compounds (TCCs) on elicited mouse peritoneal m phi and lipopolysaccharide stimulated normal human monocytes. Monocyte/m phi conditioned media were potently angiogenic when assayed in rat corneas, while conditioned media from viable monocyte/m phi s treated with TCCs (at concentrations of 8.3-16.6 x 10(-5) M) were not. TCCs inhibited production of angiogenic activity by the m phi s rather than affecting other components of the angiogenic response such as the angiogenic factors or the target microvasculature of the rat cornea. Levels of the angiogenic mediator tumor necrosis factor-alpha (TNF-alpha) were not decreased in conditioned media of monocyte/m phi s treated with TCCs. We conclude that TCCs are potent inhibitors of the production of m phi-mediated angiogenic activity. This action of TCCs on m phi s may be in part responsible for the mechanism of action of therapeutic gold compounds in rheumatoid arthritis.

Animals↗

Immunolocalization of endothelial and leukocyte adhesion molecules in human rheumatoid and osteoarthritic synovial tissues.

Leukocyte adhesion to endothelium plays an important role in the development and perpetuation of chronic inflammatory diseases such as rheumatoid arthritis (RA). In order to help define the role of adhesion molecules in arthritic disorders, we have studied the expression of CD11c, endothelial leukocyte adhesion molecule-1 (ELAM-1), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 in synovial tissues from patients with RA and osteoarthritis (OA) by immunohistochemistry. CD11c is expressed predominantly on macrophages deep within RA and OA synovial tissues, as well as on some synovial tissue lining cells. ELAM-1 has endothelial reactivity, being present mainly on venules and capillaries and staining more blood vessels in RA than OA. VCAM-1 is present predominantly on synovial tissue macrophages and, to a lesser degree, on synovial tissue endothelial cells of venules, capillaries, and arterioles in both RA and OA. Like ELAM-1, VCAM-1 appears to be present more often on endothelial cells in RA than in OA tissues. VCAM-1 is present on macrophages isolated from RA synovium as well as macrophages in situ. Intercellular adhesion molecule-1 is more broadly distributed than the other adhesion molecules, being found on endothelium, macrophages, some fibroblasts, and some lymphocytes in both RA and OA tissues. This study shows that ELAM-1, a molecule that was previously thought to be important mainly in acute inflammatory reactions, is also found in RA, a chronic inflammatory disease, as well as in OA. Thus, ELAM-1 as well as VCAM-1 and intercellular adhesion molecule-1 may be involved in mediating the leukocyte traffic into RA and OA synovium.

Arthritis, Rheumatoid↗

Monoclonal antibodies detect monocyte/macrophage activation and differentiation antigens and identify functionally distinct subpopulations of human rheumatoid synovial tissue macrophages.

Monoclonal antibodies (MAbs) to functionally heterogeneous populations of human rheumatoid arthritis (RA) synovial tissue macrophages and lipopolysaccharide (LPS)-activated U937 cells were generated. These MAbs were used to characterize macrophages in situ in the synovial pannus and to study relative antigen expression on the surface of cells isolated from the synovium and from normal peripheral blood. Monoclonal antibody 3D8, an anti-CD13 MAb, reacts with an antigen expressed on the surface of blood monocytes and is a monocyte activation-related antigen that is upregulated by exposure of monocytes to interferon-gamma (IFN-gamma) and LPS. The expression of the 3D8 antigen increases in parallel with MHC class II antigen expression and also is upregulated in culture as monocytes mature to macrophages. 3D8 antigen is expressed strongly on RA synovial tissue lining cells, which are thought to be composed of macrophages. 8D7 antigen expression, detected by MAb 8D7, increases on blood monocytes on cellular activation with LPS and interferon-gamma, but in contrast to the 3D8 antigen, does not increase with monocyte maturation in vitro. The 8D7 antigen is expressed differentially on density-defined macrophage subpopulations isolated from RA synovial tissue and is expressed more strongly on macrophages that are nonangiogenic than those that are angiogenic.

Antibodies, Monoclonal↗

Reactivity of human tissues with monoclonal antibodies to myeloid activation and differentiation antigens. An immunohistochemical study.

We have characterized antimyeloid monoclonal antibodies (mAbs) produced to human rheumatoid arthritis (RA) synovial tissue macrophages (MPs) (8D7) and to lipopolysaccharide (LPS)-treated U937 cells (3D8). The 3D8 antigen is upregulated with LPS stimulation of monocytes/MPs and during monocyte maturation. The 8D7 antigen is upregulated on functionally distinct subpopulations of RA synovial tissue MPs. We used immunohistochemistry to determine the spectrum of reactivity of these unique mAbs on myeloid cell suspensions, monocytes, and mature tissue inflammatory and noninflammatory MPs. The antigens identified by the mAbs were characterized biochemically, by immunoprecipitation of solubilized 125I-labelled antigens from cell surfaces, and immunohistochemically by enzymatic digestion of myeloid cells followed by a cellular ELISA. MAb 3D8, characterized as an anti-CD13 antibody, recognizes a 150-170 kd antigen, has almost exclusive myeloid reactivity, but reacts with Langerhans' cells of the skin and thymus, pointing to shared antigens between these cells and MPs. Unlike 3D8 antigen, 8D7 antigen is strongly expressed in inflammatory states, being present on MPs in granulomata as well as in sarcoid lymph nodes. Both mAbs react with frozen and methanol-Carnoy's fixed, paraffin-embedded tissues and detect antigenic differences among human mononuclear phagocytes present in different anatomical sites and in varying stages of differentiation and activation. These mAbs should prove to be a valuable tool for studying heterogenous populations of myeloid cells.

Antibodies, Monoclonal↗