Anti-endothelial cell IgG fractions from systemic lupus erythematosus patients bind to human endothelial cells and induce a pro-adhesive and a pro-inflammatory phenotype in vitro.

Affinity purified immunoglobulin G (IgG) fractions from systemic lupus erythematosus (SLE) patients positive for anti-endothelial cell antibodies (AECA) bind human umbilical vein endothelial cell (HUVEC) monolayers. In vitro incubation of serial protein concentrations of SLE AECA IgG induces a dose-dependent endothelial activation: i) increase of functional adhesion of the monocytic cell line U937; ii) upregulation of E-Selectin, ICAM-1, VCAM-1 expression evaluated by a cell solid-phase enzyme linked immunoassay; and iii) increased secretion of interleukin (IL)-6 in the culture supernatants. Control experiments carried out with HUVEC monolayers incubated with IgG fractions from normal healthy controls or from AECA negative SLE sera do not affect at all endothelial adhesion molecule expression or pro-inflammatory cytokine secretion. The AECA IgG effects are not related to both anti-phospholipid or anti-DNA activities. Taken together the findings suggest that these autoantibodies might be important in recruiting and in activating mononuclear leukocytes responsible for vessel wall infiltration and raise the possibility that AECA might display a pathogenic role in SLE vessel damage.     

Distribution of cell adhesion molecules in skeletal muscle from patients with systemic lupus erythematosus.

OBJECTIVE--To investigate the pathophysiology of perivascular mononuclear cell infiltrates observed in skeletal muscle from patients with systemic lupus erythematosus (SLE). METHODS--Immunocytochemical techniques were used to examine frozen 5 microns sections from the quadriceps needle muscle biopsy specimens of 14 patients with SLE (including seven with infiltrates) for the expression of the cytokine inducible adhesion molecules intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. RESULTS--Vessels in 6/7 SLE biopsy specimens with perivascular infiltrates expressed VCAM-1 at a density of > 2 vessels/mm2 in contrast with 0/7 SLE biopsy specimens without infiltrates and 1/6 control specimens. In contrast, E-selectin expression was increased ( > 0.3 positive vessels/mm2) in SLE biopsy specimens compared with control tissue regardless of the presence of perivascular infiltration. VCAM-1 and ICAM-1 were also noted on extravascular cells in the infiltrates, being particularly prominent on the intermuscle fibre dendritic processes of CD68+ HLA-DR+ cells. CONCLUSION--Expression of these cytokine inducible adhesion molecules may be important in the migration of mononuclear cells into skeletal muscle and may be involved in intercellular interactions within the tissue.     

Vasculitis and expression of vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and E-selectin in salivary glands of patients with Sjögren's syndrome

OBJECTIVE: We investigated the relationship between clinical symptoms and the grade of histopathological damage and expression of adhesion molecules in salivary glands of patients with Sj?gren's syndrome (SS). METHODS: We studied untreated and recently diagnosed patients with primary (n =20) and secondary SS [10 with SS and rheumatoid arthritis (RA); 10 with SS and systemic lupus erythematosus (SLE)] and 3 healthy controls. Salivary gland biopsies were performed in patients and controls and clinical data were obtained. Salivary gland biopsies were assessed for lymphocyte focus score and expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. In serum, antinuclear antibodies, rheumatoid factor, anti-Ro and anti-La antibodies, anti-alpha-fodrin IgA and IgG antibodies, and gamma-globulin concentrations were measured. RESULTS: In salivary gland samples, ICAM-1 was expressed on vascular endothelial cells and lymphocyte foci, while VCAM-1 was expressed on vascular endothelial cells and follicular dendritic reticulin cells. There was a positive correlation between lymphocyte focus score and ICAM-1 expression (p < 0.05). We detected correlation between expression of ICAM-1 and VCAM-1, and the expression of VCAM-1 was significantly related to vasculitis (p < 0.05). The areas of E-selectin expression and the dispersion and severity of staining were not correlated with the focus score or with patients' clinical features (p > 0.05). There was no correlation between the staining and autoantibody positivity and gamma-globulin levels. CONCLUSION: ICAM-1 may be important for lymphocyte recruitment and glandular damage and VCAM-1 may be important for the development of vasculitis in patients with SS.     

Lymphocyte apoptosis in systemic lupus erythematosus: relationships with Fas expression, serum soluble Fas and disease activity.

Lupus specific autoantigens are exposed on apoptotic cells. The increased number of apoptotic lymphocytes reported in systemic lupus erythematosus (SLE) may be attributable to abnormalities of lymphocyte Fas expression or serum soluble Fas. In the present study we analysed the count of circulating apoptotic lymphocytes in SLE patients (n=50), by flow cytometry using Annexin V, compared to rheumatoid arthritis patients (RA, n=20), inflammatory bowel disease patients (IBD, n=20) and normal controls (n=20). Lymphocyte Fas expression and serum soluble Fas were measured and related to numbers of apoptotic lymphocytes. The percentage of apoptotic lymphocytes, determined by Annexin V binding, was significantly increased in peripheral blood of SLE patients (median=4.2%) compared with normal healthy donors (median=1.1%) and IBD patients (median=2. 0%) but not RA (median=3.9%). SLE lymphocyte Fas expression was not significantly different from RA or IBD patients. Serum soluble Fas in SLE patients correlated positively with apoptotic lymphocytes and antibodies to double stranded DNA. This study suggests that increased apoptotic lymphocytes and increased lymphocyte Fas expression may not be specific to SLE. Serum soluble Fas may have a role in the regulation of lymphocyte apoptosis in SLE.     

Telomerase activity in B and T lymphocytes of patients with systemic lupus erythematosus

OBJECTIVE: To evaluate telomerase activity as a marker of lymphocyte proliferation in systemic lupus erythematosus (SLE). METHODS: CD19+, CD4+, and CD8+ lymphocytes were isolated from the peripheral blood of nine patients with SLE and nine healthy controls by means of magnetic bead-coupled antibodies and tested for telomerase activity with the TRAP assay. RESULTS: Telomerase activity was significantly increased in CD19+ B cells from patients with SLE. CD4+ and CD8+ T cells from lupus patients displayed increased mean telomerase activity, although the difference from normal controls did not reach statistical significance. CONCLUSIONS: Increased telomerase activity in the B and the T cell lineage might indicate activation and proliferation of these lymphocytes.     

Cell adhesion molecules in the development of inflammatory infiltrates in giant cell arteritis: inflammation-induced angiogenesis as the preferential site of leukocyte-endothelial cell interactions

OBJECTIVE: To investigate the expression pattern of adhesion molecules involved in leukocyte-endothelial cell interactions in giant cell arteritis (GCA). METHODS: Immunohistochemical analysis was performed on frozen temporal artery sections from 32 patients with biopsy-proven GCA and from 12 control patients with other diseases. Adhesion molecules identified were intercellular adhesion molecule 1 (ICAM-1), ICAM-2, ICAM-3, vascular cell adhesion molecule 1 (VCAM-1), platelet endothelial cell adhesion molecule 1 (PECAM-1), E-selectin, P-selectin, L-selectin, lymphocyte function-associated antigen 1 (LFA-1), very late activation antigen 4 (VLA-4), Mac-1 (CD18/CD11b), and gp 150,95 (CD18/CD11c). Clinical and biochemical parameters of inflammation in the patients, as well as the duration of previous corticosteroid treatment, were prospectively recorded. RESULTS: Constitutive (PECAM-1, ICAM-1, ICAM-2, and P-selectin) and inducible (E-selectin and VCAM-1) endothelial adhesion molecules for leukocytes were mainly expressed by adventitial microvessels and neovessels within inflammatory infiltrates. Concurrent analysis of leukocyte receptors indicated a preferential use of VLA-4/VCAM-1 and LFA-1/ICAM-1 at the adventitia and Mac-1/ICAM-1 at the intima-media junction. The intensity of inducible endothelial adhesion molecule expression (E-selectin and VCAM-1) correlated with the intensity of the systemic inflammatory response. Previous corticosteroid treatment reduced, but did not completely abrogate, the expression of the inducible endothelial adhesion molecules E-selectin and VCAM-1. CONCLUSION: Inflammation-induced angiogenesis is the main site of leukocyte-endothelial cell interactions leading to the development of inflammatory infiltrates in GCA. The distribution of leukocyte-endothelial cell ligand pairs suggests a heterogeneity in leukocyte-endothelial cell interactions used by different functional cell subsets at distinct areas of the temporal artery.     

Clinical immunologic studies in systemic lupus erythematosus

This review of recent and new directions in clinical immunologic studies of systemic lupus erythematosus (SLE) is restricted to the areas of lymphocyte surface markers, antigen binding lymphocytes, immune complexes, and lymphocyte hyporesponsiveness in lupus patients. First, it is not clear whether the T-lymphopenia observed in SLE is related to viral destruction of T cells, anti-lymphocyte antibodies, or tissue sequestration. Second, the increase in DNA-binding B lymphocytes observed in active lupus patients may be related to minor alterations in the balance of immunoregulatory T cells or to a bypass of DNA-specific helper T cells. Third, it is speculated that the removal of immune complexes which play a role in lupus glomerulitis by various extracorporeal immune absorbents may be important in the future therapy of SLE. Fourth, the mechanisms of T-lymphocyte hypofunction are unexplained. It is postulated from studies done in other diseases that this hypoactivity may be mediated by the secretion of prostaglandin or other humoral agents from one leukocyte subpopulation suppressing another potentially responsive lymphocyte subpopulation. Also an investigation into the lymphocyte subpopulation reactive with virus-infected fibroblasts may be useful in delineating immunoregulatory lymphocytes important in the pathogenesis of SLE.     

神经颗粒素在系统性红斑狼疮患者外周血单个核细胞中的表达

目的 探讨神经颗粒素在系统性红斑狼疮(SLE)患者和正常人外周血单个核细胞(PBMCs)的表达状态.方法 对比分析SLE PBMCs基因表达系列分析(SAGE)文库的高表达标签,并采用反转录聚合酶链反应(RT-PCR)法检测与正常人群有明显差异表达的神经颗粒素在SLE患者PBMCs的mRNA表达水平.结果 对比分析SLE PBMCs和正常人各类淋巴细胞SAGE文库显示:神经颗粒素标签仅异位高表达于SLE患者,而几乎不表达于正常人各类淋巴细胞.RT-PCR检测证实:活动组SLE患者神经颗粒素mRNA表达水平较正常对照明显增加(P＜O.001),而缓解组SLE患者其表达水平仅稍有增加(P＞O.05).结论 神经颗粒素作为一种前凋亡因子,高表达于SLE PBMCs,可能介导或参与SLE异常的免疫调节反应.     

Increased soluble vascular cell adhesion molecule 1 concentrations in patients with primary or systemic lupus erythematosus-related antiphospholipid syndrome: correlations with the severity of thrombosis

OBJECTIVE: Recent studies have shown that in vitro endothelial cells are activated by antiphospholipid antibodies and may support leukocyte adhesion. We studied levels of soluble intercellular adhesion molecule 1 (sICAM-1, sCD54), soluble vascular cell adhesion molecule 1 (sVCAM-1, sCD106), and soluble E-selectin (soluble endothelial leukocyte adhesion molecule 1 [sELAM-1, sCD62E]) in sera from patients with primary antiphospholipid syndrome (primary APS), and compared them with those from patients with systemic lupus erythematosus-associated APS (SLE-APS) or pure SLE, as well as with those from 2 control groups composed of healthy volunteers and patients with thrombosis unrelated to autoimmune diseases. METHODS: Serum samples from 24 patients with primary APS, 15 patients with SLE-APS, 22 patients with pure SLE, 48 control patients with thrombosis, and 18 healthy volunteers were examined using enzyme-linked immunosorbent assays specific for sICAM-1, sVCAM-1, and sELAM-1. RESULTS: Serum levels of sVCAM-1, but not sICAM-1 or sELAM-1, were significantly increased in all patient study groups compared with thrombosis control patients and healthy volunteers, but did not differ between the groups of patients with primary APS, SLE-APS, or pure SLE. Concentrations of sVCAM-1 were significantly higher in primary APS or SLE-APS patients with severe, recurrent thrombosis and were negatively correlated with platelet counts in primary APS patients. In patients with primary APS, sVCAM-1 levels were higher if there was thrombotic kidney involvement and correlated with creatinemia. CONCLUSION: Serum sVCAM-1 concentrations are increased in patients with primary APS, especially those with repeated thrombotic events or kidney involvement. These findings suggest that endothelial/ monocyte interaction may be important in the pathogenesis of primary APS.     

Adhesion molecules, mycophenolate mofetil and systemic lupus erythematosus

Mycophenolate mofetil (MMF) has been reproducibly shown to inhibit lymphocyte adhesion and penetration of endothelial cell surfaces. The mechanism is not yet elucidated. In vitro studies on the effects of MMF on cell adhesion molecules (CAM) using human umbilical vein endothelial cells (HUVEC) have shown conflicting results. Different studies have independently shown that MMF increased, decreased or had no effect on intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM-1). Several studies suggest MMF may reduce the endothelial expression of E-selectin. Recent studies have been unable to replicate initial work, which suggested that MMF impaired glycosylation of lymphocyte CAM. The same studies concluded that MMF had no effect on the surface expression of lymphocyte CAM, but altered the binding ability of these molecules. ICAM-1/LFA-1 (lymphocyte function-associated antigen-1), VCAM-1/VLA-4 (very late antigen-4) and P-selectin/PSGL-1 (P-selectin glycoprotein ligand-1) ligand pairs are most likely to be involved. Few in vivo and no conclusive human studies have been carried out. The literature relevant to cell adhesion molecules in systemic lupus erythematosus (SLE) is reviewed in detail.     

Elevated soluble intercellular adhesion molecule-1 levels in patients with systemic lupus erythematosus: relation to insulin resistance

OBJECTIVE: Intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) are members of the immunoglobulin supergene family and play a central role in cell-to-cell and in cell-to-extracellular matrix-mediated immune responses. Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by a wide variety of immunological abnormalities. The relationship between soluble adhesion molecules and insulin resistance has been observed in different populations. However, the association of circulating levels of soluble cell adhesion molecules with insulin resistance and/or hyperinsulinemia in patients with SLE has not been extensively established. METHODS: We evaluated the relationship of soluble ICAM-1 (sICAM-1) and VCAM-1 (sVCAM-1) to insulin resistance in 68 patients with SLE and 34 age-matched healthy controls. RESULTS: Patients with SLE had significantly higher fasting insulin levels, homeostasis model assessment insulin resistance (HOMA-IR), HOMA beta-cell, and plasma levels of sICAM-1 and sVCAM-1 than controls. SLE patients with HOMA-IR in the top quartile had the highest plasma levels of sICAM-1. However, there was no statistical difference in plasma levels of sVCAM-1 between patients in the respective quartiles of insulin sensitivity-related variables. Plasma levels of sICAM-1, but not sVCAM-1, were significantly correlated with fasting insulin (r = 0.327, p = 0.006), HOMA-IR (r = 0.278, p = 0.022), and HOMA beta-cell (r = 0.359, p = 0.003). In addition, fasting insulin was responsible for sICAM-1 variability in patients with SLE. CONCLUSION: The elevation of plasma levels of sICAM-1 was associated with a status of insulin resistance in patients with SLE.     

Up-Regulation of Endothelial Cell Adhesion Molecules Characterizes Disease Activity in Systemic Lupus Erythematosus

Objective. To test the hypothesis that during exacerbations of systemic lupus erythematosus (SLE), endothelial cells are activated to increase their expression of adhesion molecules. Methods. Endothelial cell expression of E-selectin, vascular cell adhesion molecule 1 (VCAM-1), and intercellular adhesion molecule 1 (ICAM-1) was quantitated immunohistochemically in 20 biopsy specimens from nonlesional, non-sun-exposed skin from 16 SLE patients. Disease activity was evaluated with the SLE Disease Activity Index (SLEDAI) and with measurements of complement components C3a desArg, C3, and C4. Results. The mean expression of all 3 adhesion molecules was significantly elevated in patients with SLE versus healthy controls, as well as in patients with active versus inactive SLE. The mean C3a desArg level was significantly higher in patients with active SLE compared with those with inactive SLE. The SLEDAI scores correlated directly with C3a desArg levels and inversely with C3 and with C4 levels. Evaluation of serial biopsy specimens demonstrated loss of endothelial cell adhesion molecules and reduction of C3a levels with clinical improvement. Conclusion. Our findings demonstrate up-regulation of the surface expression of 3 distinct adhesion molecules, E-selectin, VCAM-1, and ICAM-1, in patients with SLE. The abnormal expression of these endothelial cell adhesion molecules is most marked in patients with active disease characterized by significant elevations of the complement split product C3a desArg. We suggest that in certain SLE patients, excessive complement activation in association with primed endothelial cells induces leukocyte-endothelial cell adhesion and leuko-occlusive vasculopathy.     

Recruitment mechanisms of primary and malignant B cells to the human liver

B cells are present within chronically inflamed liver tissue and recent evidence implicates them in the progression of liver disease. In addition, a large proportion of hepatic lymphomas are of B-cell origin. The molecular signals that regulate normal and malignant B-cell recruitment into peripheral tissue from blood are poorly understood, leading us to study human B-cell migration through hepatic sinusoidal endothelial cells in flow-based adhesion assays. In such assays, human blood-derived B cells were captured from shear flow without a previous rolling phase and underwent firm adhesion mediated by vascular cell adhesion molecule-1 (VCAM-1). Unlike T cells, which displayed vigorous crawling behavior on the endothelium, B cells remained static before a proportion underwent transendothelial migration mediated by a combination of intercellular adhesion molecule-1 (ICAM-1), vascular adhesion protein-1, common lymphatic endothelial and vascular endothelial receptor-1/stabilin-1, and the chemokine receptors, CXCR3 and CXCR4. B-cell lymphoma cell lines and primary malignant B cells from patients with chronic lymphocytic leukemia and marginal zone B cell lymphoma also underwent integrin-mediated firm adhesion involving ICAM-1 and/or VCAM-1 and demonstrated ICAM-1-dependent shape-change and crawling behavior. Unlike primary lymphocytes, the malignant cells did not undergo transendothelial migration, which could explain why lymphomas are frequently characterized by the intravascular accumulation of malignant cells in the hepatic sinusoids. Conclusion: Our findings demonstrate that distinct combinations of signals promote B-cell recruitment to the liver, suggesting the possibility of novel targets to modulate liver inflammation in disease. Certain features of lymphocyte homing are maintained in lymphoma recruitment to the liver, suggesting that therapeutic targets for lymphocyte recruitment may also prevent hepatic lymphoma dissemination. (HEPATOLOGY 2012).     

Urinary soluble VCAM-1 in systemic lupus erythematosus: a clinical marker for monitoring disease activity and damage

OBJECTIVE: To determine the urinary levels of soluble vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) in patients with systemic lupus erythematosus (SLE) and to assess their relationship with clinical and laboratory features and the degree of activity and damage associated with the disease. METHODS: The study sample included 24 consecutive patients with SLE. 24-hour urine samples were collected for the determination of soluble VCAM-1 and ICAM-1 levels by ELISA. Disease activity was defined by the SLE Disease Active Index (SLEDAI) and disease outcome by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ ACR) damage index. RESULTS: The urinary soluble VCAM-1 level was significantly higher in patients with SLE compared to normal controls (32.35+/-34.27 vs. 4.66+/-3.8 ng/mg creatinine, p = 0.0005) and statistically significantly correlated with disease activity (SLEDAI), a low serum C3 level, decreased creatinine clearance and albuminuria, as well as with disease damage (SLICC/ACR damage index). In contrast, the urinary soluble ICAM-1 level was not significantly higher in the patients' group compared with the controls (4.5+/-5.19 vs. 2.72+/-2.31 ng/mg creatinine, p=0.2), but was statistically significantly correlated with hematuria and albuminuria. CONCLUSION: Our data suggest that the urinary level of soluble VCAM-1 significantly correlates with overall disease activity and damage scores, but not with nephritis in SLE.     

Tumor necrosis factor induced adhesion molecule serum concentrations in Henoch-Schönlein purpura and pediatric systemic lupus erythematosus

OBJECTIVE: Animal models of immune complex mediated tissue injury have shown that tumor necrosis factor (TNF) and TNF induced adhesion molecules play an important role in the pathogenesis of tissue damage mediated by IgG, but not in that mediated by IgA, immune complexes. We compared possible differences in the behavior of 2 TNF induced adhesion molecules (VCAM-1 and ICAM-1) in Henoch-Sch?nlein purpura (HSP), which is characterized by the formation of IgA immune complexes, versus systemic lupus erythematosus (SLE), which is mostly associated with the vascular deposition of IgG immune complexes. METHODS: Serum concentrations of soluble (s)VCAM-1 and ICAM-1 were determined by ELISA methods in 20 patients with pediatric SLE showing variably active disease, 20 active patients with active HSP, and 19 healthy controls. TNF-alpha as well as p55 and p75 soluble receptors (sTNF-R) were simultaneously tested by enzyme amplified sensitivity immunoassay in 22 patients (12 SLE, 10 HSP). RESULTS: Serum sVCAM-1 concentration was significantly higher in patients with SLE (mean +/- SD, 608 +/- 76 ng/ml), than in patients with HSP (501.9 +/- 63.3 ng/ml) and controls (446.8 +/- 139.2 ng/ml) (p < 0.001). In SLE patients, sVCAM-1 correlated positively with ESR (r = 0.45, p = 0.02) and negatively with C4 serum levels (r = -0.57, p = 0.004), platelets (r = -0.38, p = 0.03), and lymphocyte count (r = -0.42, p = 0.03). No differences in sICAM-1 serum concentrations were detected among SLE, HSP, or control groups. Soluble VCAM, but not sICAM-1, showed a positive correlation with TNF-alpha (r = 0.71, p = 0.01), p55 (r = 0.63, p = 0.02), and p75 (r = 0.7, p = 0.01) sTNF-R serum concentrations in SLE, but not in patients with HSP. CONCLUSION: Our study provides additional evidence of a possible differential involvement of TNF and TNF induced adhesion molecules in the pathogenesis of tissue damage between pediatric SLE and HSP.     

淋巴细胞趋化因子受体mRNA在系统性红斑狼疮患者外周血单个核细胞的表达

目的探讨淋巴细胞趋化因子受体(XCR1)mRNA在系统性红斑狼疮(SLE)患者外周血单个核细胞(PBMC)中的表达,及其与疾病的相关性。方法收集93例确诊的SLE患者和30名健康对照组,收集PBMC,提取RNA。应用反转录-聚合酶链反应(RT-PCR)方法检测研究对象XCR1mRNA表达水平。结果!"XCR1mRNA在PBMC中表达水平,患者组(1.57±0.84)与正常对照组(0.19±0.14),两者差异无统计学意义(P>0.05)。活动期(2.09±1.38)与对照组比较,两者差异有统计学意义(t=2.392,P=0.02);活动期与非活动期(0.31±0.24)比较,差异有统计学意义(t=3.091,P=0.003);非活动期与对照组比较,差异无统计学意义(P>0.05)。"#SLE患者组XCR1mRNA水平与疾病活动度评分(SLEDAI)关系:SLE患者组PBMC中XCR1mRNA表达水平与SLEDAI作直线相关性分析,XCR1mRNA水平与SLEDAI(r=0.540,t=5.445,P=0.000)呈正相关。"$SLE患者PBMC中XCR1mRNA表达与临床表现及实验室检查相关性:SLE抗SSA抗体阳性患者(17/68,1.4±1.2)比阴性患者(51/68,3.5±4.9),其XCR1mRNA表达水平降低,差异有统计学意义(t=2.78,P=0.007)。结论XCR1mRNA表达水平在PBMC中活动期SLE患者比非活动期及对照组增高,与疾病的活动性(SLEDAI)正相关,非活动期与对照组差异无统计学意义。SLE抗SSA抗体阳性患者比阴性患者,其XCR1mRNA表达水平降低,两组均较健康对照组增高。提示XCR1参与疾病的发展,与疾病的活动性相关,XCR1可能参与抗SSA抗体的形成过程,造成组织损伤。     

Direct demonstration of P-selectin- and VCAM-1-dependent mononuclear cell rolling in early atherosclerotic lesions of apolipoprotein E-deficient mice.

Apolipoprotein E-deficient (ApoE-/-) mice develop atherosclerotic lesions throughout the arterial tree, including the carotid bifurcation. Although the expression of adhesion molecules such as ICAM-1, vascular cell adhesion molecule-1 (VCAM-1), and P-selectin on endothelium that overlie atherosclerotic plaques has been implicated in monocyte recruitment to developing lesions, monocyte adhesion in atherosclerotic vessels has not been observed directly. To investigate which adhesion molecules may be important in monocyte adhesion to atherosclerotic lesions, an isolated mouse carotid artery preparation was developed and perfused with mononuclear cells. We show rolling and attachment of the human monocytic cell line U937 and the mouse monocyte-macrophage cell line P388D1 in carotid arteries from 10- to 12-week-old ApoE-/- and C57BL/6 wild-type mice fed a Western-type diet (21% fat wt/wt) for 4 to 5 weeks. No rolling was observed in carotid arteries from C57BL/6 or BALB/c wild-type mice fed a chow diet and little was observed in BALB/c mice fed a Western-type diet. This model represents early lesion development as shown by minimal macrophage infiltration in the intima of carotid arteries from ApoE-/- mice fed a Western-type diet. Rolling was observed at shear stresses that were characteristic of the low-shear recirculation zone near the carotid bifurcation. Mononuclear cell attachment and rolling were significantly inhibited by monoclonal antibody blockade of P-selectin or its leukocyte ligand P-selectin glycoprotein ligand-1. Rolling velocities increased after monoclonal antibody blockade of mononuclear cell alpha4-integrin or VCAM-1, which indicates that alpha4-integrin interacting with VCAM-1 stabilizes rolling interactions and prolongs monocyte transit times.     

Systemic lupus erythematosus and rheumatoid arthritis patients differ from healthy controls in their cytokine pattern after stress exposure

OBJECTIVE: To study whether patients with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) differ from healthy individuals in their immune responses to acute psychological stress. METHODS: The phenotype and function of peripheral blood lymphocytes were analysed before and after stress exposure in patients and healthy subjects. RESULTS: Natural killer (NK) cell numbers increased transiently in all groups under stress. NK activity, however, increased in healthy controls only. We observed a stress-induced increase in interleukin (IL)-4-producing (IL-4(+)) cells in SLE patients only, whereas interferon (IFN) gamma(+) cell numbers increased due to stress in all three groups. An analysis of supernatants from phytohaemagglutinin (PHA) cultures revealed increased IFN gamma and IL-10 levels in healthy subjects but not in SLE or RA patients after stress exposure. CONCLUSIONS: These data demonstrate that RA and SLE patients differ in their immune response to stress from healthy controls. Changes in cytokine patterns might be responsible for stress-induced exacerbation of disease activity in RA and SLE patients.     

Postanoxic T lymphocyte-endothelial cell interactions induce tumor necrosis factor-alpha production and neutrophil adhesion: role of very late antigen-4/vascular cell adhesion molecule-1

The objective of this study was to define the influence of postanoxic T-lymphocyte-endothelial cell interactions on anoxia-reoxygenation (A/R)-induced neutrophil-endothelial cell adhesion and cell adhesion molecule (CAM) expression on human umbilical vein endothelial cells (HUVECs). HUVEC monolayers were exposed to 60 minutes of anoxia, followed by 24 hours of reoxygenation, wherein freshly isolated human T lymphocytes were added at 6 hours during reoxygenation. After an additional 18 hours of incubation (ie, total of 24 hours of reoxygenation), the T-cell/endothelial cell (TC/EC) coculture media were collected and added to naive HUVEC monolayers incubated with neutrophils. Although the A/R-conditioned media per se had no effect on neutrophil adhesion, the media from TC/EC cocultures significantly increased the adhesion response. This enhanced adhesive interaction was associated with significant increases in tumor necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8) levels in the TC/EC coculture media and was accompanied by a pronounced increase in endothelial E-selectin expression. Treatment of the TC/EC coculture media with anti-TNF-alpha or anti-IL-8 antibodies reduced the media-induced neutrophil adhesion response. The enhanced neutrophil adhesion and the elevated medium levels of TNF-alpha, but not IL-8, were markedly reduced by inserts that prevented direct TC/EC contact and by monoclonal antibodies directed against vascular cell adhesion molecule-1 (VCAM-1) or very late antigen-4 (VLA-4). Collectively, these findings show that VLA-4-/VCAM-1-mediated interactions between T lymphocytes and postanoxic endothelial cells stimulates TNF-alpha production, which in turn elicits endothelial cell adhesion molecule expression and a corresponding increase in neutrophil adhesion.