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Biomedical subjects

Mary K Crow

Publications and source records attributed to Mary K Crow.

At least 19 recordsLinked to original sources

Distinct inflammatory gene pathways induced by particles.

The biologic response to particulate load after arthroplasty has not been fully characterized but is believed mediated by proinflammatory cytokines released from mononuclear cells in the periprosthetic region. To investigate the contribution of lymphocytes to expression of proinflammatory genes induced by metal particles, we compared gene expression of mononuclear cells in response to metal and polymethylmethacrylate particles using cDNA microarray profiling. Peripheral blood mononuclear cells and monocytes were stimulated with polymethylmethacrylate and titanium particles of clinically relevant sizes. Polymethylmethacrylate elicited a six- to 12-fold increase in gene expression of tumor necrosis factor alpha, interleukin 1alpha, interleukin 1beta, interleukin 6, and interleukin 8 in purified monocytes and unfractionated peripheral blood mononuclear cells. Although the effect of titanium on stimulation of purified monocytes was modest, stimulation of lymphocyte-containing peripheral blood mononuclear cells by titanium particles resulted in monocyte-derived proinflammatory cytokine expression. In contrast to polymethylmethacrylate, titanium particles stimulated increased expression of T lymphocyte-derived cytokines, including interleukin 2, interferon gamma, interleukin 9, and interleukin 22, in peripheral blood mononuclear cell cultures. The induction of T cell activation by titanium particles suggests lymphocytes may contribute to the inflammation that mediates osteolysis in patients with metallic particulate debris after total joint replacement.

Cell Survival↗

Characterization of human complement receptor type 2 (CR2/CD21) as a receptor for IFN-alpha: a potential role in systemic lupus erythematosus.

Human complement receptor type 2 (CR2/CD21) is a B lymphocyte membrane glycoprotein that plays a central role in the immune responses to foreign Ags as well as the development of autoimmunity to nuclear Ags in systemic lupus erythematosus. In addition to these three well-characterized ligands, C3d/iC3b, EBV-gp350, and CD23, a previous study has identified CR2 as a potential receptor for IFN-alpha. IFN-alpha, a multifunctional cytokine important in the innate immune system, has recently been proposed to play a major pathogenic role in the development of systemic lupus erythematosus in humans and mice. In this study, we have shown using surface plasmon resonance and ELISA approaches that CR2 will bind IFN-alpha in the same affinity range as the other three well-characterized ligands studied in parallel. In addition, we show that IFN-alpha interacts with short consensus repeat domains 1 and 2 in a region that serves as the ligand binding site for C3d/iC3b, EBV-gp350, and CD23. Finally, we show that treatment of purified human peripheral blood B cells with the inhibitory anti-CR2 mAb 171 diminishes the induction of IFN-alpha-responsive genes. Thus, IFN-alpha represents a fourth class of extracellular ligands for CR2 and interacts with the same domain as the other three ligands. Defining the role of CR2 as compared with the well-characterized type 1 IFN-alpha receptor 1 and 2 in mediating innate immune and autoimmune roles of this cytokine should provide additional insights into the biologic roles of this interaction.

Antibodies, Monoclonal↗

Modification of accessory molecule signaling.

The concept of costimulation, the requirement for an independent accessory cellular activation signal that supplements the signal delivered to a lymphocyte by antigen, has been a focal point of progress in understanding the regulation of the immune system. While considerable attention has been directed to new developments related to the activation of cells of the innate immune system through Toll-like receptors, resulting in the production of soluble mediators, augmented expression of cell surface costimulatory molecules on antigen-presenting cells is arguably the most significant early outcome of immune system activation. It is those cell surface molecules that provide the essential afferent costimulatory signals to T cells of the adaptive immune response. Once fully activated, T cells express their own cell surface accessory molecules that permit those T cells to instruct interacting B cells, macrophages, and dendritic cells to further implement an effective immune response. Significantly for patients with autoimmune diseases, the manipulation of costimulatory signals represents a rational and effective approach to modulating the chronic immune system activation that characterizes those diseases. Further elucidation of the complexities of members of the accessory molecule families and their functions should lead to an ever greater capacity for therapeutic modulation of the immune response in autoimmune and inflammatory diseases.

Animals↗

Elevated levels of soluble CD40 ligand (sCD40L) in serum of patients with systemic autoimmune diseases.

The CD40-CD40L costimulatory pathway is involved in the evolution of many autoimmune diseases including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA) and Sjögren's syndrome (SS). Increased levels of sCD40L in the serum have been associated with disease activity in SLE. The aim of this study was to investigate the role of sCD40L in the development of lupus nephritis and examine its possible association with cryoglobulinemia in Sjögren's syndrome. We used a 2-site sandwich ELISA to measure the levels of sCD40L in sera, from 64 patients with SLE, RA and SS and 17 healthy blood donors. Biological specimens from the affected tissues such as urine from patients with lupus nephritis and saliva from patients with SS were also tested. In this regard, paired sera and first morning urine samples from 6 SLE patients (3 with active lupus nephritis and 3 with inactive lupus nephritis) were tested with the sCD40L ELISA protocol as well as paired sera and salivary samples from 5 patients with SS and cryoglobulinemia, 5 patients with SS and anti-Ro or anti-La autoantibodies and 5 age-matched healthy control donors. We also examined possible correlations of sCD40L levels with several laboratory and clinical parameters in SS and SLE. We found that sera from SLE and SS patients had significantly higher levels of sCD40L compared to sera from healthy control donors. No sCD40L was detected, in urine samples of patients with either active or inactive nephritis and in salivary samples from SS patients or normal subjects. Soluble CD40L is elevated in sera of SS and SLE patients but further investigation is needed to determine its possible role in SLE nephritis and Sjögren's syndrome.

Arthritis, Rheumatoid↗

Preclinical carotid atherosclerosis in patients with rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis is associated with increased morbidity and mortality because of cardiovascular disease, independent of traditional risk factors. OBJECTIVE: To determine the prevalence of preclinical atherosclerosis in patients with rheumatoid arthritis and to identify clinical and biological markers for atherosclerotic disease in this patient population. DESIGN: Matched, cross-sectional study. SETTING: Hospital for Special Surgery in New York City. PATIENTS: 98 consecutive outpatients with rheumatoid arthritis who were followed by rheumatologists and 98 controls matched on age, sex, and ethnicity. MEASUREMENTS: Cardiovascular risk factor ascertainment and carotid ultrasonography in all participants; disease severity, disease treatment, and inflammatory markers in patients with rheumatoid arthritis. RESULTS: Despite a more favorable risk factor profile, patients with rheumatoid arthritis had a 3-fold increase in carotid atherosclerotic plaque (44% vs. 15%; P < 0.001). The relationship between rheumatoid arthritis and carotid atherosclerotic plaque remained after accounting for age, serum cholesterol levels, smoking history, and hypertensive status; adjusted predicted prevalence was 7.4% (95% CI, 3.4% to 15.2%) for the control group and 38.5% (CI, 25.4% to 53.5%) for patients with rheumatoid arthritis. Age (P < 0.001) and current cigarette use (P < 0.014) were also significantly associated with carotid atherosclerotic plaque. Among patients with rheumatoid arthritis, atherosclerosis was related to age, hypertension status, and use of tumor necrosis factor-alpha inhibitors (a possible marker of disease severity). LIMITATIONS: The study had a cross-sectional design, and inflammatory markers were determined only once. CONCLUSIONS: Patients with rheumatoid arthritis have a high prevalence of preclinical atherosclerosis independent of traditional risk factors, suggesting that chronic inflammation and, possibly, disease severity are atherogenic in this population.

Adult↗

Early growth response-1 is required for CD154 transcription.

CD154 (CD40 ligand) expression on CD4 T cells is normally tightly controlled, but abnormal or dysregulated expression of CD154 has been well documented in autoimmune diseases, such as systemic lupus erythematosus. Beyond regulation by NFAT proteins, little is known about the transcriptional activation of the CD154 promoter. We identified a species-conserved purine-rich sequence located adjacent to the CD154 transcriptional promoter proximal NFAT site, which binds early growth response (Egr) transcription factors. Gel shift assays and chromatin immunoprecipitation assays reveal that Egr-1, Egr-3, and NFAT1 present in primary human CD4 T cells are capable of binding this combinatorial site in vitro and in vivo, respectively. Multimerization of this NFAT/Egr sequence in the context of a reporter gene demonstrates this sequence is transcriptionally active upon T cell activation in primary human CD4 T cells. Overexpression of Egr-1, but not Egr-3, is capable of augmenting transcription of this reporter gene as well as that of an intact CD154 promoter. Conversely, overexpression of small interfering RNA specific for Egr-1 in primary human CD4 T cells inhibits CD154 expression. Similarly, upon activation, CD154 message is notably decreased in splenic CD4 T cells from Egr-1-deficient mice compared with wild-type controls. Our data demonstrate that Egr-1 is required for CD154 transcription in primary CD4 T cells. This has implications for selective targeting of Egr family members to control abnormal expression of CD154 in autoimmune diseases such as systemic lupus erythematosus.

Animals↗

Functional assay of type I interferon in systemic lupus erythematosus plasma and association with anti-RNA binding protein autoantibodies.

OBJECTIVE: Peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE) have increased expression of genes typically induced by type I interferon (IFN). However, it has been difficult to identify and quantify the factors responsible for activation of the IFN pathway in SLE. To characterize these mediators, we developed an assay that measures the functional effects of plasma or serum components on the gene expression of cultured target cells. METHODS: WISH epithelial cell line cells were cultured with medium, with recombinant IFNalpha, IFNbeta, or IFNgamma, or with 50% plasma from SLE patients (n = 73), rheumatoid arthritis (RA) patients (n = 19), or healthy donors (n = 30). Real-time quantitative polymerase chain reaction was used to determine WISH cell expression of IFN target genes, including PRKR, IFIT1, IFI44, MX1, and C1orf29 (preferentially induced by IFNalpha) and CXCL9 (Mig) (preferentially induced by IFNgamma). RESULTS: IFNalpha-regulated genes were induced by SLE plasma samples, but not by most of the RA or healthy control plasma samples. The activity in SLE plasma was inhibited >90% by anti-IFNalpha antibody, but not by anti-IFNbeta or anti-IFNgamma antibodies. The expression of each IFNalpha target gene induced by SLE plasma correlated with the expression of that gene studied ex vivo in PBMCs from the same patients and with the titer of anti-RNA binding protein (anti-RBP)-specific autoantibodies. Plasma activity paralleled PBMC expression of IFNalpha-inducible genes over time. CONCLUSION: IFNalpha in SLE plasma is a major stimulus of IFN target gene expression and is related to expression of those genes in PBMCs from SLE patients and to the titer of anti-RBP autoantibodies. These data provide additional support for the view that IFNalpha mediates immune system activation and dysregulation in SLE.

Antibodies↗

Relationship of antiphospholipid antibodies to cardiovascular manifestations of systemic lupus erythematosus.

OBJECTIVE: Although antiphospholipid antibodies (aPL) are associated with arterial and venous thrombosis in systemic lupus erythematosus (SLE), the extent to which they influence other cardiovascular manifestations is either controversial or uncertain. We undertook this study to examine the relationships of aPL with valvular, myocardial, and arterial disease in SLE. METHODS: Two hundred patients in an SLE registry, recruited at the time of outpatient visits, underwent comprehensive interviews, physical examinations, laboratory assessments, echocardiography to assess left ventricular (LV) and valvular status, carotid ultrasonography to detect atherosclerosis (discrete plaque), and radial applanation tonometry to measure arterial stiffness. RESULTS: Antiphospholipid antibodies were present(defined as IgG or IgM anticardiolipin > or =40 IU/ml or the presence of lupus anticoagulant) in 42 patients (21%). Mitral valve nodules and moderate-to-severe mitral regurgitation were more common in aPL-positive patients (both 14.3% versus 4.4%; P = 0.02). Thirty-one percent of patients with high titers of IgG aPL (>80 IU/ml) had mitral valve nodules, compared with 20% of patients with mildly to moderately elevated levels of IgG aPL (16-80 IU/ml) and 4% of patients without IgG aPL (overall P < 0.001). Levels of soluble tumor necrosis factor receptors were higher in the presence of both aPL and mitral valve nodules. LV dimensions, systolic function, and carotid artery stiffness as well as prevalences of Raynaud's phenomenon, pulmonary hypertension, and atherosclerosis were similar in aPL-positive and aPL-negative patients. CONCLUSION: Antiphospholipid antibodies in SLE are associated with mitral valve nodules and significant mitral regurgitation, possibly due to valvular endothelial cell activation. However, in this population, they are not associated with evidence of myocardial hypertrophy, systolic dysfunction, coronary or carotid atherosclerosis, or other vascular abnormalities.

Adult↗

Soluble mediators as therapeutic targets in systemic lupus erythematosus: cytokines, immunoglobulin receptors, and the complement system.

After many years of anticipation, we have entered a period of promise for new lupus therapies; several clinical trials are planned or are in progress. The accelerated activity in systemic lupus erythematosus therapeutics has been driven by scientific advances. Enhanced understanding of the cells and mediators that drive autoimmunity and tissue damage has led to the identification of rational therapeutic targets. The conventional immunosuppressive therapies, including corticosteroids and cyclophosphamide, can be effective but at a high and unacceptable cost of adverse effects. There is high optimism that targeted therapies, including those that are specific for soluble mediators, will allow effective control of disease activity while sparing patients the damaging toxicities that are associated with traditional immunosuppressive agents.

Complement Activation↗

Arterial stiffness in chronic inflammatory diseases.

Chronic inflammatory diseases are associated with premature atherosclerosis; however, it is unknown whether arterial stiffness is increased in this setting, possibly as a manifestation of vascular disease preceding and/or independent of atherosclerosis. Carotid ultrasonography and radial applanation tonometry were performed in 101 patients with systemic lupus erythematosus, 80 patients with rheumatoid arthritis, and 105 healthy control subjects. The 3 groups were comparable in age, gender, and carotid artery absolute and relative wall thickness. Atherosclerotic plaque was more common in lupus (46%) and rheumatoid arthritis (38%) patients than in controls (23%) (P<0.003). Although control subjects had higher central and peripheral blood pressures, arterial stiffness was increased in patient groups compared with controls (lupus, rheumatoid arthritis, controls, respectively: beta: 3.36 versus 3.22 versus 2.60, P<0.001; Young's modulus: 441 versus 452 versus 366 mm Hg/cm, P=0.004; Peterson's elastic modulus: 278 versus 273 versus 216 mm Hg, P<0.001) after adjustment for differences in mean brachial pressure. In multivariate analysis involving the entire population, arterial stiffness was independently related to age, serum glucose, and the presence of chronic inflammatory disease. In multivariate analysis restricted to the patients, arterial stiffness was independently related to age at diagnosis, disease duration, serum cholesterol, and C-reactive protein (and IL-6, when substituted for C-reactive protein). When analyses were repeated in the 186 study subjects without carotid plaque, arterial stiffness remained significantly elevated in patient groups after adjustment for differences in age and mean brachial pressure. In conclusion, arterial stiffness is increased in chronic inflammatory disorders independent of the presence of atherosclerosis and is related to disease duration, cholesterol, and the inflammatory mediator C-reactive protein and the cytokine that stimulates its production, IL-6.

Adult↗

Activation of the interferon-alpha pathway identifies a subgroup of systemic lupus erythematosus patients with distinct serologic features and active disease.

OBJECTIVE: Gene-expression studies have demonstrated increased expression of interferon (IFN)-inducible genes (IFIGs) in peripheral blood mononuclear cells (PBMCs) of many patients with systemic lupus erythematosus (SLE), with a predominant effect of type I IFN. This study examined the hypothesis that increased disease severity and activity, as well as distinct autoantibody specificities, characterize SLE patients with activation of the type I IFN pathway. METHODS: Freshly isolated PBMCs from 77 SLE patients, 22 disease controls, and 28 healthy donors were subjected to real-time polymerase chain reaction for 3 IFIGs that are preferentially induced by IFNalpha, and the data were used to derive IFNalpha scores for all individuals. Expression of IFIGs was significantly higher in SLE patients compared with disease controls or healthy donors. SLE patients with high and low IFNalpha scores were compared for clinical manifestations of disease, disease severity, disease activity, serologic features, and potential confounders, by bivariate and multivariate analyses. RESULTS: SLE patients with a high IFNalpha score had a significantly higher prevalence of renal disease, a greater number of American College of Rheumatology criteria for SLE, and a higher Systemic Lupus International Collaborating Clinics damage index (SDI) score than did SLE patients with low IFNalpha scores. Patients with high scores showed increased disease activity, as measured by lower C3 levels, hemoglobin levels, absolute lymphocyte counts, and albumin levels, and a higher anti-double-stranded DNA (dsDNA) titer, erythrocyte sedimentation rate, and SLE Disease Activity Index 2000 score. The presence of antibodies specific for Ro, U1 RNP, Sm, and dsDNA, but not phospholipids, was significantly associated with a high IFNalpha score. Logistic regression analysis confirmed that renal disease, higher SDI scores, low complement levels, and presence of anti-RNA binding protein (RBP) autoantibodies were associated with a high IFNalpha score. CONCLUSION: Activation of the IFNalpha pathway defines a subgroup of SLE patients whose condition is characterized by increased disease severity, including renal disease, increased disease activity, reflected in complement activation, and autoreactivity to RBP.

Adolescent↗

Interferon pathway activation in systemic lupus erythematosus.

The recognition that a multitude of interferon (IFN)- inducible genes are coordinately expressed in peripheral blood cells of patients with systemic lupus erythematosus (SLE) has contributed to considerable interest in the IFN pathway as a therapeutic target in lupus. Together with data that have accumulated over the past four decades implicating IFN-alpha in SLE, the gene expression data have resulted in emergence of this cytokine pathway as a focal point for understanding mechanisms of autoimmunity and inflammation in systemic autoimmune diseases. Assays that measure IFN-inducible gene expression in patient cells and tissues and plasma assays that quantify IFN-alpha protein are providing tools for identification of patients with active disease and who may be responsive to inhibition of the innate immune system component of the altered immune response in SLE. In addition, investigations of the mechanisms of induction of IFN pathway activation are suggesting clues to the triggers of autoimmunity in SLE.

Female↗

Coordinate overexpression of interferon-alpha-induced genes in systemic lupus erythematosus.

OBJECTIVE: To study the contribution of interferon-alpha (IFNalpha) and IFNgamma to the IFN gene expression signature that has been observed in microarray screens of peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE). METHODS: Quantitative real-time polymerase chain reaction analysis of healthy control PBMCs was used to determine the relative induction of a panel of IFN-inducible genes (IFIGs) by IFNalpha and IFNgamma. PBMCs from 77 SLE patients were compared with those from 22 disease controls and 28 healthy donors for expression of IFIGs. RESULTS: Expression of IFNalpha-inducible genes was significantly higher in SLE PBMCs than in those from disease controls or healthy donors. The level of expression of all IFIGs in PBMCs from SLE patients with IFNalpha pathway activation correlated highly with the inherent responsiveness of those genes to IFNalpha, suggesting coordinate activation of that cytokine pathway. Expression of genes preferentially induced by IFNgamma was not significantly increased in SLE PBMCs compared with control PBMCs. IFNalpha-regulated gene-inducing activity was detected in some SLE plasma samples. CONCLUSION: The coordinate activation of IFNalpha-induced genes is a characteristic of PBMCs from many SLE patients, supporting the hypothesis that IFNalpha is the predominant stimulus for IFIG expression in lupus.

Adaptor Proteins, Signal Transducing↗

Costimulatory molecules and T-cell-B-cell interactions.

This article focuses on activating and inhibiting costimulatory signals that are delivered to the T cell from antigen-presenting cells, mediating and modulating T-cell clonal expansion and development of effector functions, as well as costimulatory signals that are delivered by activated T cells to interacting target cells. The coordinated expression and interaction of these molecules regulates responses to foreign antigens and avoidance of response to self-antigens. Knowledge of the structure and function of these costimulatory molecules can be used to manipulate immune function and inhibit autoimmunity and inflammation in the setting of disease.

Animals↗

Interferon-alpha in systemic lupus erythematosus.

PURPOSE OF REVIEW: To describe the lines of evidence supporting a significant role for interferon-alpha (IFNalpha) in the pathogenesis of systemic lupus erythematosus (SLE) and to propose potential mechanisms by which IFNalpha contributes to the autoimmunity and immune dysfunction of SLE. RECENT FINDINGS: Long-standing data indicating elevated levels of IFNalpha in the circulation of patients with SLE have recently been supplemented by reports from clinical practice, gene expression data, analysis of patient cells studied ex vivo, and studies of mechanisms of induction of IFNalpha production to provide complementary data strongly supporting a pathogenic role for IFNalpha in SLE. Recombinant IFNalpha, when administered as a therapy to patients with malignancy or hepatitis infection, can induce SLE. IFNalpha-regulated genes are highly expressed in SLE peripheral blood cells compared with cells from control subjects. Functional alterations of SLE mononuclear cells have been attributed to effects of IFNalpha. In addition, immune complexes bearing lupus autoantibodies and RNA or DNA have been shown to induce IFNalpha production. Finally, progress in understanding the role of Toll-like receptors (TLR) in the activation of the innate immune response has suggested potential mechanisms by which adjuvant-like factors act through TLR to induce IFNalpha as well as effective processing of self-antigens, resulting in activation of an adaptive immune response directed against self, as well as cytokine-mediated immune dysfunction. SUMMARY: Substantial evidence supports a significant role for IFNalpha in the pathogenesis of lupus. The IFNalpha pathway represents a promising target for therapeutic intervention in patients with SLE.

Animals↗

Measurement of cytokines in autoimmune disease.

Systemic autoimmune diseases are characterized by extensive alterations in immune system function, with cytokines and autoantibodies contributing to impaired immunoregulation and tissue damage. Characterization of the expression and function of cytokines is important for elucidation of pathogenic mechanisms and for identification of therapeutic targets and strategies. We reviewed the utility of assays that reflect individual variability in cytokine gene sequence, expression of messenger ribonucleic acid (mRNA) or protein, as well as measurement of expression of target genes regulated by cytokines. Real-time reverse transcriptase polymerase chain reaction and intracellular staining for cytokine expression are two sensitive and quantitative approaches for analysis of cytokine mRNA and protein, respectively. Detailed methods are provided for these assays.

Autoimmune Diseases↗

Prevalence and correlates of accelerated atherosclerosis in systemic lupus erythematosus.

BACKGROUND: Although systemic lupus erythematosus is associated with premature myocardial infarction, the prevalence of underlying atherosclerosis and its relation to traditional risk factors for cardiovascular disease and lupus-related factors have not been examined in a case-control study. METHODS: In 197 patients with lupus and 197 matched controls, we performed carotid ultrasonography, echocardiography, and an assessment for risk factors for cardiovascular disease. The patients were also evaluated with respect to their clinical and serologic features, inflammatory mediators, and disease treatment. RESULTS: The risk factors for cardiovascular disease were similar among patients and controls. Atherosclerosis (carotid plaque) was more prevalent among patients than the controls (37.1 percent vs. 15.2 percent, P<0.001). In multivariate analysis, only older age, the presence of systemic lupus erythematosus (odds ratio, 4.8; 95 percent confidence interval, 2.6 to 8.7), and a higher serum cholesterol level were independently related to the presence of plaque. As compared with patients without plaque, patients with plaque were older, had a longer duration of disease and more disease-related damage, and were less likely to have multiple autoantibodies or to have been treated with prednisone, cyclophosphamide, or hydroxychloroquine. In multivariate analyses including patients with lupus, independent predictors of plaque were a longer duration of disease, a higher damage-index score, a lower incidence of the use of cyclophosphamide, and the absence of anti-Smith antibodies. CONCLUSIONS: Atherosclerosis occurs prematurely in patients with systemic lupus erythematosus and is independent of traditional risk factors for cardiovascular disease. The clinical profile of patients with lupus and atherosclerosis suggests a role for disease-related factors in atherogenesis and underscores the need for trials of more focused and effective antiinflammatory therapy.

Adrenal Cortex Hormones↗