Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Erythematosus

  • active systemic lupus erythematosus
  • childhood-onset systemic lupus erythematosus
  • lupus erythematosus
  • pediatric systemic lupus erythematosus
  • systemic lupus erythematosus

  • Terms modified by Erythematosus

  • erythematosus patient

  • Selected Abstracts

    Quinacrine and hydroxychloroquine, a forgotten combination for patients with active systemic lupus erythematosus in Australasia?

    Daniel W. T. Ching
    Abstract In 1994, A 39-year-old Female Patient With Systemic Lupus Erythematosus (Sle) Was Diagnosed As Having Lupus-induced Serositis. She Was Commenced On Hydroxychloroquine (Hcq) And Prednisone. Her Disease Kept Relapsing Whenever She Was Tailed Off Prednisone. In 1997, Quinacrine (Qn) Was Commenced, And Prednisone Was Gradually Stopped. Her Disease Has Remained In Remission On The Combination Of Hcq And Qn. In December 2000 She Ran Out Of Qn For A Week, And Within This Period She Started To Experience Fatigue And Polyarthralgia Again. Quinacrine Is Available From Compounding Pharmacies, And Is Relatively Cheap. The Combination Of Hcq And Qn In The Treatment Of Sle Should Be Considered More Often. [source]

    Roles of CD147 on T lymphocytes activation and MMP-9 secretion in Systemic Lupus Erythematosus

    Gina Pistol
    Abstract The cellular and molecular mechanisms involved in many abnormalities described in Systemic Lupus Erythematosus (SLE) are still unclear. Some of these abnormalities referred to the hyperactivation of T lymphocytes and the enhanced secretion of MMP-9 by peripheral blood mononuclear cells (PBMCs). Therefore, in this paper we investigated the potential role of CD147 molecule in these abnormalities. Our results demonstrated that CD147 molecule is overexpressed on CD3+T lymphocytes from SLE patients when compared with CD3+T lymphocytes from healthy donors. Monoclonal anti-CD147 antibodies, MEM-M6/1 clone, were able to inhibit protein tyrosine phosphorylation only in CD3 × CD28 costimulated T lymphocytes from SLE patients. However, this monoclonal antibody was unable to inhibit the enhanced activity of MMP-9 secreted by SLE PBMCs. [source]

    Bullous Lupus: An Unusual Initial Presentation of Systemic Lupus Erythematosus in an Adolescent Girl

    Monica Tincopa B.S
    Autoimmunity in bullous systemic lupus erythematosus is characterized by the presence of circulating anti-type VII collagen antibodies. We report here a case of a child whose initial systemic lupus erythematosus presentation was a diffuse bullous eruption. [source]

    Papulonodular Mucinosis in a Child with Systemic Lupus Erythematosus

    No abstract is available for this article. [source]

    Shrinking Lung Syndrome in a 14-Year-Old Boy with Systemic Lupus Erythematosus

    Polly J. Ferguson MD
    Abstract Pulmonary complications occur frequently in people with systemic lupus erythematosus. We report on an adolescent with an acute onset of dyspnea and pleuritic chest pain with severe restrictive lung physiology on pulmonary function testing (forced vital capacity, 20% of predicted) who had no evidence of parenchymal lung or pleural disease. He was found to have restricted diaphragmatic movement as assessed by fluoroscopy, without evidence of generalized respiratory muscle weakness. His clinical presentation and results of diagnostic tests were typical for shrinking lung syndrome. Given the rarity of shrinking lung syndrome in the pediatric age range, many clinicians are not aware of it as a clinical entity. Shrinking lung syndrome should be included in the differential diagnosis of dyspnea in both children and adults with systemic lupus erythematosus. Pediatr Pulmonol. © 2005 Wiley-Liss, Inc. [source]

    Systemic Lupus Erythematosus and Breast Cancer

    THE BREAST JOURNAL, Issue 1 2008
    Michalis Kontos MD
    Abstract:, There is evidence that certain connective tissue diseases such as scleroderma are associated with an increased risk of malignancy. Although it has been claimed that systemic lupus erythematosus (SLE) carries an increased risk of breast cancer, review of the available literature suggests that this is not the case, or, any increase is very small. Women with SLE do not need to be under close surveillance for breast cancer. In patients suffering from both SLE and breast cancer, radiotherapy has been regarded as relatively contraindicated because of fears concerning early and late complications. This view is not supported by the available literature and the majority of such cases can be treated by standard breast-conserving therapy, including breast irradiation. [source]

    Preferential recognition of the phosphorylated major linear B-cell epitope of La/SSB 349,368aa by anti-La/SSB autoantibodies from patients with systemic autoimmune diseases

    A. G. Terzoglou
    Summary Sera from patients with primary Sjögren Syndrome (pSS) or Systemic Lupus Erythematosus (SLE) often contain autoantibodies directed against La/SSB. The sequence 349,368aa represents the major B-cell epitope of La/SSB, also it contains, at position 366, a serine aminoacid residue which constitutes the main phosphorylation site of the protein. In this study we investigated the differential recognition of the 349,368aa epitope and its phosphorylated form by antibodies found in sera from patients with systemic autoimmune diseases. Peptides corresponding to the sequence of the unphosphorylated (pep349,368aa) and the phosphorylated form (pep349,368aaPh) of the La/SSB epitope 349,368aa, as well as to a truncated form spanning the sequence 349,364aa and lacking the phosphorylation site (pep349,364aa), were synthesized. Sera from 53 patients with pSS and SLE with anti-La/SSB specificity, 30 patients with pSS and SLE without anti-La/SSB antibodies, 25 patients with rheumatoid arthritis and 32 healthy individuals were investigated by ELISA experiments. Autoantibodies to pep349,368aaPh were detected in sera of anti-La/SSB positive patients with a higher prevalence compared to the pep349,368aa (66%versus 45%). Pep349,368aaPh inhibited the antibody binding almost completely (92%), while pep349,368aa inhibited the binding only partially (45%). Anti-La/SSB antibodies presented a higher relative avidity for the phosphorylated than the unphosphorylated peptide. Immunoadsorbent experiments using the truncated peptide pep349,364aa indicated that the flowthrough showed a selective specificity for pep349,368aaPh, while the eluted antibodies reacted with both peptide analogues of the La/SSB epitope. These data suggest that sera from pSS and SLE patients with anti-La/SSB reactivity possess autoantibodies that bind more frequently and with a higher avidity to the phosphorylated major B-cell epitope of the molecule. [source]

    Monocytes and T lymphocytes contribute to a predominance of interleukin 6 and interleukin 10 in systemic lupus erythematosus,

    CYTOMETRY, Issue 4 2009
    Susana Mellor-Pita
    Abstract Objective To investigate the contribution of T lymphocytes and monocytes to cytokine production in systemic lupus erythematosus (SLE). Methods Forty-five SLE patients and 19 healthy volunteers were included. Serum levels of tumor necrosis factor alpha (TNF,), interferon gamma (IFN,), interleukin (IL)-6, and IL10 were quantified by ELISA. The cytokine production capacities of peripheral blood mononuclear cells were assessed by culturing in vitro with PMA+Ionomycin or LPS. The intracellular cytokine expression was measured by flow cytometry in T lymphocytes and monocytes, respectively. The influence of the disease activity (measured as the SLE-disease activity index; SLEDAI) and the treatment the patients were receiving was evaluated. Results Serum IL10, IL6, and TNF, levels were increased in patients (P , 0.01), and a higher spontaneous (without stimuli) intracellular expression of IL10 in CD4+ and CD8+ T lymphocytes (P < 0.05) and of IL6 in monocytes (P = 0.01) were found. After stimulation, patients presented a higher percentage of CD4+ and CD8+ T lymphocytes producing IL4 and IL10 (P , 0.01), and of monocytes producing IL6 (P = 0.04) and IL10 (P = 0.008). The SLEDAI score was positively correlated with the percentage of CD4+IL10+ and CD8+IL10+ T lymphocytes (P < 0.01), and inversely correlated with CD8+TNF,+ (P= 0.02), CD4+IFN,+ (P = 0.04) and CD8+ IFN,+ (P = 0.002) T lymphocytes. Patients receiving high dose prednisone produced higher IL10, but they also were the patients with a more active disease. Conclusion Monocytes and T lymphocytes (CD4+ and CD8+) contribute to an overproduction of IL6 and IL10 in SLE; this correlates with the disease activity but is independent of the treatment the patients are receiving. © 2009 Clinical Cytometry Society [source]

    Phenotypic and genetic analyses of T-cell-mediated immunoregulation in patients with Type 1 diabetes

    DIABETIC MEDICINE, Issue 10 2006
    Y. Tsutsumi
    Abstract Aims To investigate the contribution of regulatory T cells and co-stimulatory molecules in CD4+ T cells to the development of Type 1 diabetes (T1D). Methods Twelve patients with T1D, nine patients with systemic lupus erythematosus (SLE), and 12 age-matched healthy control subjects participated. We analysed the proportions of CD25+CD4+ T cells and natural killer T cells (NKT cells), and the expression levels of Foxp3, CTLA-4, CD28, ICOS, PD-1 and BTLA in peripheral blood mononuclear cells and purified CD4+ T cells. Results There were no significant differences in the proportions of CD25+ CD4+ T cells or NKT cells among the three groups. PD-1 expression levels of peripheral CD4+ T cells from T1D patients were significantly lower than those from healthy control subjects (P = 0.00066). In contrast, PD-1 expression levels were similar in SLE patients and healthy control subjects. The expression levels of Foxp3, CTLA-4, CD28, ICOS and BTLA were similar in the three groups. Conclusions Decreased expression of the PD-1 gene in CD4+ T cells may contribute to the development and/or maintenance of autoimmune T1D. As the population studied was small and heterogeneous, further studies are required to confirm the findings. [source]

    Prevalence of Anti-cardiolipin, Anti-,2 Glycoprotein I, and Anti-prothrombin Antibodies in Young Patients with Epilepsy

    EPILEPSIA, Issue 1 2002
    R. Cimaz
    Summary: ,Purpose: To measure anti-cardiolipin (aCL), anti-,2 glycoprotein I (anti-,2GPI), and anti-prothrombin (aPT) antibodies in young patients with epilepsy, and to correlate their presence with demographic data, clinical diagnoses, laboratory and neuroradiologic findings, and antiepileptic drugs (AEDs). Methods: Sera from one hundred forty-two consecutive patients with epilepsy with a median age of 10 years were tested for aCL and anti-,2GPI autoantibodies by solid-phase assays. aPT antibodies also were assayed in sera from 90 patients. Positive results were confirmed after a minimum of 6 weeks. Antinuclear antibodies (ANAs) and antibodies against extractable nuclear antigens (ENAs) also were tested. Results: An overall positivity of 41 (28.8%) of 142 sera was found. Fifteen patients were positive for aCL, 25 for anti-,2GPI, and 18 for aPT antibodies. Several patients (12%) displayed more than one specificity in their serum. Only one of these patients had a concurrent positivity for ANAs and ENAs. A predominance of younger patients was found in the antibody-positive group. All types of epilepsy were represented in the positive group. No relation between antibody positivity and AEDs was found. Diffuse ischemic lesions at computed tomography (CT)/magnetic resonance imaging (MRI) scans were present in higher percentages in patients who were antibody positive. No positive patient had a history of previous thrombosis or other features related to systemic lupus erythematosus (SLE), and no patient was born of a mother with SLE. Conclusions: Our study suggests a relation between epilepsy and aPL in young patients. A pathogenetic role for these autoantibodies cannot be excluded, and their determination might prove useful even from a therapeutic point of view. [source]

    Clinical importance of antibodies against platelet activating factor in antiphospholipid syndrome manifestations

    Background We assessed whether antibodies against platelet activating factor (PAF) are related to the presence of antiphospholipid syndrome (APS) clinical manifestations, in particular thrombosis, in patients with connective tissue diseases. Materials and methods Anti-PAF, anticardiolipin (aCL), anti,2 glycoprotein I (anti,2GPI) and antiphosphatidylcholine (anti-PC) antibodies were determined in 52 patients with APS, 29 patients with systemic lupus erythematosus (SLE) aCL but without APS, 30 patients with SLE without aCL, and 30 patients with scleroderma. A new enzyme-linked immunosorbent assay (ELISA) was developed for determining anti-PAF antibodies in a bovine serum-free fashion. Results The ELISA showed high specificity. Homologous inhibition experiments showed 60,70% inhibition. Anti-PAF antibodies were found in 18/52 APS patients, 10/29 SLE/aCL+ patients, 9/30 SLE/aCL, patients and 3/30 scleroderma patients. Anti-PAF antibodies were significantly associated with anti-PC antibodies (odds ratio [OR] 12.7, P < 0.01), and there was a modest association with immunoglobulin G (IgG) aCL (OR 3.1, P > 0.10), but not with IgM aCL or anti,2GPI. Three SLE/aCL+ patients and five SLE/aCL, patients had clinical manifestations characteristic of APS. All these patients had anti-PAF antibodies, while none had high titres of aCL or anti,2GPI antibodies and only one had anti-PC antibodies. Among the combined APS and SLE groups, the presence of anti-PAF antibodies was significantly associated with clinical manifestations which are characteristic of APS (OR 2.6, P = 0.02). The effect was independent of IgG aCL and anti,2GPI antibodies. Conclusions Anti-PAF antibodies are common in APS and SLE and comprise an independent factor for the development of thrombosis. Several patients experiencing thromboses have anti-PAF antibodies without other antiphospholipid specificities. [source]

    Acquired thrombotic thrombocytopenic purpura as the presenting symptom of systemic lupus erythematosus.

    Successful treatment with plasma exchange, immunosuppression, report of two cases
    Abstract:, Thrombotic thrombocytopenic purpura (TTP) is a rare but life-threatening syndrome characterized by platelet aggregation causing occlusive microangiopathy. It has been described as a complication in systemic lupus erythematosus (SLE). Recent research indicated that genetic or autoantibody-induced deficiency of the metalloprotease ADAMTS13 plays a key role in the pathogenesis of TTP. Here we report two uncommon cases of TTP as the first presenting symptom of SLE. Both patients were treated with combined plasma exchange and immunosuppressive therapy, and recovered completely. Although TTP and SLE have several clinical findings in common, and both disorders may coexist more frequently than we currently assume, features of one disease should not mislead to reject the alternative disorder. [source]

    Abnormal CTLA-4 function in T cells from patients with systemic lupus erythematosus

    Elizabeth C. Jury
    Abstract CTLA-4 is a critical gatekeeper of T-cell activation and immunological tolerance and has been implicated in patients with a variety of autoimmune diseases through genetic association. Since T cells from patients with the autoimmune disease systemic lupus erythematosus (SLE) display a characteristic hyperactive phenotype, we investigated the function of CTLA-4 in SLE. Our results reveal increased CTLA-4 expression in FOXP3, responder T cells from patients with SLE compared with other autoimmune rheumatic diseases and healthy controls. However, CTLA-4 was unable to regulate T-cell proliferation, lipid microdomain formation and phosphorylation of TCR-, following CD3/CD28 co-stimulation, in contrast to healthy T cells. Although lupus T cells responded in vitro to CD3/CD28 co-stimulation, there was no parallel increase in CTLA-4 expression, which would normally provide a break on T-cell proliferation. These defects were associated with exclusion of CTLA-4 from lipid microdomains providing an anatomical basis for its loss of function. Collectively our data identify CTLA-4 dysfunction as a potential cause for abnormal T-cell activation in patients with SLE, which could be targeted for therapy. [source]

    Development of nephritis but not sialadenitis in autoimmune-prone BAFF transgenic mice lacking marginal zone B cells

    Abstract B cell-activating factor belonging to the TNF family (BAFF) is a B cell survival factor required for B cell maturation. BAFF transgenic (Tg) mice develop autoimmune disorders characterized by autoantibody production, which leads to nephritis and salivary gland destruction (sialadenitis), features reminiscent of systemic lupus erythematosus and Sjögren's syndrome (SS), respectively. Disease in BAFF Tg mice correlates with the expansion of the marginal zone (MZ) B cell compartment and the abnormal presence of MZ-like B cells in the blood, LN and inflamed salivary glands, suggesting a role for these cells in BAFF-induced autoimmunity. Lymphotoxin-, (LT,)-deficient mice show disrupted splenic architecture, lack MZ B cells and some peripheral LN, and are unable to mount T cell-dependent immune responses. BAFF Tg mice lacking LT, (LT,,-BTg) retained these defects, yet still developed nephritis associated with the presence of B-1 B cells in the kidneys. However, in contrast to old BAFF Tg mice, aging LT,,-BTg mice no longer developed sialadenitis. Thus, autoimmune disorders in BAFF Tg mice are possibly events coordinated by MZ and B-1 B cells at separate anatomical sites. [source]

    Toll-like receptor engagement stimulates anti-snRNP autoreactive B cells for activation

    Chuanlin Ding
    Abstract Autoreactive B cells are the source of pathogenic autoantibodies (autoAb) in systemic lupus erythematosus (SLE). Previous studies have demonstrated that anti-small nuclear ribonucleoprotein particles (snRNP) B cells from normal background mice tolerize T cells in the periphery and do not secrete autoAb. In this study, we examined whether these anti-snRNP B cells can be activated for autoAb production by the engagement of Toll-like receptors (TLR). Anti-snRNP B cells proliferated vigorously and secreted abundant anti-snRNP autoAb upon exposure to CpG or polyriboinosinic polyribocytidylic acid [poly,(I:C)] in vitro. In addition, the costimulatory molecules CD80 and CD86 were up-regulated. While both anti-snRNP B cells and wild-type B cells produced similar levels of IL-6 and IL-10, anti-snRNP B cells secreted predominately IFN-, in response to CpG or poly,(I:C) stimulation. Furthermore, we showed that in vivo engagement of TLR stimulated immature anti-snRNP B cells to further differentiate and produce autoAb and form germinal centers. The activated anti-snRNP B cells became expanded and migrated into the T-B cell interface. Moreover, TLR engagement directly or indirectly activated autoreactive B cells via a CD4 T cell-independent manner. These results provide in vitro and in vivo evidence that BCR/TLR co-engagement promotes the activation of anti-snRNP B cells for autoAb production. [source]

    Systemic autoimmune disease induced by dendritic cells that have captured necrotic but not apoptotic cells in susceptible mouse strains

    Liang Ma
    Abstract Systemic lupus erythematosus (SLE) is an autoimmune disorder of a largely unknown etiology. Anti-double-stranded (ds) DNA antibodies are a classic hallmark of the disease, although the mechanism underlying their induction remains unclear. We demonstrate here that, in both lupus-prone and normal mouse strains, strong anti-dsDNA antibody responses can be induced by dendritic cells (DC) that have ingested syngeneic necrotic (DC/nec), but not apoptotic (DC/apo), cells. Clinical manifestations of lupus were evident, however, only in susceptible mouse strains, which correlate with the ability of DC/nec to release IFN-, and to induce the pathogenic IgG2a anti-dsDNA antibodies. Injection of DC/nec not only accelerated disease progression in the MRL/MpJ- lpr/lpr lupus-prone mice but also induced a lupus-like disease in the MRL/MpJ-+/+ wild-type control strain. Immune complex deposition was readily detectable in the kidneys, and the mice developed proteinuria. Strikingly, female MRL/MpJ-+/+ mice that had received DC/nec, but not DC/apo, developed a ,butterfly' facial lesion resembling a cardinal feature of human SLE. Our study therefore demonstrates that DC/nec inducing a Th1 type of responses, which are otherwise tightly regulated in a normal immune system, may play a pivotal role in SLE pathogenesis. [source]

    Toll-like receptor 9 binds single-stranded CpG-DNA in a sequence- and pH-dependent manner

    Mark Rutz
    Abstract Toll-like receptors (TLR) recognize bacterial and viral components, but direct interaction of receptor and ligand is unclear. Here, we demonstrate that TLR9 binds directly and sequence-specifically to single-stranded unmethylated CpG-DNA containing a phosphodiester backbone. TLR9-CpG-DNA interaction occurs at the acidic pH (6.5,5.0) found in endosomes and lysosomes. By sequence comparison we identified a potential CpG-DNA binding domain homologous to that described for methyl-CpG-DNA binding proteins. Amino acid substitutions in this region abrogated CpG-DNA binding and led to loss of NF-,B activation. Furthermore, chloroquine and quinacrine, therapeutic agents for autoimmune diseases like rheumatoid arthritis and systemic lupus erythematosus, directly blocked TLR9-CpG-DNA interaction but not TLR2-Pam3Cys binding. Our results demonstrate direct binding of TLR9 to CpG-DNA and suggest that the therapeutic activity of chloroquine and quinacrine in autoimmune diseases may be due to its activity as a TLR9 antagonist and inhibitor of endosomal acidification. [source]

    Fc,RIIB deficiency with Fas mutation is sufficient for the development of systemic autoimmune disease

    Kaori Yajima
    Abstract MRL.Faslpr/lpr mice, a model for systemic lupus erythematosus (SLE) and arthritis in humans, have a Fas mutation that results in spontaneous development of systemic autoimmune diseases and a short life span. Half of them die by 5,6,months of age due to massive progression of systemic autoimmune diseases, such as lupus nephritis. However, C57BL/6 (B6).Faslpr/lpr strain does not develop such disorders within the normal life span, indicating that suppressor gene(s) in B6 mice may control the onset and exacerbation of disease. Here, we show that the gene for a unique inhibitory Fc receptor for IgG (Fc,RIIB) is a critical SLE suppressor. Fc,RIIB-deficient B6.Faslpr/lpr (B6.IIB,/,Faslpr/lpr) mice developed systemic autoimmune diseases, including anti-DNA and anti-type,II collagen autoantibodies and cryoglobulin production, immune complex glomerulonephritis and arthritis. They were short-lived, due to enhanced autoantibody production by B cells culminating in fatal lupus nephritis. Thus, Fc,RIIB deletion with Fas mutation is sufficient for the development of systemic autoimmunity in B6 mice. The inhibitory signaling cascade via Fc,RIIB may be critical for suppressing SLE in humans. [source]

    Neuropsychiatric disturbances in SLE are associated with antibodies against NMDA receptors

    R. Omdal
    To determine whether neuropsychiatric manifestations in patients with systemic lupus erythematosus (SLE) are influenced by antibodies against the human N-methyl- d -aspartate (NMDA) receptor types NR2a or NR2b. A decapeptide was synthesized containing a sequence motif present in the extracellular ligand-binding domain of NMDA receptors NR2a and NR2b, bound by the monoclonal murine anti-DNA antibody R4A. In an ELISA with the murine monoclonal R4v as positive control, plasma samples of 57 patients with SLE were examined for the anti-peptide (anti-NR2) antibody after the patients had been subjected to comprehensive psychological and cognitive testing. Poor performance on the Visual Paired Associates test (immediate), the Grooved Pegboard test, as well as high scores on the Beck Depression Inventory, and scales D-2 (depression), Pd-4 (psychopathic deviate), Sc-8 (schizophrenia), and Ma-9 (hypomania) of the MMPI-2 were significantly associated with elevated levels of anti-NR2 antibodies. The findings in several domains indicate an association between anti-NR2 antibodies and depressed mood in addition to decreased short-time memory and learning. Antibodies to NMDA receptors thus may represent one of several mechanisms for cerebral dysfunction in patients with SLE. [source]

    Elevated serum BAFF levels in patients with localized scleroderma in contrast to other organ-specific autoimmune diseases

    Takashi Matsushita
    Abstract:, Serum levels of B-cell activating factor belonging to the tumor necrosis factor family (BAFF), a potent B-cell survival factor, are elevated in patients with systemic autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis and systemic sclerosis (SSc). The objective of this study was to determine serum BAFF levels and relate the results to the clinical features in patients with organ-specific autoimmune diseases of the skin, such as localized scleroderma and autoimmune bullous diseases. Serum BAFF levels were examined by enzyme-linked immunosorbent assay in 44 patients with localized scleroderma, 20 with pemphigus vulgaris/pemphigus foliaceus, 20 with bullous pemphigoid and 30 healthy controls. Twenty patients with SSc and 20 with SLE were also examined as disease controls. Serum BAFF levels were elevated in localized scleroderma patients compared with healthy controls. Concerning localized scleroderma subgroups, patients with generalized morphea, the severest form of localized scleroderma, had higher serum BAFF levels than linear scleroderma or morphea patients. The BAFF levels of generalized morphea were comparable with those of SSc or SLE. Furthermore, serum BAFF levels correlated positively with antihistone antibody levels and the severity of skin lesion as well as the number of skin lesions. By contrast, serum BAFF levels were not significantly elevated in patients with pemphigus or pemphigoid. These results suggest that BAFF may be contributing to autoimmunity and disease development in localized scleroderma. [source]

    Abstract no.: 10 DNA fragmentation, but not caspase-3 activation or PARP-1 cleavage, combined with macrophage immunostaining as a tool to study phagocytosis of apoptotic cells in situ

    Dorien M. Schrijvers
    Efficient phagocytosis of cells undergoing apoptosis by macrophages is important to prevent immunological responses and development of chronic inflammatory disorders, such as systemic lupus erythematosus, cystic fibrosis or atherosclerosis. To study phagocytosis of apoptotic cells (AC) by macrophages in tissue, we validated different apoptosis markers (DNA fragmentation, caspase-3 activation and cleavage of its substrate poly (ADP-ribose) polymerase-1) in combination with macrophage immunostaining. Human tonsils were used as a model because they show a high apoptosis frequency under physiological conditions as well as efficient phagocytosis of AC by macrophages. On the other hand, advanced human atherosclerotic plaques were examined since phagocytosis of AC in a plaque is severely impaired. Our results demonstrate that the presence of non-phagocytized TUNEL-positive AC represents a suitable marker for poor phagocytosis by macrophages in situ. Other markers for apoptosis, such as cleavage of caspase-3 or PARP-1, should not be used to assess phagocytosis efficiency, because activation of the caspase cascade and cleavage of their substrates can occur in AC when they have not yet been phagocytized by macrophages. [source]

    Toll-like receptors, endogenous ligands, and systemic autoimmune disease

    Ian R. Rifkin
    Summary:, The critical role of Toll-like receptors (TLRs) as mediators of pathogen recognition by the innate immune system is now firmly established. Such recognition results in the initiation of an inflammatory immune response and subsequent instruction of the adaptive immune system, both of which are designed to rid the host of the invading pathogen. More controversial is the potential role of TLRs in the recognition of endogenous ligands and what effect this might have on the consequent development of autoimmune or other chronic sterile inflammatory disorders. An increasing number of studies implicate TLRs as being involved in the immune response to self-molecules that have in some way been altered from their native state or accumulate in non-physiologic sites or amounts, although questions have been raised about possible contaminants in certain of these studies. In this review, we discuss the evidence for endogenous ligand,TLR interactions with particular emphasis on mammalian chromatin, systemic lupus erythematosus, and atherosclerosis. Overall, the data support the general concept of a role for TLRs in the recognition of endogenous ligands. However, the precise details of the interactions and the extent to which they may contribute to the pathogenesis of human disease remain to be clarified. [source]

    Interferon-alpha regulates the dynamic balance between human activated regulatory and effector T cells: implications for antiviral and autoimmune responses

    IMMUNOLOGY, Issue 1 2010
    Amit Golding
    Summary An adequate effector response against pathogens and its subsequent inactivation after pathogen clearance are critical for the maintenance of immune homeostasis. This process involves an initial phase of T-cell effector (Teff) activation followed by the expansion of regulatory T cells (Tregs), a unique cell population that limits Teff functions. However, significant questions remain unanswered about the mechanisms that regulate the balance between these cell populations. Using an in vitro system to mimic T-cell activation in human peripheral blood mononuclear cells (PBMC), we analysed the patterns of Treg and Teff activation, with special attention to the role of type I interferon (IFN-I). Interestingly, we found that IFN-,, either exogenously added or endogenously induced, suppressed the generation of CD4+ FoxP3HI IFN-,Neg activated Tregs (aTregs) while simultaneously promoting propagation of CD4+ FoxP3Low/Neg IFN-,Pos activated Teffs (aTeffs). We also showed that IFN-,-mediated inhibition of interleukin (IL)-2 production may play an essential role in IFN-,-induced suppression of aTregs. In order to test our findings in a disease state with chronically elevated IFN-,, we investigated systemic lupus erythematosus (SLE). Plasma from patients with SLE was found to contain IFN-I activity that suppressed aTreg generation. Furthermore, anti-CD3 activated SLE PBMCs exhibited preferential expansion of aTeffs with a very limited increase in aTreg numbers. Together, these observations support a model whereby a transient production of IFN-, (such as is seen in an early antiviral response) may promote CD4 effector functions by delaying aTreg generation, but a chronic elevation of IFN-, may tip the aTeff:aTreg balance towards aTeffs and autoimmunity. [source]

    A tolerogenic peptide down-regulates mature B cells in bone marrow of lupus-afflicted mice by inhibition of interleukin-7, leading to apoptosis

    IMMUNOLOGY, Issue 2 2009
    Hava Ben-David
    Summary Systemic lupus erythematosus (SLE) is an autoimmune disease mediated by T and B cells. It is characterized by a variety of autoantibodies and systemic clinical manifestations. A tolerogenic peptide, designated hCDR1, ameliorated the serological and clinical manifestations of SLE in both spontaneous and induced models of lupus. In the present study, we evaluated the status of mature B cells in the bone marrow (BM) of SLE-afflicted mice, and determined the effect of treatment with the tolerogenic peptide hCDR1 on these cells. We demonstrate herein that mature B cells of the BM of SLE-afflicted (New Zealand Black × New Zealand White)F1 mice were largely expanded, and that treatment with hCDR1 down-regulated this population. Moreover, treatment with hCDR1 inhibited the expression of the pathogenic cytokines [interferon-, and interleukin (IL)-10], whereas it up-regulated the expression of transforming growth factor-, in the BM. Treatment with hCDR1 up-regulated the rates of apoptosis of mature B cells. The latter was associated with inhibited expression of the survival Bcl-xL gene and of IL-7 by BM cells. Furthermore, the addition of recombinant IL-7 abrogated the suppressive effects of hCDR1 on Bcl-xL in the BM cells and resulted in elevated levels of apoptosis. Hence, the down-regulated production of IL-7 contributes to the hCDR1-mediated apoptosis of mature B cells in the BM of SLE-afflicted mice. [source]

    Induction of 150-kDa adenosine deaminase that acts on RNA (ADAR)-1 gene expression in normal T lymphocytes by anti-CD3-, and anti-CD28

    IMMUNOLOGY, Issue 4 2007
    Dama Laxminarayana
    Summary We and other investigators have demonstrated up-regulation of the expression of the RNA-editing gene 150-kDa adenosine deaminase that acts on RNA (ADAR1) in systemic lupus erythematosus (SLE) T cells and B cells, peripheral blood mononuclear cells (PBMC), natural killer (NK) cells. The presence of a small proportion of activated T cells is the hallmark of SLE. Therefore, it was hypothesized that 150-kDa ADAR1 gene expression is induced by the physiological activation of T cells. To examine this hypothesis, normal T cells were activated by anti-CD3-, plus anti-CD28 for various time periods from 0 to 48 hr. The expression of 110-kDa and 150-kDa ADAR1, and interleukin (IL)-2 and ,-actin gene transcripts was analysed. An approximately fourfold increase in 150-kDa ADAR1 gene expression was observed in activated T cells. ADAR2 gene transcripts are substrates for ADAR1 and ADAR2 enzymes. Therefore, we assessed the role of the 150-kDa ADAR enzyme in editing of ADAR2 gene transcripts. In activated T cells, site-selective editing of the ,2 site was observed. Previous studies indicate that this site is predominantly edited by ADAR1. In addition to this, novel editing sites at base positions ,56, ,48, ,45, ,28, ,19, ,15, +46 and +69 were identified in activated T cells. On the basis of these results, it is proposed that 150-kDa ADAR1 gene expression is selectively induced in T cells by anti-CD3-, and anti-CD28 stimulation and that it may play a role in site-selective editing of gene transcripts and in altering the functions of several gene products of T cells during activation and proliferation. [source]

    Interleukin-6 is responsible for aberrant B-cell receptor-mediated regulation of RAG expression in systemic lupus erythematosus

    IMMUNOLOGY, Issue 3 2007
    Sophie Hillion
    Summary Defective regulation of secondary immunoglobulin V(D)J gene rearrangement promotes the production of autoantibodies in systemic lupus erythematosus (SLE). It remains unclear, however, whether the regulation of the recombination-activating genes RAG1 and RAG2 is effective in SLE. RAG1 and RAG2 messenger RNA expression was analysed before and after in vitro activation of sorted CD19+ CD5, B cells with anti-immunoglobulin M antibodies, in 20 SLE patients and 17 healthy controls. The expression of CDK2 and p27Kip1 regulators of the RAG2 protein, were examined. The levels of interleukin-6 (IL-6) and its influence on RAG regulation were also evaluated in vitro. SLE patients had increased frequency of RAG-positive B cells. B-cell receptor (BCR) engagement induced a shift in the frequency of ,- and ,-positive cells, associated with a persistence of RAG messenger RNA and the maintenance of RAG2 protein within the nucleus. While expression of the RAG2-negative regulator CDK2 was normal, the positive regulator p27Kip1 was up-regulated and enhanced by BCR engagement. This effect was the result of the aberrant production of IL-6 by SLE B cells. Furthermore, IL-6 receptor blockade led to a reduction in p27Kip1 expression, and allowed the translocation of RAG2 from the nucleus to the cytoplasm. Our study indicates that aberrant production of IL-6 contributes to the inability of SLE B cells to terminate RAG protein production. Therefore, we hypothesize that because of constitutive IL-6 signalling in association with BCR engagement, SLE B cells would become prone to secondary immunoglobulin gene rearrangements and autoantibody production. [source]

    Anti-interleukin-6 monoclonal antibody inhibits autoimmune responses in a murine model of systemic lupus erythematosus

    IMMUNOLOGY, Issue 3 2006
    Bailin Liang
    Summary Systemic lupus erythematosus (SLE) is an autoimmune disease resulting from dysregulation of the immune system. Interleukin-6 (IL-6) is a multifunctional cytokine produced by macrophages, monocytes and T and B cells. It stimulates B-cell differentiation/maturation, immunoglobulin secretion, and T-cell functions. Elevated levels of IL-6 in serum, urine and renal glomeruli were detected in patients with active SLE and in murine models of SLE. Our study investigated the role of IL-6 in an SLE-like disease in New Zealand Black/White (NZB/W) F1 mice by administration of an anti-murine IL-6 monoclonal antibody (mAb). Intraperitoneal administration of the anti-IL-6 mAb suppressed the production of anti-dsDNA autoantibody. B-cell proliferation induced by anti-IgM and anti-CD40 was lower in the anti-IL-6 mAb-treated mice, ex vivo studies demonstrated that anti-IL-6 mAb treatment inhibited anti-dsDNA production. Anti-CD3-induced T-cell proliferation and mixed lymphocyte reactions were inhibited by anti-IL-6 mAb treatment, indicating a partial down-regulation of T cells. Histological analysis showed that treatment with anti-IL-6 mAb prevented the development of severe kidney disease. These results suggest that treatment with anti-IL-6 mAb has a beneficial effect on autoimmunity in murine SLE and that autoreactive B cells may be the primary target for anti-IL-6 mAb treatment; its effect on autoreactive T cells is also indicated. [source]

    Human autologous mixed lymphocyte reaction as an in vitro model for autoreactivity to apoptotic antigens

    IMMUNOLOGY, Issue 3 2002
    Mohammad R. Amel Kashipaz
    Summary Recent studies have indicated that cells undergoing apoptosis are the source of autoantigens which drive autoimmune responses in systemic lupus erythematosus (SLE). It has been recognized for many years that in vitro stimulation of T cells with irradiated major histocompatibility complex (MHC) class II-bearing autologous cells results in T-cell proliferation with immunological specificity and memory, namely the autologous mixed lymphocyte reaction (AMLR). The nature of the major stimulants in the AMLR is still unclear. We investigated whether apoptotic fragments from irradiated cells act as antigenic stimulators for AMLR or nucleohistone-primed T cells. T-cell proliferation in the primary AMLR was significantly suppressed by the presence of a caspase inhibitor Z-Val-Ala-Asp-CH2F (Z-VAD.fmk), indicating that apoptotic antigens released from irradiated autologous feeder cells act as stimulators of AMLR T cells. This inhibitory effect of Z-VAD was not caused by toxic effects, because the T-cell response to the mitogen phytohaemagglutinin (PHA) was not inhibited by Z-VAD. A nucleohistone preparation was shown to contain antigens that are important in the AMLR, as culture with nucleohistone (but not with thyroglobulin or hen-egg lysozyme) primed T cells to respond with secondary kinetics in a subsequent AMLR that was also suppressed by Z-VAD. Our data provide evidence that the AMLR constitutes a model for the evaluation of cellular and molecular mechanisms that may be relevant to the pathogenesis of SLE and similar autoimmune diseases. [source]

    Crohn disease versus systemic lupus erythematosus.

    An autopsy diagnosis of predominantly extraintestinal Crohn disease
    No abstract is available for this article. [source]

    Systemic lupus erythematosus with vasculitis confined to the coronary arteries

    W. A. C. DOUGLAS
    No abstract is available for this article. [source]