Systemic lupus erythematosus and apoptosis: a question of balance

CAR T cell therapy for refractory pediatric systemic lupus erythematosus: a new era of hope?

Systemic lupus erythematosus (SLE) is a chronic autoimmune condition that can affect multiple organ systems and is heterogenous in its presentation and response to therapy. When diagnosed in childhood, SLE is associated with increased morbidity and mortality compared to adult SLE, often requiring substantial immunosuppression with the risk of significant side effects. There remains a significant unmet need for new therapies that can improve disease control and reduce glucocorticoid and other toxic medication exposure for patients with severe or refractory disease. The pathogenesis of SLE involves B cell dysregulation and autoantibody production, which are a hallmark of the disease. Currently approved B cell directed therapies often result in incomplete B cell depletion and may not target long-lived plasma cells responsible for SLE autoantibodies. It is hypothesized that by persistently eliminating both B cells and plasmablasts, CAR T therapy can halt autoimmunity and prevent organ damage in patient's refractory to current B cell-depleting treatments. Herein we summarize the current preclinical and clinical data utilizing CAR T cells for SLE and discuss the future of this treatment modality for lupus.

MicroRNA-30e-5p has an Integrated Role in the Regulation of the Innate Immune Response during Virus Infection and Systemic Lupus Erythematosus

Precise regulation of innate immunity is crucial for development of appropriate host immunity against microbial infections and maintenance of immune homeostasis. MicroRNAs are small non-coding RNAs, post-transcriptional regulator of multiple genes, and act as a rheostat for protein expression. Here, we identified microRNA-30e-5p induced by hepatitis B virus and other viruses that act as a master regulator for innate immunity. Moreover, pegylated interferons treatment of patients with HBV for viral reduction also reduces miRNA. Additionally, we have also shown the immuno-pathological effects of miR-30e in patients with systemic lupus erythematosus (SLE) and mouse model. Mechanistically, miR-30e targets multiple negative regulators of innate immune signaling and enhances immune responses. Furthermore, sequestering of miR-30e in patients with SLE and mouse model significantly reduces type-I interferon and pro-inflammatory cytokines. Collectively, our study demonstrates the novel role of miR-30e in innate immunity and its prognostic and therapeutic potential in infectious and autoimmune diseases.

Expression Pattern of Telomerase Reverse Transcriptase (hTERT) Variants and Bcl-2 in Peripheral Lymphocytes of Systemic Lupus Erythematosus Patients

Background & Objective:

It is not clear whether activated lymphocytes of patients with systemic lupus erythematosus (SLE) are more proliferative or less apoptotic. We aimed to delineate potential differences between B and T cells of SLE patients compared to healthy controls regarding the telomerase activity and apoptosis status.

Methods:

In this cross-sectional case control study, Blood samples were taken from 10 SLE patients and 10 healthy controls. B and T cells were separated using magnetic cell sorting system. Telomeric repeat amplification protocol (TRAP) assay and real-time PCR were used to determine the telomerase activity and the expression of alternatively spliced variants.

Results:

Four patients under treatment showed significant telomerase activity in their T cells. Four of the newly diagnosed patients showed telomerase activity in their B cells (20% of all patients and 40% of new onset patients). There was no specific pattern of human telomerase reverse transcriptase variant expression within the patients’ lymphocytes. A significantly reduced expression of Bcl-2 was detected in B cells (P=0.018) and a trend toward lower Bcl-2 expression in T cells was seen in SLE patients compared to healthy controls.

Conclusion:

Although not definitive, our results may suggest that B cells may have more active roles during the earlier phases of the disease attack, while T cells take over when the disease reaches its chronic stages.

Investigation of MicroRNA in Mitochondrial Apoptotic Pathway in Systemic Lupus Erythematosus

Background

Accumulating evidence indicates that microRNAs play a pivotal role in the pathogenesis of systemic lupus erythematosus (SLE). This study tested the hypothesis that microRNA is associated with the mitochondrial apoptotic pathway in patients with SLE.

Methods

Thirteen patients were in the clinical comparison study and microRNA study and overall 19 patients in the study of intracellular protein. Levels of microRNAs were determined by miRNeasy kit in 13 patients with SLE and 29 volunteer normal controls. Intracellular levels of caspase-9, caspase-10, MAVS, MDA5, and pIRF7 in mononuclear cells from 19 patiens and the SLE disease activity index (SLEDAI) were determined in all SLE patients. Correlation analyses were performed among microRNAs, intracellular adaptor proteins, and caspase levels and mean SLEDAI.

Results

The ΔCT, defined by test reading difference between the target and the internal control microRNA (miR-451a), of miR-21-5p, miR-150-5p, and miR221-3p were significantly higher in plasma from SLE patients than in normal controls. miR-150-5pΔCT was positively correlated with both CRP and SLEDAI value. miR-150-5pΔCT was negatively associated with MAVS 70 kD. Caspase-10 protein levels were negatively associated with plasma miR-22-3pΔCT and miR-21-5pΔCT levels.

Conclusions

Our study confirmed the hypothesis that these microRNAs were associated with the mitochondrial apoptotic pathway in SLE. miR-150-5pΔCT was positively associated with SLE disease activity and it was negatively correlated with MAVS 70 kD, which may facilitate viral survival and further enhance inflammation. On the other hand, miR-22-3pΔCT and miR-21-5pΔCT, were negatively correlated with caspase-10 levels, which may repress extrinsic apoptosis and increase cell survival.

Alternatively activated dendritic cells derived from systemic lupus erythematosus patients have tolerogenic phenotype and function

Tolerogenic dendritic cells (DCs) are potential cell-based therapy in autoimmune diseases. In this study, we generated alternatively activated DCs (aaDCs) by treating monocyte-derived DCs from patients with systemic lupus erythematosus (SLE) and healthy subjects with combination of 1,25 dihydroxyvitamin D(3) (vitD3) and dexamethasone followed by lipopolysaccharide-induced maturation. Lupus aaDCs were found to acquire semi-mature phenotype that remained maturation-resistant to immunostimulants. They produced low level of IL-12 but high level of IL-10. They had attenuated allostimulatory effects on T cell activation and proliferation comparable to normal aaDCs and demonstrated differential immunomodulatory effects on naïve and memory T cells. These aaDCs were capable of inducing IL-10 producing regulatory T effectors from naïve T cells whereas they modulated cytokine profile with suppressed production of IFN-γ and IL-17 by co-cultured memory T cells with attenuated proliferation. These aaDCs were shown to be superior to those generated using vitD3 alone in lupus patients.

IRF5-mediated signaling and implications for SLE

Transcription of the type I IFN genes is regulated by members of the Interferon Regulatory Factor (IRF) family of transcription factors, composed in humans of 9 distinct proteins. In addition to IRF3 and IRF7, the transcription factor IRF5 has been shown to be involved in type I IFN production and interestingly, polymorphisms of the IRF5 gene in humans can result in risk or protective haplotypes with regard to SLE susceptibility. In addition to regulation of type I IFN expression, IRF5 is involved in other signaling pathways, including IgG switching in B cells, macrophage polarization and apoptosis, and its role in SLE pathogenesis may therefore not be limited to dysregulated control of IFN expression. In this review we will comprehensively discuss the role of IRF5 in immune-mediated responses and its potential multifaceted role in conferring SLE susceptibility.

Statin use and markers of immunity in the Doetinchem cohort study

It has been suggested that statins can both stimulate and suppress the immune system, and thereby, may influence autoimmune diseases. Therefore, we studied effects of statins on innate and adaptive immunity, and self-tolerance by measuring serological levels of C-reactive protein (CRP), neopterin, immunoglobulin E (IgE) antibodies and the presence of autoantibodies (antinuclear antibodies (ANA) and IgM rheumatoid factor (RF)) in the general population. We conducted a nested case-control study within the population-based Doetinchem cohort. Data from health questionnaires, serological measurements and information on medication from linkage to pharmacy-dispensing records were available. We selected 332 statin users (cases) and 331 non-users (controls), matched by age, sex, date of serum collection, history of cardiovascular diseases, diabetes mellitus type II and stroke. Multivariate regression analyses were performed to estimate effect of statins on the immune system. The median level of CRP in statin users (1.28 mg/L, interquartile range (IQR): 0.59-2.79) was lower than in non-users (1.62 mg/L, IQR: 0.79-3.35), which after adjustment was estimated to be a 28% lower level. We observed an inverse association between duration of statin use and CRP levels. Elevated levels of IgE (>100 IU/mL) were more prevalent in statin users compared to non-users. A trend towards increased levels of IgE antibodies in statin users was observed, whereas no associations were found between statin use and levels of neopterin or the presence of autoantibodies. In this general population sub-sample, we observed an anti-inflammatory effect of statin use and a trend towards an increase of IgE levels, an surrogate marker for Th (helper) 2 responses without a decrease in neopterin levels, a surrogate marker for Th1 response and/or self-tolerance. We postulate that the observed decreased inflammatory response during statin therapy may be important but is insufficient to induce loss of self-tolerance.

Dissociation between mature phenotype and impaired transmigration in dendritic cells from heparanase-deficient mice

To reach the lymphatics, migrating dendritic cells (DCs) need to interact with the extracellular matrix (ECM). Heparanase, a mammalian endo-β-D-glucuronidase, specifically degrades heparan sulfate proteoglycans ubiquitously associated with the cell surface and ECM. The role of heparanase in the physiology of bone marrow-derived DCs was studied in mutant heparanase knock-out (Hpse-KO) mice. Immature DCs from Hpse-KO mice exhibited a more mature phenotype; however their transmigration was significantly delayed, but not completely abolished, most probably due to the observed upregulation of MMP-14 and CCR7. Despite their mature phenotype, uptake of beads was comparable and uptake of apoptotic cells was more efficient in DCs from Hpse-KO mice. Heparanase is an important enzyme for DC transmigration. Together with CCR7 and its ligands, and probably MMP-14, heparanase controls DC trafficking.

High ACSL5 transcript levels associate with systemic lupus erythematosus and apoptosis in Jurkat T lymphocytes and peripheral blood cells

BACKGROUND

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease in which increased apoptosis and decreased apoptotic cells removal has been described as most relevant in the pathogenesis. Long-chain acyl-coenzyme A synthetases (ACSLs) have been involved in the immunological dysfunction of mouse models of lupus-like autoimmunity and apoptosis in different in vitro cell systems. The aim of this work was to assess among the ACSL isoforms the involvement of ACSL2, ACSL4 and ACSL5 in SLE pathogenesis.

FINDINGS

With this end, we determined the ACSL2, ACSL4 and ACSL5 transcript levels in peripheral blood mononuclear cells (PBMCs) of 45 SLE patients and 49 healthy controls by quantitative real time-PCR (q-PCR). We found that patients with SLE had higher ACSL5 transcript levels than healthy controls [median (range), healthy controls = 16.5 (12.3-18.0) vs. SLE = 26.5 (17.8-41.7), P = 3.9×10 E-5] but no differences were found for ACSL2 and ACSL4. In in vitro experiments, ACSL5 mRNA expression was greatly increased when inducing apoptosis in Jurkat T cells and PBMCs by Phorbol-Myristate-Acetate plus Ionomycin (PMA+Io). On the other hand, short interference RNA (siRNA)-mediated silencing of ACSL5 decreased induced apoptosis in Jurkat T cells up to the control levels as well as decreased mRNA expression of FAS, FASLG and TNF.

CONCLUSIONS

These findings indicate that ACSL5 may play a role in the apoptosis that takes place in SLE. Our results point to ACSL5 as a potential novel functional marker of pathogenesis and a possible therapeutic target in SLE.

Drug-induced lupus erythematosus: incidence, management and prevention

The generation of autoantibodies and autoimmune diseases such as systemic lupus erythematosus has been associated with the use of certain drugs in humans. Early reports suggested that procainamide and hydralazine were associated with the highest risk of developing lupus, quinidine with a moderate risk and all other drugs were considered low or very low risk. More recently, drug-induced lupus has been associated with the use of the newer biological modulators such as tumour necrosis factor (TNF)-α inhibitors and interferons. The clinical features and laboratory findings of TNFα inhibitor-induced lupus are different from that of traditional drug-induced lupus or idiopathic lupus, and standardized criteria for the diagnosis of drug-induced lupus have not been established. The mechanism(s) responsible for the development of drug-induced lupus may vary depending on the drug or even on the patient. Besides lupus, other autoimmune diseases have been associated with drugs or toxins. Diagnosis of drug-induced lupus requires identification of a temporal relationship between drug administration and symptom development, and in traditional drug-induced lupus there must be no pre-existing lupus. Resolution of symptoms generally occurs after cessation of the drug. In this review, we will discuss those drugs that are more commonly associated with drug-induced lupus, with an emphasis on the new biologicals and the difficulty of making the diagnosis of drug-induced lupus against a backdrop of the autoimmune diseases that these drugs are used to treat. Stimulation of the immune system by these drugs to cause autoimmunity may in fact be associated with an increased effectiveness in treating the pathology for which they are prescribed, leading to the dilemma of deciding which is worse, the original disease or the adverse effect of the drug. Optimistically, one must hope that ongoing research in drug development and in pharmacogenetics will help to treat patients with the maximum effectiveness while minimizing side effects. Vigilance and early diagnosis are critical. The purpose of this review is to summarize the most recent developments in our understanding of the incidence, pathogenesis, diagnosis and treatment of drug-induced lupus.

Serum adenosine deaminase activity in patients with systemic lupus erythematosus: a study based on ADA1 and ADA2 isoenzymes pattern

Adenosine deaminase (ADA) plays a crucial role in the development and maintenance of normal immune system. So, any immunological imbalances could associate with its altered activity in serum. This study evaluated the activity of total ADA and its isoenzymes in serum of 45 patients with systemic lupus erythematosus (SLE). Included were 23 patients with active SLE, 22 during the inactive phase of the disease, and 45 healthy subjects. Our results provided evidence that the significantly elevated total ADA activity in serum of SLE patients is correlated mainly with the increased ADA2 level. The highest mean ADA2 activity during the relapse phase of the disease could be an indication to the macrophages, the main source of ADA2. It might be concluded that ADA and its isoenzymes analysis in serum of patients could be used as a useful and non-invasive diagnostic tool in evaluation of SLE active phase and the disease severity.

B cells and autoantibodies: complex roles in CNS injury

Emerging data indicate that traumatic injury to the brain or spinal cord activates B lymphocytes, culminating in the production of antibodies specific for antigens found within and outside the central nervous system (CNS). Here, we summarize what is known about the effects of CNS injury on B cells. We outline the potential mechanisms for CNS trauma-induced B cell activation and discuss the potential consequences of these injury-induced B cell responses. On the basis of recent data, we hypothesize that a subset of autoimmune B cell responses initiated by CNS injury are pathogenic and that targeted inhibition of B cells could improve recovery in cases of brain and spinal cord injury.

(S)-armepavine from Chinese medicine improves experimental autoimmune crescentic glomerulonephritis

OBJECTIVE

Intra-renal T cells and macrophages play a key pathogenic role in the development and progression of glomerular crescents. We aimed to establish (S)-armepavine [(S)-ARM], a major bioactive compound of a Chinese medicinal plant, Nelumbo nucifera, as a potential therapeutic agent in the treatment of autoimmune crescentic glomerulonephritis (ACGN).

METHODS

A mouse ACGN model associated with T-cell dysregulation, was used to evaluate the therapeutic effects of (S)-ARM on the rapidly progressive glomerular disorder.

RESULTS

The results showed that (S)-ARM administered in the established phase of ACGN is capable of dramatically decreasing glomerular crescents in the kidney and improving proteinuria and renal dysfunction. These effects were associated with greatly inhibited infiltration of T cells/macrophages and suppressed nuclear factor (NF)-κB activation in the kidney, lowered serum levels of autoantibodies and both serum and intra-renal levels of pro-inflammatory cytokines, suppressed T/B-cell activation and T-cell proliferation of the spleen, reduced glomerular immune deposits and apoptosis in both the spleen and kidney in (S)-ARM-treated ACGN mice, compared with the vehicle-treated (disease control) group of ACGN mice.

CONCLUSION

We demonstrated therapeutic effects of (S)-ARM on ACGN as a result of: (i) early systemic negative modulation of T/B cells; (ii) intra-renal regulation of combined NF-κB activation and mononuclear leucocytic infiltration, thereby preventing glomerular crescent formation; and (iii) protection from apoptosis in both the spleen and kidney.

The complement cascade as a therapeutic target in intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is the second most common and deadliest form of stroke. Currently, no pharmacologic treatment strategies exist for this devastating disease. Following the initial mechanical injury suffered at hemorrhage onset, secondary brain injury proceeds through both direct cellular injury and inflammatory cascades, which trigger infiltration of granulocytes and monocytes, activation of microglia, and disruption of the blood-brain barrier with resulting cerebral edema. The complement cascade has been shown to play a central role in the pathogenesis of secondary injury following ICH, although the specific mechanisms responsible for the proximal activation of complement remain incompletely understood. Cerebral injury following cleavage of complement component 3 (C3) proceeds through parallel but interrelated pathways of anaphylatoxin-mediated inflammation and direct toxicity secondary to membrane attack complex-driven erythrocyte lysis. Complement activation also likely plays an important physiologic role in recovery following ICH. As such, a detailed understanding of the variation in functional effects of complement activation over time is critical to exploiting this target as an exciting translational strategy for intracerebral hemorrhage.

Flow Cytometric Analysis of the LE Cell Phenomenon

A flow cytometry-based phagocytosis assay was developed and utilized to measure the LE cell phenomenon at the single cell level in vitro. Since the lupus erythematosus (LE) cell phenomenon is a special form of necro-phagocytosis in the presence of anti-dsDNA antibodies, dead substrate cells or chicken erythrocytes nuclei (CEN) served as targets that were labeled with propidiumiodide (PI). Phagocytes (PMN) were stained by anti-CD45 mAb FITC. After co-incubation phagocytosis was measured by flow cytometry. Flow cytometric analysis enabled the discrimination between PI+/CD45- targets, PI-/CD45+ phagocytes, and PI+/CD45+ phagocytes with engulfed targets. Maintaining the samples on ice significantly reduced the phagocytic uptake as compared to samples co-cultivated at 37 degrees C (p < 0.0002). The phagocytic up-take was lowest after substrate pre-treatment in normal serum as compared to samples with either no serum exposure or pre-treatment in LE-serum with anti-dsDNA antibodies (p < 0.05). Taken together, these data suggest the phagocytosis-based flow cytometry assay is suitable for analyzing the LE cell phenomenon. This method provides an interesting, simple and rapid new tool, and will possibly alleviate further studies on the LE cell phenomenon with modified cell models and/or conditions.

Identification of new SLE-associated genes with a two-step Bayesian study design

In our earlier study, we utilized a Bayesian design to probe the association of approximately 1000 genes (approximately 10,000 single-nucleotide polymorphisms (SNPs)) with systemic lupus erythematosus (SLE) on a moderate number of trios of parents and children with SLE. Two genes associated with SLE, with a multitest-corrected false discovery rate (FDR) of <0.05, were identified, and a number of noteworthy genes with FDR of <0.8 were also found, pointing out a future direction for the study. In this report, using a large population of controls and adult- or childhood-onset SLE cases, we have extended the earlier investigation to explore the SLE association of 10 of these noteworthy genes (109 SNPs). We have found that seven of these genes exhibit a significant (FDR<0.05) association with SLE, both confirming some genes that have earlier been found to be associated with SLE (PTPN22 and IRF5) and presenting novel findings of genes (KLRG1, interleukin-16, protein tyrosine phosphatase receptor type T, toll-like receptor (TLR)8 and CASP10), which have not been reported earlier. The results signify that the two-step candidate pathway design is an efficient way to study the genetic foundations of complex diseases. Furthermore, the novel genes identified in this study point to new directions in both the diagnosis and the eventual treatment of this debilitating disease.

Decoy receptor 3 ameliorates an autoimmune crescentic glomerulonephritis model in mice

Autoimmune crescentic glomerulonephritis (ACGN) is a variant of crescentic glomerulonephritis. The outcome of treatment of crescentic glomerulonephritis is poor. Binding of decoy receptor 3 (DCR3) to its ligand is capable of downregulating the alloresponsiveness of T cells. DCR3 has also been shown to benefit an experimental autoimmune model of diabetes. This study tested the hypothesis that a potential immune regulator, DCR3, could prevent the evolution of ACGN. With the use of an established ACGN model in mice, mice were treated with 100 microg/10 g body wt human DCR3 by hydrodynamics-based gene delivery at 14-d intervals. The results showed that the gene therapy resulted in (1) suppression of T and B cell activation and T cell proliferation; (2) a reduction in serum levels of proinflammatory cytokines; (3) improvement of proteinuria and renal dysfunction; (4) prevention of glomerular crescent formation, renal interstitial inflammation, and glomerulosclerosis; (5) a reduction in serum levels of autoantibodies and glomerular immune deposits; (6) inhibition of apoptosis in the spleen and kidney; (7) prevention of T cell and macrophage infiltration of the kidney; and (8) suppression of fibrosis-related gene expression in the kidney compared with empty vector-treated (disease control) ACGN mice. On the basis of these findings, it is proposed that human DCR3 exerts its preventive and protective effects on ACGN through modulation of T cell activation/proliferation, B cell activation, protection against apoptosis, and suppression of mononuclear leukocyte infiltration in the kidney.

Physiopathologie du lupus érythémateux systémique

Innate immunity is directly implicated in the pathophysiology of lupus through the dendritic cell system and the activation by immune complexes of some toll-like receptors (TLR). Interferon-alpha plays a key role in the pathophysiology of lupus and represents a promising target for immune therapy. Dendritic cells are activated and able to capture large quantities of nuclear antigen-containing bodies to stimulate specific adaptive immune response.

Antibody-enhanced cross-presentation of self antigen breaks T cell tolerance

We have developed a model of autoimmunity to investigate autoantibody-mediated cross-presentation of self antigen. RIP-mOVA mice, expressing OVA in pancreatic beta cells, develop severe autoimmune diabetes when given OT-I cells (OVA-specific CD8(+) T cells) and anti-OVA IgG but not when given T cells alone. Anti-OVA IgG is not directly injurious to the islets but rather enhances cross-presentation of apoptotic islet antigen to the OT-I cells, leading to their differentiation into potent effector cells. Antibody-driven effector T cell activation is dependent on the presence of activating Fc receptors for IgG (FcgammaRs) and cross-priming DCs. As a consequence, diabetes incidence and severity was reduced in mice lacking activating FcgammaRs. An intact complement pathway was also required for disease development, as C3 deficiency was also partially protective. C3-deficient animals exhibited augmented T cell priming overall, indicating a proinflammatory role for complement activation after the T cell priming phase. Thus, we show that autoreactive antibody can potently enhance the activation of effector T cells in response to cross-presented self antigen, thereby contributing to T cell-mediated autoimmunity.

Lupus erythematosus and other autoimmune diseases related to statin therapy: a systematic review

BACKGROUND

Statins have been increasingly associated with drug-induced autoimmune reactions, including lupus erythematosus.

OBJECTIVE

To identify and determine the clinical and biological characteristics of statin-induced autoimmune reactions.

MATERIAL AND METHODS

The MEDLINE database (1966 to September 2005) was used to identify all reported cases of statin-induced autoimmune diseases. The keywords used were statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, adverse effects, autoimmune disease, lupus erythematosus, dermatomyositis and polymyositis.

RESULTS

Twenty-eight cases of statin-induced autoimmune diseases have been published so far. Systemic lupus erythematosus was reported in 10 cases, subacute cutaneous lupus erythematosus in three cases, dermatomyositis and polymyositis in 14 cases and lichen planus pemphigoides in one case. Autoimmune hepatitis was observed in two patients with systemic lupus erythematosus. The mean time of exposure before disease onset was 12.8+/-18 months; range 1 month-6 years. Systemic immunosuppressive therapy was required in the majority of cases. In many patients, antinuclear antibodies were still positive many months after clinical recovery. A lethal outcome has been recorded in two patients despite aggressive immunosuppressive therapy.

CONCLUSION

Long-term exposure to statins may be associated with drug-induced lupus erythematosus and other autoimmune disorders. Fatal cases have been reported despite early drug discontinuation and aggressive systemic immunosuppressive therapy.

Alterations in plasma complement levels after human ischemic stroke

OBJECTIVE

Stroke is a leading cause of morbidity and mortality in the United States. Recent animal studies have implicated the complement system in cerebral ischemia/reperfusion injury and suggest that complement inhibition may improve stroke outcomes. To assess the applicability of these findings to humans, we evaluated the characteristics and time course of human complement activation after stroke.

METHODS

We compared peripheral blood levels of complement factor 3a (C3a), 5a (C5a), and sC5b-9 drawn from 15 patients on poststroke Days 1, 2, 3, 7, 14, 21, and 28 to age-, race/ethnicity-, and sex-matched controls from the same population. Statistical analysis was performed using unpaired Mann-Whitney nonparametric tests with Bonferroni correction. All data is presented as the mean +/- standard deviation.

RESULTS

Mean C3a concentrations showed significant early elevations in stroke patients relative to matched controls (controls: 1080 +/- 189 ng/ml; Day 1: 1609 +/- 422 ng/ml, P = 0.0008; Day 3: 1520 +/- 317 ng/ml, P = 0.0005; Day 7: 1526 +/- 386 ng/ml, P = 0.001). C3a was also significantly elevated on Day 28 (1448 +/- 386 ng/ml, P = 0.004). Before poststroke Day 7, mean C5a levels did not differ significantly from controls. However, beginning on Day 7 and continuing through Day 14, there were significant elevations in C5a (controls: 3.33 +/- 2.1 ng/ml; day 7: 6.86 +/- 3.5 ng/ml, P = 0.005; Day 14: 7.65 +/- 4.6 ng/ml, P = 0.004). Mean sC5b-9 concentrations showed early depressions that reached significance on Days 1 and 2 (controls: 275.6 +/- 107 ng/ml; Day 1: 167.0 +/- 108 ng/ml, P = 0.006; Day 2: 156.3 +/- 80.0 ng/ml, P = 0.005) and did not differ significantly from controls at any other time point.

CONCLUSION

C3a is acutely elevated after human ischemic stroke, C5a shows delayed elevations 7 to 14 days after cerebral ischemia, and sC5b-9 is acutely depressed after stroke. Together, these data confirm complement activation after stroke and suggest that this activation is a heterogeneous process, with varying responses for different components.

Abnormal Fas/FasL and caspase-3-mediated apoptotic signaling pathways of T lymphocyte subset in patients with systemic lupus erythematosus

OBJECTIVES

To explore the relationships between Fas-FasL-mediated signaling pathway and apoptosis disturbance of T lymphocyte subset in patients with SLE.

METHODS

Flow cytometry was used to determine the percentage of apoptotic lymphocytes and necrotic lymphocytes by AnnexinV-FITC/PI double staining. Cell surface expression rates of Fas, FasL, and intracellular expression rates of activated caspase-3 were evaluated by two-color flow cytometry analysis in peripheral T lymphocyte subsets of SLE patients with inactive disease (n=22) and with active disease (n=17). The serum concentration of anti-nucleosome antibodies in SLE patients were assayed by ELISA immunoassay methods. Health volunteers (n=13) served as controls.

RESULTS

The percentage of early apoptotic cells was enhanced in patients with active disease (P=0.001, vs. control) and in patients with inactive disease (P=0.004, vs. control). Compared with health control, the percentage of necrotic cells was significant higher in patients with active disease (P=0.001). The percentages of CD4(+)T cells expressing Fas (P=0.023, vs. control) and FasL (P=0.001, vs. control) were increased in patients with active disease. But there were no obvious differences of expression rates of Fas and FasL on T cell subset between two disease groups (P>0.05). In patients with active disease the percentage of CD4(+)T cells or CD8(+)T cells expressing intracellular activated caspase-3 significantly increased compared to inactive disease patients (P=0.018, P=0.027, respectively) and health controls (P=0.001, P=0.001, respectively). The serum concentration of anti-nucleosome antibodies was strikingly higher in patients with active disease (P=0.002, vs. patients with inactive disease; P=0.001, vs. control, respectively), however, the serum concentration of anti-nucleosome antibodies was not obviously different between patients with inactive disease and health control group (P=0.473). The percentage of apoptotic cells correlated with the serum concentration of anti-nucleosome antibodies in SLE patients (r(s)=0.350, P=0.031).

CONCLUSIONS

Apoptosis of T lymphocyte subset in SLE patients increases. CD4(+)T cells are a state of active apoptosis. Fas/FasL-mediated apoptotic pathways are especially important for CD4(+)T cells undergoing apoptosis in SLE patients with active disease. Increased Fas expression results in a higher susceptibility to Fas-mediated apoptosis, which contributes to the increased levels of intracellular activated caspase-3 and accelerates apoptosis of T lymphocytes. The degree of lymphocytic apoptosis disturbance correlates with the level of anti-nucleosome antibodies in the circulation. Acceleration of lymphocytic apoptosis plays important roles in immune pathologic injury and immune regulation dysfunction.

A peptide based on the complementarity-determining region 1 of an autoantibody ameliorates lupus by up-regulating CD4+CD25+ cells and TGF-beta

Systemic lupus erythematosus is an autoimmune disease characterized by autoantibodies and systemic clinical manifestations. A peptide, designated hCDR1, based on the complementarity-determining region (CDR) 1 of an autoantibody, ameliorated the serological and clinical manifestations of lupus in both spontaneous and induced murine models of lupus. The objectives of the present study were to determine the mechanism(s) underlying the beneficial effects induced by hCDR1. Adoptive transfer of hCDR1-treated cells to systemic lupus erythematosus-afflicted (NZBxNZW)F1 female mice down-regulated all disease manifestations. hCDR1 treatment up-regulated (by 30-40%) CD4+CD25+ cells in association with CD45RBlow, cytotoxic T lymphocyte antigen 4, and Foxp3 expression. Depletion of the CD25+ cells diminished significantly the therapeutic effects of hCDR1, whereas administration of the enriched CD4+CD25+ cell population was beneficial to the diseased mice. Amelioration of disease manifestations was associated with down-regulation of the pathogenic cytokines (e.g., IFN-gamma and IL-10) and up-regulation of the immunosuppressive cytokine TGF-beta, which substantially contributed to the suppressed autoreactivity. TGF-beta was secreted by CD4+ cells that were affected by hCDR1-induced immunoregulatory cells. The hCDR1-induced CD4+CD25+ cells suppressed autoreactive CD4+ cells, resulting in reduced rates of activation-induced apoptosis. Thus, hCDR1 ameliorates lupus through the induction of CD4+CD25+ cells that suppress activation of the autoreactive cells and trigger the up-regulation of TGF-beta.

Fas/FasL interaction: a novel immune therapy approach with immobilized biologicals

Systemically applied agents to modulate the Fas/FasL system, e.g., by stimulation of Fas on activated leukocytes or tumor cells failed as strategies in immune therapy due to severe toxic effects in the host. Recently, a novel strategy has been developed by using immobilized immune active biologicals in a medical device that may allow immune management without expensive systemic therapy. This review reports on the potential role of Fas/FasL in immune therapy and summarizes current experimental and clinical data with the leukocyte inhibition module (LIM), an immobilized anti-Fas antibody containing device yet used in extracorporeal blood circulation. This proof of principal may stimulate the development of other devices based on the regulation of Fas/FasL or other targets relevant for immune disorders.

The putative role of apoptosis in the induction of pemphigus

The apoptotic cell has recently been shown to play a central role in tolerizing B cells and T cells to both tissue-specific and ubiquitously expressed self-antigens, and to possibly drive the autoimmune response in systemic lupus erythematosus, an autoimmune disease which bears many similarities to pemphigus. We now propose a similar mechanism in the induction of pemphigus, namely, that a dysregulation in apoptosis expressed as an impairment of normal programmed cell death of epidermal keratinocytes and/or deficient and inadequate clearance of apoptotic material (specifically, desmoglein) may render it antigenic with the consequent production of autoantibodies. The fact that some thiol-containing compounds which are well-known inducers of acantholysis in vitro and pemphigus in vivo were shown to inhibit apoptosis might support our hypothesis.

Accelerated autoimmune disease in MRL/MpJ-Fas(lpr) but not in MRL/MpJ following immunization with high load of syngeneic late apoptotic cells

Numerous studies have shown that autoantigens may be clustered in the blebs of apoptotic cells. However, it is not yet clear in what circumstances apoptotic cells could be immunogenic rather than tolerogenic when interacting with macrophages, dendritic cells, and B cells. In order to further study this question we compared immunization of high load of syngeneic late apoptotic cells in two genetically close pro-autoimmune mice strains: MRL/MpJ and MRL/MpJ-Fas(lpr). We show that high apoptotic load could accelerate the generation of anti-dsDNA and anticardiolipin, and the extent of kidney disease, in MRL/MpJ-Fas(lpr) but could not generate autoimmunity in MRL/MpJ. Thus, in this model, a high load of apoptotic cells could augment the autoimmune response in established autoimmunity, but did not generate de novo autoimmune response in pro-autoimmune mice. Taken together with previous observations, apoptotic cell load may modify autoimmune disease generating either immune inhibition and down regulation of autoimmunity or immune stimulation and acceleration of an autoimmune disease.

Lupus-Like Syndrome Associated with Statin Therapy

Statins are among the most widely prescribed drugs. An increasing number of lupus-like syndrome has recently been reported with these lipid-lowering agents. We describe a new case associated with simvastatin therapy. The presence of anti-dsDNA antibodies in the serum is for the first time reported confirming that statins may also induce a systemic autoimmune reaction. Statin-induced lupus-like syndrome is characterized by the long delay between the beginning of therapy and the skin eruption. Antinuclear antibodies may persist for many months after drug discontinuation. The causal relationship may be therefore difficult to establish, and probably many cases are unrecognized. Early diagnosis may avoid unnecessary immunosuppressive therapy.