Immunity-Based Diagnosis for a Motherboard

We have utilized immunity-based diagnosis to detect abnormal behavior of components on a motherboard. The immunity-based diagnostic model monitors voltages of some components, CPU temperatures, and fan speeds. We simulated abnormal behaviors of some components on the motherboard, and we utilized the immunity-based diagnostic model to evaluate motherboard sensors in two experiments. These experiments showed that the immunity-based diagnostic model was an effective method for detecting abnormal behavior of components on the motherboard

Enhanced Formation and Disordered Regulation of NETs in Myeloperoxidase-ANCA-Associated Microscopic Polyangiitis.

Microscopic polyangiitis (MPA) is an ANCA-associated vasculitis that affects small vessels, especially renal glomeruli. We recently demonstrated that the abnormal formation and impaired degradation of neutrophil extracellular traps (NETs) may be crucially involved in the generation of myeloperoxidase (MPO)-ANCA and subsequent development of MPA. This study assessed the formation and regulation of NETs in patients with MPO-ANCA-associated MPA. Peripheral blood samples were obtained from 38 patients with MPO-ANCA-associated MPA, 23 patients with systemic lupus erythematosus (SLE), and 8 healthy controls. IgG eluted from MPO-ANCA-associated MPA sera demonstrated the highest ability to induce NETs, and this ability correlated with disease activity and paralleled ANCA affinity for MPO. Moreover, addition of recombinant human MPO to these IgG samples reduced NET induction. Additionally, MPO-ANCA-associated MPA sera exhibited lower rates of NET degradation that recovered partially upon depletion of IgG. The activity of DNase I, an important regulator of NETs, was also lower in MPO-ANCA-associated MPA and SLE sera. IgG depletion from MPO-ANCA-associated MPA sera partially restored the rate of NET degradation, and addition of DNase I synergistically enhanced this restoration. Addition of anti-MPO antibodies did not inhibit DNase I activity, and some MPO-ANCA-associated MPA sera contained anti-NET antibodies at levels not correlated with MPO-ANCA titers, suggesting the involvement of unidentified autoantibodies as well. The collective evidence suggests a vicious cycle involving MPO-ANCA and the regulation of NETs could be critically involved in the pathogenesis of MPO-ANCA-associated MPA

Elevated Myeloperoxidase-DNA Complex Levels in Sera of Patients with IgA Vasculitis

Introduction: IgA vasculitis is a systemic disease that results from the entrapment of circulating IgA-containing immune complexes in small-vessel walls in the skin, kidneys, and gastrointestinal tract. An excessive formation of neutrophil extracellular traps (NETs) is involved in the pathogenesis of vasculitis, especially in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. This study aimed to clarify whether NETs are implicated in IgA vasculitis. Methods: Twenty-two patients with IgA vasculitis and 4 healthy volunteers were enrolled in this study. Serum levels of myeloperoxidase (MPO)-DNA complex, a fragment derived from NETs, were determined by enzyme-linked immunosorbent assay (ELISA), and the association between MPO-DNA complex levels and clinical parameters was examined. The presence of the ANCA was also assessed by ELISA specific for MPO and proteinase 3 (PR3) and indirect immunofluorescence (IIF), followed by assessing the differences in clinical parameters with and without the ANCA. Results: Serum MPO-DNA complex levels were significantly higher in patients with IgA vasculitis than those in healthy controls. A significant positive correlation between the serum MPO-DNA complex and IgA levels was noted. Interestingly, 63.6% of IgA vasculitis patients were ANCA-positive in IIF with an atypical pattern, whereas neither MPO-ANCA nor PR3-ANCA was detected by ELISA. These findings indicated that some IgA vasculitis patients possessed the so called minor ANCA. Serum IgA and MPO-DNA complex levels and the frequency of hematuria in the minor ANCA-positive group were significantly higher than in the minor ANCA-negative group. Conclusion: The collective findings suggested that NETs are certainly involved in the pathogenesis of IgA vasculitis

The responses of macrophages in interaction with neutrophils that undergo NETosis

Neutrophil extracellular traps (NETs) are net-like chromatin fibers decorated with antimicrobial proteins, which are released from dying neutrophils. The death of neutrophils with NET formation is called NETosis. Although NETs play important roles in the innate immunity, especially in the elimination of microbes, the extracellular release of DNA and intra-cytoplasmic/nuclear proteins can, on the other hand, result in diverse adversities to the hosts. Therefore, NETosis is adequately regulated in vivo. Currently, two mechanisms, namely DNase I-dependent digestion and phagocytosis by macrophages, have been shown as such regulatory mechanisms. In this study, we focused on the interaction of macrophages and neutrophils that underwent NETosis. Results demonstrated that macrophages displayed a phenotype dependent response after degradation of NETs. Several hours after the interaction, M2 macrophages induced a pro-inflammatory response, while M1 macrophages underwent cell death with nuclear decondensation. This nuclear decondensation of M1 macrophages occurred in a peptidylarginine deiminase 4-dependent manner and resulted in a local release of extracellular DNA. Thereafter, M1 macrophages degraded DNA derived from themselves in a caspase-activated DNase-dependent manner resulting in the clearance of extracellular DNA within 24 h. This transient increase and subsequent clearance mechanism of extracellular DNA seems very reasonable in terms of the double-edged sword-like property of NETs. The collective findings demonstrate a novel phenotype- and time-dependent regulation of NETosis by macrophages. (C) 2015 The Authors. Published by Elsevier Ltd

Circulating Neutrophil Extracellular Trap Levels in Well-Controlled Type 2 Diabetes and Pathway Involved in Their Formation Induced by High-Dose Glucose

Objectives: Although intensive therapy for type 2 diabetes (T2D) prevents microvascular complications, 10% of well-controlled T2D patients develop microangiopathy. Therefore, the identification of risk markers for microvascular complications in well-controlled T2D patients is important. Recent studies have demonstrated that high-dose glucose induces neutrophil extracellular trap (NET) formation, which can be a risk for microvascular disorders. Thus, we attempted to determine the correlation of circulating NET levels with clinical/laboratory parameters in well-controlled T2D patients and to reveal the mechanism of NET formation induced by high-dose glucose. Methods: Circulating NET levels represented by myeloperoxidase (MPO)-DNA complexes in the serum of 11 well-controlled T2D patients and 13 healthy volunteers were determined by enzyme-linked immunosorbent assay. The pathway involved in the NET formation induced by high-dose glucose was determined using specific inhibitors. Results: Serum MPO-DNA complex levels were significantly higher in some well-controlled T2D patients in correlation with the clinical/laboratory parameters which have been regarded as risk markers for microvascular complications. The aldose reductase inhibitor, ranirestat, could inhibit the NET formation induced by high-dose glucose. Conclusions: Elevated levels of circulating NETs can be a risk marker for microvascular complications in well-controlled T2D patients. The polyol pathway is involved in the NET formation induced by high-dose glucose

The presence of anti-neutrophil extracellular trap antibody in patients with microscopic polyangiitis

Objective Although anti-neutrophil cytoplasmic antibody (ANCA) is the major autoantibody in patients with ANCA-associated vasculitis (AAV), previous studies have suggested the presence of anti-neutrophil extracellular trap (NET) antibody in patients with microscopic polyangiitis (MPA), one type of AAV. In this study, we aimed to determine the prevalence and pathogenic role of anti-NET antibody (ANETA) in MPA. Methods We examined the presence or absence of ANETA in sera obtained from 19 MPA patients by indirect immunofluorescence. We compared the clinical parameters, including age, sex, myeloperoxidase (MPO)-ANCA, creatinine, C-reactive protein, MPO-DNA complexes, and vasculitis activity, in ANETA-positive and ANETA-negative MPA patients. We investigated the serum NET induction and degradation abilities of ANETA-positive and ANETA-negative MPA patients with reference to healthy controls (n=8). Furthermore, we assessed the relationship of ANETA with the effect of IgG depletion on the serum NET degradation ability. Results ANETA was present in 10 of the 19 MPA patients. There was no significant difference in the clinical parameters in ANCA-positive and ANCA-negative MPA patients. Although the NET induction ability was higher and the NET degradation ability was lower in MPA sera than those in healthy controls, these abilities were not different between ANETA-positive and ANETA-negative MPA sera. Interestingly, the NET degradation ability in some sera with ANETA was markedly increased by IgG depletion. Conclusion Some MPA patients produce ANETA and some ANETA possess an inhibitory function against the serum NET degradation ability. Although further studies are needed, ANETA is worthy of attention for understanding the pathophysiology of MPA

Measurement of NET formation in vitro and in vivo by flow cytometry

Neutrophil extracellular traps (NETs) are extracellular chromatin fibers adorned with antimicrobial proteins, such as myeloperoxidase (MPO), which are extruded from activated neutrophils. NETosis is the metamorphosis of neutrophils with NET formation that follows decondensation of DNA and rupture of the plasma membrane. Although NETs play important roles in innate immunity, excessive formation of NETs can be harmful to the hosts. Until now, various methods for evaluation of NETs have been reported. Although each has a virtue, the gold standard has not been established. Here we demonstrate a simple, objective, and quantitative method to detect NETs using flow cytometry. This method uses a plasma membrane-impermeable DNA-binding dye, SYTOX Green. SYTOX Greenpositive cells were detected in human peripheral polymorphonuclear cells exposed to a NET inducer, phorbol 12-myristate 13-acetate (PMA). The number of SYTOX Greenpositive cells was increased depending on the exposure duration and concentrations of PMA. Furthermore, co-localization of MPO and plasma membrane-appendant DNA of SYTOX Green-positive cells was demonstrated. Moreover, a NET inhibitor, diphenylene iodonium, could significantly reduce the number of SYTOX Green-positive cells induced by PMA. The collective evidence suggests that SYTOX Green-positive cells include neutrophils that formed NETs. The established method could detect neutrophils that underwent NETosis but not early apoptosis with equivalence in quantification to another well-used image analysis, which is based on fluorescent staining. Additionally, NETs that were formed in vivo were also detectable by this method. It is conceivable that the established method will bring us better understanding of the relation between NETosis and human diseases

The Presence of Anti-Lactoferrin Antibodies in a Subgroup of Eosinophilic Granulomatosis with Polyangiitis Patients and Their Possible Contribution to Enhancement of Neutrophil Extracellular Trap Formation

Lactoferrin (Lf) is one of the antigens of antineutrophil cytoplasmic antibodies (ANCA) and functions as an endogenous suppressor of neutrophil extracellular trap (NET) formation. However, the prevalence and pathogenicity of anti-lactoferrin antibodies (aLf) in ANCA-associated vasculitis (AAV) remain unrevealed. This study aimed to examine the significance of aLf in AAV, initially. Sixty-five sera from AAV patients, including 41 microscopic polyangiitis, 5 granulomatosis with polyangiitis, and 19 eosinophilic granulomatosis with polyangiitis (EGPA) patients, were subjected to aLf detection using enzyme-linked immunosorbent assay. Clinical characteristics were compared between aLf-positive and aLf-negative patients. Neutrophils from healthy donors were exposed to suboptimal dose (10 nM) of phorbol myristate acetate (PMA) with aLf followed by evaluation of NET formation. Results demonstrated that 4 out of 65 AAV sera (6.2%) were positive for aLf. All of them were EGPA sera (4/19, 21.1%). In EGPA, the frequency of renal involvement, serum CRP levels, and Birmingham Vasculitis Activity Score (BVAS) in the aLf-positive patients was significantly higher than those in the aLf-negative patients, and the aLf titer correlated positively with the serum CRP level and BVAS. The NET formation was particularly enhanced by combined stimulation of 10 nM PMA and 1 µg/mL aLf. IgG isolated from sera of the aLf-positive EGPA patients (250 µg/mL) enhanced NET formation induced by 10 nM of PMA, and the effect was abolished completely by absorption of the aLf. This pilot study suggests that aLf enhance NET formation induced by PMA and are associated with disease activity of EGPA