Formation of a complex of human plasma myeloperoxidase and opsonins

Human neutrophil myeloperoxidase adsorbs on immobilized fibronectin or IgG under conditions approaching the physiological ones. Immobilized myeloperoxidase binds liquid-phase plasma fibronectins and thermoaggregated IgG, but not native IgG. Protein-myeloperoxidase interaction is thought to be the mechanism arming phagocytes with this enzyme in the course of phagocytosis of pathogenic microorganisms and to be one means of preventing tissue injury by oxidants generated by extracellular myeloperoxidase. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o . 9, pp. 320–322, September, 1995 Presented by A. N. Klimov. Member of the Russian Academy of Medical Sciences     

How human neutrophils kill and degrade microbes: an integrated view

Summary:  Neutrophils constitute the dominant cell in the circulation that mediates the earliest innate immune human responses to infection. The morbidity and mortality from infection rise dramatically in patients with quantitative or qualitative neutrophil defects, providing clinical confirmation of the important role of normal neutrophils for human health. Neutrophil-dependent anti-microbial activity against ingested microbes represents the collaboration of multiple agents, including those prefabricated during granulocyte development in the bone marrow and those generated de novo following neutrophil activation. Furthermore, neutrophils cooperate with extracellular agents as well as other immune cells to optimally kill and degrade invading microbes. This brief review focuses attention on two examples of the integrated nature of neutrophil-mediated anti-microbial action within the phagosome. The importance and complexity of myeloperoxidase-mediated events illustrate a collaboration of anti-microbial responses that are endogenous to the neutrophil, whereas the synergy between the phagocyte NADPH (nicotinamide adenine dinucleotide phosphate) oxidase and plasma-derived group IIA phospholipase A₂ exemplifies the collective effects of the neutrophil with an exogenous factor to achieve degradation of ingested staphylococci.     

C-antineutrophil cytoplasmic antibody positivity in vasculitis patients is associated with the Z allele of alpha-1-antitrypsin, and P-antineutrophil cytoplasmic antibody positivity with the S allele

BACKGROUND.: Antineutrophil cytoplasmic antibodies (ANCA) in vasculitis haveeither cANCA or pANCA patterns as defined by immunofluorescence.The target autoantigen of cANCA is usually proteinase 3 (PR3),whereas that of pANCA is usually myeloperoxidase (MPO). Alpha-1-antitrypsin(1AT) is the major physiological inhibitor of PR3, while MPOis an inhibitor of 1AT. METHODS.: To determine whether there was an association between ANCA positivevasculitis, ANCA pattern, and 1AT deficiency alleles, we studied1AT phenotypes of 99 cANCA and 99 pANCA positive vasculitispatients by isoelectric focusing and immunoblotting, and comparedthem with 2310 controls from the same geographical area. RESULTS.: C-ANCA patients showed an increased frequency of the Z allele(0.055 versus 0.018 in controls), conferring a relative riskof 3. They showed no increase in frequency of the S allele.P-ANCA patients showed an increased frequency of the S allele(0.091 versus 0.046 in controls) conferring a relative riskof 2. The frequency of the Z allele also appeared to be increased(0.030 versus 0.018 in controls), but this was not statisticallysignificant. CONCLUSIONS.: These findings demonstrate an association between ANCA-positivevasculitis and deficiency phenotypes of 1AT, and suggest a rolefor 1AT in the development of systemic vasculitis.     

黄芪提取物对大鼠全脑缺血再灌后炎症反应的影响

目的:探讨黄芪提取物对大鼠全脑缺血再灌后炎症反应的影响。方法:采用四血管阻塞法,复制大鼠全脑缺血再灌注模型;观察黄芪提取物对大鼠全脑缺血再灌后外周血白细胞和中性粒细胞计数、脑组织皮质和海马骨髓过氧化物酶(MPO)活性的影响;并对脑组织皮质做病理学检查。结果:与假手术组相比,模型组大鼠全脑缺血再灌注后外周血白细胞和中性粒细胞计数、脑组织皮质和海马MPO活性均明显升高;与模型组相比,黄芪提取物(20、40、80mg·kg-1)均可降低大鼠全脑缺血再灌注后升高的外周血白细胞和中性粒细胞计数、降低脑组织升高的皮质和海马MPO活性;改善脑组织皮质的缺血性改变。结论:黄芪提取物对大鼠全脑缺血再灌注损伤有明显的保护作用,其作用机制可能与其抗炎作用有关。     

补阳还五汤对脑缺血后中性粒细胞浸润及ICAM-1表达的影响

目的观察补阳还五汤对脑缺血再灌注后中性粒细胞浸润和ICAM-1表达的影响。方法术前7天开始罐胃,然后用线栓法诱导大鼠大脑中动脉阻塞模型,再灌24h后采用神经症状评分和梗死周边区存活神经元数评价脑损伤情况,用髓质过氧化物酶(MPO)和ICAM-1免疫组化方法,评价中性粒细胞浸润和ICAM-1表达情况。结果缺血90min再灌24h后,补阳还五汤能显著改善神经症状(P<0·05或P<0·01),增加缺血半球皮层周边区存活神经元数(P<0·05或P<0·01)。与模型组比较,补阳还五汤显著减少缺血半球皮层MPO阳性细胞数(P<0·01)和ICAM-1阳性血管数(P<0·01)。结论补阳还五汤对脑缺血损伤有保护作用,并能减少中性粒细胞浸润和ICAM-1表达。     

蕲蛇酶减轻大鼠局灶性脑缺血再灌注损伤的实验研究

目的 :探讨蕲蛇酶 (acutobin)在局灶性脑缺血再灌注损伤模型中的保护作用及其机制。方法 :线栓法制备大鼠大脑中动脉闭塞 (MCAO)模型 ,缺血3h后恢复血流再灌 2 4h。观察蕲蛇酶对脑梗死面积、脑组织中髓过氧化物酶 (MPO)、诱导型一氧化氮合酶 (iNOS)活性、一氧化氮 (NO)、丙二醛 (MDA)含量和超氧化物歧化酶 (SOD)活性的影响。结果 :蕲蛇酶能有效减小脑梗死灶 ,缓解MPO升高、降低MDA含量、抑制iNOS活性 ,降低NO含量。结论 :蕲蛇酶对脑缺血再灌注损伤有保护作用 ,其机制可能与缓解MPO升高以及抑制脑组织中iNOS活性 ,降低NO、MDA含量有关     

Fatal unexpected death due to X-linked lymphoproliferative disease

X-linked lymphoproliferative disease (XLP) is a rare immunodeficiency disease characterized by severe immune disorder and extreme vulnerability to Epstein-Barr virus (EBV) infections. Here we report a 14-month-old Chinese boy presenting with fulminant infectious mononucleosis (FIM) following EBV infection, and died of hepatic failure within one week of disease progression. Postmortem examination revealed icterus, ascites, extensive enlarged mesenteric lymph nodes and hepatosplenomegaly. Histopathological examination showed diffuse proliferation of cytotoxic T lymphoid cells and hemophagocytosis in multiple organs. The family history revealed his brother had died under similar circumstances at 5 five years of age. The cause of death of the boy was ascribed to XLP. To the best of our knowledge, there is few autopsy-confirmed XLP case in the forensic practice. The complicated manifestations and systemic pathological changes should be well recognized by clinicians and forensic pathologists.     

Nanomedicine for acute respiratory distress syndrome: The latest application,targeting strategy,and rational design

Acute respiratory distress syndrome (ARDS) is characterized by the severe inflammation and destruction of the lung air–blood barrier, leading to irreversible and substantial respiratory function damage. Patients with coronavirus disease 2019 (COVID-19) have been encountered with a high risk of ARDS, underscoring the urgency for exploiting effective therapy. However, proper medications for ARDS are still lacking due to poor pharmacokinetics, non-specific side effects, inability to surmount pulmonary barrier, and inadequate management of heterogeneity. The increased lung permeability in the pathological environment of ARDS may contribute to nanoparticle-mediated passive targeting delivery. Nanomedicine has demonstrated unique advantages in solving the dilemma of ARDS drug therapy, which can address the shortcomings and limitations of traditional anti-inflammatory or antioxidant drug treatment. Through passive, active, or physicochemical targeting, nanocarriers can interact with lung epithelium/endothelium and inflammatory cells to reverse abnormal changes and restore homeostasis of the pulmonary environment, thereby showing good therapeutic activity and reduced toxicity. This article reviews the latest applications of nanomedicine in pre-clinical ARDS therapy, highlights the strategies for targeted treatment of lung inflammation, presents the innovative drug delivery systems, and provides inspiration for strengthening the therapeutic effect of nanomedicine-based treatment.     

Toll-like receptor 9 signaling mediates the anti-inflammatory effects of probiotics in murine experimental colitis

BACKGROUND & AIMS: We tested whether the attenuation of experimental colitis by live probiotic bacteria is due to their immunostimulatory DNA, whether toll-like receptor (TLR) signaling is required, and whether nonviable probiotics are effective. METHODS: Methylated and unmethylated genomic DNA isolated from probiotics (VSL-3), DNAse-treated probiotics and Escherichia coli (DH5 alpha) genomic DNA were administered intragastrically (i.g.) or subcutaneously (s.c.) to mice prior to the induction of colitis. Viable or gamma-irradiated probiotics were administered i.g. to wild-type mice and mice deficient in different TLR or in the adaptor protein MyD88, 10 days prior to administration of dextran sodium sulfate (DSS) to their drinking water and for 7 days thereafter. RESULTS: Intragastric and s.c. administration of probiotic and E. coli DNA ameliorated the severity of DSS-induced colitis, whereas methylated probiotic DNA, calf thymus DNA, and DNase-treated probiotics had no effect. The colitis severity was attenuated to the same extent by i.g. delivery of nonviable gamma-irradiated or viable probiotics. Mice deficient in MyD88 did not respond to gamma-irradiated probiotics. The severity of DSS-induced colitis in TLR2 and TLR4 deficient mice was significantly decreased by i.g. administration of gamma-irradiated probiotics, whereas, in TLR9-deficient mice, gamma-irradiated probiotics had no effect. CONCLUSIONS: The protective effects of probiotics are mediated by their own DNA rather than by their metabolites or ability to colonize the colon. TLR9 signaling is essential in mediating the anti-inflammatory effect of probiotics, and live microorganisms are not required to attenuate experimental colitis because nonviable probiotics are equally effective.