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1.
J Immunother ; 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38532708

ABSTRACT

SUMMARY: Anti-programmed cell death protein 1 (PD-1) therapy is considered effective in the treatment of metastatic or locally advanced cutaneous squamous cell carcinoma but the use of these agents in solid organ transplant recipients (SOTRs) is often taken with caution. While anti-tumor effects without graft rejection have been reported, studies have shown high rates of fatal graft rejection with immune checkpoint therapy. In this case report, we present an SOTR patient with life-threatening, acute hypoxic respiratory failure due to rapidly progressive metastatic cutaneous squamous cell carcinoma with lung and pleural involvement. Modification of their immunosuppressive regimen and treatment with front-line anti-PD-1 inhibitor, pembrolizumab, led to rapid clinical response with near complete resolution of metastatic pulmonary disease and no long-term evidence of graft rejection. Our case report shows that front-line treatment with PD-1 inhibitors can be safely administered in SOTR patients with rapid metastatic disease control.

2.
Front Immunol ; 14: 1174537, 2023.
Article in English | MEDLINE | ID: mdl-37600805

ABSTRACT

Introduction: Typical Western diet, rich in salt, contributes to autoimmune disease development. However, conflicting reports exist about the effect of salt on neutrophil effector functions, also in the context of arthritis. Methods: We investigated the effect of sodium chloride (NaCl) on neutrophil viability and functions in vitro, and in vivo employing the murine K/BxN-serum transfer arthritis (STA) model. Results and discussion: The effects of NaCl and external reactive oxygen species (H2O2) were further examined on osteoclasts in vitro. Hypertonic sodium-rich media caused primary/secondary cell necrosis, altered the nuclear morphology, inhibited phagocytosis, degranulation, myeloperoxidase (MPO) peroxidation activity and neutrophil extracellular trap (NET) formation, while increasing total ROS production, mitochondrial ROS production, and neutrophil elastase (NE) activity. High salt diet (HSD) aggravated arthritis by increasing inflammation, bone erosion, and osteoclast differentiation, accompanied by increased NE expression and activity. Osteoclast differentiation was decreased with 25 mM NaCl or 100 nM H2O2 addition to isotonic media. In contrast to NaCl, external H2O2 had pro-resorptive effects in vitro. We postulate that in arthritis under HSD, increased bone erosion can be attributed to an enhanced oxidative milieu maintained by infiltrating neutrophils, rather than a direct effect of NaCl.


Subject(s)
Arthritis , Sodium , Animals , Mice , Sodium Chloride/pharmacology , Neutrophils , Reactive Oxygen Species , Hydrogen Peroxide , Oxidative Stress , Sodium Chloride, Dietary
3.
PET Clin ; 18(4): 441-458, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37268505

ABSTRACT

Breast carcinomas classified based on traditional morphologic assessment provide useful prognostic information. Although morphology is still the gold standard of classification, recent advances in molecular technologies have enabled the classification of these tumors into four distinct subtypes based on its intrinsic molecular profile that provide both predictive and prognostic information. This article describes the association between the different molecular subtypes with the histologic subtypes of breast cancer and illustrates how these subtypes may affect the appearance of tumors on imaging studies.


Subject(s)
Breast Neoplasms , Humans , Female , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Receptor, ErbB-2 , Biomarkers, Tumor , Prognosis
4.
Cells ; 11(24)2022 12 12.
Article in English | MEDLINE | ID: mdl-36552786

ABSTRACT

Neutrophils are the most abundant innate immune cells in humans and the first line of defense against invading pathogens [...].


Subject(s)
Extracellular Traps , Humans , Neutrophils
5.
Int J Mol Sci ; 23(23)2022 Dec 01.
Article in English | MEDLINE | ID: mdl-36499449

ABSTRACT

Vascular occlusions in patients with coronavirus diseases 2019 (COVID-19) have been frequently reported in severe outcomes mainly due to a dysregulation of neutrophils mediating neutrophil extracellular trap (NET) formation. Lung specimens from patients with COVID-19 have previously shown a dynamic morphology, categorized into three types of pleomorphic occurrence based on histological findings in this study. These vascular occlusions in lung specimens were also detected using native endogenous fluorescence or NEF in a label-free method. The three types of vascular occlusions exhibit morphology of DNA rich neutrophil elastase (NE) poor (type I), NE rich DNA poor (type II), and DNA and NE rich (type III) cohort of eleven patients with six males and five females. Age and gender have been presented in this study as influencing variables linking the occurrence of several occlusions with pleomorphic contents within a patient specimen and amongst them. This study reports the categorization of pleomorphic occlusions in patients with COVID-19 and the detection of these occlusions in a label-free method utilizing NEF.


Subject(s)
COVID-19 , Extracellular Traps , Vascular Diseases , Male , Female , Humans , COVID-19/complications , COVID-19/pathology , SARS-CoV-2 , Lung/pathology , Neutrophils/pathology , Vascular Diseases/pathology
6.
J Vis Exp ; (186)2022 08 04.
Article in English | MEDLINE | ID: mdl-35993744

ABSTRACT

Ocular surface diseases include a range of disorders that disturb the functions and structures of the cornea, conjunctiva, and the associated ocular surface gland network. Meibomian glands (MG) secrete lipids that create a covering layer that prevents the evaporation of the aqueous part of the tear film. Neutrophils and extracellular DNA traps populate MG and the ocular surface in a mouse model of allergic eye disease. Aggregated neutrophil extracellular traps (aggNETs) formulate a mesh-like matrix composed of extracellular chromatin that occludes MG outlets and conditions MG dysfunction. Here, a method for inducing ocular surface inflammation and MG dysfunction is presented. The procedures for collecting organs related to the ocular surface, such as the cornea, conjunctiva, and eyelids, are described in detail. Using established techniques for processing each organ, the major morphological and histopathological features of MG dysfunction are also shown. Ocular exudates offer the opportunity to assess the inflammatory state of the ocular surface. These procedures enable the investigation of topical and systemic anti-inflammatory interventions at the preclinical level.


Subject(s)
Dry Eye Syndromes , Meibomian Gland Dysfunction , Animals , Conjunctiva/pathology , Dry Eye Syndromes/pathology , Inflammation/pathology , Meibomian Glands/pathology , Mice , Tears/chemistry
7.
Cells ; 10(9)2021 08 26.
Article in English | MEDLINE | ID: mdl-34571857

ABSTRACT

The enlightenment of the formation of neutrophil extracellular traps (NETs) as a part of the innate immune system shed new insights into the pathologies of various diseases. The initial idea that NETs are a pivotal defense structure was gradually amended due to several deleterious effects in consecutive investigations. NETs formation is now considered a double-edged sword. The harmful effects are not limited to the induction of inflammation by NETs remnants but also include occlusions caused by aggregated NETs (aggNETs). The latter carries the risk of occluding tubular structures like vessels or ducts and appear to be associated with the pathologies of various diseases. In addition to life-threatening vascular clogging, other occlusions include painful stone formation in the biliary system, the kidneys, the prostate, and the appendix. AggNETs are also prone to occlude the ductal system of exocrine glands, as seen in ocular glands, salivary glands, and others. Last, but not least, they also clog the pancreatic ducts in a murine model of neutrophilia. In this regard, elucidating the mechanism of NETs-dependent occlusions is of crucial importance for the development of new therapeutic approaches. Therefore, the purpose of this review is to address the putative mechanisms of NETs-associated occlusions in the pathogenesis of disease, as well as prospective treatment modalities.


Subject(s)
Embolism/immunology , Extracellular Traps/physiology , Thrombosis/immunology , Animals , Body Fluids/immunology , Body Fluids/physiology , Embolism/physiopathology , Extracellular Traps/immunology , Extracellular Traps/metabolism , Humans , Inflammation/pathology , Neutrophils/immunology , Prospective Studies , Thrombosis/physiopathology
8.
Front Immunol ; 12: 550236, 2021.
Article in English | MEDLINE | ID: mdl-34025634

ABSTRACT

Purpose: Agonistic ß2-adrenergic receptor autoantibodies (ß2-agAAbs) were recently observed in sera of patients with ocular hypertension (OHT), primary (POAG), and secondary open-angle glaucoma (SOAG), yet not in healthy controls (HCs). It was the aim of the present study to investigate the presence of ß2-agAAb in aqueous humor (AH) samples of OAG patients and to correlate these with the corresponding ß2-agAAb serum data. Material and Methods: Thirty-nine patients (21 male, 18 female) were recruited from the Department of Ophthalmology, University of Erlangen-Nürnberg: twenty-one POAG, 18 SOAG. Aqueous humor samples were collected during minimal invasive glaucoma surgery. Serum and AH samples were analyzed for ß2-agAAb by a bioassay quantifying the beating rate of cultured cardiomyocyte (cut-off: 2 U). Results: Thirty-six of 39 (92.3%) and 34 of 39 (87.2%) of OAG patients showed a ß2-agAAb in their sera and AH samples, respectively. All ß2-agAAb AH-positive OAG patients were also seropositive. We also observed a ß2-agAAb seropositivity in 95 and 89% of patients with POAG and SOAG, respectively. Beta2-agAAbs were seen in 86% (POAG) and 78% (SOAG) of AH samples. The ß2-agAAb adrenergic activity was increased in the AH of patients with POAG (6.5 ± 1.5 U) when compared with those with SOAG (4.1 ± 1.1 U; p = 0.004). Serum ß2-agAAb adrenergic activity did not differ between the cohorts [POAG (4.5 ± 1.5 U); SOAG (4.6 ± 2.1 U; p=0.458)]. No correlation of the beating rates were observed between serum and AH samples for group and subgroup analyses. Conclusion: The detection of ß2-agAAb in systemic and local circulations supports the hypothesis of a direct functional impact of these agAAbs on ocular G-protein coupled receptors. The high prevalence of ß2-agAAb in serum and AH samples of patients with POAG or SOAG suggests a common role of these AAbs in the etiopathogenesis of glaucoma, independent of open-angle glaucoma subtype.


Subject(s)
Adrenergic beta-2 Receptor Agonists/immunology , Aqueous Humor/immunology , Autoantibodies/immunology , Glaucoma, Open-Angle/immunology , Receptors, Adrenergic, beta-2/metabolism , Aged , Aged, 80 and over , Animals , Aqueous Humor/physiology , Autoantibodies/blood , Autoantibodies/pharmacology , Cells, Cultured , Female , Glaucoma, Open-Angle/blood , Glaucoma, Open-Angle/physiopathology , Humans , Intraocular Pressure , Male , Middle Aged , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Myocytes, Cardiac/physiology , Rats, Sprague-Dawley
9.
Cell Death Differ ; 28(11): 3125-3139, 2021 11.
Article in English | MEDLINE | ID: mdl-34031543

ABSTRACT

SARS-CoV-2 infection poses a major threat to the lungs and multiple other organs, occasionally causing death. Until effective vaccines are developed to curb the pandemic, it is paramount to define the mechanisms and develop protective therapies to prevent organ dysfunction in patients with COVID-19. Individuals that develop severe manifestations have signs of dysregulated innate and adaptive immune responses. Emerging evidence implicates neutrophils and the disbalance between neutrophil extracellular trap (NET) formation and degradation plays a central role in the pathophysiology of inflammation, coagulopathy, organ damage, and immunothrombosis that characterize severe cases of COVID-19. Here, we discuss the evidence supporting a role for NETs in COVID-19 manifestations and present putative mechanisms, by which NETs promote tissue injury and immunothrombosis. We present therapeutic strategies, which have been successful in the treatment of immunο-inflammatory disorders and which target dysregulated NET formation or degradation, as potential approaches that may benefit patients with severe COVID-19.


Subject(s)
COVID-19/pathology , Extracellular Traps/metabolism , Neutrophils/immunology , COVID-19/complications , COVID-19/immunology , Citrullination , Complement Activation , Humans , Neutrophils/metabolism , Platelet Activation , SARS-CoV-2/isolation & purification , Severity of Illness Index , Thrombosis/etiology
10.
Gynecol Oncol Rep ; 35: 100690, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33490351

ABSTRACT

Ovarian cancer typically presents at advanced stage with intra-abdominal metastases. Rarely, ovarian cancer presents with distant metastases with little to no intra-abdominal disease burden. The patient was a BRCA-2 germline mutation carrier diagnosed with a Stage IVB high-grade carcinoma of the fallopian tube following discovery of a right axillary breast mass on screening mammography. Pre-operative imaging was without evidence of metastatic disease in the abdomen or pelvis. She underwent surgical staging followed by adjuvant chemotherapy and maintenance poly-ADP ribose polymerase (PARP) inhibition. She is without evidence of disease 24 months following her surgical staging procedure. An isolated oligo metastasis in the axilla is a rare presentation of ovarian carcinoma. Extra-abdominal metastases can present a diagnostic challenge in ovarian cancer necessitating thorough pathologic and radiologic work-up, particularly in the absence of intra-abdominal disease.

11.
Ocul Surf ; 20: 1-12, 2021 04.
Article in English | MEDLINE | ID: mdl-33401018

ABSTRACT

PURPOSE: Obstructive Meibomian gland dysfunction (MGD) is one of the leading causes of evaporative dry eye disease. Meibomian glands at the eyelid secrete lipids that prevent evaporation of the aqueous tear film. The pathogenesis of obstructive MGD is incompletely understood to date. Herein, we aim to investigate the pathogenesis of obstructive MGD using murine and human samples with various forms of ocular surface inflammation. METHOD: The presence of Neutrophil extracellular Traps (NETs) was detected with immunofluorescence analysis of ocular surface discharge and biopsy samples from patients with blepharitis. Tear fluid from patients with MGD and blepharitis were evaluated for the presence of inflammatory mediators using bead based immunoassay. Murine model of allergic eye disease (AED) was performed to investigate the role of NETs in MG occlusion. RESULTS: we show that the ocular discharge from patients with blepharitis contains aggregated neutrophil extracellular traps (aggNETs). Furthermore, the ducts of human Meibomian glands affected by blepharitis were largely congested by aggNETs. Tear fluid from patients with MGD showed elevated neutrophil chemoattractants (C5a, IL6, IL8 and IL18). C5a and IL8 correlated with the degree of deficiency of tear fluid. In the murine model of allergic eye disease (AED), aggNETs accumulated in the MG leading to occlusion of their ducts and the retrograde pent-up of the fluid followed by acinar atrophy. Constraining aggNET formation by genetic or pharmacological inhibition of peptidyl arginine deiminase type 4 (PADI4) effectively reduced MG damage. CONCLUSION: We conclude that aggNETs occlude MG causing MGD after ocular surface inflammation.


Subject(s)
Dry Eye Syndromes , Extracellular Traps , Eyelid Diseases , Animals , Humans , Inflammation , Meibomian Glands , Mice , Tears
12.
J Nucl Med ; 62(4): 500-506, 2021 04.
Article in English | MEDLINE | ID: mdl-32859700

ABSTRACT

Activating mutations in the estrogen receptor (ER) α-gene (ESR1) result in constitutive transcriptional activity in the absence of estrogen and are associated with endocrine resistance in metastatic ER-positive (+) breast cancer. It is not known how activating ESR1 mutations may alter the predictive values of molecular imaging agents for endocrine therapy response. This study investigated the effect of an activating ESR1 mutation on pretreatment 18F-fluoroestradiol (18F-FES) uptake and early assessment of endocrine therapy response using 18F-FDG and 18F-fluorofuranylnorprogesterone (18F-FFNP) PET/CT imaging of tumor glucose metabolism and progesterone receptor (PR) expression, respectively. Methods: ER+, PR+ T47D breast cancer cells expressing wild-type (WT) ER or an activating ESR1 mutation, Y537S-ER, were used to generate tumor xenografts in ovariectomized female immunodeficient mice supplemented with 17ß-estradiol. Tumor growth curves were determined in the presence or absence of estrogen and for ethanol vehicle control or fulvestrant treatment, a selective ER degrader. Pretreatment 18F-FES uptake was compared between Y537S-ER and WT-ER tumors. Longitudinal PET/CT imaging with 18F-FFNP and 18F-FDG was performed before and 7-9 d after the start of endocrine therapy with fulvestrant. Radiopharmaceutical uptake in Y537S-ER and WT-ER tumors was compared between baseline and follow-up scans. Statistical significance was determined using paired t testing for longitudinal imaging and 2-way ANOVA for the 18F-FFNP tissue biodistribution assay. Results: Y537S-ER xenografts showed estrogen-independent growth, whereas WT-ER tumors grew only with estrogen. Fulvestrant treatment for 28 d significantly reduced tumor volumes for WT-ER but only stabilized volumes for Y537S-ER. Baseline 18F-FES uptake did not significantly differ between WT-ER and Y537S-ER tumors. Fulvestrant treatment induced a similar early metabolic response for both WT-ER and Y537S-ER tumors. 18F-FFNP uptake in WT-ER tumors was significantly reduced after 7 d of fulvestrant treatment; however, this reduction did not occur in Y537S-ER tumors, which showed no significant change between baseline and follow-up PET/CT. Conclusion: Molecular imaging of PR expression dynamics could be a noninvasive approach for early identification of reduced effectiveness of endocrine therapy resulting from activating ESR1 mutations.


Subject(s)
Breast Neoplasms/diagnostic imaging , Breast Neoplasms/genetics , Estrogen Receptor alpha/genetics , Mutation , Positron Emission Tomography Computed Tomography , Receptors, Progesterone/metabolism , Animals , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Cell Line, Tumor , Cell Transformation, Neoplastic , Estradiol/pharmacology , Estradiol/therapeutic use , Estrogens/pharmacology , Estrogens/therapeutic use , Female , Fluorodeoxyglucose F18 , Gene Expression Regulation, Neoplastic/drug effects , Glycosylation/drug effects , Humans , Longitudinal Studies , Mice , Treatment Outcome
13.
Cells ; 9(9)2020 09 22.
Article in English | MEDLINE | ID: mdl-32971767

ABSTRACT

Salivary gland stones, or sialoliths, are the most common cause of the obstruction of salivary glands. The mechanism behind the formation of sialoliths has been elusive. Symptomatic sialolithiasis has a prevalence of 0.45% in the general population, is characterized by recurrent painful periprandial swelling of the affected gland, and often results in sialadenitis with the need for surgical intervention. Here, we show by the use of immunohistochemistry, immunofluorescence, computed tomography (CT) scans and reconstructions, special dye techniques, bacterial genotyping, and enzyme activity analyses that neutrophil extracellular traps (NETs) initiate the formation and growth of sialoliths in humans. The deposition of neutrophil granulocyte extracellular DNA around small crystals results in the dense aggregation of the latter, and the subsequent mineralization creates alternating layers of dense mineral, which are predominantly calcium salt deposits and DNA. The further agglomeration and appositional growth of these structures promotes the development of macroscopic sialoliths that finally occlude the efferent ducts of the salivary glands, causing clinical symptoms and salivary gland dysfunction. These findings provide an entirely novel insight into the mechanism of sialolithogenesis, in which an immune system-mediated response essentially participates in the physicochemical process of concrement formation and growth.


Subject(s)
Calcium/metabolism , Extracellular Traps/immunology , Neutrophils/pathology , Salivary Gland Calculi/pathology , Salivary Glands/pathology , Sialadenitis/pathology , Adult , Biomarkers/metabolism , Calcium/chemistry , Cohort Studies , DNA/genetics , DNA/metabolism , Female , Gene Expression , Humans , Image Processing, Computer-Assisted , Leukocyte Elastase/genetics , Leukocyte Elastase/immunology , Lithotripsy , Male , Middle Aged , Neutrophils/immunology , Salivary Gland Calculi/diagnostic imaging , Salivary Gland Calculi/immunology , Salivary Gland Calculi/surgery , Salivary Glands/diagnostic imaging , Salivary Glands/immunology , Salivary Glands/surgery , Sialadenitis/diagnostic imaging , Sialadenitis/immunology , Sialadenitis/surgery , Ultrasonography , X-Ray Microtomography
14.
EBioMedicine ; 58: 102925, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32745993

ABSTRACT

BACKGROUND: Coronavirus induced disease 2019 (COVID-19) can be complicated by severe organ damage leading to dysfunction of the lungs and other organs. The processes that trigger organ damage in COVID-19 are incompletely understood. METHODS: Samples were donated from hospitalized patients. Sera, plasma, and autopsy-derived tissue sections were examined employing flow cytometry, enzyme-linked immunosorbent assays, and immunohistochemistry. PATIENT FINDINGS: Here, we show that severe COVID-19 is characterized by a highly pronounced formation of neutrophil extracellular traps (NETs) inside the micro-vessels. Intravascular aggregation of NETs leads to rapid occlusion of the affected vessels, disturbed microcirculation, and organ damage. In severe COVID-19, neutrophil granulocytes are strongly activated and adopt a so-called low-density phenotype, prone to spontaneously form NETs. In accordance, markers indicating NET turnover are consistently increased in COVID-19 and linked to disease severity. Histopathology of the lungs and other organs from COVID-19 patients showed congestions of numerous micro-vessels by aggregated NETs associated with endothelial damage. INTERPRETATION: These data suggest that organ dysfunction in severe COVID-19 is associated with excessive NET formation and vascular damage. FUNDING: Deutsche Forschungsgemeinschaft (DFG), EU, Volkswagen-Stiftung.


Subject(s)
Coronavirus Infections/pathology , Extracellular Traps/metabolism , Microvessels/pathology , Neutrophils/metabolism , Pneumonia, Viral/pathology , Thrombosis/metabolism , COVID-19 , Cells, Cultured , Coronavirus Infections/complications , Coronavirus Infections/metabolism , Endothelium, Vascular/metabolism , Endothelium, Vascular/pathology , Humans , Microvessels/metabolism , Neutrophils/pathology , Pandemics , Pneumonia, Viral/complications , Pneumonia, Viral/metabolism , Thrombosis/etiology , Thrombosis/pathology
15.
Horm Cancer ; 11(2): 63-75, 2020 04.
Article in English | MEDLINE | ID: mdl-31942683

ABSTRACT

Tumor mutations in the gene encoding estrogen receptor alpha (ESR1) have been identified in metastatic breast cancer patients with endocrine therapy resistance. However, relatively little is known about the occurrence of mutations in the progesterone receptor (PGR) gene in this population. The study objective was to determine the frequency and prognostic significance of tumor PGR mutations for patients with estrogen receptor (ER)-positive metastatic breast cancer. Thirty-five women with metastatic or locally recurrent ER+ breast cancer were included in this IRB-approved, retrospective study. Targeted next-generation sequencing of the PGR gene was performed on isolated tumor DNA. Associations between mutation status and clinicopathologic factors were analyzed as well as overall survival (OS) from time of metastatic diagnosis. The effect of the PGR variant Y890C (c.2669A>G) identified in this cohort on PR transactivation function was tested using ER-PR- (MDA-MB-231), ER+PR+ (T47D), and ER+PR- (T47D PR KO) breast cancer cell lines. There were 71 occurrences of protein-coding PGR variants in 67% (24/36; 95% CI 49-81%) of lesions. Of the 49 unique variants, 14 are single nucleotide polymorphisms (SNPs). Excluding SNPs, the median OS of patients with PGR variants was 32 months compared to 79 months with wild-type PGR (p = 0.42). The most frequently occurring (4/36 lesions) non-SNP variant was Y890C. Cells expressing Y890C had reduced progestin-stimulated PR transactivation compared to cells expressing wild-type PR. PGR variants occur frequently in ER+ metastatic breast cancer. Although some variants are SNPs, others are predicted to be functionally deleterious as demonstrated with Y890C PR.


Subject(s)
Breast Neoplasms/genetics , Receptors, Progesterone/genetics , Animals , Breast Neoplasms/pathology , Female , Genetic Variation , High-Throughput Nucleotide Sequencing/methods , Humans , Mice , Middle Aged , Neoplasm Metastasis , Prognosis , Receptors, Progesterone/metabolism , Transfection
16.
Nat Commun ; 11(1): 120, 2020 01 08.
Article in English | MEDLINE | ID: mdl-31913287

ABSTRACT

Monomeric serum immunoglobulin A (IgA) can contribute to the development of various autoimmune diseases, but the regulation of serum IgA effector functions is not well defined. Here, we show that the two IgA subclasses (IgA1 and IgA2) differ in their effect on immune cells due to distinct binding and signaling properties. Whereas IgA2 acts pro-inflammatory on neutrophils and macrophages, IgA1 does not have pronounced effects. Moreover, IgA1 and IgA2 have different glycosylation profiles, with IgA1 possessing more sialic acid than IgA2. Removal of sialic acid increases the pro-inflammatory capacity of IgA1, making it comparable to IgA2. Of note, disease-specific autoantibodies in patients with rheumatoid arthritis display a shift toward the pro-inflammatory IgA2 subclass, which is associated with higher disease activity. Taken together, these data demonstrate that IgA effector functions depend on subclass and glycosylation, and that disturbances in subclass balance are associated with autoimmune disease.


Subject(s)
Immunoglobulin A/immunology , Polysaccharides/metabolism , Adult , Arthritis, Rheumatoid/immunology , Arthritis, Rheumatoid/metabolism , Autoantibodies/chemistry , Autoantibodies/immunology , Autoantibodies/metabolism , Female , Glycosylation , Humans , Immunoglobulin A/chemistry , Immunoglobulin A/metabolism , Macrophages/immunology , Male , Middle Aged , Neutrophils/immunology
17.
Appl Immunohistochem Mol Morphol ; 28(4): 290-295, 2020 04.
Article in English | MEDLINE | ID: mdl-30664533

ABSTRACT

The purpose of this investigation is to directly compare G175-405 and E6H4 p16-specific antibodies as immunomarkers of HPV-driven oropharyngeal carcinoma. The investigators designed a retrospective analysis using specimens from an archived tissue bank with known in situ hybridization and polymerase chain reaction status for HPV DNA. Fifty randomly selected oropharyngeal specimens were evaluated with both the G175-405 and E6H4 p16-specific monoclonal antibodies. Two pathologists, blinded to the HPV-specific testing status, evaluated p16 positivity for both antibody clones. Interrater agreement was determined using a Cohen κ coefficient. Sensitivity and specificity values were calculated using a standard 2×2 contingency table, then compared using McNemar test. Interrater agreement for interpretation of p16 expression was 92% (κ=0.84) for the G175-405 clone and 100% for the E6H4 clone (κ=1.0). The G175-405 stain had a sensitivity of 0.917 and specificity of 0.846. The E6H4 stain had a sensitivity of 1.000 and specificity of 0.769. Using McNemar test, there were no significant differences found for sensitivity (P=0.480) or specificity (P=0.480) values. The results of this study suggest that though both G175-405 and E6H4 antibody stains are statistically comparable immunomarkers for HPV-driven oropharyngeal carcinoma, the E6H4 clone offers improved interobserver reliability.


Subject(s)
Antibodies, Monoclonal/chemistry , Antibodies, Neoplasm/chemistry , Cyclin-Dependent Kinase Inhibitor p16/metabolism , Immunohistochemistry , Oropharyngeal Neoplasms , Papillomavirus Infections , Squamous Cell Carcinoma of Head and Neck , Aged , Antibody Specificity , Female , Humans , Male , Middle Aged , Oropharyngeal Neoplasms/metabolism , Oropharyngeal Neoplasms/pathology , Oropharyngeal Neoplasms/virology , Papillomaviridae , Papillomavirus Infections/metabolism , Papillomavirus Infections/pathology , Squamous Cell Carcinoma of Head and Neck/metabolism , Squamous Cell Carcinoma of Head and Neck/pathology , Squamous Cell Carcinoma of Head and Neck/virology
18.
Semin Arthritis Rheum ; 49(3S): S43-S48, 2019 12.
Article in English | MEDLINE | ID: mdl-31779852

ABSTRACT

Following a recent presentation at ATT Mallorca in May 2019, this paper gives insight into the current research of neutrophil extracellular traps (NETs) and their role in conditions of health and disease. Though NETs reportedly support disease progression and play a role in the development of autoimmune diseases, we argue that NETs are mandatory for the mammalian immune system. They are especially important to patrol and surveil outer and inner body surfaces and are capable to perform major anti-microbial activities. Neutrophils are the first cells to be recruited to wounds, where they form NETs and aggregated NETs (aggNETs). The latter close the wounds and are ever-present in skinfolds, where the integrity of the skin is impaired. On infected ocular surfaces NETs form an antimicrobial barrier, which prevents bacterial dissemination into the brain. In the oral cavity, NETs display anti-bacterial properties. Although NETs on internal body surfaces like ducts and vessels offer superficial surveillance, exaggerated aggNET formation may directly block vessels and ducts and thus cause thrombi and ductal occlusion, respectively. In the case of biliopancreatic ducts, clogging by aggNETs may even cause acute pancreatitis. Insufficient clearance of apoptotic remnants and NETs can lead to autoimmune diseases or unwanted, chronic inflammation. To prevent this, macrophages cloak dead cells, while apoptotic cells are cleared. We conclude that neutrophils, NETs and aggNETs can be considered double edged swords that orchestrate the innate immune response but carry the risk to precipitate autoimmunity and epithelial damage.


Subject(s)
Apoptosis , Autoimmune Diseases/pathology , Extracellular Traps , Immunity, Innate , Animals , Autoimmune Diseases/immunology , Autoimmune Diseases/metabolism , Humans
19.
Front Immunol ; 10: 2481, 2019.
Article in English | MEDLINE | ID: mdl-31695698

ABSTRACT

Neutrophils respond to various stimuli by decondensing and releasing nuclear chromatin characterized by citrullinated histones as neutrophil extracellular traps (NETs). This achieves pathogen immobilization or initiation of thrombosis, yet the molecular mechanisms of NET formation remain elusive. Peptidyl arginine deiminase-4 (PAD4) achieves protein citrullination and has been intricately linked to NET formation. Here we show that citrullination represents a major regulator of proteolysis in the course of NET formation. Elevated cytosolic calcium levels trigger both peptidylarginine deiminase-4 (PAD4) and calpain activity in neutrophils resulting in nuclear decondensation typical of NETs. Interestingly, PAD4 relies on proteolysis by calpain to achieve efficient nuclear lamina breakdown and chromatin decondensation. Pharmacological or genetic inhibition of PAD4 and calpain strongly inhibit chromatin decondensation of human and murine neutrophils in response to calcium ionophores as well as the proteolysis of nuclear proteins like lamin B1 and high mobility group box protein 1 (HMGB1). Taken together, the concerted action of PAD4 and calpain induces nuclear decondensation in the course of calcium-mediated NET formation.


Subject(s)
Calpain/immunology , Citrullination/immunology , Extracellular Traps/immunology , Neutrophils/immunology , Nuclear Lamina/immunology , Animals , Calpain/genetics , Citrullination/genetics , Extracellular Traps/genetics , Humans , Mice , Mice, Knockout , Neutrophils/cytology , Nuclear Lamina/genetics , Protein-Arginine Deiminase Type 4/genetics , Protein-Arginine Deiminase Type 4/immunology
20.
Semin Immunopathol ; 41(6): 681-697, 2019 11.
Article in English | MEDLINE | ID: mdl-31696251

ABSTRACT

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease with prominent chronic inflammatory aspects. SLE most often affects women (9:1) in childbearing age. The multifactorial nature of the etiopathogenesis of SLE involves a deficient clearance of dead and dying cells. This is supported by the occurrence of autoantibodies directed against autoantigens modified in dying and dead cells (dsDNA, high mobility group box 1 protein, apoptosis-associated chromatin modifications, e.g., histones H3-K27-me3; H2A/H4 AcK8,12,16; and H2B-AcK12) that are deposited in various tissues, including skin, kidneys, joints, muscles, and brain. The subsequent hyperinflammatory response often leads to irreparable tissue damage and organ destruction. In healthy individuals, dead and dying cells are rapidly removed by macrophages in an anti-inflammatory manner, referred to as efferocytosis. In SLE, extensive and prolonged cell death (apoptosis, necrosis, neutrophil extracellular trap (NET) formation) leads to autoantigens leaking out of the not cleared cell debris. These neo-epitopes are subsequently presented to B cells by follicular dendritic cells in the germinal centers of secondary lymphoid tissues conditioning the break of self-tolerance. Activation of autoreactive B cells and subsequent production of autoantibodies facilitate the formation of immune complexes (ICs) fueling the inflammatory response and leading to further tissue damage. ICs may also be ingested by phagocytes, which then produce further pro-inflammatory cytokines. These processes establish a vicious circle that leads to sustained inflammation. This review highlights the cell death-related events in SLE, the protagonists involved in SLE pathogenesis, the resolution of inflammation in various tissues affected in SLE, and explores strategies for intervention to restore hemostasis in a hyperinflammatory state.


Subject(s)
Lupus Erythematosus, Systemic/etiology , Animals , Apoptosis/genetics , Apoptosis/immunology , Cell Death , Disease Susceptibility , Humans , Immune System/immunology , Immune System/metabolism , Lupus Erythematosus, Systemic/metabolism , Phagocytes/immunology , Phagocytes/metabolism , Phagocytosis/genetics , Phagocytosis/immunology
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