ABSTRACT
Since the 1960 s, our health has been compromised by exposure to over 350,000 newly introduced toxic substances, contributing to the current pandemic in allergic, autoimmune and metabolic diseases. The "Epithelial Barrier Theory" postulates that these diseases are exacerbated by persistent periepithelial inflammation (epithelitis) triggered by exposure to a wide range of epithelial barrier-damaging substances as well as genetic susceptibility. The epithelial barrier serves as the body's primary physical, chemical, and immunological barrier against external stimuli. A leaky epithelial barrier facilitates the translocation of the microbiome from the surface of the afflicted tissues to interepithelial and even deeper subepithelial locations. In turn, opportunistic bacterial colonization, microbiota dysbiosis, local inflammation and impaired tissue regeneration and remodelling follow. Migration of inflammatory cells to susceptible tissues contributes to damage and inflammation, initiating and aggravating many chronic inflammatory diseases. The objective of this review is to highlight and evaluate recent studies on epithelial physiology and its role in the pathogenesis of chronic diseases in light of the epithelial barrier theory.
Subject(s)
Hypersensitivity , Metabolic Diseases , Microbiota , Humans , Inflammation , Chronic Disease , DysbiosisABSTRACT
The most severe forms of coronavirus disease 2019 (COVID-19) are often associated with the presence of syncytia in the lungs resulting from cell-cell fusion mediated by the SARS-CoV-2 spike protein. In this issue, Rajah and colleagues show that the SARS-CoV-2 alpha, beta, and delta variants promote enhanced syncytia formation as compared to the original strain.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Spike Glycoprotein, Coronavirus/geneticsABSTRACT
SARS-CoV-2 is a newly emerged coronavirus that caused the global COVID-19 outbreak in early 2020. COVID-19 is primarily associated with lung injury, but many other clinical symptoms such as loss of smell and taste demonstrated broad tissue tropism of the virus. Early SARS-CoV-2-host cell interactions and entry mechanisms remain poorly understood. Investigating SARS-CoV-2 infection in tissue culture, we found that the protease TMPRSS2 determines the entry pathway used by the virus. In the presence of TMPRSS2, the proteolytic process of SARS-CoV-2 was completed at the plasma membrane, and the virus rapidly entered the cells within 10 min in a pH-independent manner. When target cells lacked TMPRSS2 expression, the virus was endocytosed and sorted into endolysosomes, from which SARS-CoV-2 entered the cytosol via acid-activated cathepsin L protease 40-60 min post-infection. Overexpression of TMPRSS2 in non-TMPRSS2 expressing cells abolished the dependence of infection on the cathepsin L pathway and restored sensitivity to the TMPRSS2 inhibitors. Together, our results indicate that SARS-CoV-2 infects cells through distinct, mutually exclusive entry routes and highlight the importance of TMPRSS2 for SARS-CoV-2 sorting into either pathway.
Subject(s)
COVID-19/metabolism , Cathepsin L/metabolism , SARS-CoV-2/physiology , Serine Endopeptidases/metabolism , Animals , COVID-19/genetics , Caco-2 Cells , Chlorocebus aethiops , Endocytosis , Host Microbial Interactions , Humans , Hydrogen-Ion Concentration , Proteolysis , Serine Endopeptidases/genetics , Signal Transduction , Vero Cells , Virus InternalizationABSTRACT
Similar to the brain, the eye is considered an immune-privileged organ where tissue-resident macrophages provide the major immune cell constituents. However, little is known about spatially restricted macrophage subsets within different eye compartments with regard to their origin, function, and fate during health and disease. Here, we combined single-cell analysis, fate mapping, parabiosis, and computational modeling to comprehensively examine myeloid subsets in distinct parts of the eye during homeostasis. This approach allowed us to identify myeloid subsets displaying diverse transcriptional states. During choroidal neovascularization, a typical hallmark of neovascular age-related macular degeneration (AMD), we recognized disease-specific macrophage subpopulations with distinct molecular signatures. Our results highlight the heterogeneity of myeloid subsets and their dynamics in the eye that provide new insights into the innate immune system in this organ which may offer new therapeutic targets for ophthalmological diseases.
Subject(s)
Choroid/blood supply , Eye/immunology , Macrophages/immunology , Myeloid Cells/immunology , Neovascularization, Physiologic/physiology , Animals , Choroid/embryology , Computational Biology , Computer Simulation , Eye/cytology , Eye/metabolism , Female , Homeostasis/immunology , Humans , Immunity, Innate/immunology , Macular Degeneration/pathology , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Microglia/physiology , Myeloid Cells/metabolism , Sequence Analysis, RNA , Single-Cell Analysis , Transcription, Genetic/geneticsABSTRACT
Toscana virus is a major cause of arboviral disease in humans in the Mediterranean basin during summer. However, early virus-host cell interactions and entry mechanisms remain poorly characterized. Investigating iPSC-derived human neurons and cell lines, we found that virus binding to the cell surface was specific, and 50% of bound virions were endocytosed within 10 min. Virions entered Rab5a+ early endosomes and, subsequently, Rab7a+ and LAMP-1+ late endosomal compartments. Penetration required intact late endosomes and occurred within 30 min following internalization. Virus entry relied on vacuolar acidification, with an optimal pH for viral membrane fusion at pH 5.5. The pH threshold increased to 5.8 with longer pre-exposure of virions to the slightly acidic pH in early endosomes. Strikingly, the particles remained infectious after entering late endosomes with a pH below the fusion threshold. Overall, our study establishes Toscana virus as a late-penetrating virus and reveals an atypical use of vacuolar acidity by this virus to enter host cells.
Subject(s)
Sandfly fever Naples virus , Humans , Endocytosis , Endosomes/metabolism , Vacuoles , Virus Internalization , Hydrogen-Ion ConcentrationABSTRACT
Hexosylceramides (HexCer) are implicated in the infection process of various pathogens. However, the molecular and cellular functions of HexCer in infectious cycles are poorly understood. Investigating the enveloped virus Uukuniemi (UUKV), a bunyavirus of the Phenuiviridae family, we performed a lipidomic analysis with mass spectrometry and determined the lipidome of both infected cells and derived virions. We found that UUKV alters the processing of HexCer to glycosphingolipids (GSL) in infected cells. The infection resulted in the overexpression of glucosylceramide (GlcCer) synthase (UGCG) and the specific accumulation of GlcCer and its subsequent incorporation into viral progeny. UUKV and several pathogenic bunyaviruses relied on GlcCer in the viral envelope for binding to various host cell types. Overall, our results indicate that GlcCer is a structural determinant of virions crucial for bunyavirus infectivity. This study also highlights the importance of glycolipids on virions in facilitating interactions with host cell receptors and infectious entry of enveloped viruses.
Subject(s)
Orthobunyavirus , Glucosylceramides , Virus Attachment , Lipidomics , Mass SpectrometryABSTRACT
BACKGROUND: The eye is a highly specialized sensory organ which encompasses the retina as a part of the central nervous system, but also non-neural compartments such as the transparent vitreous body ensuring stability of the eye globe and a clear optical axis. Hyalocytes are the tissue-resident macrophages of the vitreous body and are considered to play pivotal roles in health and diseases of the vitreoretinal interface, such as proliferative vitreoretinopathy or diabetic retinopathy. However, in contrast to other ocular macrophages, their embryonic origin as well as the extent to which these myeloid cells might be replenished by circulating monocytes remains elusive. RESULTS: In this study, we combine transgenic reporter mice, embryonic and adult fate mapping approaches as well as parabiosis experiments with multicolor immunofluorescence labeling and confocal laser-scanning microscopy to comprehensively characterize the murine hyalocyte population throughout development and in adulthood. We found that murine hyalocytes express numerous well-known myeloid cell markers, but concomitantly display a distinct immunophenotype that sets them apart from retinal microglia. Embryonic pulse labeling revealed a yolk sac-derived origin of murine hyalocytes, whose precursors seed the developing eye prenatally. Finally, postnatal labeling and parabiosis established the longevity of hyalocytes which rely on Colony Stimulating Factor 1 Receptor (CSF1R) signaling for their maintenance, independent of blood-derived monocytes. CONCLUSION: Our study identifies hyalocytes as long-living progeny of the yolk sac hematopoiesis and highlights their role as integral members of the innate immune system of the eye. As a consequence of their longevity, immunosenescence processes may culminate in hyalocyte dysfunction, thereby contributing to the development of vitreoretinal diseases. Therefore, myeloid cell-targeted therapies that convey their effects through the modification of hyalocyte properties may represent an interesting approach to alleviate the burden imposed by diseases of the vitreoretinal interface.
Subject(s)
Macrophages , Mice, Transgenic , Vitreous Body , Yolk Sac , Animals , Mice , Vitreous Body/cytology , Yolk Sac/cytology , Macrophages/metabolism , Mice, Inbred C57BL , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/genetics , Animals, NewbornABSTRACT
With more than 80 members worldwide, the Orthobunyavirus genus in the Peribunyaviridae family is a large genus of enveloped RNA viruses, many of which are emerging pathogens in humans and livestock. How orthobunyaviruses (OBVs) penetrate and infect mammalian host cells remains poorly characterized. Here, we investigated the entry mechanisms of the OBV Germiston (GERV). Viral particles were visualized by cryo-electron microscopy and appeared roughly spherical with an average diameter of 98 nm. Labeling of the virus with fluorescent dyes did not adversely affect its infectivity and allowed the monitoring of single particles in fixed and live cells. Using this approach, we found that endocytic internalization of bound viruses was asynchronous and occurred within 30 to 40 min. The virus entered Rab5a-positive (Rab5a+) early endosomes and, subsequently, late endosomal vacuoles containing Rab7a but not LAMP-1. Infectious entry did not require proteolytic cleavage, and endosomal acidification was sufficient and necessary for viral fusion. Acid-activated penetration began 15 to 25 min after initiation of virus internalization and relied on maturation of early endosomes to late endosomes. The optimal pH for viral membrane fusion was slightly below 6.0, and penetration was hampered when the potassium influx was abolished. Overall, our study provides real-time visualization of GERV entry into host cells and demonstrates the importance of late endosomal maturation in facilitating OBV penetration. IMPORTANCE Orthobunyaviruses (OBVs), which include La Crosse, Oropouche, and Schmallenberg viruses, represent a growing threat to humans and domestic animals worldwide. Ideally, preventing OBV spread requires approaches that target early stages of infection, i.e., virus entry. However, little is known about the molecular and cellular mechanisms by which OBVs enter and infect host cells. Here, we developed accurate, sensitive tools and assays to investigate the penetration process of GERV. Our data emphasize the central role of late endosomal maturation in GERV entry, providing a comprehensive overview of the early stages of an OBV infection. Our study also brings a complete toolbox of innovative methods to study each step of the OBV entry program in fixed and living cells, from virus binding and endocytosis to fusion and penetration. The information gained herein lays the foundation for the development of antiviral strategies aiming to block OBV entry.
Subject(s)
Endosomes , Orthobunyavirus , Virus Internalization , Animals , Cryoelectron Microscopy , Endosomes/virology , Mammals , Orthobunyavirus/physiologyABSTRACT
BACKGROUND: A prospective observational cohort study of COVID-19 patients in a single Emergency Department (ED) showed that sTREM-1- and IL-6-based algorithms were highly predictive of adverse outcome (Van Singer et al. J Allergy Clin Immunol 2021). We aim to validate the performance of these algorithms at ED presentation. METHODS: This multicentric prospective observational study of PCR-confirmed COVID-19 adult patients was conducted in the ED of three Swiss hospitals. Data of the three centers were retrospectively completed and merged. We determined the predictive accuracy of the sTREM-1-based algorithm for 30-day intubation/mortality. We also determined the performance of the IL-6-based algorithm using data from one center for 30-day oxygen requirement. RESULTS: 373 patients were included in the validation cohort, 139 (37%) in Lausanne, 93 (25%) in St.Gallen and 141 (38%) in EOC. Overall, 18% (93/373) patients died or were intubated by day 30. In Lausanne, 66% (92/139) patients required oxygen by day 30. The predictive accuracy of sTREM-1 and IL-6 were similar compared to the derivation cohort. The sTREM-1-based algorithm confirmed excellent sensitivity (90% versus 100% in the derivation cohort) and negative predictive value (94% versus 100%) for 30-day intubation/mortality. The IL-6-based algorithm performance was acceptable with a sensitivity of 85% versus 98% in the derivation cohort and a negative predictive value of 60% versus 92%. CONCLUSION: The sTREM-1 algorithm demonstrated good reproducibility. A prospective randomized controlled trial, comparing outcomes with and without the algorithm, is necessary to assess its safety and impact on hospital and ICU admission rates. The IL-6 algorithm showed acceptable validity in a single center and need additional validation before widespread implementation.
Subject(s)
COVID-19 , Adult , Humans , Algorithms , COVID-19/diagnosis , Interleukin-6 , Prospective Studies , Reproducibility of Results , Retrospective StudiesABSTRACT
OBJECTIVES: To investigate electronic care notes to better understand reporting and management of neuropsychiatric symptoms (NPS) by residential aged care (RAC) staff. METHODS: We examined semi-structured care notes from electronic healthcare notes of 77 residents (67% female; aged 67-101; 79% with formal dementia diagnosis) across three RAC facilities. As part of standard clinical practice, staff documented the NPS presentation and subsequent management amongst residents. Using a mixed-method approach, we analyzed the type of NPS reported and explored care staff responses to NPS using inductive thematic analysis. RESULTS: 465 electronic care notes were recorded during the 18-month period. Agitation-related behaviors were most frequently reported across residents (48.1%), while psychosis (15.6%), affective symptoms (14.3%), and apathy (1.3%) were less often reported. Only 27.5% of the notes contained information on potential causes underlying NPS. When faced with NPS, care staff responded by either providing emotional support, meeting resident's needs, removing identified triggers, or distracting. CONCLUSION: Results suggest that RAC staff primarily detected and responded to those NPS they perceived as distressing. Findings highlight a potential under-recognition of specific NPS types, and lack of routine examination of NPS causes or systematic assessment and management of NPS. These observations are needed to inform the development and implementation of non-pharmacological interventions and care programs targeting NPS in RAC.Supplemental data for this article is available online at https://doi.org/10.1080/13607863.2022.2032597 .
Subject(s)
Dementia , Psychotic Disorders , Aged , Humans , Female , Male , Nursing Homes , Dementia/diagnosis , Dementia/therapy , Dementia/psychology , Homes for the Aged , Delivery of Health CareABSTRACT
Regulatory non-coding RNAs (ncRNAs) including small non-coding RNAs (sRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) have gained considerable attention in the last few years. This is mainly due to their condition- and tissue-specific expression and their various modes of action, which suggests them as promising biomarkers and therapeutic targets. One important mechanism of ncRNAs to regulate gene expression is through translation of short open reading frames (sORFs). These sORFs can be located in lncRNAs, in non-translated regions of mRNAs where upstream ORFs (uORFs) represent the majority, or in circRNAs. Regulation of their translation can function as a quick way to adapt protein production to changing cellular or environmental cues, and can either depend solely on the initiation and elongation of translation, or on the roles of the produced functional peptides. Due to the experimental challenges to pinpoint translation events and to detect the produced peptides, translational regulation through regulatory RNAs is not well studied yet. In the case of circRNAs, they have only recently started to be recognized as regulatory molecules instead of mere artifacts of RNA biosynthesis. Of the many roles described for regulatory ncRNAs, we will focus here on their regulation during inflammation and in immunity.
Subject(s)
RNA, Long Noncoding , Humans , Inflammation/genetics , Peptides , Protein Biosynthesis , RNA, Circular , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolismABSTRACT
BACKGROUND: Microglia cells represent the resident innate immune cells of the retina and are important for retinal development and tissue homeostasis. However, dysfunctional microglia can have a negative impact on the structural and functional integrity of the retina under native and pathological conditions. METHODS: In this study, we examined interferon-regulatory factor 8 (Irf8)-deficient mice to determine the transcriptional profile, morphology, and temporospatial distribution of microglia lacking Irf8 and to explore the effects on retinal development, tissue homeostasis, and formation of choroidal neovascularisation (CNV). RESULTS: Our study shows that Irf8-deficient MG exhibit a considerable loss of microglial signature genes accompanied by a severely altered MG morphology. An in-depth characterisation by fundus photography, fluorescein angiography, optical coherence tomography and electroretinography revealed no major retinal abnormalities during steady state. However, in the laser-induced CNV model, Irf8-deficient microglia showed an increased activity of biological processes critical for inflammation and cell adhesion and a reduced MG cell density near the lesions, which was associated with significantly increased CNV lesion size. CONCLUSIONS: Our results suggest that loss of Irf8 in microglia has negligible effects on retinal homeostasis in the steady state. However, under pathological conditions, Irf8 is crucial for the transformation of resident microglia into a reactive phenotype and thus for the suppression of retinal inflammation and CNV formation.
Subject(s)
Choroidal Neovascularization/metabolism , Interferon Regulatory Factors/metabolism , Microglia/metabolism , Retina/metabolism , Animals , Homeostasis/physiology , Mice , Mice, Inbred C57BL , Mice, Knockout , Microglia/pathology , Retina/pathologyABSTRACT
During the past years, there has been a global outbreak of allergic diseases, presenting a considerable medical and socioeconomical burden. A large fraction of allergic diseases is characterized by a type 2 immune response involving Th2 cells, type 2 innate lymphoid cells, eosinophils, mast cells, and M2 macrophages. Biomarkers are valuable parameters for precision medicine as they provide information on the disease endotypes, clusters, precision diagnoses, identification of therapeutic targets, and monitoring of treatment efficacies. The availability of powerful omics technologies, together with integrated data analysis and network-based approaches can help the identification of clinically useful biomarkers. These biomarkers need to be accurately quantified using robust and reproducible methods, such as reliable and point-of-care systems. Ideally, samples should be collected using quick, cost-efficient and noninvasive methods. In recent years, a plethora of research has been directed toward finding novel biomarkers of allergic diseases. Promising biomarkers of type 2 allergic diseases include sputum eosinophils, serum periostin and exhaled nitric oxide. Several other biomarkers, such as pro-inflammatory mediators, miRNAs, eicosanoid molecules, epithelial barrier integrity, and microbiota changes are useful for diagnosis and monitoring of allergic diseases and can be quantified in serum, body fluids and exhaled air. Herein, we review recent studies on biomarkers for the diagnosis and treatment of asthma, chronic urticaria, atopic dermatitis, allergic rhinitis, chronic rhinosinusitis, food allergies, anaphylaxis, drug hypersensitivity and allergen immunotherapy. In addition, we discuss COVID-19 and allergic diseases within the perspective of biomarkers and recommendations on the management of allergic and asthmatic patients during the COVID-19 pandemic.
Subject(s)
COVID-19 , Hypersensitivity , Rhinitis, Allergic , Biomarkers , Humans , Hypersensitivity/diagnosis , Immunity, Innate , Lymphocytes , Pandemics , SARS-CoV-2ABSTRACT
In this review, we discuss recent publications on asthma and review the studies that have reported on the different aspects of the prevalence, risk factors and prevention, mechanisms, diagnosis, and treatment of asthma. Many risk and protective factors and molecular mechanisms are involved in the development of asthma. Emerging concepts and challenges in implementing the exposome paradigm and its application in allergic diseases and asthma are reviewed, including genetic and epigenetic factors, microbial dysbiosis, and environmental exposure, particularly to indoor and outdoor substances. The most relevant experimental studies further advancing the understanding of molecular and immune mechanisms with potential new targets for the development of therapeutics are discussed. A reliable diagnosis of asthma, disease endotyping, and monitoring its severity are of great importance in the management of asthma. Correct evaluation and management of asthma comorbidity/multimorbidity, including interaction with asthma phenotypes and its value for the precision medicine approach and validation of predictive biomarkers, are further detailed. Novel approaches and strategies in asthma treatment linked to mechanisms and endotypes of asthma, particularly biologicals, are critically appraised. Finally, due to the recent pandemics and its impact on patient management, we discuss the challenges, relationships, and molecular mechanisms between asthma, allergies, SARS-CoV-2, and COVID-19.
Subject(s)
Asthma/epidemiology , Hypersensitivity/epidemiology , Asthma/diagnosis , Asthma/therapy , Biomarkers , COVID-19 , Comorbidity , Dysbiosis , Exposome , Humans , Hypersensitivity/diagnosis , Hypersensitivity/therapy , Pandemics , Phenotype , Precision Medicine , Risk FactorsABSTRACT
The JAK-STAT signalling pathway regulates cellular processes like cell division, cell death and immune regulation. Dysregulation has been identified in solid tumours and STAT3 activation is a marker for poor outcome. The aim of this study was to explore potential therapeutic strategies by targeting this pathway in bladder cancer (BC). High STAT3 expression was detected in 51.3% from 149 patient specimens with invasive bladder cancer by immunohistochemistry. Protein expression of JAK, STAT and downstream targets were confirmed in 10 cell lines. Effects of the JAK inhibitors Ruxolitinib and BSK-805, and STAT3/5 inhibitors Stattic, Nifuroxazide and SH-4-54 were analysed by cell viability assays, immunoblotting, apoptosis and cell cycle progression. Treatment with STAT3/5 but not JAK1/2 inhibitors reduced survival, levels of phosphorylated STAT3 and Cyclin-D1 and increased apoptosis. Tumour xenografts, using the chicken chorioallantoic membrane (CAM) model responded to Stattic monotherapy. Combination of Stattic with Cisplatin, Docetaxel, Gemcitabine, Paclitaxel and CDK4/6 inhibitors showed additive effects. The combination of Stattic with the oncolytic adenovirus XVir-N-31 increased viral replication and cell lysis. Our results provide evidence that inhibitors against STAT3/5 are promising as novel mono- and combination therapy in bladder cancer.
Subject(s)
Antineoplastic Agents/pharmacology , Cell Proliferation/drug effects , Oncolytic Virotherapy/methods , Protein Kinase Inhibitors/pharmacology , STAT3 Transcription Factor/antagonists & inhibitors , STAT6 Transcription Factor/antagonists & inhibitors , Urinary Bladder Neoplasms/therapy , Animals , Apoptosis/drug effects , Cell Line, Tumor , Chick Embryo , Combined Modality Therapy/methods , Cyclic S-Oxides/pharmacology , Cyclin-Dependent Kinase 4/antagonists & inhibitors , Cyclin-Dependent Kinase 6/antagonists & inhibitors , Humans , Hydroxybenzoates/pharmacology , Janus Kinases/antagonists & inhibitors , Nitriles , Nitrofurans/pharmacology , Pyrazoles/pharmacology , Pyrimidines , Quinoxalines/pharmacology , Urinary Bladder Neoplasms/metabolismABSTRACT
PURPOSE: The use of high-dose chemotherapy and radiotherapy combined with haematopoietic stem cell transplantation (HSCT) may negatively affect a woman's reproductive potential. Reproductive outcomes such as infertility are a major concern for women who undergo treatment for a haematological cancer diagnosis. OBJECTIVE: This systematic review and meta-analysis explores reproductive outcomes following a haematological cancer requiring HSCT. METHODS: Electronic databases were searched to identify studies that reported on reproductive outcomes after treatment for a haematological cancer diagnosis. Studies were included that reported on pregnancy and reproductive outcomes following HSCT for a haematological malignancy. RESULTS: The meta-analysis included 14 studies, collectively involving 744 female patients. The subgroup analysis showed an overall pooled estimated pregnancy rate, for autologous or allogeneic HSCT recipients, of 22.7% (n = 438). There were 25% (n = 240) of women who became pregnant after autologous HSCT compared with 22% (n = 198) who subsequently became pregnant following allogeneic HSCT. CONCLUSIONS: This meta-analysis reflects low pregnancy rates for cancer survivors desiring a family. However, live births are improving over time with new technology and novel therapies. Hence, female cancer patients should be offered timely discussions, counselling and education around fertility preservation options prior to starting treatment with gonadotoxic therapy.
Subject(s)
Cancer Survivors/statistics & numerical data , Hematologic Neoplasms/epidemiology , Hematopoietic Stem Cell Transplantation/statistics & numerical data , Pregnancy Rate , Female , Fertility Preservation , Hematologic Neoplasms/therapy , Hematopoietic Stem Cell Transplantation/adverse effects , Hematopoietic Stem Cell Transplantation/methods , Humans , Pregnancy , Randomized Controlled Trials as TopicABSTRACT
Phleboviruses constitute a large group of arthropod-borne viruses (arboviruses), mainly transmitted to their hosts by sandflies and ticks, occasionally by mosquitoes. These viruses have a worldwide distribution and many cause serious diseases - often fatal - in both domestic animals and humans. The global warming, the apparent wide distribution of arthropod reservoirs, and the increasing number of outbreaks show that phleboviruses must be taken seriously as emerging disease agents. This review proposes to focus on the early steps of phlebovirus infection, from virus binding to penetration into the cytosol. We address the most recent knowledge and advances in the entry of these viruses into vertebrate host cells, including virus receptors, cellular factors, endocytic pathways, and fusion.
Subject(s)
Arboviruses , Phlebovirus , Psychodidae , Ticks , Animals , Animals, Domestic , HumansABSTRACT
Rift Valley fever virus (RVFV) is a mosquito-borne pathogen that represents a significant threat to both human and veterinary public health. Since its discovery in the Great Rift Valley of Kenya in the 1930s, the virus has spread across Africa and beyond, now posing a risk of introduction into Southern Europe and Asia. Despite recent progresses, early RVFV-host cell interactions remain largely uncharacterized. In this method chapter, we delineate the procedure for labeling RVFV particles with fluorescent organic dyes. This approach makes it feasible to visualize single viral particles in both fixed and living cells and study RVFV entry into host cells. We provide additional examples with two viruses closely related to RVFV, namely, Toscana virus and Uukuniemi virus. Furthermore, we illustrate how to utilize fluorescent viral particles to examine and quantify each step of the cell entry program of RVFV, which includes state-of-the-art fluorescence-based detection techniques such as fluorescence microscopy, flow cytometry, and fluorimetry.
Subject(s)
Fluorescent Dyes , Microscopy, Fluorescence , Rift Valley fever virus , Virion , Rift Valley fever virus/isolation & purification , Humans , Virion/isolation & purification , Animals , Fluorescent Dyes/chemistry , Microscopy, Fluorescence/methods , Flow Cytometry/methods , Virus Internalization , Rift Valley Fever/virology , Rift Valley Fever/diagnosis , Staining and Labeling/methods , Cell LineABSTRACT
BACKGROUND: The analysis of substrates of polymorphic cytochrome P450 (CYP) enzymes is important information to enable drug-drug interactions (DDIs) analysis and the relevance of pharmacogenetics in this context in large datasets. Our aim was to compare different approaches to assess the substrate properties of drugs for certain polymorphic CYP2 enzymes. METHODS: A standardized manual method and an automatic method were developed and compared to assess the substrate properties for the metabolism of drugs by CYP2D6, 2C9, and 2C19. The automatic method used a matching approach to three freely available resources. We applied the manual and automatic methods to a large real-world dataset deriving from a prospective multicenter study collecting adverse drug reactions in emergency departments in Germany (ADRED). RESULTS: In total, 23,878 medication entries relating to 895 different drugs were analyzed in the real-world dataset. The manual method was able to assess 12.2% (n = 109) of drugs, and the automatic method between 12.1% (n = 109) and 88.9% (n = 796), depending on the resource used. The CYP substrate classifications demonstrated moderate to almost perfect agreements for CYP2D6 and CYP2C19 (Cohen's Kappa (κ) 0.48-0.90) and fair to moderate agreements for CYP2C9 (κ 0.20-0.48). CONCLUSION: A closer look at different classifications between methods revealed that both methods are prone to error in different ways. While the automated method excels in time efficiency, completeness, and actuality, the manual method might be better able to identify CYP2 substrates with clinical relevance.
ABSTRACT
Neoadjuvant radiochemotherapy (RCT) and lately total neoadjuvant therapy (TNT) improved local recurrence rates of rectal cancer significantly compared to total mesorectal excision (TME) alone. Yet the occurrence and impact of late local recurrences after many years appears to be a distinct biological problem. We included n = 188 patients with rectal cancer after RCT and radical resection in this study; n = 38 of which had recurrent disease (sites: local (8.0%), liver (6.4%), lung (3.7%)). We found that 68% of all recurrences developed within the first two years. Four patients, however, experience recurrence >8 years after surgery. Here, we report and characterize four cases of late local recurrence (10% of patients with recurrent disease), suggesting that neoadjuvant therapy in principle delays local recurrence.