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Viruses May 2024The pathogenesis of viral infection is attributed to two folds: intrinsic cell death pathway activation due to the viral cytopathic effect, and immune-mediated extrinsic... (Review)
Review
The pathogenesis of viral infection is attributed to two folds: intrinsic cell death pathway activation due to the viral cytopathic effect, and immune-mediated extrinsic cellular injuries. The immune system, encompassing both innate and adaptive immunity, therefore acts as a double-edged sword in viral infection. Insufficient potency permits pathogens to establish lifelong persistent infection and its consequences, while excessive activation leads to organ damage beyond its mission to control viral pathogens. The innate immune response serves as the front line of defense against viral infection, which is triggered through the recognition of viral products, referred to as pathogen-associated molecular patterns (PAMPs), by host cell pattern recognition receptors (PRRs). The PRRs-PAMPs interaction results in the induction of interferon-stimulated genes (ISGs) in infected cells, as well as the secretion of interferons (IFNs), to establish a tissue-wide antiviral state in an autocrine and paracrine manner. Cumulative evidence suggests significant variability in the expression patterns of PRRs, the induction potency of ISGs and IFNs, and the IFN response across different cell types and species. Hence, in our understanding of viral hepatitis pathogenesis, insights gained through hepatoma cell lines or murine-based experimental systems are uncertain in precisely recapitulating the innate antiviral response of genuine human hepatocytes. Accordingly, this review article aims to extract and summarize evidence made possible with bona fide human hepatocytes-based study tools, along with their clinical relevance and implications, as well as to identify the remaining gaps in knowledge for future investigations.
Topics: Humans; Hepatitis D; Hepatitis Delta Virus; Hepatocytes; Host-Pathogen Interactions; Immunity, Innate; Interferons; Pathogen-Associated Molecular Pattern Molecules; Receptors, Pattern Recognition
PubMed: 38793622
DOI: 10.3390/v16050740 -
Viruses Apr 2024Chronic Hepatitis B and D Virus (HBV and HDV) co-infection is responsible for the most severe form of viral Hepatitis, the Hepatitis Delta. Despite an efficient vaccine... (Review)
Review
Chronic Hepatitis B and D Virus (HBV and HDV) co-infection is responsible for the most severe form of viral Hepatitis, the Hepatitis Delta. Despite an efficient vaccine against HBV, the HBV/HDV infection remains a global health burden. Notably, no efficient curative treatment exists against any of these viruses. While physiologically distinct, HBV and HDV life cycles are closely linked. HDV is a deficient virus that relies on HBV to fulfil is viral cycle. As a result, the cellular response to HDV also influences HBV replication. In vitro studying of HBV and HDV infection and co-infection rely on various cell culture models that differ greatly in terms of biological relevance and amenability to classical virology experiments. Here, we review the various cell culture models available to scientists to decipher HBV and HDV virology and host-pathogen interactions. We discuss their relevance and how they may help address the remaining questions, with one objective in mind: the development of new therapeutic approaches allowing viral clearance in patients.
Topics: Humans; Hepatitis Delta Virus; Hepatitis B virus; Hepatitis D; Virus Replication; Animals; Host-Pathogen Interactions; Coinfection; Cell Culture Techniques; Hepatitis B
PubMed: 38793598
DOI: 10.3390/v16050716 -
Molecular Therapy : the Journal of the... May 2024Sepsis-associated encephalopathy (SAE) is a frequent complication of severe systemic infection resulting in delirium, premature death, and long-term cognitive...
Sepsis-associated encephalopathy (SAE) is a frequent complication of severe systemic infection resulting in delirium, premature death, and long-term cognitive impairment. We closely mimicked SAE in a murine peritoneal contamination and infection (PCI) model. We found long-lasting synaptic pathology in the hippocampus including defective long-term synaptic plasticity, reduction of mature neuronal dendritic spines, and severely affected excitatory neurotransmission. Genes related to synaptic signaling, including the gene for activity-regulated cytoskeleton-associated protein (Arc/Arg3.1) and members of the transcription-regulatory EGR gene family, were downregulated. At the protein level, ARC expression and mitogen-activated protein kinase signaling in the brain were affected. For targeted rescue we used adeno-associated virus-mediated overexpression of ARC in the hippocampus in vivo. This recovered defective synaptic plasticity and improved memory dysfunction. Using the enriched environment paradigm as a non-invasive rescue intervention, we found improvement of defective long-term potentiation, memory, and anxiety. The beneficial effects of an enriched environment were accompanied by an increase in brain-derived neurotrophic factor (BDNF) and ARC expression in the hippocampus, suggesting that activation of the BDNF-TrkB pathway leads to restoration of the PCI-induced reduction of ARC. Collectively, our findings identify synaptic pathomechanisms underlying SAE and provide a conceptual approach to target SAE-induced synaptic dysfunction with potential therapeutic applications to patients with SAE.
PubMed: 38788710
DOI: 10.1016/j.ymthe.2024.05.001 -
Journal of Virology Jun 2024Obesity is well established as a risk factor for many noncommunicable diseases; however, its consequences for infectious disease are poorly understood. Here, we...
Obesity is well established as a risk factor for many noncommunicable diseases; however, its consequences for infectious disease are poorly understood. Here, we investigated the impact of host obesity on influenza A virus (IAV) genetic variation using a diet-induced obesity ferret model and the A/Hong Kong/1073/1999 (H9N2) strain. Using a co-caging study design, we investigated the maintenance, generation, and transmission of intrahost IAV genetic variation by sequencing viral genomic RNA obtained from nasal wash samples over multiple days of infection. We found evidence for an enhanced role of positive selection acting on mutations in obese hosts that led to nonsynonymous changes that rose to high frequency. In addition, we identified numerous cases of mutations throughout the genome that were specific to obese hosts and that were preserved during transmission between hosts. Despite detection of obese-specific variants, the overall viral genetic diversity did not differ significantly between obese and lean hosts. This is likely due to the high supply rate of variation and common evolutionary adaptations to the ferret host regardless of obesity status, which we show are mediated by variation in the hemagglutinin and polymerase genes (PB2 and PB1). We also identified defective viral genomes (DVGs) that were found uniquely in either obese or lean hosts, but the overall DVG diversity and dynamics did not differ between the two groups. Our study suggests that obesity may result in a unique selective environment impacting intrahost IAV evolution, highlighting the need for additional genetic and functional studies to confirm these effects.IMPORTANCEObesity is a chronic health condition characterized by excess adiposity leading to a systemic increase in inflammation and dysregulation of metabolic hormones and immune cell populations. Influenza A virus (IAV) is a highly infectious pathogen responsible for seasonal and pandemic influenza. Host risk factors, including compromised immunity and pre-existing health conditions, can contribute to increased infection susceptibility and disease severity. During viral replication in a host, the negative-sense single-stranded RNA genome of IAV accumulates genetic diversity that may have important consequences for viral evolution and transmission. Our study provides the first insight into the consequences of host obesity on viral genetic diversity and adaptation, suggesting that host factors associated with obesity alter the selective environment experienced by a viral population, thereby impacting the spectrum of genetic variation.
Topics: Animals; Obesity; Influenza A virus; Genetic Variation; Orthomyxoviridae Infections; Ferrets; Genome, Viral; Mutation; RNA, Viral; Disease Models, Animal
PubMed: 38785423
DOI: 10.1128/jvi.01778-23 -
Frontiers in Molecular Neuroscience 2024Chronic pain is common and inadequately treated, making the development of safe and effective analgesics a high priority. Our previous data indicate that carbonic...
Chronic pain is common and inadequately treated, making the development of safe and effective analgesics a high priority. Our previous data indicate that carbonic anhydrase-8 (CA8) expression in dorsal root ganglia (DRG) mediates analgesia via inhibition of neuronal ER inositol trisphosphate receptor-1 (ITPR1) via subsequent decrease in ER calcium release and reduction of cytoplasmic free calcium, essential to the regulation of neuronal excitability. This study tested the hypothesis that novel JDNI8 replication-defective herpes simplex-1 viral vectors (rdHSV) carrying a CA8 transgene (vHCA8) reduce primary afferent neuronal excitability. Whole-cell current clamp recordings in small DRG neurons showed that vHCA8 transduction caused prolongation of their afterhyperpolarization (AHP), an essential regulator of neuronal excitability. This AHP prolongation was completely reversed by the specific Kv7 channel inhibitor XE-991. Voltage clamp recordings indicate an effect via Kv7 channels in vHCA8-infected small DRG neurons. These data demonstrate for the first time that vHCA8 produces Kv7 channel activation, which decreases neuronal excitability in nociceptors. This suppression of excitability may translate as non-opioid dependent behavioral- or clinical analgesia, if proven behaviorally and clinically.
PubMed: 38783904
DOI: 10.3389/fnmol.2024.1398839 -
Nature Communications May 2024Human immunodeficiency virus type-1 (HIV-1) is responsible for significant mortality and morbidity worldwide. Despite complete control of viral replication with...
Human immunodeficiency virus type-1 (HIV-1) is responsible for significant mortality and morbidity worldwide. Despite complete control of viral replication with antiretrovirals, cells with integrated HIV-1 provirus can produce viral transcripts. In a cross-sectional study of 84 HIV+ individuals of whom 43 were followed longitudinally, we found that HIV-1 RNAs are present in extracellular vesicles (EVs) derived from cerebrospinal fluid and serum of all individuals. We used seven digital droplet polymerase chain reaction assays to evaluate the transcriptional status of the latent reservoir. EV-associated viral RNA was more abundant in the CSF and correlated with neurocognitive dysfunction in both, the cross-sectional and longitudinal studies. Sequencing studies suggested compartmentalization of defective viral transcripts in the serum and CSF. These findings suggest previous studies have underestimated the viral burden and there is a significant relationship between latent viral transcription and CNS complications of long-term disease despite the adequate use of antiretrovirals.
Topics: Humans; Extracellular Vesicles; HIV-1; RNA, Viral; Male; Cross-Sectional Studies; HIV Infections; Female; Adult; Middle Aged; Longitudinal Studies; Viral Load; Virus Latency; Neurocognitive Disorders
PubMed: 38782925
DOI: 10.1038/s41467-024-48644-z -
Current Opinion in Immunology Apr 2024The essential and redundant functions of human type I and II interferons (IFNs) have been delineated over the last three decades by studies of patients with inborn... (Review)
Review
The essential and redundant functions of human type I and II interferons (IFNs) have been delineated over the last three decades by studies of patients with inborn errors of immunity or their autoimmune phenocopies, but much less is known about type III IFNs. Patients with cells that do not respond to type III IFNs due to inherited IL10RB deficiency display no overt viral disease, and their inflammatory disease phenotypes can be explained by defective signaling via other interleukine10RB-dependent pathways. Moreover, patients with inherited deficiencies of interferon-stimulated gene factor 3 (ISGF-3) (STAT1, STAT2, IRF9) present viral diseases also seen in patients with inherited deficiencies of the type I IFN receptor (IFNAR1/2). Finally, patients with autoantibodies neutralizing type III IFNs have no obvious predisposition to viral disease. Current findings thus suggest that type III IFNs are largely redundant in humans. The essential functions of human type III IFNs, particularly in antiviral defenses, remain to be discovered.
Topics: Humans; Interferons; Interferon Lambda; Virus Diseases; Animals; Signal Transduction; STAT2 Transcription Factor; Interferon-Stimulated Gene Factor 3, gamma Subunit; STAT1 Transcription Factor; Interleukin-10 Receptor beta Subunit
PubMed: 38781720
DOI: 10.1016/j.coi.2024.102427 -
Journal of Clinical Virology : the... Aug 2024HDV antibody testing is recommended for universal screening and as the first line in an HDV double reflex testing strategy for effectively identifying patients with...
BACKGROUND
HDV antibody testing is recommended for universal screening and as the first line in an HDV double reflex testing strategy for effectively identifying patients with active infection for therapeutic treatments.
OBJECTIVE
The aim of this study is to evaluate the performance of a newly developed ARCHITECT HDV Total Ig (ARCHITECT HDV Ig) prototype assay.
STUDY DESIGN
Performance characteristics were determined for the ARCHITECT HDV Ig and a reference test, LIAISON XL Anti-HDV using a well-characterized specimen panel, comprising HDV RNA positive (n = 62) and negative (n = 70) samples, and healthy US blood donors.
RESULTS
Healthy US blood donors (n=200) showed 99.5% (199/200, 95%CI=97.65-99.98) specificity with ARCHITECT HDV Ig and 98.5 % (197/200, 95 %CI = 96.10-99.64) with LIAISON Anti-HDV. Among known HDV RNA positive samples, ARCHITECT HDV Ig detected 59/62 demonstrating 95.2 % sensitivity while LIAISON Anti-HDV sensitivity was 90.3 % (56/62). Among 101 HBV positive samples, 70 were reactive in the ARCHITECT test, 59 of which tested positive for HDV RNA for a positive predictive value (PPV) for the presence of HDV RNA was 84.3 %. For LIAISON Anti-HDV, 79 specimens were reactive and 56 contained HDV RNA: PPV for HDV RNA was 70.9 %. Among 70 HDV RNA negative samples, 39 were HBV positive. ARCHITECT HDV Ig negative predictive value (NPV) was 71.8 % and LIAISON Anti-HDV NPV was 41 % for the HBV positive group, respectively.
CONCLUSION
When compared to the LIASON Anti-HDV test, the ARCHITECT HDV Ig assay demonstrated enhanced sensitivity and specificity and better NPV and PPV values for HDV RNA status. The ARCHITECT HDV Ig assay represents a promising tool for universal screening of all HBsAg-positive persons.
Topics: Humans; Sensitivity and Specificity; Hepatitis D; Hepatitis Delta Virus; Hepatitis Antibodies; High-Throughput Screening Assays; Serologic Tests; Automation, Laboratory; Blood Donors
PubMed: 38781633
DOI: 10.1016/j.jcv.2024.105689 -
The Journal of General Virology May 2024Since its discovery in 1965, our understanding of the hepatitis B virus (HBV) replication cycle and host immune responses has increased markedly. In contrast, our... (Review)
Review
Since its discovery in 1965, our understanding of the hepatitis B virus (HBV) replication cycle and host immune responses has increased markedly. In contrast, our knowledge of the molecular biology of hepatitis delta virus (HDV), which is associated with more severe liver disease, is less well understood. Despite the progress made, critical gaps remain in our knowledge of HBV and HDV replication and the mechanisms underlying viral persistence and evasion of host immunity. The International HBV Meeting is the leading annual scientific meeting for presenting the latest advances in HBV and HDV molecular virology, immunology, and epidemiology. In 2023, the annual scientific meeting was held in Kobe, Japan and this review summarises some of the advances presented at the Meeting and lists gaps in our knowledge that may facilitate the development of new therapies.
Topics: Hepatitis B virus; Humans; Virus Replication; Hepatitis Delta Virus; Hepatitis B; Molecular Biology; Japan; Hepatitis D; Host-Pathogen Interactions
PubMed: 38757942
DOI: 10.1099/jgv.0.001978 -
Journal For Immunotherapy of Cancer May 2024Cancer-intrinsic type I interferon (IFN-I) production triggered by radiotherapy (RT) is mainly dependent on cytosolic double-stranded DNA (dsDNA)-mediated cGAS/STING...
BACKGROUND
Cancer-intrinsic type I interferon (IFN-I) production triggered by radiotherapy (RT) is mainly dependent on cytosolic double-stranded DNA (dsDNA)-mediated cGAS/STING signaling and increases cancer immunogenicity and enhances the antitumor immune response to increase therapeutic efficacy. However, cGAS/STING deficiency in colorectal cancer (CRC) may suppress the RT-induced antitumor immunity. Therefore, we aimed to evaluate the importance of the dsRNA-mediated antitumor immune response induced by RT in patients with CRC.
METHODS
Cytosolic dsRNA level and its sensors were evaluated via cell-based assays (co-culture assay, confocal microscopy, pharmacological inhibition and immunofluorescent staining) and in vivo experiments. Biopsies and surgical tissues from patients with CRC who received preoperative chemoradiotherapy (neoCRT) were collected for multiplex cytokine assays, immunohistochemical analysis and SNP genotyping. We also generated a cancer-specific adenovirus-associated virus (AAV)-IFNβ1 construct to evaluate its therapeutic efficacy in combination with RT, and the immune profiles were analyzed by flow cytometry and RNA-seq.
RESULTS
Our studies revealed that RT stimulates the autonomous release of dsRNA from cancer cells to activate TLR3-mediated IFN-I signatures to facilitate antitumor immune responses. Patients harboring a dysfunctional TLR3 variant had reduced serum levels of IFN-I-related cytokines and intratumoral CD8 immune cells and shorter disease-free survival following neoCRT treatment. The engineered cancer-targeted construct AAV-IFNβ1 significantly improved the response to RT, leading to systematic eradication of distant tumors and prolonged survival in defective TLR3 preclinical models.
CONCLUSION
Our results support that increasing cancer-intrinsic IFNβ1 expression is an immunotherapeutic strategy that enhances the RT-induced antitumor immune response in locally patients with advanced CRC with dysfunctional TLR3.
Topics: Humans; Colorectal Neoplasms; RNA, Double-Stranded; Interferon-beta; Mice; Animals; Interferon Type I; Signal Transduction; Female; Male
PubMed: 38749537
DOI: 10.1136/jitc-2023-008515