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Journal of Virology Sep 2023Bats carry genetically diverse severe acute respiratory syndrome-related coronaviruses (SARSr-CoVs). Some of them utilize human angiotensin-converting enzyme 2 (hACE2)...
Bats carry genetically diverse severe acute respiratory syndrome-related coronaviruses (SARSr-CoVs). Some of them utilize human angiotensin-converting enzyme 2 (hACE2) as a receptor and cannot efficiently replicate in wild-type mice. Our previous study demonstrated that the bat SARSr-CoV rRsSHC014S induces respiratory infection and lung damage in hACE2 transgenic mice but not wild-type mice. In this study, we generated a mouse-adapted strain of rRsSHC014S, which we named SMA1901, by serial passaging of wild-type virus in BALB/c mice. SMA1901 showed increased infectivity in mouse lungs and induced interstitial lung pneumonia in both young and aged mice after intranasal inoculation. Genome sequencing revealed mutations in not only the spike protein but the whole genome, which may be responsible for the enhanced pathogenicity of SMA1901 in wild-type BALB/c mice. SMA1901 induced age-related mortality similar to that observed in SARS and COVID-19. Drug testing using antibodies and antiviral molecules indicated that this mouse-adapted virus strain can be used to test prophylactic and therapeutic drug candidates against SARSr-CoVs. IMPORTANCE The genetic diversity of SARSr-CoVs in wildlife and their potential risk of cross-species infection highlights the importance of developing a powerful animal model to evaluate the antibodies and antiviral drugs. We acquired the mouse-adapted strain of a bat-origin coronavirus named SMA1901 by natural serial passaging of rRsSHC014S in BALB/c mice. The SMA1901 infection caused interstitial pneumonia and inflammatory immune responses in both young and aged BALB/c mice after intranasal inoculation. Our model exhibited age-related mortality similar to SARS and COVID-19. Therefore, our model will be of high value for investigating the pathogenesis of bat SARSr-CoVs and could serve as a prospective test platform for prophylactic and therapeutic candidates.
Topics: Animals; Mice; Chiroptera; Severe acute respiratory syndrome-related coronavirus; Mice, Inbred BALB C; COVID-19; Severe Acute Respiratory Syndrome; Serial Passage; Antiviral Agents; Antibodies, Viral; Viral Zoonoses; Lung Diseases, Interstitial; Aging; Drug Evaluation, Preclinical
PubMed: 37607058
DOI: 10.1128/jvi.00790-23 -
Nature Communications Aug 2023RIG-I-MAVS signaling pathway plays a crucial role in defending against pathogen infection and maintaining immune balance. Upon detecting viral RNA, RIG-I triggers the...
RIG-I-MAVS signaling pathway plays a crucial role in defending against pathogen infection and maintaining immune balance. Upon detecting viral RNA, RIG-I triggers the formation of prion-like aggregates of the adaptor protein MAVS, which then activates the innate antiviral immune response. However, the mechanisms that regulate the aggregation of MAVS are not yet fully understood. Here, we identified WDR77 as a MAVS-associated protein, which negatively regulates MAVS aggregation. WDR77 binds to MAVS proline-rich region through its WD2-WD3-WD4 domain and inhibits the formation of prion-like filament of recombinant MAVS in vitro. In response to virus infection, WDR77 is recruited to MAVS to prevent the formation of its prion-like aggregates and thus downregulate RIG-I-MAVS signaling in cells. WDR77 deficiency significantly potentiates the induction of antiviral genes upon negative-strand RNA virus infections, and myeloid-specific Wdr77-deficient mice are more resistant to RNA virus infection. Our findings reveal that WDR77 acts as a negative regulator of the RIG-I-MAVS signaling pathway by inhibiting the prion-like aggregation of MAVS to prevent harmful inflammation.
Topics: Animals; Mice; Adaptor Proteins, Signal Transducing; Antiviral Agents; Immunity, Innate; Prions; RNA Virus Infections; Signal Transduction
PubMed: 37563140
DOI: 10.1038/s41467-023-40567-5 -
Nature Communications Dec 2023Autophagy receptor NDP52 triggers bacterial autophagy against infection. However, the ability of NDP52 to protect against viral infection has not been established. We...
Autophagy receptor NDP52 triggers bacterial autophagy against infection. However, the ability of NDP52 to protect against viral infection has not been established. We show that NDP52 binds to envelope proteins of hepatitis B virus (HBV) and triggers a degradation process that promotes HBV clearance. Inactivating NDP52 in hepatocytes results in decreased targeting of viral envelopes in the lysosome and increased levels of viral replication. NDP52 inhibits HBV at both viral entry and late replication stages. In contrast to NDP52-mediated bacterial autophagy, lysosomal degradation of HBV envelopes is independent of galectin 8 and ATG5. NDP52 forms complex with Rab9 and viral envelope proteins and links HBV to Rab9-dependent lysosomal degradation pathway. These findings reveal that NDP52 acts as a sensor for HBV infection, which mediates a unique antiviral response to eliminate the virus. This work also suggests direct roles for autophagy receptors in other lysosomal degradation pathways than canonical autophagy.
Topics: Humans; Hepatitis B virus; Hepatitis B; Hepatocytes; Autophagy; Lysosomes; Antiviral Agents; Virus Replication
PubMed: 38114531
DOI: 10.1038/s41467-023-44201-2 -
Single-cell atlas of the liver myeloid compartment before and after cure of chronic viral hepatitis.Journal of Hepatology Feb 2024Chronic viral infections present serious public health challenges; however, direct-acting antivirals (DAAs) are now able to cure nearly all patients infected with...
BACKGROUND & AIMS
Chronic viral infections present serious public health challenges; however, direct-acting antivirals (DAAs) are now able to cure nearly all patients infected with hepatitis C virus (HCV), representing the only cure of a human chronic viral infection to date. DAAs provide a valuable opportunity to study immune pathways in the reversal of chronic immune failures in an in vivo human system.
METHODS
To leverage this opportunity, we used plate-based single-cell RNA-seq to deeply profile myeloid cells from liver fine needle aspirates in patients with HCV before and after DAA treatment. We comprehensively characterised liver neutrophils, eosinophils, mast cells, conventional dendritic cells, plasmacytoid dendritic cells, classical monocytes, non-classical monocytes, and macrophages, and defined fine-grained subpopulations of several cell types.
RESULTS
We discovered cell type-specific changes post-cure, including an increase in MCM7+STMN1+ proliferating CD1C+ conventional dendritic cells, which may support restoration from chronic exhaustion. We observed an expected downregulation of interferon-stimulated genes (ISGs) post-cure as well as an unexpected inverse relationship between pre-treatment viral load and post-cure ISG expression in each cell type, revealing a link between viral loads and sustained modifications of the host's immune system. We found an upregulation of PD-L1/L2 gene expression in ISG-high neutrophils and IDO1 expression in eosinophils, pinpointing cell subpopulations crucial for immune regulation. We identified three recurring gene programmes shared by multiple cell types, distilling core functions of the myeloid compartment.
CONCLUSIONS
This comprehensive single-cell RNA-seq atlas of human liver myeloid cells in response to cure of chronic viral infections reveals principles of liver immunity and provides immunotherapeutic insights.
CLINICAL TRIAL REGISTRATION
This study is registered at ClinicalTrials.gov (NCT02476617).
IMPACT AND IMPLICATIONS
Chronic viral liver infections continue to be a major public health problem. Single-cell characterisation of liver immune cells during hepatitis C and post-cure provides unique insights into the architecture of liver immunity contributing to the resolution of the first curable chronic viral infection of humans. Multiple layers of innate immune regulation during chronic infections and persistent immune modifications after cure are revealed. Researchers and clinicians may leverage these findings to develop methods to optimise the post-cure environment for HCV and develop novel therapeutic approaches for other chronic viral infections.
Topics: Humans; Antiviral Agents; Persistent Infection; Hepatitis C, Chronic; Hepatitis C; Hepacivirus
PubMed: 36972796
DOI: 10.1016/j.jhep.2023.02.040 -
Journal of Veterinary Science Jan 2024Canine parvoviral enteritis (CPE) is a fatal disease worldwide. The treatment of CPE is based mainly on supportive and symptomatic treatment. Antiviral addition to the...
BACKGROUND
Canine parvoviral enteritis (CPE) is a fatal disease worldwide. The treatment of CPE is based mainly on supportive and symptomatic treatment. Antiviral addition to the treatment may result in a higher survival.
OBJECTIVES
This study evaluated the effects of antiviral treatments with a standardized treatment (ST) on the clinical and inflammatory response of dogs with naturally occurring CPE.
METHODS
Twenty-eight dogs with CPE caused by canine parvovirus type 2 were divided randomly into treatment groups. The ST group received fluid, antibiotic, antiemetic, and deworming treatments. The antiviral treatment groups received the same ST with an additional antiviral drug, recombinant feline interferon omega (rFeIFN-ω), oseltamivir (OSEL) or famciclovir (FAM).
RESULTS
Compared to the healthy control, the tumor necrosis factor-α, interleukin-1β, interferon (IFN)-α, IFN-γ, haptoglobin, and C-reactive protein values were high ( < 0.05) on day zero. At presentation, mild lymphopenia, neutropenia, and a high neutrophil to lymphocyte (LYM) ratio (NLR) were also observed. Adding rFeIFN-ω to the ST produced the best improvement in the clinical score with a decreased NLR, while leucocytes remained low and inflammatory markers stayed high on day three. The survival rates of the groups were 85.7% in ST+IFN, 71.4% in ST+OSEL, 71.4% in ST+FAM, and 57.1% in ST groups on day seven.
CONCLUSIONS
Antiviral drugs may be valuable in treating CPE to improve the clinical signs and survival. In addition, the decrease in NLR in favor of LYM may be an indicator of the early prognosis before the improvement of leukocytes, cytokines, and acute phase proteins in CPE.
Topics: Animals; Dogs; Cats; Parvoviridae Infections; Parvovirus, Canine; Oseltamivir; Antiviral Agents; Enteritis; Dog Diseases; Cat Diseases
PubMed: 38311324
DOI: 10.4142/jvs.23139 -
Nature Communications Dec 2023Modified vaccinia Ankara (MVA) virus does not replicate in human cells and is the vaccine deployed to curb the current outbreak of mpox. Here, we conduct a multiplexed...
Modified vaccinia Ankara (MVA) virus does not replicate in human cells and is the vaccine deployed to curb the current outbreak of mpox. Here, we conduct a multiplexed proteomic analysis to quantify >9000 cellular and ~80% of viral proteins throughout MVA infection of human fibroblasts and macrophages. >690 human proteins are down-regulated >2-fold by MVA, revealing a substantial remodelling of the host proteome. >25% of these MVA targets are not shared with replication-competent vaccinia. Viral intermediate/late gene expression is necessary for MVA antagonism of innate immunity, and suppression of interferon effectors such as ISG20 potentiates virus gene expression. Proteomic changes specific to infection of macrophages indicate modulation of the inflammatory response, including inflammasome activation. Our approach thus provides a global view of the impact of MVA on the human proteome and identifies mechanisms that may underpin its abortive infection. These discoveries will prove vital to design future generations of vaccines.
Topics: Humans; Vaccinia; Proteome; Proteomics; Vaccinia virus; Cell Death; Antiviral Agents
PubMed: 38065956
DOI: 10.1038/s41467-023-43299-8 -
Cells Dec 2023Cellular nucleocytoplasmic trafficking is mediated by the importin family of nuclear transport proteins. The well-characterized importin alpha (IMPA) and importin beta... (Review)
Review
Cellular nucleocytoplasmic trafficking is mediated by the importin family of nuclear transport proteins. The well-characterized importin alpha (IMPA) and importin beta (IMPB) nuclear import pathway plays a crucial role in the innate immune response to viral infection by mediating the nuclear import of transcription factors such as IRF3, NFκB, and STAT1. The nuclear transport of these transcription factors ultimately leads to the upregulation of a wide range of antiviral genes, including IFN and IFN-stimulated genes (ISGs). To replicate efficiently in cells, viruses have developed mechanisms to block these signaling pathways. One strategy to evade host innate immune responses involves blocking the nuclear import of host antiviral transcription factors. By binding IMPA proteins, these viral proteins prevent the nuclear transport of key transcription factors and suppress the induction of antiviral gene expression. In this review, we describe examples of proteins encoded by viruses from several different families that utilize such a competitive inhibition strategy to suppress the induction of antiviral gene expression.
Topics: Active Transport, Cell Nucleus; alpha Karyopherins; Immunity, Innate; Antiviral Agents; Organophosphorus Compounds
PubMed: 38201275
DOI: 10.3390/cells13010071 -
JAMA Network Open Sep 2023Some payers and clinicians require alcohol abstinence to receive direct-acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) infection.
IMPORTANCE
Some payers and clinicians require alcohol abstinence to receive direct-acting antiviral (DAA) therapy for chronic hepatitis C virus (HCV) infection.
OBJECTIVE
To evaluate whether alcohol use at DAA treatment initiation is associated with decreased likelihood of sustained virologic response (SVR).
DESIGN, SETTING, AND PARTICIPANTS
This retrospective cohort study used electronic health records from the US Department of Veterans Affairs (VA), the largest integrated national health care system that provides unrestricted access to HCV treatment. Participants included all patients born between 1945 and 1965 who were dispensed DAA therapy between January 1, 2014, and June 30, 2018. Data analysis was completed in November 2020 with updated sensitivity analyses performed in 2023.
EXPOSURE
Alcohol use categories were generated using responses to the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) questionnaire and International Classification of Diseases, Ninth Revision and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnoses for alcohol use disorder (AUD): abstinent without history of AUD, abstinent with history of AUD, lower-risk consumption, moderate-risk consumption, and high-risk consumption or AUD.
MAIN OUTCOMES AND MEASURES
The primary outcome was SVR, which was defined as undetectable HCV RNA for 12 weeks or longer after completion of DAA therapy. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% CIs of SVR associated with alcohol category.
RESULTS
Among 69 229 patients who initiated DAA therapy (mean [SD] age, 62.6 [4.5] years; 67 150 men [97.0%]; 34 655 non-Hispanic White individuals [50.1%]; 28 094 non-Hispanic Black individuals [40.6%]; 58 477 individuals [84.5%] with HCV genotype 1), 65 355 (94.4%) achieved SVR. A total of 32 290 individuals (46.6%) were abstinent without AUD, 9192 (13.3%) were abstinent with AUD, 13 415 (19.4%) had lower-risk consumption, 3117 (4.5%) had moderate-risk consumption, and 11 215 (16.2%) had high-risk consumption or AUD. After adjustment for potential confounding variables, there was no difference in SVR across alcohol use categories, even for patients with high-risk consumption or AUD (OR, 0.95; 95% CI, 0.85-1.07). There was no evidence of interaction by stage of hepatic fibrosis measured by fibrosis-4 score (P for interaction = .30).
CONCLUSIONS AND RELEVANCE
In this cohort study, alcohol use and AUD were not associated with lower odds of SVR. Restricting access to DAA therapy according to alcohol use creates an unnecessary barrier to patients and challenges HCV elimination goals.
Topics: United States; Male; Humans; Middle Aged; Hepacivirus; Antiviral Agents; Alcoholism; Hepatitis C, Chronic; Sustained Virologic Response; Cohort Studies; Retrospective Studies; Hepatitis C
PubMed: 37751206
DOI: 10.1001/jamanetworkopen.2023.35715 -
Nature Communications Nov 2023The underlying mechanism of chronic hepatitis B virus (HBV) functional cure by interferon (IFN), especially in patients with low HBsAg and/or young ages, is still...
The underlying mechanism of chronic hepatitis B virus (HBV) functional cure by interferon (IFN), especially in patients with low HBsAg and/or young ages, is still unresolved due to the lack of surrogate models. Here, we generate a type I interferon receptor humanized mouse (huIFNAR mouse) through a CRISPR/Cas9-based knock-in strategy. Then, we demonstrate that human IFN stimulates gene expression profiles in huIFNAR peripheral blood mononuclear cells (PBMCs) are similar to those in human PBMCs, supporting the representativeness of this mouse model for functionally analyzing human IFN in vivo. Next, we reveal the tissue-specific gene expression atlas across multiple organs in response to human IFN treatment; this pattern has not been reported in healthy humans in vivo. Finally, by using the AAV-HBV model, we test the antiviral effects of human interferon. Fifteen weeks of human PEG-IFNα2 treatment significantly reduces HBsAg and HBeAg and even achieves HBsAg seroconversion. We observe that activation of intrahepatic monocytes and effector memory CD8 T cells by human interferon may be critical for HBsAg suppression. Our huIFNAR mouse can authentically respond to human interferon stimulation, providing a platform to study interferon function in vivo. PEG-IFNα2 treatment successfully suppresses intrahepatic HBV replication and achieves HBsAg seroconversion.
Topics: Humans; Mice; Animals; Hepatitis B virus; Hepatitis B, Chronic; Hepatitis B Surface Antigens; Antiviral Agents; Interferon-alpha; Leukocytes, Mononuclear; Hepatitis B; Recombinant Proteins; Polyethylene Glycols; DNA, Viral; Treatment Outcome
PubMed: 37968364
DOI: 10.1038/s41467-023-43078-5 -
Biochemical Society Transactions Jun 2023Interferons (IFNs) are crucial components of the cellular innate immune response to viral infections. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)... (Review)
Review
Interferons (IFNs) are crucial components of the cellular innate immune response to viral infections. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has shown a remarkable capacity to suppress the host IFN production to benefit viral replication and spread. Thus far, of the 28 known virus-encoded proteins, 16 have been found to impair the host's innate immune system at various levels ranging from detection and signaling to transcriptional and post-transcriptional regulation of expression of the components of the cellular antiviral response. Additionally, there is evidence that the viral genome encodes non-protein-coding microRNA-like elements that could also target IFN-stimulated genes. In this brief review, we summarise the current state of knowledge regarding the factors and mechanisms by which SARS-CoV-2 impairs the production of IFNs and thereby dampens the host's innate antiviral immune response.
Topics: Humans; SARS-CoV-2; COVID-19; Cell Line; Interferons; Antiviral Agents; Immunity, Innate; Viral Proteins
PubMed: 37199495
DOI: 10.1042/BST20221037