Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 289
Filter
1.
PLoS Pathog ; 18(1): e1010219, 2022 01.
Article in English | MEDLINE | ID: covidwho-2197167

ABSTRACT

Excessive inflammation is a major cause of morbidity and mortality in many viral infections including influenza. Therefore, there is a need for therapeutic interventions that dampen and redirect inflammatory responses and, ideally, exert antiviral effects. Itaconate is an immunomodulatory metabolite which also reprograms cell metabolism and inflammatory responses when applied exogenously. We evaluated effects of endogenous itaconate and exogenous application of itaconate and its variants dimethyl- and 4-octyl-itaconate (DI, 4OI) on host responses to influenza A virus (IAV). Infection induced expression of ACOD1, the enzyme catalyzing itaconate synthesis, in monocytes and macrophages, which correlated with viral replication and was abrogated by DI and 4OI treatment. In IAV-infected mice, pulmonary inflammation and weight loss were greater in Acod1-/- than in wild-type mice, and DI treatment reduced pulmonary inflammation and mortality. The compounds reversed infection-triggered interferon responses and modulated inflammation in human cells supporting non-productive and productive infection, in peripheral blood mononuclear cells, and in human lung tissue. All three itaconates reduced ROS levels and STAT1 phosphorylation, whereas AKT phosphorylation was reduced by 4OI and DI but increased by itaconate. Single-cell RNA sequencing identified monocytes as the main target of infection and the exclusive source of ACOD1 mRNA in peripheral blood. DI treatment silenced IFN-responses predominantly in monocytes, but also in lymphocytes and natural killer cells. Ectopic synthesis of itaconate in A549 cells, which do not physiologically express ACOD1, reduced infection-driven inflammation, and DI reduced IAV- and IFNγ-induced CXCL10 expression in murine macrophages independent of the presence of endogenous ACOD1. The compounds differed greatly in their effects on cellular gene homeostasis and released cytokines/chemokines, but all three markedly reduced release of the pro-inflammatory chemokines CXCL10 (IP-10) and CCL2 (MCP-1). Viral replication did not increase under treatment despite the dramatically repressed IFN responses. In fact, 4OI strongly inhibited viral transcription in peripheral blood mononuclear cells, and the compounds reduced viral titers (4OI>Ita>DI) in A549 cells whereas viral transcription was unaffected. Taken together, these results reveal itaconates as immunomodulatory and antiviral interventions for influenza virus infection.


Subject(s)
Influenza A virus/immunology , Macrophages/immunology , Orthomyxoviridae Infections/drug therapy , Succinates/pharmacology , A549 Cells , Animals , Carboxy-Lyases/deficiency , Carboxy-Lyases/immunology , Cytokines/genetics , Cytokines/immunology , Humans , Macrophages/virology , Mice , Mice, Knockout , Orthomyxoviridae Infections/genetics , Orthomyxoviridae Infections/immunology , THP-1 Cells
2.
Viruses ; 14(11)2022 Oct 31.
Article in English | MEDLINE | ID: covidwho-2113143

ABSTRACT

This study aimed to analyze the genetic and evolutionary characteristics of the influenza A/H3N2 viruses circulating in Myanmar from 2015 to 2019. Whole genomes from 79 virus isolates were amplified using real-time polymerase chain reaction and successfully sequenced using the Illumina iSeq100 platforms. Eight individual phylogenetic trees were retrieved for each segment along with those of the World Health Organization (WHO)-recommended Southern Hemisphere vaccine strains for the respective years. Based on the WHO clades classification, the A/H3N2 strains in Myanmar from 2015 to 2019 collectively belonged to clade 3c.2. These strains were further defined based on hemagglutinin substitutions as follows: clade 3C.2a (n = 39), 3C.2a1 (n = 2), and 3C.2a1b (n = 38). Genetic analysis revealed that the Myanmar strains differed from the Southern Hemisphere vaccine strains each year, indicating that the vaccine strains did not match the circulating strains. The highest rates of nucleotide substitution were estimated for hemagglutinin (3.37 × 10-3 substitutions/site/year) and neuraminidase (2.89 × 10-3 substitutions/site/year). The lowest rate was for non-structural protein segments (4.19 × 10-5 substitutions/site/year). The substantial genetic diversity that was revealed improved phylogenetic classification. This information will be particularly relevant for improving vaccine strain selection.


Subject(s)
Influenza A virus , Influenza Vaccines , Influenza, Human , Humans , Influenza, Human/prevention & control , Influenza A Virus, H3N2 Subtype/genetics , Influenza A virus/genetics , Hemagglutinin Glycoproteins, Influenza Virus/genetics , Hemagglutinins , Phylogeny , Myanmar/epidemiology , Sequence Analysis, DNA , Seasons
3.
J Virol ; 96(22): e0134122, 2022 Nov 23.
Article in English | MEDLINE | ID: covidwho-2097919

ABSTRACT

We observed the interference between two prevalent respiratory viruses, respiratory syncytial virus (RSV) and influenza A virus (IAV) (H1N1), and characterized its molecular underpinnings in alveolar epithelial cells (A549). We found that RSV induces higher levels of interferon beta (IFN-ß) production than IAV and that IFN-ß priming confers higher-level protection against infection with IAV than with RSV. Consequently, we focused on the sequential infection scheme of RSV and then IAV. Using A549 wild-type (WT), IFNAR1 knockout (KO), IFNLR1 KO, and IFNAR1-IFNLR1 double-KO cell lines, we found that both IFN-ß and IFN-λ are necessary for maximum protection against subsequent infection. Immunostaining revealed that preinfection with RSV partitions the cell population into a subpopulation susceptible to subsequent infection with IAV and an IAV-proof subpopulation. Strikingly, the susceptible cells turned out to be those already compromised and efficiently expressing RSV, whereas the bystander, interferon-primed cells are resistant to IAV infection. Thus, virus-virus exclusion at the cell population level is not realized through direct competition for a shared ecological niche (single cell) but rather is achieved with the involvement of specific cytokines induced by the host's innate immune response. IMPORTANCE Influenza A virus (IAV) and respiratory syncytial virus (RSV) are common recurrent respiratory infectants that show a relatively high coincidence. We demonstrated that preinfection with RSV partitions the cell population into a subpopulation susceptible to subsequent infection with IAV and an IAV-proof subpopulation. The susceptible cells are those already compromised and efficiently expressing RSV, whereas the bystander cells are resistant to IAV infection. The cross-protective effect critically depends on IFN-ß and IFN-λ signaling and thus ensues when the proportion of cells preinfected with RSV is relatively low yet sufficient to trigger a pervasive antiviral state in bystander cells. Our study suggests that mild, but not severe, respiratory infections may have a short-lasting protective role against more dangerous respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).


Subject(s)
COVID-19 , Influenza A Virus, H1N1 Subtype , Influenza A virus , Influenza, Human , Respiratory Syncytial Virus, Human , Humans , SARS-CoV-2 , Interferons/metabolism
4.
MMWR Morb Mortal Wkly Rep ; 71(43): 1353-1358, 2022 Oct 28.
Article in English | MEDLINE | ID: covidwho-2091065

ABSTRACT

The COVID-19 pandemic has affected influenza virus transmission, with historically low activity, atypical timing, or altered duration of influenza seasons during 2020-22 (1,2). Community mitigation measures implemented since 2020, including physical distancing and face mask use, have, in part, been credited for low influenza detections globally during the pandemic, compared with those during prepandemic seasons (1). Reduced population exposure to natural influenza infections during 2020-21 and relaxed community mitigation measures after introduction of COVID-19 vaccines could increase the possibility of severe influenza epidemics. Partners in Chile and the United States assessed Southern Hemisphere influenza activity and estimated age-group-specific rates of influenza-attributable hospitalizations and vaccine effectiveness (VE) in Chile in 2022. Chile's most recent influenza season began in January 2022, which was earlier than during prepandemic seasons and was associated predominantly with influenza A(H3N2) virus, clade 3C.2a1b.2a.2. The cumulative incidence of influenza-attributable pneumonia and influenza (P&I) hospitalizations was 5.1 per 100,000 person-years during 2022, which was higher than that during 2020-21 but lower than incidence during the 2017-19 influenza seasons. Adjusted VE against influenza A(H3N2)-associated hospitalization was 49%. These findings indicate that influenza activity continues to be disrupted after emergence of SARS-CoV-2 in 2020. Northern Hemisphere countries might benefit from preparing for an atypical influenza season, which could include early influenza activity with potentially severe disease during the 2022-23 season, especially in the absence of prevention measures, including vaccination. Health authorities should encourage all eligible persons to seek influenza vaccination and take precautions to reduce transmission of influenza (e.g., avoiding close contact with persons who are ill).


Subject(s)
COVID-19 , Influenza A virus , Influenza Vaccines , Influenza, Human , United States , Humans , Influenza, Human/epidemiology , Influenza, Human/prevention & control , Seasons , Influenza A Virus, H3N2 Subtype/genetics , Incidence , Pandemics/prevention & control , COVID-19 Vaccines , Chile/epidemiology , Vaccine Efficacy , SARS-CoV-2 , Vaccination , Influenza B virus
5.
Signal Transduct Target Ther ; 7(1): 367, 2022 10 17.
Article in English | MEDLINE | ID: covidwho-2077027

ABSTRACT

The biosynthesis of host lipids and/or lipid droplets (LDs) has been studied extensively as a putative therapeutic target in diverse viral infections. However, directly targeting the LD lipolytic catabolism in virus-infected cells has not been widely investigated. Here, we show the linkage of the LD-associated lipase activation to the breakdown of LDs for the generation of free fatty acids (FFAs) at the late stage of diverse RNA viral infections, which represents a broad-spectrum antiviral target. Dysfunction of membrane transporter systems due to virus-induced cell injury results in intracellular malnutrition at the late stage of infection, thereby making the virus more dependent on the FFAs generated from LD storage for viral morphogenesis and as a source of energy. The replication of SARS-CoV-2 and influenza A virus (IAV), which is suppressed by the treatment with LD-associated lipases inhibitors, is rescued by supplementation with FFAs. The administration of lipase inhibitors, either individually or in a combination with virus-targeting drugs, protects mice from lethal IAV infection and mitigates severe lung lesions in SARS-CoV-2-infected hamsters. Moreover, the lipase inhibitors significantly reduce proinflammatory cytokine levels in the lungs of SARS-CoV-2- and IAV-challenged animals, a cause of a cytokine storm important for the critical infection or mortality of COVID-19 and IAV patients. In conclusion, the results reveal that lipase-mediated intracellular LD lipolysis is commonly exploited to facilitate RNA virus replication and furthermore suggest that pharmacological inhibitors of LD-associated lipases could be used to curb current COVID-19- and future pandemic outbreaks of potentially troublesome RNA virus infection in humans.


Subject(s)
COVID-19 , Lipolysis , Orthomyxoviridae Infections , Animals , Humans , Mice , Antiviral Agents/pharmacology , COVID-19/drug therapy , Cytokines , Fatty Acids, Nonesterified , Influenza A virus , Lipase , Membrane Transport Proteins , RNA , SARS-CoV-2 , Orthomyxoviridae Infections/drug therapy
6.
Lancet ; 400(10353): 693-706, 2022 08 27.
Article in English | MEDLINE | ID: covidwho-2076865

ABSTRACT

Annual seasonal influenza epidemics of variable severity caused by influenza A and B virus infections result in substantial disease burden worldwide. Seasonal influenza virus circulation declined markedly in 2020-21 after SARS-CoV-2 emerged but increased in 2021-22. Most people with influenza have abrupt onset of respiratory symptoms and myalgia with or without fever and recover within 1 week, but some can experience severe or fatal complications. Prevention is primarily by annual influenza vaccination, with efforts underway to develop new vaccines with improved effectiveness. Sporadic zoonotic infections with novel influenza A viruses of avian or swine origin continue to pose pandemic threats. In this Seminar, we discuss updates of key influenza issues for clinicians, in particular epidemiology, virology, and pathogenesis, diagnostic testing including multiplex assays that detect influenza viruses and SARS-CoV-2, complications, antiviral treatment, influenza vaccines, infection prevention, and non-pharmaceutical interventions, and highlight gaps in clinical management and priorities for clinical research.


Subject(s)
COVID-19 , Influenza A virus , Influenza Vaccines , Influenza, Human , Animals , Humans , SARS-CoV-2 , Swine
7.
Virology ; 576: 105-110, 2022 11.
Article in English | MEDLINE | ID: covidwho-2061964

ABSTRACT

As SARS-CoV-2 and influenza viruses co-circulate, co-infections with these viruses generate an increasing concern to public health. To evaluate the prevalence and clinical impacts of SARS-CoV-2 and influenza A virus co-infections during the 2021-2022 influenza season, SARS-CoV-2-positive samples from 462 individuals were collected from October 2021 to January 2022. Of these individuals, 152 tested positive for influenza, and the monthly co-infection rate ranged from 7.1% to 48%. Compared to the Delta variant, individuals infected with Omicron were less likely to be co-infected and hospitalized, and individuals who received influenza vaccines were less likely to become co-infected. Three individuals had two samples collected on different dates, and all three developed a co-infection after their initial SARS-CoV-2 infection. This study demonstrates high prevalence of co-infections in central Missouri during the 2021-2022 influenza season, differences in co-infection prevalence between the Delta and the Omicron waves, and the importance of influenza vaccinations against co-infections.


Subject(s)
COVID-19 , Coinfection , Influenza A virus , Influenza Vaccines , Influenza, Human , Humans , Influenza, Human/epidemiology , SARS-CoV-2 , Coinfection/epidemiology , Cross-Sectional Studies , Seasons , Missouri/epidemiology , COVID-19/epidemiology , Influenza A virus/genetics
8.
Sci Adv ; 8(38): eabm6668, 2022 09 23.
Article in English | MEDLINE | ID: covidwho-2053083

ABSTRACT

Viruses exploit host cell machinery to support their replication. Defining the cellular proteins and processes required for a virus during infection is crucial to understanding the mechanisms of virally induced disease and designing host-directed therapeutics. Here, we perform a genome-wide CRISPR-Cas9-based screening in lung epithelial cells infected with the PR/8/NS1-GFP virus and use GFPhi cell as a unique screening marker to identify host factors that inhibit influenza A virus (IAV) infection. We discovered that APOE affects influenza virus infection both in vitro and in vivo. Cell deficiency in APOE conferred substantially increased susceptibility to IAV; mice deficient in APOE manifested more severe lung pathology, increased virus load, and decreased survival rate. Mechanistically, lack of cell-produced APOE results in impaired cell cholesterol homeostasis, enhancing influenza virus attachment. Thus, we identified a previously unrecognized role of APOE in restraining IAV infection.


Subject(s)
Communicable Diseases , Influenza A virus , Influenza, Human , Orthomyxoviridae Infections , Animals , Apolipoproteins , Apolipoproteins E/genetics , Cholesterol , Host-Pathogen Interactions , Humans , Influenza, Human/genetics , Mice , Orthomyxoviridae Infections/genetics , Virus Replication
9.
Transbound Emerg Dis ; 69(5): e1445-e1459, 2022 Sep.
Article in English | MEDLINE | ID: covidwho-2052989

ABSTRACT

The Mexican lineage H5N2 low pathogenic avian influenza viruses (LPAIVs) were first detected in 1994 and mutated to highly pathogenic avian influenza viruses (HPAIVs) in 1994-1995 causing widespread outbreaks in poultry. By using vaccination and other control measures, the HPAIVs were eradicated but the LPAIVs continued circulating in Mexico and spread to several other countries. To get better resolution of the phylogenetics of this virus, the full genome sequences of 44 H5N2 LPAIVs isolated from 1994 to 2011, and 6 detected in 2017 and 2019, were analysed. Phylogenetic incongruence demonstrated genetic reassortment between two separate groups of the Mexican lineage H5N2 viruses between 2005 and 2010. Moreover, the recent H5N2 viruses reassorted with previously unidentified avian influenza viruses. Bayesian phylogeographic results suggested that mechanical transmission involving human activity is the most probable cause of the virus spillover to Central American, Caribbean, and East Asian countries. Increased infectivity and transmission of a 2011 H5N2 LPAIV in chickens compared to a 1994 virus demonstrates improved adaptation to chickens, while low virus shedding, and limited contact transmission was observed in mallards with the same 2011 virus. The sporadic increase in basic amino acids in the HA cleavage site, changes in potential N-glycosylation sites in the HA, and truncations of PB1-F2 should be further examined in relation to the increased infectivity and transmission in poultry. The genetic changes that occur as this lineage of H5N2 LPAIVs continues circulating in poultry is concerning not only because of the effect of these changes on vaccination efficacy, but also because of the potential of the viruses to mutate to the highly pathogenic form. Continued vigilance and surveillance efforts, and the pathogenic and genetic characterization of circulating viruses, are required for the effective control of this virus.


Subject(s)
Influenza A Virus, H5N2 Subtype , Influenza A virus , Influenza in Birds , Amino Acids, Basic/genetics , Animals , Bayes Theorem , Chickens , Humans , Influenza A Virus, H5N2 Subtype/genetics , Influenza A virus/genetics , Mexico/epidemiology , Phylogeny , Poultry
10.
Infect Genet Evol ; 104: 105356, 2022 10.
Article in English | MEDLINE | ID: covidwho-2036365

ABSTRACT

An H3N1 avian influenza virus was detected in a laying hens farm in May 2019 which had experienced 25% mortality in Northern France. The complete sequencing of this virus showed that all segment sequences belonged to the Eurasian lineage and were phylogenetically very close to many of the Belgian H3N1 viruses detected in 2019. The French virus presented two genetic particularities with NA and NS deletions that could be related to virus adaptation from wild to domestic birds and could increase virulence, respectively. Molecular data of H3N1 viruses suggest that these two deletions occurred at two different times.


Subject(s)
Influenza A virus , Influenza in Birds , Animals , Chickens , Female , Influenza A virus/genetics , Phylogeny
11.
Curr Opin Immunol ; 78: 102252, 2022 Oct.
Article in English | MEDLINE | ID: covidwho-2031214

ABSTRACT

The outbreak of the COVID-19 pandemic one year after the centennial of the 1918 influenza pandemic reaffirms the catastrophic impact respiratory viruses can have on global health and economy. A key feature of SARS-CoV-2 and influenza A viruses (IAV) is their remarkable ability to suppress or dysregulate human immune responses. Here, we summarize the growing knowledge about the interplay of SARS-CoV-2 and antiviral innate immunity, with an emphasis on the regulation of type-I or -III interferon responses that are critically implicated in COVID-19 pathogenesis. Furthermore, we draw parallels to IAV infection and discuss shared innate immune sensing mechanisms and the respective viral countermeasures.


Subject(s)
COVID-19 , Influenza, Human , Interferons , SARS-CoV-2 , Humans , COVID-19/immunology , COVID-19/metabolism , COVID-19/virology , Immunity, Innate , Influenza A virus/immunology , Influenza, Human/immunology , Influenza, Human/metabolism , Influenza, Human/virology , Interferons/immunology , Pandemics , SARS-CoV-2/immunology
12.
PLoS One ; 17(9): e0274222, 2022.
Article in English | MEDLINE | ID: covidwho-2021957

ABSTRACT

INTRODUCTION: Using respiratory virus rapid diagnostic tests in the emergency department could allow better and faster clinical management. Point-of-care PCR instruments now provide results in less than 30 minutes. The objective of this study was to assess the impact of the use of a rapid molecular diagnostic test, the cobas® Influenza A/B & RSV Assay, during the clinical management of emergency department patients. METHODS: Patients (adults and children) requiring admission or suffering from an underlying condition at risk of respiratory complications were prospectively recruited in the emergency department of four hospitals in the Brussels region. Physicians' intentions regarding admission, isolation, antibiotic, and antiviral use were collected before and after performing the rapid molecular test. Additionally, a comparison of the analytical performance of this test against antigen rapid tests and viral culture was performed as well as a time-to-result evaluation. RESULTS: Among the 293 patients recruited, 90 had a positive PCR, whereas 44 had a positive antigen test. PCR yielded a sensitivity of 100% for all targets. Antigen tests yielded sensitivities ranging from 66.7% for influenza B to 83.3% for respiratory syncytial virus (RSV). The use of PCR allowed a decrease in the overall need for isolation and treatment by limiting the isolation of negative patients and antibiotic use for positive patients. Meanwhile, antiviral treatments better targeted patients with a positive influenza PCR. CONCLUSION: The use of a rapid influenza and RSV molecular test improves the clinical management of patients admitted to the emergency department by providing a fast and reliable result. Their additional cost compared to antigen tests should be balanced with the benefit of their analytical performance, leading to efficient reductions in the need for isolation and antibiotic use.


Subject(s)
Herpesvirus 1, Cercopithecine , Influenza A virus , Influenza, Human , Respiratory Syncytial Virus Infections , Respiratory Syncytial Virus, Human , Adult , Anti-Bacterial Agents/therapeutic use , Antiviral Agents , Child , Emergency Service, Hospital , Humans , Influenza A virus/genetics , Influenza B virus/genetics , Influenza, Human/diagnosis , Respiratory Syncytial Virus Infections/diagnosis , Respiratory Syncytial Virus, Human/genetics , Sensitivity and Specificity
13.
Vaccine ; 40(38): 5569-5578, 2022 09 09.
Article in English | MEDLINE | ID: covidwho-2016159

ABSTRACT

Alphavirus-derived RNA replicon particle (RP) vaccines represent the next generation of swine influenza A virus (IAV) vaccines, as they were shown to be safe, effective, and offer advantages over traditional vaccine platforms. IAV is a significant respiratory pathogen of swine and there is a critical need to improve current commercial swine IAV vaccine platforms. Adjuvanted whole inactivated virus (WIV) IAV swine vaccines provide limited heterologous protection and may lead to vaccine-associated enhanced respiratory disease (VAERD). This study investigated the ability of RP IAV hemagglutinin (HA) vaccines to avoid VAERD and evaluated experimental multivalent HA and neuraminidase (NA) RP vaccines. RP vaccines were formulated with HA or NA heterologous or homologous to the challenge virus in monovalent HA or HA and NA bivalent combinations (HA/NA bivalent). Pigs were vaccinated with an HA RP, HA/NA bivalent RP, or heterologous HA WIV, followed by IAV challenge and necropsy 5 days post infection. RP vaccines provided homologous protection from challenge and induced robust peripheral and local antibody responses. The RP vaccine did not induce VAERD after challenge with a virus containing the heterologous HA, in contrast to the traditional WIV vaccine. The HA monovalent and HA/NA bivalent RP vaccines showed superior protection compared to traditional WIV. Additionally, the RP platform allows greater flexibility to adjust HA and NA content to reflect circulating IAV in swine antigenic diversity.


Subject(s)
Influenza A virus , Influenza Vaccines , Influenza, Human , Orthomyxoviridae Infections , Respiratory Tract Diseases , Swine Diseases , Animals , Antibodies, Viral , Hemagglutinins , Humans , Neuraminidase/genetics , Replicon , Swine
14.
Vet Med Sci ; 8(5): 1982-1992, 2022 09.
Article in English | MEDLINE | ID: covidwho-2007117

ABSTRACT

BACKGROUND: Pigs are unique reservoirs for virus ecology. Despite the increased use of improved biosecurity measures, pig viruses readily circulate in Chinese swine farms. OBJECTIVES: The main objective of this study was to examine archived swine oral secretion samples with a panel of pan-species viral assays such that we might better describe the viral ecology of swine endemic viruses in Chinese farms. METHODOLOGY: Two hundred (n = 200) swine oral secretion samples, collected during 2015 and 2016 from healthy pigs on six swine farms in two provinces in China, were screened with molecular pan-species assays for coronaviruses (CoVs), adenoviruses (AdVs), enteroviruses (EVs), and paramyxoviruses (PMV). Samples were also screened for porcine circovirus (PCV) 3, porcine reproductive and respiratory syndrome virus (PRRSV) and influenza A virus (IAV). RESULTS: Among 200 swine oral secretion samples, 152 (76.0%) were found to have at least one viral detection. Thirty-four samples (17%) were positive for more than one virus, including 24 (70.5%) with dual detection and 10 (29.5%) with triple detection. Seventy-eight (39.0%) samples were positive for porcine AdVs, 22 (11.0%) were positive for porcine CoVs, 21 (10.5%) were positive for IAVs, 13 (6.5%) were positive for PCV, 7 (3.5%) were positive for PMV, six (3.0%) were positive for PRRSV and five (2.5%) were positive for porcine EV. CONCLUSION: Our findings underscore the high prevalence of numerous viruses among production pigs in China and highlight the need for routine, periodic surveillance for novel virus emergence with the goal of protecting pigs.


Subject(s)
Circovirus , Influenza A virus , Porcine Reproductive and Respiratory Syndrome , Porcine respiratory and reproductive syndrome virus , Swine Diseases , Animals , Porcine Reproductive and Respiratory Syndrome/epidemiology , Swine
15.
J Appl Microbiol ; 133(6): 3534-3545, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-2001658

ABSTRACT

INTRODUCTION: Quantitative reverse transcription PCR (RT-qPCR) is the leading tool to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Given that it will almost certainly continue to coexist with other respiratory viruses in the coming years, our study aimed to design a multiplex PCR system not affected by supplier outages and with reduced cost compared to the existing commercially available kits. METHODS AND RESULTS: In this study, combinations of four primers/probe sets were used to construct a flexible RT-qPCR assay which is capable of discriminating between SARS-CoV-2 and the seasonal human coronavirus HCoV-OC43, or even influenza A virus. Additionally, the human RPP30 gene was used as an internal control. To demonstrate the robustness of the assay, it was applied to a collection of 150 clinical samples. The results showed 100% sensitivity and specificity compared to the automatized system used at the hospital and were better when indeterminate samples were analysed. CONCLUSIONS: This study provides an efficient method for the simultaneous detection of SARS-CoV-2, HCoV-OC43 and influenza A virus, and its efficacy has been tested on clinical samples showing outstanding results. SIGNIFICANCE AND IMPACT OF THE STUDY: The multiplex RT-qPCR design offers an accessible and economical alternative to commercial detection kits for hospitals and laboratories with limited economic resources or facing situations of supply shortage.


Subject(s)
COVID-19 , Influenza A virus , Humans , SARS-CoV-2/genetics , Multiplex Polymerase Chain Reaction/methods , Influenza A virus/genetics , COVID-19/diagnosis , Sensitivity and Specificity , Nasopharynx
16.
Proc Natl Acad Sci U S A ; 119(37): e2210321119, 2022 09 13.
Article in English | MEDLINE | ID: covidwho-2001009

ABSTRACT

Long noncoding RNAs (lncRNAs) have emerged as critical regulators of gene expression, yet their contribution to immune regulation in humans remains poorly understood. Here, we report that the primate-specific lncRNA CHROMR is induced by influenza A virus and SARS-CoV-2 infection and coordinates the expression of interferon-stimulated genes (ISGs) that execute antiviral responses. CHROMR depletion in human macrophages reduces histone acetylation at regulatory regions of ISG loci and attenuates ISG expression in response to microbial stimuli. Mechanistically, we show that CHROMR sequesters the interferon regulatory factor (IRF)-2-dependent transcriptional corepressor IRF2BP2, thereby licensing IRF-dependent signaling and transcription of the ISG network. Consequently, CHROMR expression is essential to restrict viral infection of macrophages. Our findings identify CHROMR as a key arbitrator of antiviral innate immune signaling in humans.


Subject(s)
COVID-19 , DNA-Binding Proteins , Immunity, Innate , Influenza A virus , Influenza, Human , RNA, Long Noncoding , SARS-CoV-2 , Transcription Factors , COVID-19/genetics , COVID-19/immunology , DNA-Binding Proteins/metabolism , Humans , Immunity, Innate/genetics , Influenza A virus/immunology , Influenza, Human/genetics , Influenza, Human/immunology , Interferon Regulatory Factors/genetics , Interferon Regulatory Factors/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/physiology , SARS-CoV-2/immunology , Transcription Factors/metabolism
17.
Emerg Microbes Infect ; 11(1): 2160-2175, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-1997031

ABSTRACT

Pandemic outbreaks of viruses such as influenza virus or SARS-CoV-2 are associated with high morbidity and mortality and thus pose a massive threat to global health and economics. Physiologically relevant models are needed to study the viral life cycle, describe the pathophysiological consequences of viral infection, and explore possible drug targets and treatment options. While simple cell culture-based models do not reflect the tissue environment and systemic responses, animal models are linked with huge direct and indirect costs and ethical questions. Ex vivo platforms based on tissue explants have been introduced as suitable platforms to bridge the gap between cell culture and animal models. We established a murine lung tissue explant platform for two respiratory viruses, influenza A virus (IAV) and SARS-CoV-2. We observed efficient viral replication, associated with the release of inflammatory cytokines and the induction of an antiviral interferon response, comparable to ex vivo infection in human lung explants. Endolysosomal entry could be confirmed as a potential host target for pharmacological intervention, and the potential repurposing potentials of fluoxetine and interferons for host-directed therapy previously seen in vitro could be recapitulated in the ex vivo model.


Subject(s)
COVID-19 , Lung , Orthomyxoviridae Infections , Animals , Antiviral Agents/pharmacology , COVID-19/pathology , Fluoxetine/pharmacology , Humans , Influenza A virus/physiology , Influenza, Human/pathology , Interferons , Lung/virology , Mice , Orthomyxoviridae Infections/pathology , SARS-CoV-2/physiology , Tissue Culture Techniques , Virus Replication
18.
Infect Genet Evol ; 104: 105355, 2022 10.
Article in English | MEDLINE | ID: covidwho-1996425

ABSTRACT

The rampant spread of highly pathogenic avian influenza A (H5N6) virus has drawn additional concerns along with ongoing Covid-19 pandemic. Due to its migration-related diffusion, the situation is deteriorating. Without an existing effective therapy and vaccines, it will be baffling to take control measures. In this regard, we propose a revers vaccinology approach for prediction and design of a multi-epitope peptide based vaccine. The induction of humoral and cell-mediated immunity seems to be the paramount concern for a peptide vaccine candidate; thus, antigenic B and T cell epitopes were screened from the surface, membrane and envelope proteins of the avian influenza A (H5N6) virus, and passed through several immunological filters to determine the best possible one. Following that, the selected antigenic with immunogenic epitopes and adjuvant were linked to finalize the multi-epitope-based peptide vaccine by appropriate linkers. For the prediction of an effective binding, molecular docking was carried out between the vaccine and immunological receptors (TLR8). Strong binding affinity and good docking scores clarified the stringency of the vaccines. Furthermore, molecular dynamics simulation was performed within the highest binding affinity complex to observe the stability, and minimize the designed vaccine's high mobility region to order to increase its stability. Then, Codon optimization and other physicochemical properties were performed to reveal that the vaccine would be suitable for a higher expression at cloning level and satisfactory thermostability condition. In conclusion, predicting the overall in silico assessment, we anticipated that our designed vaccine would be a plausible prevention against avian influenza A (H5N6) virus.


Subject(s)
COVID-19 , Influenza A virus , Influenza in Birds , Influenza, Human , Animals , Computational Biology , Epitopes, B-Lymphocyte , Epitopes, T-Lymphocyte , Humans , Influenza A virus/genetics , Influenza in Birds/prevention & control , Influenza, Human/prevention & control , Molecular Docking Simulation , Pandemics , Peptides , Toll-Like Receptor 8 , Vaccines, Subunit
19.
Commun Biol ; 5(1): 810, 2022 08 12.
Article in English | MEDLINE | ID: covidwho-1991681

ABSTRACT

There is a critical need for physiologically relevant, robust, and ready-to-use in vitro cellular assay platforms to rapidly model the infectivity of emerging viruses and develop new antiviral treatments. Here we describe the cellular complexity of human alveolar and tracheobronchial air liquid interface (ALI) tissue models during SARS-CoV-2 and influenza A virus (IAV) infections. Our results showed that both SARS-CoV-2 and IAV effectively infect these ALI tissues, with SARS-CoV-2 exhibiting a slower replication peaking at later time-points compared to IAV. We detected tissue-specific chemokine and cytokine storms in response to viral infection, including well-defined biomarkers in severe SARS-CoV-2 and IAV infections such as CXCL10, IL-6, and IL-10. Our single-cell RNA sequencing analysis showed similar findings to that found in vivo for SARS-CoV-2 infection, including dampened IFN response, increased chemokine induction, and inhibition of MHC Class I presentation not observed for IAV infected tissues. Finally, we demonstrate the pharmacological validity of these ALI tissue models as antiviral drug screening assay platforms, with the potential to be easily adapted to include other cell types and increase the throughput to test relevant pathogens.


Subject(s)
COVID-19 , Influenza A virus , Influenza, Human , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , COVID-19/drug therapy , Chemokines , Epithelium , Humans , Influenza A virus/physiology , Influenza, Human/drug therapy , Lung , SARS-CoV-2 , Virus Replication
20.
Nat Med ; 28(9): 1944-1955, 2022 09.
Article in English | MEDLINE | ID: covidwho-1991643

ABSTRACT

Influenza A virus's (IAV's) frequent genetic changes challenge vaccine strategies and engender resistance to current drugs. We sought to identify conserved and essential RNA secondary structures within IAV's genome that are predicted to have greater constraints on mutation in response to therapeutic targeting. We identified and genetically validated an RNA structure (packaging stem-loop 2 (PSL2)) that mediates in vitro packaging and in vivo disease and is conserved across all known IAV isolates. A PSL2-targeting locked nucleic acid (LNA), administered 3 d after, or 14 d before, a lethal IAV inoculum provided 100% survival in mice, led to the development of strong immunity to rechallenge with a tenfold lethal inoculum, evaded attempts to select for resistance and retained full potency against neuraminidase inhibitor-resistant virus. Use of an analogous approach to target SARS-CoV-2, prophylactic administration of LNAs specific for highly conserved RNA structures in the viral genome, protected hamsters from efficient transmission of the SARS-CoV-2 USA_WA1/2020 variant. These findings highlight the potential applicability of this approach to any virus of interest via a process we term 'programmable antivirals', with implications for antiviral prophylaxis and post-exposure therapy.


Subject(s)
COVID-19 , Influenza A virus , Animals , Antiviral Agents/pharmacology , COVID-19/drug therapy , Influenza A virus/genetics , Mice , Neuraminidase , RNA, Viral/genetics , SARS-CoV-2
SELECTION OF CITATIONS
SEARCH DETAIL