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1.
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
2.
J Virol ; 96(15): e0076522, 2022 08 10.
Article in English | MEDLINE | ID: covidwho-1992938

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A virus (IAV) represent two highly transmissible airborne pathogens with pandemic capabilities. Although these viruses belong to separate virus families-SARS-CoV-2 is a member of the family Coronaviridae, while IAV is a member of the family Orthomyxoviridae-both have shown zoonotic potential, with significant animal reservoirs in species in close contact with humans. The two viruses are similar in their capacity to infect human airways, and coinfections resulting in significant morbidity and mortality have been documented. Here, we investigate the interaction between SARS-CoV-2 USA-WA1/2020 and influenza H1N1 A/California/04/2009 virus during coinfection. Competition assays in vitro were performed in susceptible cells that were either interferon type I/III (IFN-I/-III) nonresponsive or IFN-I/-III responsive, in addition to an in vivo golden hamster model. We find that SARS-CoV-2 infection does not interfere with IAV biology in vivo, regardless of timing between the infections. In contrast, we observe a significant loss of SARS-CoV-2 replication following IAV infection. The latter phenotype correlates with increased levels of IFN-I/-III and immune priming that interferes with the kinetics of SARS-CoV-2 replication. Together, these data suggest that cocirculation of SARS-CoV-2 and IAV is unlikely to result in increased severity of disease. IMPORTANCE The human population now has two circulating respiratory RNA viruses with high pandemic potential, namely, SARS-CoV-2 and influenza A virus. As both viruses infect the airways and can result in significant morbidity and mortality, it is imperative that we also understand the consequences of getting coinfected. Here, we demonstrate that the host response to influenza A virus uniquely interferes with SARS-CoV-2 biology although the inverse relationship is not evident. Overall, we find that the host response to both viruses is comparable to that to SARS-CoV-2 infection alone.


Subject(s)
COVID-19 , Coinfection , Cross-Priming , Influenza A Virus, H1N1 Subtype , Influenza, Human , SARS-CoV-2 , Virus Replication , Animals , COVID-19/immunology , COVID-19/mortality , COVID-19/virology , Coinfection/immunology , Coinfection/virology , Cross-Priming/immunology , Humans , Influenza A Virus, H1N1 Subtype/immunology , Influenza, Human/immunology , Influenza, Human/virology , Interferons/immunology , Mesocricetus/immunology , Mesocricetus/virology , SARS-CoV-2/growth & development , SARS-CoV-2/immunology , Virus Replication/immunology
3.
PLoS One ; 17(7): e0270814, 2022.
Article in English | MEDLINE | ID: covidwho-1919122

ABSTRACT

INTRODUCTION: Influenza A virus infection is a contagious acute respiratory infection which mostly evolves in an epidemic form, less frequently as pandemic outbreaks. It can take a severe clinical form that needs to be managed in intensive care unit (ICU). The aim of this study was to describe the epidemiological and clinical aspects of influenza A, then to determine independent predictive factors of ICU mortality in Abderrahmen Mami hospital, Ariana, Tunisia. METHODS: It was a single-center study, including all hospitalized patients in intensive care, between November 1st, 2009 and October 31st, 2019, with influenza A virus infection. We recorded demographic, clinical and biological data, evolving features; then multivariate analysis of the predictive factors of ICU mortality was realized. RESULTS: During the study period (10 consecutive seasons), 120 patients having severe Influenza A were admitted (Proportion = 2.5%) from all hospitalized patients, with a median age of 48 years and a gender-ratio of 1.14. Among women, 14 were pregnant. Only 7 patients (5.8%) have had seasonal flu vaccine during the year before ICU admission. The median values of the Simplified Acute Physiology Score II, Acute Physiologic and Chronic Health Evaluation II and Sepsis-related Organ Failure Assessment were respectively 26, 10 and 3. Virus strains identified with polymerase chain reaction were H1N1 pdm09 (84.2%) and H3N2 (15.8%). Antiviral therapy was prescribed in 88 (73.3%) patients. A co-infection was recorded in 19 cases: bacterial (n = 17) and aspergillaire (n = 2). An acute respiratory distress syndrome (ARDS) was diagnosed in 82 patients. Non-invasive ventilation (NIV) was conducted for 72 (60%) patients with success in 34 cases. Endotracheal intubation was performed in 59 patients with median duration of invasive mechanical ventilation 8 [3.25-13] days. The most frequent complications were acute kidney injury (n = 50, 41.7%), shock (n = 48, 40%), hospital-acquired infections (n = 46, 38.8%) and thromboembolic events (n = 19, 15.8%). The overall ICU mortality rate was of 31.7% (deceased n = 38). Independent predictive factors of ICU mortality identified were: age above 56 years (OR = 7.417; IC95% [1.474-37.317]; p = 0.015), PaO2/FiO2 ≤ 95 mmHg (OR = 9.078; IC95% [1.636-50.363]; p = 0.012) and lymphocytes count ≤ 1.325 109/L (OR = 10.199; IC95% [1.550-67.101]; p = 0.016). CONCLUSION: Influenza A in ICU is not uncommon, even in A(H1N1) dominant seasons; its management is highly demanding. It is responsible for considerable morbi-mortality especially in elderly patients.


Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza A Virus, H3N2 Subtype , Influenza, Human , Aged , Female , Hospital Mortality , Humans , Influenza, Human/epidemiology , Influenza, Human/mortality , Influenza, Human/therapy , Influenza, Human/virology , Intensive Care Units , Male , Middle Aged , Noninvasive Ventilation , Patient Acuity , Pregnancy , Risk Factors , Tunisia/epidemiology
4.
Int J Infect Dis ; 121: 195-202, 2022 Aug.
Article in English | MEDLINE | ID: covidwho-1851259

ABSTRACT

OBJECTIVES: Because of the spread of the Omicron variant, many countries have experienced COVID-19 case numbers unseen since the start of the pandemic. We aimed to compare the epidemiological characteristics of Omicron with previous variants and different strains of influenza to provide context for public health responses. METHODS: We developed transmission models for SARS-CoV-2 variants and influenza, in which transmission, death, and vaccination rates were taken to be time-varying. We fit our model based on publicly available data in South Africa, the United States, and Canada. We used this model to evaluate the relative transmissibility and mortality of Omicron compared with previous variants and influenza. RESULTS: We found that Omicron is more transmissible and less fatal than both seasonal and 2009 H1N1 influenza and the Delta variant; these characteristics make Omicron epidemiologically more similar to influenza than it is to Delta. We estimate that as of February 7, 2022, booster doses have prevented 4.29×107 and 1.14×106 Omicron infections in the United States and Canada, respectively. CONCLUSION: Our findings indicate that the high infectivity of Omicron will keep COVID-19 endemic, similar to influenza. However, because of Omicron's lower fatality rate, our work suggests that human populations living with SARS-CoV-2 are most likely.


Subject(s)
COVID-19 , Influenza A Virus, H1N1 Subtype , Influenza, Human , Mutation , SARS-CoV-2 , COVID-19/epidemiology , COVID-19/virology , Humans , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H1N1 Subtype/pathogenicity , Influenza, Human/prevention & control , Influenza, Human/virology , SARS-CoV-2/genetics , SARS-CoV-2/pathogenicity , United States/epidemiology
5.
PLoS One ; 17(1): e0262258, 2022.
Article in English | MEDLINE | ID: covidwho-1841144

ABSTRACT

Although patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A, influenza B and respiratory syncytial virus (RSV) show comparable or very similar manifestations, the therapeutic approaches of these respiratory viral infections are different, which requires an accurate diagnosis. Recently, the novel multiplex real-time reverse transcription-polymerase chain reaction assay AMPLIQUICK® Respiratory Triplex (BioSynex SA, Illkirch-Graffenstaden, France) allows simultaneous detection and differentiation of SARS-CoV-2, influenza A, influenza B, and RSV in respiratory tract samples. We herein evaluated the performance of the AMPLIQUICK® Respiratory Triplex for the detection of the four viruses in respiratory specimens, using Allplex™ Respiratory Panel 1 and 2019-nCoV assays (Seegene, Seoul, Korea) as reference comparator assays. A total of 359 archived predetermined respiratory samples, including 83, 145, 19 and 95 positive specimens for SARS-CoV-2, influenza A, influenza B and RSV respectively, were included. The AMPLIQUICK® Respiratory Triplex showed high concordance with the reference assays, with an overall agreement for SARS-CoV-2, influenza A, influenza B, and RSV at 97.6%, 98.8%, 98.3% and 100.0%, respectively, and high κ values ranging from 0.93 to 1.00, indicating an almost perfect agreement between assays. Furthermore, high correlations of cycle threshold (Ct) values were observed for positive samples of the four viruses between the AMPLIQUICK® Respiratory Triplex and comparator assays, with an overall high agreement between Ct values assessed by Bland-Altman analyses. In conclusion, these observations demonstrate that the multiplex AMPLIQUICK® Respiratory Triplex is a reliable assay for the qualitative detection and differentiation of SARS-CoV-2, influenza A, influenza B, and RSV in respiratory specimens, which may prove useful for streamlining diagnostics during the winter influenza-seasons.


Subject(s)
COVID-19/diagnosis , Influenza, Human/diagnosis , Multiplex Polymerase Chain Reaction/methods , Real-Time Polymerase Chain Reaction/methods , Respiratory Syncytial Virus Infections/diagnosis , COVID-19/virology , Humans , Influenza, Human/virology , Molecular Diagnostic Techniques , Nasopharynx/virology , Respiratory Syncytial Virus Infections/virology , Retrospective Studies , Sensitivity and Specificity
7.
Pediatr Infect Dis J ; 41(4): e146-e148, 2022 04 01.
Article in English | MEDLINE | ID: covidwho-1706949

ABSTRACT

Respiratory viruses were detected by multiplex-polymerase chain reaction from oropharyngeal swabs in 114/168 (67.9%) children with acute respiratory infection presenting to 5 pediatric practices in Germany between November 2020 and April 2021. In contrast to rhino- (48.8%), adeno- (14.3%) and endemic coronaviruses (14.9%), SARS-CoV-2 and influenza virus were detected only once; respiratory syncytial virus was not detected. This demonstrates differing impacts of pandemic infection control measures on the spread of respiratory viruses.


Subject(s)
Primary Health Care , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/etiology , Virus Diseases/epidemiology , Virus Diseases/etiology , Adolescent , COVID-19/epidemiology , COVID-19/virology , Child , Child, Preschool , Disease Susceptibility , Female , Humans , Incidence , Infant , Infant, Newborn , Influenza, Human/epidemiology , Influenza, Human/virology , Male , Pandemics , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus Infections/virology , Respiratory Tract Infections/diagnosis , Respiratory Tract Infections/therapy , SARS-CoV-2 , Virus Diseases/diagnosis , Virus Diseases/therapy
8.
Int J Mol Sci ; 23(5)2022 Feb 23.
Article in English | MEDLINE | ID: covidwho-1700574

ABSTRACT

Influenza A virus (IAV) is a member of the single-stranded RNA (ssRNA) family of viruses. The most recent global pandemic caused by the SARS-CoV-2 virus has shown the major threat that RNA viruses can pose to humanity. In comparison, influenza has an even higher pandemic potential as a result of its high rate of mutations within its relatively short (<13 kbp) genome, as well as its capability to undergo genetic reassortment. In light of this threat, and the fact that RNA structure is connected to a broad range of known biological functions, deeper investigation of viral RNA (vRNA) structures is of high interest. Here, for the first time, we propose a secondary structure for segment 8 vRNA (vRNA8) of A/California/04/2009 (H1N1) formed in the presence of cellular and viral components. This structure shows similarities with prior in vitro experiments. Additionally, we determined the location of several well-defined, conserved structural motifs of vRNA8 within IAV strains with possible functionality. These RNA motifs appear to fold independently of regional nucleoprotein (NP)-binding affinity, but a low or uneven distribution of NP in each motif region is noted. This research also highlights several accessible sites for oligonucleotide tools and small molecules in vRNA8 in a cellular environment that might be a target for influenza A virus inhibition on the RNA level.


Subject(s)
Gene Expression Regulation, Viral , Genome, Viral/genetics , Influenza A Virus, H1N1 Subtype/genetics , Nucleic Acid Conformation , RNA, Viral/chemistry , Animals , Base Sequence , Dogs , Humans , Influenza A Virus, H1N1 Subtype/metabolism , Influenza, Human/virology , Madin Darby Canine Kidney Cells , Models, Molecular , Nucleotide Motifs/genetics , RNA Folding , RNA, Viral/genetics , Viral Proteins/genetics , Viral Proteins/metabolism
9.
J Virol ; 95(24): e0117421, 2021 11 23.
Article in English | MEDLINE | ID: covidwho-1691429

ABSTRACT

Defective interfering particles (DIPs) of influenza A virus (IAV) are naturally occurring mutants that have an internal deletion in one of their eight viral RNA (vRNA) segments, rendering them propagation-incompetent. Upon coinfection with infectious standard virus (STV), DIPs interfere with STV replication through competitive inhibition. Thus, DIPs are proposed as potent antivirals for treatment of the influenza disease. To select corresponding candidates, we studied de novo generation of DIPs and propagation competition between different defective interfering (DI) vRNAs in an STV coinfection scenario in cell culture. A small-scale two-stage cultivation system that allows long-term semi-continuous propagation of IAV and its DIPs was used. Strong periodic oscillations in virus titers were observed due to the dynamic interaction of DIPs and STVs. Using next-generation sequencing, we detected a predominant formation and accumulation of DI vRNAs on the polymerase-encoding segments. Short DI vRNAs accumulated to higher fractions than longer ones, indicating a replication advantage, yet an optimum fragment length was observed. Some DI vRNAs showed breaking points in a specific part of their bundling signal (belonging to the packaging signal), suggesting its dispensability for DI vRNA propagation. Over a total cultivation time of 21 days, several individual DI vRNAs accumulated to high fractions, while others decreased. Using reverse genetics for IAV, purely clonal DIPs derived from highly replicating DI vRNAs were generated. We confirm that these DIPs exhibit a superior in vitro interfering efficacy compared to DIPs derived from lowly accumulated DI vRNAs and suggest promising candidates for efficacious antiviral treatment. IMPORTANCE Defective interfering particles (DIPs) emerge naturally during viral infection and typically show an internal deletion in the viral genome. Thus, DIPs are propagation-incompetent. Previous research suggests DIPs as potent antiviral compounds for many different virus families due to their ability to interfere with virus replication by competitive inhibition. For instance, the administration of influenza A virus (IAV) DIPs resulted in a rescue of mice from an otherwise lethal IAV dose. Moreover, no apparent toxic effects were observed when only DIPs were administered to mice and ferrets. IAV DIPs show antiviral activity against many different IAV strains, including pandemic and highly pathogenic avian strains, and even against nonhomologous viruses, such as SARS-CoV-2, by stimulation of innate immunity. Here, we used a cultivation/infection system, which exerted selection pressure toward accumulation of highly competitive IAV DIPs. These DIPs showed a superior interfering efficacy in vitro, and we suggest them for effective antiviral therapy.


Subject(s)
Antiviral Agents/pharmacology , Drug Design/methods , Influenza A virus , Influenza, Human/virology , RNA, Viral , Animals , Cell Culture Techniques , Cell Line , Defective Viruses/genetics , Dogs , Gene Deletion , Genome, Viral , Humans , Immunity, Innate/drug effects , Madin Darby Canine Kidney Cells , Oscillometry , Real-Time Polymerase Chain Reaction , Viral Load/drug effects , Virus Replication/drug effects
10.
J Virol ; 96(3): e0192821, 2022 02 09.
Article in English | MEDLINE | ID: covidwho-1691422

ABSTRACT

From 2014 to week 07/2020 the Centre for Health Protection in Hong Kong conducted screening for influenza C virus (ICV). A retrospective analysis of ICV detections to week 26/2019 revealed persistent low-level circulation with outbreaks occurring biennially in the winters of 2015 to 2016 and 2017 to 2018 (R. S. Daniels et al., J Virol 94:e01051-20, 2020, https://doi.org/10.1128/JVI.01051-20). Here, we report on an outbreak occurring in 2019 to 2020, reinforcing the observation of biennial seasonality in Hong Kong. All three outbreaks occurred in similar time frames, were subsequently dwarfed by seasonal epidemics of influenza types A and B, and were caused by similar proportions of C/Kanagawa/1/76 (K)-lineage and C/São Paulo/378/82 S1- and S2-sublineage viruses. Ongoing genetic drift was observed in all genes, with some evidence of amino acid substitution in the hemagglutinin-esterase-fusion (HEF) glycoprotein possibly associated with antigenic drift. A total of 61 ICV genomes covering the three outbreaks were analyzed for reassortment, and 9 different reassortant constellations were identified, 1 K-lineage, 4 S1-sublineage, and 4 S2-sublineage, with 6 of these being identified first in the 2019-1920 outbreak (2 S2-lineage and 4 S1-lineage). The roles that virus interference/enhancement, ICV persistent infection, genome evolution, and reassortment might play in the observed seasonality of ICV in Hong Kong are discussed. IMPORTANCE Influenza C virus (ICV) infection of humans is common, with the great majority of people being infected during childhood, though reinfection can occur throughout life. While infection normally results in "cold-like" symptoms, severe disease cases have been reported in recent years. However, knowledge of ICV is limited due to poor systematic surveillance and an inability to propagate the virus in large amounts in the laboratory. Following recent systematic surveillance in Hong Kong SAR, China, and direct ICV gene sequencing from clinical specimens, a 2-year cycle of disease outbreaks (epidemics) has been identified, with gene mixing playing a significant role in ICV evolution. Studies like those reported here are key to developing an understanding of the impact of influenza C virus infection in humans, notably where comorbidities exist and severe respiratory disease can develop.


Subject(s)
Disease Outbreaks , Influenza, Human/epidemiology , Influenza, Human/virology , Influenzavirus C/classification , Influenzavirus C/genetics , Reassortant Viruses , Hemagglutinins, Viral/chemistry , Hemagglutinins, Viral/genetics , Hong Kong/epidemiology , Humans , Models, Molecular , Mutation , Phylogeny , Public Health Surveillance , Sequence Analysis, DNA , Structure-Activity Relationship , Viral Fusion Proteins/chemistry , Viral Fusion Proteins/genetics
11.
J Med Virol ; 93(8): 4748-4755, 2021 08.
Article in English | MEDLINE | ID: covidwho-1610624

ABSTRACT

Respiratory infections are one of the most frequent reasons for medical consultations in children. In low resource settings such as in Lao People's Democratic Republic, knowledge gaps and the dearth of laboratory capacity to support differential diagnosis may contribute to antibiotic overuse. We studied the etiology, temporal trends, and genetic diversity of viral respiratory infections in children to provide evidence for prevention and treatment guidelines. From September 2014 to October 2015, throat swabs and nasopharyngeal aspirates from 445 children under 10 years old with symptoms of acute respiratory infection were collected at the Children Hospital in Vientiane. Rapid antigen tests were performed for influenza A and B and respiratory syncytial virus. Real-time reverse-transcription polymerase chain reactions (RT-PCRs) were performed to detect 16 viruses. Influenza infections were detected with a higher sensitivity using PCR than with the rapid antigen test. By RT-PCR screening, at least one pathogen could be identified for 71.7% of cases. Human rhinoviruses were most frequently detected (29.9%), followed by influenza A and B viruses combined (15.9%). We identify and discuss the seasonality of some of the infections. Altogether these data provide a detailed characterization of respiratory pathogens in Lao children and we provide recommendations for vaccination and further studies.


Subject(s)
Coinfection/epidemiology , Respiratory Tract Infections/epidemiology , Virus Diseases/epidemiology , Viruses/genetics , Acute Disease/epidemiology , Child , Child, Preschool , Coinfection/virology , Female , Humans , Infant , Infant, Newborn , Influenza, Human/diagnosis , Influenza, Human/epidemiology , Influenza, Human/virology , Laos/epidemiology , Male , Prevalence , Respiratory Syncytial Virus Infections/diagnosis , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus Infections/virology , Respiratory Tract Infections/virology , Viruses/classification , Viruses/isolation & purification
12.
Viruses ; 14(1)2021 12 29.
Article in English | MEDLINE | ID: covidwho-1628815

ABSTRACT

Outbreaks of influenza, caused by the influenza A virus (IAV), occur almost every year in various regions worldwide, seriously endangering human health. Studies have shown that host non-coding RNA is an important regulator of host-virus interactions in the process of IAV infection. In this paper, we comprehensively analyzed the research progress on host non-coding RNAs with regard to the regulation of IAV replication. According to the regulation mode of host non-coding RNAs, the signal pathways involved, and the specific target genes, we found that a large number of host non-coding RNAs directly targeted the PB1 and PB2 proteins of IAV. Nonstructural protein 1 and other key genes regulate the replication of IAV and indirectly participate in the regulation of the retinoic acid-induced gene I-like receptor signaling pathway, toll-like receptor signaling pathway, Janus kinase signal transducer and activator of transcription signaling pathway, and other major intracellular viral response signaling pathways to regulate the replication of IAV. Based on the above findings, we mapped the regulatory network of host non-coding RNAs in the innate immune response to the influenza virus. These findings will provide a more comprehensive understanding of the function and mechanism of host non-coding RNAs in the cellular anti-virus response as well as clues to the mechanism of cell-virus interactions and the discovery of antiviral drug targets.


Subject(s)
Host-Pathogen Interactions , Influenza A virus/genetics , Influenza, Human/immunology , RNA, Untranslated , Virus Replication , Antiviral Agents/immunology , Cell Cycle , Humans , Immunity, Innate , Influenza, Human/virology , MicroRNAs , RNA, Circular , Signal Transduction
14.
Cells ; 11(3)2022 01 30.
Article in English | MEDLINE | ID: covidwho-1667057

ABSTRACT

The global outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still ongoing, as is research on the molecular mechanisms underlying cellular infection by coronaviruses, with the hope of developing therapeutic agents against this pandemic. Other important respiratory viruses such as 2009 pandemic H1N1 and H7N9 avian influenza virus (AIV), influenza A viruses, are also responsible for a possible outbreak due to their respiratory susceptibility. However, the interaction of these viruses with host cells and the regulation of post-transcriptional genes remains unclear. In this study, we detected and analyzed the comparative transcriptome profiling of SARS-CoV-2, panH1N1 (A/California/07/2009), and H7N9 (A/Shanghai/1/2013) infected cells. The results showed that the commonly upregulated genes among the three groups were mainly involved in autophagy, pertussis, and tuberculosis, which indicated that autophagy plays an important role in viral pathogenicity. There are three groups of commonly downregulated genes involved in metabolic pathways. Notably, unlike panH1N1 and H7N9, SARS-CoV-2 infection can inhibit the m-TOR pathway and activate the p53 signaling pathway, which may be responsible for unique autophagy induction and cell apoptosis. Particularly, upregulated expression of IRF1 was found in SARS-CoV-2, panH1N1, and H7N9 infection. Further analysis showed SARS-CoV-2, panH1N1, and H7N9 infection-induced upregulation of lncRNA-34087.27 could serve as a competitive endogenous RNA to stabilize IRF1 mRNA by competitively binding with miR-302b-3p. This study provides new insights into the molecular mechanisms of influenza A virus and SARS-CoV-2 infection.


Subject(s)
COVID-19/immunology , Immunity/immunology , Influenza A Virus, H1N1 Subtype/immunology , Influenza A Virus, H7N9 Subtype/immunology , Influenza, Human/immunology , RNA/immunology , Transcriptome/immunology , A549 Cells , Animals , COVID-19/genetics , COVID-19/virology , HEK293 Cells , Host-Pathogen Interactions/immunology , Humans , Immunity/genetics , Influenza A Virus, H1N1 Subtype/physiology , Influenza A Virus, H7N9 Subtype/physiology , Influenza, Human/genetics , Influenza, Human/virology , Interferon Regulatory Factor-1/genetics , Interferon Regulatory Factor-1/immunology , Interferon Regulatory Factor-1/metabolism , MicroRNAs/genetics , MicroRNAs/immunology , MicroRNAs/metabolism , Pandemics/prevention & control , RNA/genetics , RNA/metabolism , RNA, Long Noncoding/genetics , RNA, Long Noncoding/immunology , RNA, Long Noncoding/metabolism , RNA, Messenger/genetics , RNA, Messenger/immunology , RNA, Messenger/metabolism , RNA-Seq/methods , SARS-CoV-2/physiology , Signal Transduction/genetics , Signal Transduction/immunology , Transcriptome/genetics
16.
Elife ; 102021 11 17.
Article in English | MEDLINE | ID: covidwho-1662831

ABSTRACT

The poor efficacy of seasonal influenza virus vaccines is often attributed to pre-existing immunity interfering with the persistence and maturation of vaccine-induced B cell responses. We previously showed that a subset of vaccine-induced B cell lineages are recruited into germinal centers (GCs) following vaccination, suggesting that affinity maturation of these lineages against vaccine antigens can occur. However, it remains to be determined whether seasonal influenza vaccination stimulates additional evolution of vaccine-specific lineages, and previous work has found no significant increase in somatic hypermutation among influenza-binding lineages sampled from the blood following seasonal vaccination in humans. Here, we investigate this issue using a phylogenetic test of measurable immunoglobulin sequence evolution. We first validate this test through simulations and survey measurable evolution across multiple conditions. We find significant heterogeneity in measurable B cell evolution across conditions, with enrichment in primary response conditions such as HIV infection and early childhood development. We then show that measurable evolution following influenza vaccination is highly compartmentalized: while lineages in the blood are rarely measurably evolving following influenza vaccination, lineages containing GC B cells are frequently measurably evolving. Many of these lineages appear to derive from memory B cells. We conclude from these findings that seasonal influenza virus vaccination can stimulate additional evolution of responding B cell lineages, and imply that the poor efficacy of seasonal influenza vaccination is not due to a complete inhibition of vaccine-specific B cell evolution.


When the immune system encounters a disease-causing pathogen, it releases antibodies that can bind to specific regions of the bacterium or virus and help to clear the infection. These proteins are generated by B cells which, upon detecting the pathogen, can begin to mutate and alter the structure of the antibody they produce: the better the antibody is at binding to the pathogen, the more likely the B cell is to survive. This process of evolution produces B cells that make more effective antibodies. After the infection, some of these cells become 'memory B cells' which can be stimulated in to action when the pathogen invades again. Many vaccines also depend on this process to trigger the production of memory B cells that can fight off a specific disease-causing agent. However, it is unclear to what extent memory B cells that already exist are able to continue to evolve and modify their antibodies. This is particularly important for the flu vaccine, as the virus that causes influenza rapidly mutates. To provide high levels of protection, the memory B cells formed following the vaccine may therefore need to evolve to make different antibodies that recognize mutated forms of the virus. It is thought that the low effectiveness of the flu vaccine is partially because the response it triggers does not stimulate additional evolution of memory B cells. To test this theory, Hoehn et al. developed a computational method that can detect the evolution of B cells over time. The tool was applied to samples collected from the blood and lymph nodes (organ where immune cells reside) of people who recently received the flu vaccine. The results were then compared to B cells taken from people after different infections, vaccinations, and other conditions. Hoehn et al. found the degree to which B cells evolve varies significantly between conditions. For example, B cells produced during chronic HIV infections frequently evolved over time, while such evolution was rarely observed during the autoimmune disease myasthenia gravis. The analysis also showed that memory B cells produced by the flu vaccine were able to evolve if recruited to the lymph nodes, but this was rarely detected in B cells in the blood. These findings suggest the low efficacy of the flu vaccine is not due to a complete lack of B cell evolution, but likely due to other factors. For instance, it is possible the evolutionary process it stimulates is not as robust as in other conditions, or is less likely to produce long-lived B cells that release antibodies. More research is needed to explore these ideas and could lead to the development of more effective flu vaccines.


Subject(s)
B-Lymphocytes/immunology , Evolution, Molecular , Germinal Center/immunology , Influenza Vaccines/immunology , Humans , Influenza, Human/virology , Phylogeny , Vaccination
17.
Cell Rep Med ; 3(2): 100522, 2022 02 15.
Article in English | MEDLINE | ID: covidwho-1650891

ABSTRACT

The molecular mechanisms underlying the clinical manifestations of coronavirus disease 2019 (COVID-19), and what distinguishes them from common seasonal influenza virus and other lung injury states such as acute respiratory distress syndrome, remain poorly understood. To address these challenges, we combine transcriptional profiling of 646 clinical nasopharyngeal swabs and 39 patient autopsy tissues to define body-wide transcriptome changes in response to COVID-19. We then match these data with spatial protein and expression profiling across 357 tissue sections from 16 representative patient lung samples and identify tissue-compartment-specific damage wrought by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, evident as a function of varying viral loads during the clinical course of infection and tissue-type-specific expression states. Overall, our findings reveal a systemic disruption of canonical cellular and transcriptional pathways across all tissues, which can inform subsequent studies to combat the mortality of COVID-19 and to better understand the molecular dynamics of lethal SARS-CoV-2 and other respiratory infections.


Subject(s)
COVID-19/genetics , COVID-19/pathology , Lung/pathology , SARS-CoV-2 , Transcriptome/genetics , Adult , Aged , Aged, 80 and over , COVID-19/metabolism , COVID-19/virology , Case-Control Studies , Cohort Studies , Female , Gene Expression Regulation , Humans , Influenza, Human/genetics , Influenza, Human/pathology , Influenza, Human/virology , Lung/metabolism , Male , Middle Aged , Orthomyxoviridae , RNA-Seq/methods , Respiratory Distress Syndrome/genetics , Respiratory Distress Syndrome/microbiology , Respiratory Distress Syndrome/pathology , Viral Load
18.
Signal Transduct Target Ther ; 7(1): 18, 2022 01 19.
Article in English | MEDLINE | ID: covidwho-1639142

ABSTRACT

Emerging SARS-CoV-2 variants are the most serious problem for COVID-19 prophylaxis and treatment. To determine whether the SARS-CoV-2 vaccine strain should be updated following variant emergence like seasonal flu vaccine, the changed degree on antigenicity of SARS-CoV-2 variants and H3N2 flu vaccine strains was compared. The neutralization activities of Alpha, Beta and Gamma variants' spike protein-immunized sera were analysed against the eight current epidemic variants and 20 possible variants combining the top 10 prevalent RBD mutations based on the Delta variant, which were constructed using pseudotyped viruses. Meanwhile, the neutralization activities of convalescent sera and current inactivated and recombinant protein vaccine-elicited sera were also examined against all possible Delta variants. Eight HA protein-expressing DNAs elicited-animal sera were also tested against eight pseudotyped viruses of H3N2 flu vaccine strains from 2011-2019. Our results indicate that the antigenicity changes of possible Delta variants were mostly within four folds, whereas the antigenicity changes among different H3N2 vaccine strains were approximately 10-100-fold. Structural analysis of the antigenic characterization of the SARS-CoV-2 and H3N2 mutations supports the neutralization results. This study indicates that the antigenicity changes of the current SARS-CoV-2 may not be sufficient to require replacement of the current vaccine strain.


Subject(s)
Antibodies, Neutralizing/metabolism , Antibodies, Viral/metabolism , COVID-19 Vaccines/metabolism , COVID-19/prevention & control , Immunogenicity, Vaccine , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Amino Acid Substitution , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/genetics , Antibodies, Viral/chemistry , Antibodies, Viral/genetics , Binding Sites , COVID-19/immunology , COVID-19/virology , COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/chemistry , Epitopes/chemistry , Epitopes/genetics , Epitopes/immunology , Gene Expression , Humans , Immune Sera/chemistry , Influenza A Virus, H3N2 Subtype/chemistry , Influenza A Virus, H3N2 Subtype/genetics , Influenza A Virus, H3N2 Subtype/immunology , Influenza Vaccines/administration & dosage , Influenza Vaccines/chemistry , Influenza Vaccines/metabolism , Influenza, Human/immunology , Influenza, Human/prevention & control , Influenza, Human/virology , Models, Molecular , Mutation , Neutralization Tests , Protein Binding , Protein Conformation , Protein Interaction Domains and Motifs , SARS-CoV-2/chemistry , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics
19.
PLoS Pathog ; 17(12): e1010106, 2021 12.
Article in English | MEDLINE | ID: covidwho-1598647

ABSTRACT

The development of safe and effective vaccines in a record time after the emergence of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a remarkable achievement, partly based on the experience gained from multiple viral outbreaks in the past decades. However, the Coronavirus Disease 2019 (COVID-19) crisis also revealed weaknesses in the global pandemic response and large gaps that remain in our knowledge of the biology of coronaviruses (CoVs) and influenza viruses, the 2 major respiratory viruses with pandemic potential. Here, we review current knowns and unknowns of influenza viruses and CoVs, and we highlight common research challenges they pose in 3 areas: the mechanisms of viral emergence and adaptation to humans, the physiological and molecular determinants of disease severity, and the development of control strategies. We outline multidisciplinary approaches and technological innovations that need to be harnessed in order to improve preparedeness to the next pandemic.


Subject(s)
COVID-19/virology , Influenza, Human/virology , Orthomyxoviridae/physiology , SARS-CoV-2/physiology , Animals , Antiviral Agents , COVID-19/therapy , COVID-19/transmission , Drug Development , Evolution, Molecular , Humans , Influenza, Human/therapy , Influenza, Human/transmission , Orthomyxoviridae/immunology , SARS-CoV-2/immunology , Selection, Genetic , Viral Load , Viral Vaccines
20.
Viruses ; 13(12)2021 11 25.
Article in English | MEDLINE | ID: covidwho-1590034

ABSTRACT

Disease tolerance has emerged as an alternative way, in addition to host resistance, to survive viral-bacterial co-infections. Disease tolerance plays an important role not in reducing pathogen burden, but in maintaining tissue integrity and controlling organ damage. A common co-infection is the synergy observed between influenza virus and Streptococcus pneumoniae that results in superinfection and lethality. Several host cytokines and cells have shown promise in promoting tissue protection and damage control while others induce severe immunopathology leading to high levels of morbidity and mortality. The focus of this review is to describe the host cytokines and innate immune cells that mediate disease tolerance and lead to a return to host homeostasis and ultimately, survival during viral-bacterial co-infection.


Subject(s)
Immunity, Innate , Influenza, Human/immunology , Orthomyxoviridae/immunology , Pneumococcal Infections/immunology , Streptococcus pneumoniae/immunology , Coinfection , Cytokines/immunology , Homeostasis , Humans , Influenza, Human/microbiology , Influenza, Human/virology , Pneumococcal Infections/microbiology , Superinfection
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