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1.
Cell Rep ; 37(6): 109961, 2021 11 09.
Article in English | MEDLINE | ID: covidwho-1507742

ABSTRACT

Following infection or immunization, memory B cells (MBCs) and long-lived plasma cells provide humoral immunity that can last for decades. Most principles of MBC biology have been determined with hapten-protein carrier models or fluorescent protein immunizations. Here, we examine the temporal dynamics of the germinal center (GC) B cell and MBC response following mouse influenza A virus infection. We find that antiviral B cell responses within the lung-draining mediastinal lymph node (mLN) and the spleen are distinct in regard to duration, enrichment for antigen-binding cells, and class switching dynamics. While splenic GCs dissolve after 6 weeks post-infection, mLN hemagglutinin-specific (HA+) GCs can persist for 22 weeks. Persistent GCs continuously differentiate MBCs, with "peak" and "late" GCs contributing equal numbers of HA+ MBCs to the long-lived compartment. Our findings highlight critical aspects of persistent GC responses and MBC differentiation following respiratory virus infection with direct implications for developing effective vaccination strategies.


Subject(s)
Antibodies, Viral/immunology , Germinal Center/immunology , Immunologic Memory , Influenza A virus/physiology , Orthomyxoviridae Infections/immunology , T-Box Domain Proteins/physiology , Animals , Cell Differentiation , Female , Lymphocyte Activation , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Orthomyxoviridae Infections/pathology , Orthomyxoviridae Infections/virology
2.
Sci Rep ; 11(1): 21259, 2021 10 28.
Article in English | MEDLINE | ID: covidwho-1493217

ABSTRACT

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently a serious public health concern worldwide. Notably, co-infection with other pathogens may worsen the severity of COVID-19 symptoms and increase fatality. Here, we show that co-infection with influenza A virus (IAV) causes more severe body weight loss and more severe and prolonged pneumonia in SARS-CoV-2-infected hamsters. Each virus can efficiently spread in the lungs without interference by the other. However, in immunohistochemical analyses, SARS-CoV-2 and IAV were not detected at the same sites in the respiratory organs of co-infected hamsters, suggesting that either the two viruses may have different cell tropisms in vivo or each virus may inhibit the infection and/or growth of the other within a cell or adjacent areas in the organs. Furthermore, a significant increase in IL-6 was detected in the sera of hamsters co-infected with SARS-CoV-2 and IAV at 7 and 10 days post-infection, suggesting that IL-6 may be involved in the increased severity of pneumonia. Our results strongly suggest that IAV co-infection with SARS-CoV-2 can have serious health risks and increased caution should be applied in such cases.


Subject(s)
COVID-19/complications , Orthomyxoviridae Infections/complications , Pneumonia, Viral/complications , SARS-CoV-2 , Animals , COVID-19/pathology , COVID-19/virology , Coinfection/pathology , Disease Models, Animal , Female , Humans , Interleukin-6/blood , Lung/diagnostic imaging , Lung/pathology , Mesocricetus , Orthomyxoviridae/pathogenicity , Orthomyxoviridae Infections/pathology , Orthomyxoviridae Infections/virology , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , SARS-CoV-2/pathogenicity , SARS-CoV-2/physiology , Severity of Illness Index , Virus Replication
3.
Biomed Res Int ; 2021: 8112783, 2021.
Article in English | MEDLINE | ID: covidwho-1378089

ABSTRACT

Long noncoding RNAs (lncRNAs) have been reported to participate in regulating many biological processes, including immune response to influenza A virus (IAV). However, the association between lncRNA expression profiles and influenza infection susceptibility has not been well elucidated. Here, we analyzed the expression profiles of lncRNAs, miRNAs, and mRNAs among IAV-infected adult rat (IAR), normal adult rat (AR), IAV-infected junior rat (IJR), and normal junior rat (JR) by RNA sequencing. Compared with differently expressed lncRNAs (DElncRNAs) between AR and IAR, 24 specific DElncRNAs were found between IJR and JR. Then, based on the fold changes and P value, the top 5 DElncRNAs, including 3 upregulated and 2 downregulated lncRNAs, were chosen to establish a ceRNA network for further disclosing their regulatory mechanisms. To visualize the differentially expressed genes in the ceRNA network, GO and KEGG pathway analysis was performed to further explore their roles in influenza infection of junior rats. The results showed that the downregulated DElncRNA-target genes were mostly enriched in the IL-17 signaling pathway. It indicated that the downregulated lncRNAs conferred the susceptibility of junior rats to IAV via mediating the IL-17 signaling pathway.


Subject(s)
Influenza A virus/pathogenicity , MicroRNAs/genetics , Orthomyxoviridae Infections/genetics , RNA, Long Noncoding/genetics , RNA, Messenger/genetics , Animals , Disease Models, Animal , Disease Susceptibility , Gene Expression Profiling , Influenza A virus/isolation & purification , Interleukin-17/genetics , Interleukin-17/immunology , MicroRNAs/immunology , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/pathology , Orthomyxoviridae Infections/virology , RNA, Long Noncoding/immunology , RNA, Messenger/immunology , Rats , Rats, Sprague-Dawley
4.
PLoS Pathog ; 17(7): e1009381, 2021 07.
Article in English | MEDLINE | ID: covidwho-1291654

ABSTRACT

Clearance of viral infections, such as SARS-CoV-2 and influenza A virus (IAV), must be fine-tuned to eliminate the pathogen without causing immunopathology. As such, an aggressive initial innate immune response favors the host in contrast to a detrimental prolonged inflammation. The complement pathway bridges innate and adaptive immune system and contributes to the response by directly clearing pathogens or infected cells, as well as recruiting proinflammatory immune cells and regulating inflammation. However, the impact of modulating complement activation in viral infections is still unclear. In this work, we targeted the complement decay-accelerating factor (DAF/CD55), a surface protein that protects cells from non-specific complement attack, and analyzed its role in IAV infections. We found that DAF modulates IAV infection in vivo, via an interplay with the antigenic viral proteins hemagglutinin (HA) and neuraminidase (NA), in a strain specific manner. Our results reveal that, contrary to what could be expected, DAF potentiates complement activation, increasing the recruitment of neutrophils, monocytes and T cells. We also show that viral NA acts on the heavily sialylated DAF and propose that the NA-dependent DAF removal of sialic acids exacerbates complement activation, leading to lung immunopathology. Remarkably, this mechanism has no impact on viral loads, but rather on the host resilience to infection, and may have direct implications in zoonotic influenza transmissions.


Subject(s)
CD55 Antigens/physiology , Influenza A Virus, H1N1 Subtype/isolation & purification , Lung/immunology , Viremia/immunology , Animals , Bronchoalveolar Lavage Fluid/immunology , CD55 Antigens/chemistry , CD55 Antigens/deficiency , Chemotaxis, Leukocyte , Complement Activation , Hemagglutinin Glycoproteins, Influenza Virus/physiology , Host Adaptation , Host Specificity , Host-Pathogen Interactions , Influenza A Virus, H1N1 Subtype/enzymology , Influenza A Virus, H1N1 Subtype/pathogenicity , Influenza A Virus, H1N1 Subtype/physiology , Interferon-gamma/analysis , Lung/pathology , Lung/virology , Mice , Mice, Inbred C57BL , N-Acetylneuraminic Acid , Neuraminidase/physiology , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/pathology , Viral Load , Viral Proteins/physiology , Virulence , Virus Replication , Weight Loss
5.
Am J Respir Cell Mol Biol ; 64(6): 677-686, 2021 06.
Article in English | MEDLINE | ID: covidwho-1259048

ABSTRACT

There is an urgent need for new drugs for patients with acute respiratory distress syndrome (ARDS), including those with coronavirus disease (COVID-19). ARDS in influenza-infected mice is associated with reduced concentrations of liponucleotides (essential precursors for de novo phospholipid synthesis) in alveolar type II (ATII) epithelial cells. Because surfactant phospholipid synthesis is a primary function of ATII cells, we hypothesized that disrupting this process could contribute significantly to the pathogenesis of influenza-induced ARDS. The goal of this study was to determine whether parenteral liponucleotide supplementation can attenuate ARDS. C57BL/6 mice inoculated intranasally with 10,000 plaque-forming units/mouse of H1N1 influenza A/WSN/33 virus were treated with CDP (cytidine 5'-diphospho)-choline (100 µg/mouse i.p.) ± CDP -diacylglycerol 16:0/16:0 (10 µg/mouse i.p.) once daily from 1 to 5 days after inoculation (to model postexposure influenza prophylaxis) or as a single dose on Day 5 (to model treatment of patients with ongoing influenza-induced ARDS). Daily postexposure prophylaxis with CDP-choline attenuated influenza-induced hypoxemia, pulmonary edema, alterations in lung mechanics, impairment of alveolar fluid clearance, and pulmonary inflammation without altering viral replication. These effects were not recapitulated by the daily administration of CTP (cytidine triphosphate) and/or choline. Daily coadministration of CDP-diacylglycerol significantly enhanced the beneficial effects of CDP-choline and also modified the ATII cell lipidome, reversing the infection-induced decrease in phosphatidylcholine and increasing concentrations of most other lipid classes in ATII cells. Single-dose treatment with both liponucleotides at 5 days after inoculation also attenuated hypoxemia, altered lung mechanics, and inflammation. Overall, our data show that liponucleotides act rapidly to reduce disease severity in mice with severe influenza-induced ARDS.


Subject(s)
Alveolar Epithelial Cells/metabolism , Cytidine Diphosphate Choline/pharmacology , Cytidine Diphosphate Diglycerides/pharmacology , Influenza A Virus, H1N1 Subtype/metabolism , Orthomyxoviridae Infections/drug therapy , Respiratory Distress Syndrome/prevention & control , Alveolar Epithelial Cells/pathology , Alveolar Epithelial Cells/virology , Animals , COVID-19/drug therapy , COVID-19/pathology , Mice , Orthomyxoviridae Infections/complications , Orthomyxoviridae Infections/metabolism , Orthomyxoviridae Infections/pathology , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/metabolism , Respiratory Distress Syndrome/pathology , SARS-CoV-2/metabolism
6.
Emerg Microbes Infect ; 10(1): 1156-1168, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1249264

ABSTRACT

ABSTRACTThe risk of secondary infection with SARS-CoV-2 and influenza A virus is becoming a practical problem that must be addressed as the flu season merges with the COVID-19 pandemic. As SARS-CoV-2 and influenza A virus have been found in patients, understanding the in vivo characteristics of the secondary infection between these two viruses is a high priority. Here, hACE2 transgenic mice were challenged with the H1N1 virus at a nonlethal dose during the convalescent stage on 7 and 14 days post SARS-CoV-2 infection, and importantly, subsequent H1N1 infection showed enhanced viral shedding and virus tissue distribution. Histopathological observation revealed an extensive pathological change in the lungs related to H1N1 infection in mice recovered from SARS-CoV-2 infection, with severe inflammation infiltration and bronchiole disruption. Moreover, upon H1N1 exposure on 7 and 14 dpi of SARS-CoV-2 infection, the lymphocyte population activated at a lower level with T cell suppressed in both PBMC and lung. These findings will be valuable for evaluating antiviral therapeutics and vaccines as well as guiding public health work.


Subject(s)
Acute Lung Injury/pathology , Angiotensin-Converting Enzyme 2/genetics , COVID-19/pathology , Orthomyxoviridae Infections/pathology , Acute Lung Injury/virology , Animals , COVID-19/therapy , Coinfection/pathology , Coinfection/virology , Cytokines/blood , Disease Models, Animal , Female , Humans , Influenza A Virus, H1N1 Subtype/isolation & purification , Lung/pathology , Lymphocyte Count , Lymphocytes/immunology , Mice , Mice, Transgenic , Orthomyxoviridae Infections/therapy , SARS-CoV-2/isolation & purification , Viral Load , Virus Replication/physiology , Virus Shedding/physiology
7.
Signal Transduct Target Ther ; 6(1): 200, 2021 05 20.
Article in English | MEDLINE | ID: covidwho-1237988

ABSTRACT

Influenza A virus may circulate simultaneously with the SARS-CoV-2 virus, leading to more serious respiratory diseases during this winter. However, the influence of these viruses on disease outcome when both influenza A and SARS-CoV-2 are present in the host remains unclear. Using a mammalian model, sequential infection was performed in ferrets and in K18-hACE2 mice, with SARS-CoV-2 infection following H1N1. We found that co-infection with H1N1 and SARS-CoV-2 extended the duration of clinical manifestation of COVID-19, and enhanced pulmonary damage, but reduced viral shedding of throat swabs and viral loads in the lungs of ferrets. Moreover, mortality was increased in sequentially infected mice compared with single-infection mice. Compared with single-vaccine inoculation, co-inoculation of PiCoVacc (a SARS-CoV-2 vaccine) and the flu vaccine showed no significant differences in neutralizing antibody titers or virus-specific immune responses. Combined immunization effectively protected K18-hACE2 mice against both H1N1 and SARS-CoV-2 infection. Our findings indicated the development of systematic models of co-infection of H1N1 and SARS-CoV-2, which together notably enhanced pneumonia in ferrets and mice, as well as demonstrated that simultaneous vaccination against H1N1 and SARS-CoV-2 may be an effective prevention strategy for the coming winter.


Subject(s)
COVID-19 , Coinfection , Influenza A Virus, H1N1 Subtype/immunology , Orthomyxoviridae Infections , SARS-CoV-2/immunology , Animals , COVID-19/immunology , COVID-19/pathology , COVID-19/virology , Coinfection/immunology , Coinfection/pathology , Coinfection/virology , Disease Models, Animal , Ferrets , Humans , Male , Mice , Mice, Transgenic , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/pathology , Orthomyxoviridae Infections/virology
8.
Cells ; 10(4)2021 03 24.
Article in English | MEDLINE | ID: covidwho-1232574

ABSTRACT

Despite vaccination and antivirals, influenza remains a communicable disease of high burden, with limited therapeutic options available to patients that develop complications. Here, we report the development and preclinical characterization of Adipose Stromal Cell (ASC) concentrated secretome (CS), generated by process adaptable to current Good Manufacturing Practices (cGMP) standards. We demonstrate that ASC-CS limits pulmonary histopathological changes, infiltration of inflammatory cells, protein leak, water accumulation, and arterial oxygen saturation (spO2) reduction in murine model of lung infection with influenza A virus (IAV) when first administered six days post-infection. The ability to limit lung injury is sustained in ASC-CS preparations stored at -80 °C for three years. Priming of the ASC with inflammatory factors TNFα and IFNγ enhances ASC-CS ability to suppress lung injury. IAV infection is associated with dramatic increases in programmed cell death ligand (PDL1) and angiopoietin 2 (Angpt2) levels. ASC-CS application significantly reduces both PDL1 and Angpt2 levels. Neutralization of PDL1 with anti-mouse PDL1 antibody starting Day6 onward effectively ablates lung PDL1, but only non-significantly reduces Angpt2 release. Most importantly, late-phase PDL1 neutralization results in negligible suppression of protein leakage and inflammatory cell infiltration, suggesting that suppression of PDL1 does not play a critical role in ASC-CS therapeutic effects.


Subject(s)
Adipose Tissue/cytology , Influenza A virus/physiology , Lung Injury/therapy , Lung Injury/virology , Orthomyxoviridae Infections/therapy , Orthomyxoviridae Infections/virology , Angiopoietin-2/metabolism , Animals , B7-H1 Antigen/metabolism , Bronchoalveolar Lavage , Cryopreservation , Culture Media, Conditioned/pharmacology , Cytokines/metabolism , Disease Models, Animal , Female , Humans , Inflammation/complications , Inflammation/pathology , Lung Injury/complications , Lung Injury/pathology , Male , Mice , Orthomyxoviridae Infections/complications , Orthomyxoviridae Infections/pathology , Respiratory Distress Syndrome/complications , Respiratory Distress Syndrome/pathology , Respiratory Distress Syndrome/virology , Sex Characteristics , Stromal Cells/metabolism
9.
J Virol ; 95(9)2021 04 12.
Article in English | MEDLINE | ID: covidwho-1102152

ABSTRACT

Current influenza vaccines, live attenuated or inactivated, do not protect against antigenically novel influenza A viruses (IAVs) of pandemic potential, which has driven interest in the development of universal influenza vaccines. Universal influenza vaccine candidates targeting highly conserved antigens of IAV nucleoprotein (NP) are promising as vaccines that induce T cell immunity, but concerns have been raised about the safety of inducing robust CD8 T cell responses in the lungs. Using a mouse model, we systematically evaluated effects of recombinant adenovirus vectors (rAd) expressing IAV NP (A/NP-rAd) or influenza B virus (IBV) NP (B/NP-rAd) on pulmonary inflammation and function after vaccination and following live IAV challenge. After A/NP-rAd or B/NP-rAd vaccination, female mice exhibited robust systemic and pulmonary vaccine-specific B cell and T cell responses and experienced no morbidity (e.g., body mass loss). Both in vivo pulmonary function testing and lung histopathology scoring revealed minimal adverse effects of intranasal rAd vaccination compared with unvaccinated mice. After IAV challenge, A/NP-rAd-vaccinated mice experienced significantly less morbidity, had lower pulmonary virus titers, and developed less pulmonary inflammation than unvaccinated or B/NP-rAd-vaccinated mice. Based on analysis of pulmonary physiology using detailed testing not previously applied to the question of T cell damage, mice protected by vaccination also had better lung function than controls. Results provide evidence that, in this model, adenoviral universal influenza vaccine does not damage pulmonary tissue. In addition, adaptive immunity, in particular, T cell immunity in the lungs, does not cause damage when restimulated but instead mitigates pulmonary damage following IAV infection.IMPORTANCE Respiratory viruses can emerge and spread rapidly before vaccines are available. It would be a tremendous advance to use vaccines that protect against whole categories of viruses, such as universal influenza vaccines, without the need to predict which virus will emerge. The nucleoprotein (NP) of influenza virus provides a target conserved among strains and is a dominant T cell target. In animals, vaccination to NP generates powerful T cell immunity and long-lasting protection against diverse influenza strains. Concerns have been raised, but not evaluated experimentally, that potent local T cell responses might damage the lungs. We analyzed lung function in detail in the setting of such a vaccination. Despite CD8 T cell responses in the lungs, lungs were not damaged and functioned normally after vaccination alone and were protected upon subsequent infection. This precedent provides important support for vaccines based on T cell-mediated protection, currently being considered for both influenza and SARS-CoV-2 vaccines.


Subject(s)
Adenoviridae , Genetic Vectors , Influenza B virus , Influenza Vaccines , Lung , Orthomyxoviridae Infections , Adenoviridae/genetics , Adenoviridae/immunology , Animals , B-Lymphocytes/immunology , B-Lymphocytes/pathology , Disease Models, Animal , Female , Genetic Vectors/genetics , Genetic Vectors/immunology , Immunity, Cellular , Influenza B virus/genetics , Influenza B virus/immunology , Influenza Vaccines/genetics , Influenza Vaccines/immunology , Lung/immunology , Lung/pathology , Lung/virology , Mice , Orthomyxoviridae Infections/genetics , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/pathology , Orthomyxoviridae Infections/prevention & control , T-Lymphocytes/immunology , T-Lymphocytes/pathology
10.
Cell Res ; 31(4): 395-403, 2021 04.
Article in English | MEDLINE | ID: covidwho-1091494

ABSTRACT

The upcoming flu season in the Northern Hemisphere merging with the current COVID-19 pandemic raises a potentially severe threat to public health. Through experimental coinfection with influenza A virus (IAV) and either pseudotyped or live SARS-CoV-2 virus, we found that IAV preinfection significantly promoted the infectivity of SARS-CoV-2 in a broad range of cell types. Remarkably, in vivo, increased SARS-CoV-2 viral load and more severe lung damage were observed in mice coinfected with IAV. Moreover, such enhancement of SARS-CoV-2 infectivity was not observed with several other respiratory viruses, likely due to a unique feature of IAV to elevate ACE2 expression. This study illustrates that IAV has a unique ability to aggravate SARS-CoV-2 infection, and thus, prevention of IAV infection is of great significance during the COVID-19 pandemic.


Subject(s)
COVID-19/pathology , Coinfection/pathology , Influenza A virus/physiology , Orthomyxoviridae Infections/pathology , SARS-CoV-2/physiology , Angiotensin-Converting Enzyme 2/deficiency , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , COVID-19/virology , Cathepsin L/genetics , Cathepsin L/metabolism , Cell Line , Coinfection/virology , Humans , Influenza A virus/isolation & purification , Lung/pathology , Mice , Mice, Transgenic , Orthomyxoviridae Infections/virology , RNA, Guide/metabolism , SARS-CoV-2/isolation & purification , Serine Endopeptidases/genetics , Serine Endopeptidases/metabolism , Severity of Illness Index , Viral Load , Virus Internalization
11.
Front Immunol ; 11: 559113, 2020.
Article in English | MEDLINE | ID: covidwho-868963

ABSTRACT

As the recent outbreak of SARS-CoV-2 has highlighted, the threat of a pandemic event from zoonotic viruses, such as the deadly influenza A/H7N9 virus subtype, continues to be a major global health concern. H7N9 virus strains appear to exhibit greater disease severity in mammalian hosts compared to natural avian hosts, though the exact mechanisms underlying this are somewhat unclear. Knowledge of the H7N9 host-pathogen interactions have mainly been constrained to natural sporadic human infections. To elucidate the cellular immune mechanisms associated with disease severity and progression, we used a ferret model to closely resemble disease outcomes in humans following influenza virus infection. Intriguingly, we observed variable disease outcomes when ferrets were inoculated with the A/Anhui/1/2013 (H7N9) strain. We observed relatively reduced antigen-presenting cell activation in lymphoid tissues which may be correlative with increased disease severity. Additionally, depletions in CD8+ T cells were not apparent in sick animals. This study provides further insight into the ways that lymphocytes maturate and traffic in response to H7N9 infection in the ferret model.


Subject(s)
Antigen-Presenting Cells/immunology , CD8-Positive T-Lymphocytes/immunology , Host-Pathogen Interactions/immunology , Influenza A Virus, H7N9 Subtype/physiology , Orthomyxoviridae Infections/immunology , Animals , Antigen-Presenting Cells/pathology , Betacoronavirus/immunology , CD8-Positive T-Lymphocytes/pathology , COVID-19 , Coronavirus Infections/immunology , Disease Models, Animal , Ferrets , Humans , Orthomyxoviridae Infections/pathology , Pandemics , Pneumonia, Viral/immunology , SARS-CoV-2
12.
Sci Rep ; 10(1): 17090, 2020 10 13.
Article in English | MEDLINE | ID: covidwho-867590

ABSTRACT

The triterpene oil squalene is an essential component of nanoemulsion vaccine adjuvants. It is most notably in the MF59 adjuvant, a component in some seasonal influenza vaccines, in stockpiled, emulsion-based adjuvanted pandemic influenza vaccines, and with demonstrated efficacy for vaccines to other pandemic viruses, such as SARS-CoV-2. Squalene has historically been harvested from shark liver oil, which is undesirable for a variety of reasons. In this study, we have demonstrated the use of a Synthetic Biology (yeast) production platform to generate squalene and novel triterpene oils, all of which are equally as efficacious as vaccine adjuvants based on physiochemical properties and immunomodulating activities in a mouse model. These Synthetic Biology adjuvants also elicited similar IgG1, IgG2a, and total IgG levels compared to marine and commercial controls when formulated with common quadrivalent influenza antigens. Injection site morphology and serum cytokine levels did not suggest any reactogenic effects of the yeast-derived squalene or novel triterpenes, suggesting their safety in adjuvant formulations. These results support the advantages of yeast produced triterpene oils to include completely controlled growth conditions, just-in-time and scalable production, and the capacity to produce novel triterpenes beyond squalene.


Subject(s)
Adjuvants, Immunologic/chemistry , Influenza Vaccines/immunology , Triterpenes/chemistry , Animals , Antibodies, Viral/blood , Betacoronavirus/isolation & purification , COVID-19 , Coronavirus Infections/prevention & control , Coronavirus Infections/virology , Cytokines/blood , Immunoglobulin G/blood , Influenza Vaccines/chemistry , Mice , Mice, Inbred BALB C , Nanoparticles/chemistry , Orthomyxoviridae Infections/pathology , Orthomyxoviridae Infections/prevention & control , Orthomyxoviridae Infections/virology , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Pneumonia, Viral/virology , SARS-CoV-2 , Saccharomyces cerevisiae/chemistry , Saccharomyces cerevisiae/metabolism , Synthetic Biology/methods
13.
Blood Adv ; 4(13): 2967-2978, 2020 07 14.
Article in English | MEDLINE | ID: covidwho-625455

ABSTRACT

Thrombocytopenia is a common complication of influenza virus infection, and its severity predicts the clinical outcome of critically ill patients. The underlying cause(s) remain incompletely understood. In this study, in patients with an influenza A/H1N1 virus infection, viral load and platelet count correlated inversely during the acute infection phase. We confirmed this finding in a ferret model of influenza virus infection. In these animals, platelet count decreased with the degree of virus pathogenicity varying from 0% in animals infected with the influenza A/H3N2 virus, to 22% in those with the pandemic influenza A/H1N1 virus, up to 62% in animals with a highly pathogenic A/H5N1 virus infection. This thrombocytopenia is associated with virus-containing platelets that circulate in the blood. Uptake of influenza virus particles by platelets requires binding to sialoglycans and results in the removal of sialic acids by the virus neuraminidase, a trigger for hepatic clearance of platelets. We propose the clearance of influenza virus by platelets as a paradigm. These insights clarify the pathophysiology of influenza virus infection and show how severe respiratory infections, including COVID-19, may propagate thrombocytopenia and/or thromboembolic complications.


Subject(s)
Blood Platelets/virology , Influenza A virus/pathogenicity , Influenza, Human/complications , N-Acetylneuraminic Acid/metabolism , Polysaccharides/metabolism , Thrombocytopenia/etiology , Animals , Blood Platelets/metabolism , Blood Platelets/pathology , Disease Models, Animal , Ferrets , Host-Pathogen Interactions , Humans , Influenza A Virus, H1N1 Subtype/pathogenicity , Influenza A Virus, H1N1 Subtype/physiology , Influenza A Virus, H3N2 Subtype/pathogenicity , Influenza A Virus, H3N2 Subtype/physiology , Influenza A Virus, H5N1 Subtype/pathogenicity , Influenza A Virus, H5N1 Subtype/physiology , Influenza A virus/physiology , Influenza, Human/metabolism , Influenza, Human/pathology , Influenza, Human/virology , Orthomyxoviridae Infections/complications , Orthomyxoviridae Infections/metabolism , Orthomyxoviridae Infections/pathology , Orthomyxoviridae Infections/virology , Thrombocytopenia/metabolism , Thrombocytopenia/pathology , Thrombocytopenia/virology , Virus Internalization
14.
Science ; 369(6504): 712-717, 2020 08 07.
Article in English | MEDLINE | ID: covidwho-594812

ABSTRACT

Excessive cytokine signaling frequently exacerbates lung tissue damage during respiratory viral infection. Type I (IFN-α and IFN-ß) and III (IFN-λ) interferons are host-produced antiviral cytokines. Prolonged IFN-α and IFN-ß responses can lead to harmful proinflammatory effects, whereas IFN-λ mainly signals in epithelia, thereby inducing localized antiviral immunity. In this work, we show that IFN signaling interferes with lung repair during influenza recovery in mice, with IFN-λ driving these effects most potently. IFN-induced protein p53 directly reduces epithelial proliferation and differentiation, which increases disease severity and susceptibility to bacterial superinfections. Thus, excessive or prolonged IFN production aggravates viral infection by impairing lung epithelial regeneration. Timing and duration are therefore critical parameters of endogenous IFN action and should be considered carefully for IFN therapeutic strategies against viral infections such as influenza and coronavirus disease 2019 (COVID-19).


Subject(s)
Alveolar Epithelial Cells/pathology , Cytokines/metabolism , Interferon Type I/metabolism , Interferons/metabolism , Lung/pathology , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/pathology , Alveolar Epithelial Cells/immunology , Animals , Apoptosis , Bronchoalveolar Lavage Fluid/immunology , Cell Differentiation , Cell Proliferation , Cells, Cultured , Cytokines/administration & dosage , Cytokines/immunology , Female , Influenza A Virus, H3N2 Subtype , Interferon Type I/administration & dosage , Interferon Type I/pharmacology , Interferon-alpha/administration & dosage , Interferon-alpha/metabolism , Interferon-alpha/pharmacology , Interferon-beta/administration & dosage , Interferon-beta/metabolism , Interferon-beta/pharmacology , Interferons/administration & dosage , Interferons/pharmacology , Male , Mice , Orthomyxoviridae Infections/metabolism , Receptor, Interferon alpha-beta/genetics , Receptor, Interferon alpha-beta/metabolism , Receptors, Interferon/genetics , Receptors, Interferon/metabolism , Signal Transduction , Tumor Suppressor Protein p53/metabolism
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