#SNP-mediated disruption of CTCF binding at the #IFITM3 promoter is associated with #risk of severe #influenza in #humans (Nat Med., abstract)

[Source: Nature Medicine, full page: (LINK). Abstract, edited.]

SNP-mediated disruption of CTCF binding at the IFITM3 promoter is associated with risk of severe influenza in humans

E Kaitlynn Allen, Adrienne G Randolph, Tushar Bhangale, Pranay Dogra, Maikke Ohlson, Christine M Oshansky, Anthony E Zamora, John P Shannon, David Finkelstein, Amy Dressen, John DeVincenzo, Miguela Caniza, Ben Youngblood, Carrie M Rosenberger & Paul G Thomas

Nature Medicine 23, 975–983 (2017) / doi: 10.1038/nm.4370

Received 13 February 2017 – Accepted 15 June 2017 – Published online 17 July 2017

 

Abstract

Previous studies have reported associations of IFITM3 SNP rs12252 with severe influenza, but evidence of association and the mechanism by which risk is conferred remain controversial. We prioritized SNPs in IFITM3 on the basis of putative biological function and identified rs34481144 in the 5′ UTR. We found evidence of a new association of rs34481144 with severe influenza in three influenza-infected cohorts characterized by different levels of influenza illness severity. We determined a role for rs34481144 as an expression quantitative trait locus (eQTL) for IFITM3, with the risk allele associated with lower mRNA expression. The risk allele was found to have decreased IRF3 binding and increased CTCF binding in promoter-binding assays, and risk allele carriage diminished transcriptional correlations among IFITM3-neighboring genes, indicative of CTCF boundary activity. Furthermore, the risk allele disrupts a CpG site that undergoes differential methylation in CD8+ T cell subsets. Carriers of the risk allele had reduced numbers of CD8+ T cells in their airways during natural influenza infection, consistent with IFITM3 promoting accumulation of CD8+ T cells in airways and indicating that a critical function for IFITM3 may be to promote immune cell persistence at mucosal sites.Our study identifies a new regulator of IFITM3 expression that associates with CD8+ T cell levels in the airways and a spectrum of clinical outcomes.

Keywords: Influenza A; Genetics; Human.

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#Mitogenic #stimulation accelerates #influenza-induced #mortality by increasing susceptibility of alveolar type II cells to infection (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

Mitogenic stimulation accelerates influenza-induced mortality by increasing susceptibility of alveolar type II cells to infection

Nikolaos M. Nikolaidis a,1, John G. Noel b, Lori B. Pitstick a, Jason C. Gardner a,b, Yasuaki Uehara a, Huixing Wu a, Atsushi Saito a,2, Kara E. Lewnard a, Huan Liu a, Mitchell R. White c, Kevan L. Hartshorn c, and Francis X. McCormack a,1

Author Affiliations: {a}Department of Internal Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267; {b}Department of Research, Shriner’s Hospital for Children, Cincinnati, OH 45229; {c}Department of Medicine, Boston University School of Medicine, Boston, MA 02118

Edited by Peter Palese, Icahn School of Medicine at Mount Sinai, New York, NY, and approved June 29, 2017 (received for review December 23, 2016)

 

Significance

Influenza is a recurring global health threat that preferentially targets vulnerable groups such as the very young, the pregnant, the elderly, and the infirm. The spread of influenza A virus (IAV) from the epithelium of the conducting airway to the alveolar epithelium is a pivotal event in the pathogenesis of primary viral pneumonia. Host susceptibility to IAV pneumonia is often attributed to altered immunity, and cell autonomous vulnerability states of the alveolar epithelium, such as proliferative tone, are rarely considered. Here we demonstrate that mitogenic stimulation of alveolar epithelial type II cells renders them susceptible to IAV infection in an mTOR-dependent manner.

 

Abstract

Development of pneumonia is the most lethal consequence of influenza, increasing mortality more than 50-fold compared with uncomplicated infection. The spread of viral infection from conducting airways to the alveolar epithelium is therefore a pivotal event in influenza pathogenesis. We found that mitogenic stimulation with keratinocyte growth factor (KGF) markedly accelerated mortality after infectious challenge with influenza A virus (IAV). Coadministration of KGF with IAV markedly accelerated the spread of viral infection from the airways to alveoli compared with challenge with IAV alone, based on spatial and temporal analyses of viral nucleoprotein staining of lung tissue sections and dissociated lung cells. To better define the temporal relationship between KGF administration and susceptibility to IAV infection in vivo, we administered KGF 120, 48, 24, and 0 h before intrapulmonary IAV challenge and assessed the percentages of proliferating and IAV-infected, alveolar type II (AECII) cells in dispersed lung cell populations. Peak AECII infectivity coincided with the timing of KGF administration that also induced peak AECII proliferation. AECII from mice that were given intrapulmonary KGF before isolation and then infected with IAV ex vivo exhibited the same temporal pattern of proliferation and infectious susceptibility. KGF-induced increases in mortality, AECII proliferation, and enhanced IAV susceptibility were all reversed by pretreatment of the animals with the mTOR inhibitor rapamycin before mitogenic stimulation. Taken together, these data suggest mTOR signaling-dependent, mitogenic conditioning of AECII is a determinant of host susceptibility to infection with IAV.

viral pneumonia – influenza A – alveolar epithelial type II – mitogen – mTOR

 

Footnotes

1 To whom correspondence may be addressed. Email: nikolan@uc.edu or MCCORMFX@UCMAIL.UC.EDU.

2 Present address: Department of Biochemistry, Sapporo Medical University, School of Medicine, Sapporo, Japan; and Department of Respiratory Medicine and Allergology, Sapporo Medical University, School of Medicine, Sapporo, Japan.

Author contributions: N.M.N., J.G.N., L.B.P., J.C.G., H.W., K.E.L., M.R.W., K.L.H., and F.X.M. designed research; N.M.N., J.G.N., L.B.P., J.C.G., Y.U., H.W., A.S., K.E.L., and H.L. performed research; N.M.N., J.G.N., J.C.G., K.E.L., and F.X.M. analyzed data; and N.M.N. and F.X.M. wrote the paper.

The authors declare no conflict of interest.

This article is a PNAS Direct Submission.

This article contains supporting information online at http://www.pnas.org/lookup/suppl/doi:10.1073/pnas.1621172114/-/DCSupplemental.

Freely available online through the PNAS open access option.

Keywords: Influenza A; Pneumonia.

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#Epitope #Mapping of #Avian #Influenza #M2e Protein: Different Species Recognise Various Epitopes (PLoS One, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

PLoS One. 2016 Jun 30;11(6):e0156418. doi: 10.1371/journal.pone.0156418. eCollection 2016.

Epitope Mapping of Avian Influenza M2e Protein: Different Species Recognise Various Epitopes.

Hasan NH1,2, Ebrahimie E1,3,4,5, Ignjatovic J6, Tarigan S7, Peaston A1, Hemmatzadeh F1.

Author information: 1 School of Animal and Veterinary Sciences, The University of Adelaide, SA, Australia. 2 Institute for Tropical Biology and Conservation, University Malaysia Sabah, Sabah, Malaysia. 3 Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, SA, Australia. 4 School of Information Technology and Mathematical Sciences, Division of Information Technology, Engineering and the Environment, University of South Australia, Adelaide, Australia. 5 School of Biological Sciences, Faculty of Science and Engineering, Flinders University, Adelaide, Australia. 6 School of Veterinary and Agricultural Sciences, The University of Melbourne, Vic, Australia. 7 Indonesian Research Center for Veterinary Sciences, Bogor, Indonesia.

 

Abstract

A common approach for developing diagnostic tests for influenza virus detection is the use of mouse or rabbit monoclonal and/or polyclonal antibodies against a target antigen of the virus. However, comparative mapping of the target antigen using antibodies from different animal sources has not been evaluated before. This is important because identification of antigenic determinants of the target antigen in different species plays a central role to ensure the efficiency of a diagnostic test, such as competitive ELISA or immunohistochemistry-based tests. Interest in the matrix 2 ectodomain (M2e) protein of avian influenza virus (AIV) as a candidate for a universal vaccine and also as a marker for detection of virus infection in vaccinated animals (DIVA) is the rationale for the selection of this protein for comparative mapping evaluation. This study aimed to map the epitopes of the M2e protein of avian influenza virus H5N1 using chicken, mouse and rabbit monoclonal or monospecific antibodies. Our findings revealed that rabbit antibodies (rAbs) recognized epitope 6EVETPTRN13 of the M2e, located at the N-terminal of the protein, while mouse (mAb) and chicken antibodies (cAbs) recognized epitope 10PTRNEWECK18, located at the centre region of the protein. The findings highlighted the difference between the M2e antigenic determinants recognized by different species that emphasized the importance of comparative mapping of antibody reactivity from different animals to the same antigen, especially in the case of multi-host infectious agents such as influenza. The findings are of importance for antigenic mapping, as well as diagnostic test and vaccine development.

PMID: 27362795 PMCID: PMC4928777 DOI: 10.1371/journal.pone.0156418

[Indexed for MEDLINE] Free PMC Article

Keywords: Influenza A; Diagnostic Tests.

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Modelling the emergence of #influenza #drug #resistance: The roles of surface proteins, the immune response and antiviral mechanisms (PLoS One, abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

PLoS One. 2017 Jul 10;12(7):e0180582. doi: 10.1371/journal.pone.0180582. eCollection 2017.

Modelling the emergence of influenza drug resistance: The roles of surface proteins, the immune response and antiviral mechanisms.

Dobrovolny HM1,2, Beauchemin CAA2,3.

Author information: 1 Department of Physics & Astronomy, Texas Christian University, Fort Worth, TX, United States of America. 2 Department of Physics, Ryerson University, Toronto, ON, Canada. 3 Interdisciplinary Theoretical Science (iTHES) Research Group at RIKEN, Wako, Japan.

 

Abstract

The emergence of influenza drug resistance has become of particular interest as current planning for an influenza pandemic involves using massive amounts of antiviral drugs. We use semi-stochastic simulations to examine the emergence of drug resistant mutants during the course of a single infection within a patient in the presence and absence of antiviral therapy. We specifically examine three factors and their effect on the emergence of drug-resistant mutants: antiviral mechanism, the immune response, and surface proteins. We find that adamantanes, because they act at the start of the replication cycle to prevent infection, are less likely to produce drug-resistant mutants than NAIs, which act at the end of the replication cycle. A mismatch between surface proteins and internal RNA results in drug-resistant mutants being less likely to emerge, and emerging later in the infection because the mismatch gives antivirals a second chance to prevent propagation of the mutation. The immune response subdues slow growing infections, further reducing the probability that a drug resistant mutant will emerge and yield a drug-resistant infection. These findings improve our understanding of the factors that contribute to the emergence of drug resistance during the course of a single influenza infection.

PMID: 28700622 DOI: 10.1371/journal.pone.0180582

Keywords: Antivirals; Drugs Resistance; Influenza A; Amantadine; Oseltamivir.

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#Influenza #infection triggers disease in a genetic model of experimental autoimmune #encephalomyelitis (Proc Natl Acad Sci USA, abstract)

[Source: Proceedings of the National Academy of Sciences of the United States of America, full page: (LINK). Abstract, edited.]

Influenza infection triggers disease in a genetic model of experimental autoimmune encephalomyelitis

Stephen Blackmore a, Jessica Hernandez a, Michal Juda a, Emily Ryder b, Gregory G. Freund a,c, Rodney W. Johnson a,b,d, and Andrew J. Steelman a,b,d,1

Author Affiliations: a Department of Animal Sciences, University of Illinois Urbana–Champaign, Urbana, IL 61801; b Neuroscience Program, University of Illinois Urbana–Champaign, Urbana, IL 61801; c Department of Pathology, University of Illinois Urbana–Champaign, Urbana, IL 61801; d Division of Nutritional Sciences, University of Illinois Urbana–Champaign, Urbana, IL 61801

Edited by Lawrence Steinman, Stanford University School of Medicine, Stanford, CA, and approved June 13, 2017 (received for review December 13, 2016)

 

Significance

Peripheral infections exacerbate symptoms of many neurological diseases, including the most common autoimmune demyelinating disease of the central nervous system (CNS), multiple sclerosis (MS). We demonstrate that influenza viral infection of autoimmune-prone mice triggers clinical and histological disease. We further show that influenza infection alters the transcriptome of the central nervous system and facilitates immune cell trafficking to the brain. Finally, we identified a specific chemokine that is upregulated in the CNS during infection that is also increased in the cerebrospinal fluid of MS patients during relapse. These observations improve our understanding of how peripheral infection may act to exacerbate neurological diseases such as multiple sclerosis.

 

Abstract

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system. Most MS patients experience periods of symptom exacerbation (relapses) followed by periods of partial recovery (remission). Interestingly, upper-respiratory viral infections increase the risk for relapse. Here, we used an autoimmune-prone T-cell receptor transgenic mouse (2D2) and a mouse-adapted human influenza virus to test the hypothesis that upper-respiratory viral infection can cause glial activation, promote immune cell trafficking to the CNS, and trigger disease. Specifically, we inoculated 2D2 mice with influenza A virus (Puerto Rico/8/34; PR8) and then monitored them for symptoms of inflammatory demyelination. Clinical and histological experimental autoimmune encephalomyelitis was observed in ∼29% of infected 2D2 mice. To further understand how peripheral infection could contribute to disease onset, we inoculated wild-type C57BL/6 mice and measured transcriptomic alterations occurring in the cerebellum and spinal cord and monitored immune cell surveillance of the CNS by flow cytometry. Infection caused temporal alterations in the transcriptome of both the cerebellum and spinal cord that was consistent with glial activation and increased T-cell, monocyte, and neutrophil trafficking to the brain at day 8 post infection. Finally, Cxcl5 expression was up-regulated in the brains of influenza-infected mice and was elevated in cerebrospinal fluid of MS patients during relapse compared with specimens acquired during remission. Collectively, these data identify a mechanism by which peripheral infection may exacerbate MS as well as other neurological diseases.

upper-respiratory viral infection – multiple sclerosis – neuroinflammation – immune cell – surveillance – experimental autoimmune encephalomyelitis

 

Footnotes

1 To whom correspondence should be addressed. Email: asteelma@illinois.edu.

Author contributions: A.J.S. designed research; S.B., J.H., M.J., E.R., G.G.F., and A.J.S. performed research; G.G.F., R.W.J., and A.J.S. contributed new reagents/analytic tools; S.B., J.H., M.J., E.R., and A.J.S. analyzed data; and S.B. and A.J.S. wrote the paper.

The authors declare no conflict of interest.

This article is a PNAS Direct Submission.

Data deposition: The sequence reported in this paper has been deposited in the NIH Gene Expression Omnibus database (accession no. GSE96870).

This article contains supporting information online at http://www.pnas.org/lookup/suppl/doi:10.1073/pnas.1620415114/-/DCSupplemental.

Keywords: Influenza A; Multiple Sclerosis.

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Complete #Genome #Sequencing of #Influenza A Viruses within #Swine Farrow-to-Wean #Farms Reveals the Emergence, Persistence, and Subsidence of Diverse Viral Genotypes (J Virol., abstract)

[Source: Journal of Virology, full page: (LINK). Abstract, edited.]

Complete Genome Sequencing of Influenza A Viruses within Swine Farrow-to-Wean Farms Reveals the Emergence, Persistence, and Subsidence of Diverse Viral Genotypes

Andres Diaz a, Douglas Marthaler b, Marie Culhane a, Srinand Sreevatsan a, Moh Alkhamis c and Montserrat Torremorell a#

Author Affiliations: Veterinary Population Medicine Department, College of Veterinary Medicine, University of Minnesota, Saint Paul, Minnesota, USA{a}; Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Minnesota, Saint Paul, Minnesota, USA{b}; Environment and Life Sciences Research Center, Kuwait Institute for Scientific Research, Kuwait City, Kuwait{c}

 

ABSTRACT

Influenza A viruses (IAVs) are endemic in swine and represent a public health risk. However, there is limited information on the genetic diversity of swine IAVs within farrow-to-wean farms, which is where most pigs are born. In this longitudinal study, we sampled 5 farrow-to-wean farms during a year and collected 4,190 individual nasal swabs from three distinct pig subpopulations. 207 (4.9%) samples tested PCR positive for IAV, and 124 IAVs were isolated. We sequenced the complete genome of 123 IAV isolates, and found 31 H1N1, 26 H1N2, 63 H3N2 and 3 mixed IAVs. Based on the IAV hemagglutinin seven different influenza A viral groups (VGs) were identified. Most of the remaining IAV gene segments allowed us to differentiate the same VGs although an additional viral group was identified for gene segment 3 (PA). Moreover, the co-detection of more than one IAV VG was documented at different levels (farm, subpopulation, and individual pigs) highlighting the environment for potential IAV reassortment. Additionally, three out of 5 farms contained IAV isolates (n=5) with gene segments from more than one VG, and 79% of all IAVs sequenced contained a signature mutation (S31N) in the matrix gene that has been associated with resistance to the antiviral amantadine. Within farms, some IAVs were only detected once while others were detected for 283 days. Our results illustrate the maintenance and subsidence of different IAVs within swine farrow-to-wean farms over time, demonstrating that pig subpopulation dynamics is important to better understand the diversity and epidemiology of swine IAVs.

 

IMPORTANCE

At the global scale swine are one of the main reservoir species for influenza A viruses (IAVs), and play a key role on the transmission of IAVs between species. Additionally, the 2009 IAV pandemics highlighted the role of pigs in the emergence of IAVs with pandemic potential. However, limited information is available regarding the diversity and distribution of swine IAVs in farrow-to-wean farms where novel IAVs can emerge. In this study we studied 5 swine farrow-to-wean farms during a year and characterized the genetic diversity of IAVs among three different pig subpopulations commonly housed in this type of farms. Using next generation sequencing technologies, we demonstrated the complex distribution and diversity of IAVs among the pig subpopulations studied. Our results demonstrated the dynamic evolution of IAVs within farrow-to-wean farms, which is crucial to improve health interventions to reduce the risk of transmission between pigs and from pigs to people.

 

FOOTNOTES

#Address correspondence to Montserrat Torremorell, torr0033@umn.edu

Copyright © 2017 Diaz et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.

Keywords: Influenza A; Swine Influenza; Pigs; H1N2; H3N2; H1N1.

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#Rapamycin #adjuvant and exacerbation of severe #influenza in an experimental mouse model (Sci Rep., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Sci Rep. 2017 Jun 23;7(1):4136. doi: 10.1038/s41598-017-04365-6.

Rapamycin adjuvant and exacerbation of severe influenza in an experimental mouse model.

Huang CT1, Hung CY2, Chen TC3, Lin CY4, Lin YC5, Chang CS1, He YC1, Huang YL1, Dutta A6.

Author information: 1 Division of Infectious Diseases, Department of Medicine, Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Kweishan, 33333, Taoyuan, Taiwan. 2 Department of Thoracic Medicine, Chang Gung Memorial Hospital, Kweishan, 33333, Taoyuan, Taiwan. 3 Department of Pathology, Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Kweishan, 33333, Taoyuan, Taiwan. 4 Division of Hepatogastroenterology, Department of Medicine, Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Kweishan, 33333, Taoyuan, Taiwan. 5 Division of Hematology and Oncology, Department of Medicine, Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Kweishan, 33333, Taoyuan, Taiwan. 6 Division of Infectious Diseases, Department of Medicine, Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Kweishan, 33333, Taoyuan, Taiwan. duttijiva@gmail.com.

 

Abstract

Influenza virus infection often causes severe disease and acute respiratory distress syndrome. It is a common belief that overwhelming immune response contributes to the severe illness. Physicians and researchers have put forth immune modulation as salvage therapy for better recovery. However, empiric corticosteroid failed in both humans and animal models. Reported success with Rapamycin in humans prompted a comprehensive animal study and mechanistic dissection. Here we report the effect of Rapamycin alone or in combination with Oseltamivir for severe influenza in BALB/c mice. We found that Rapamycin had no antiviral effect against H1N1, H3N2 and novel-H1N1 influenza viruses in vitro. Rapamycin alone aggravated the severe disease of PR8 H1N1 influenza virus infection in mice. Timely Oseltamivir anti-viral therapy abolished the disease. Delayed Oseltamivir treatment could not prevent severe illness and Rapamycin adjuvant was associated with exacerbated disease. Rapamycin adjuvant suppressed influenza hemagglutinin antigen-specific T cell immunity and impaired virus clearance from the lungs. It also resulted in intensified lung pathology with increased intra-alveolar edema and hyaline deposition. Rapamycin may work as the salvage therapy for severe influenza but it is very difficult to define the appropriate window for such treatment to take effect.

PMID: 28646236 DOI: 10.1038/s41598-017-04365-6

Keywords: Influenza A; H1N1; H3N2; H2N2; Antivirals; Oseltamivir; Rapamycin.

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