Alphainfluenzavirus

Description: English: Genomes of influenza viruses. A) The ends of the negative strand influenza genomic RNA are complexed with the three polymerase proteins and the remaining sequence is encapsidated with nucleoprotein (vRNP (-)). The positive strand cRNP is similarly complexed. The mRNA is transcribed with a 5’ cap structure and poly-A tail (see main text for details). Figure used with permission from Resa-Infante et al., 2011. B) Schematic of the influenza A virus genome. The bold black lines represent the 3’ and 5’ untranslated regions. The blue and pink boxes represent the major protein coding regions. C) Schematic of the influenza B virus genome. The green and brown boxes represent the major protein coding regions. D) Schematic of the influenza C virus genome. The red and purple boxes represent the major protein coding regions. The protein coding regions are not to scale. Coding regions in a different reading frame are shown above or below each other, coding regions in the same frame are show as contiguous blocks. Date: 20 November 2013. Source: https://www.intechopen.com/books/current-issues-in-molecular-virology-viral-genetics-and-biotechnological-applications/gene-constellation-of-influenza-vaccine-seed-viruses. Author: Ewan P. Plant and Zhiping Ye.

Description: English: Coordination of viral ribonucleoprotein (vRNP) assembly and trafficking to the plasma membrane. Upon entry into the host cell nucleus, (i) the vRNP-associated viral polymerase transcribes the viral mRNAs. (ii) The mRNAs are either directly, or after alternative splicing, exported for translation by cytosolic ribosomes. (iii) Newly synthesized viral polymerase subunits (PA, PB1, and PB2) and nucleoprotein (NP) are imported back into the nucleus. (iv) Due to the inefficient dinucleotide priming, the vRNP-associated viral polymerase also infrequently transcribes complimentary RNA (cRNA) copies that assemble into cRNPs via (v) binding of a newly synthesized viral polymerase (PA, PB1, and PB2) and NP. (vi) The polymerase transcribes viral RNA (vRNA) copies from the positive strand in the cRNPs and these assemble into vRNPs by (vii) association with a new viral polymerase (PA, PB1, and PB2) and NP. Once assembled, the new vRNPs can (viii) transcribe additional viral mRNAs, (ix) transcribe new cRNA copies, or (x) associate with the newly synthesized viral proteins M1 and NS2 to facilitate the recruitment of CRM1, which (xi) mediates the nuclear export of the vRNP. (xiia) Once exported, the vRNPs then associate with Rab11 that assists in the trafficking of the vRNPs toward the cell surface. The vRNP trafficking either occurs by Rab11-containing vesicles associated with microtubules or (xiib) through Rab11 located in the modified endoplasmic reticulum (ER) membranes. How the vRNPs reach the budding site at the plasma membrane is currently not known. Date: 20 July 2018. Source: https://www.frontiersin.org/articles/10.3389/fimmu.2018.01581/full. Author: imageDan Dou, Rebecca Revol, Henrik Östbye, Hao Wang, and Robert Daniels.

Description: English: Transmission electron micrograph of influenza A virus, late passage. Deutsch: aviäres Influenzavirus (HPAIV), elektronenmikroskopische Aufnahme 日本語: 高病原性トリインフルエンザウイルス, 長期間継代培養したトリインフルエンザウイルスの透過電子顕微鏡像。 한국어: 조류 독감을 일으키는 인플루엔자바이러스 A형. Date: 1981. Source: : This media comes from the Centers for Disease Control and Prevention's Public Health Image Library (PHIL), with identification number #280. Note: Not all PHIL images are public domain; be sure to check copyright status and credit authors and content providers. العربية | Deutsch | English | македонски | slovenščina | +/−. Author: Photo Credit: Content Providers(s): CDC/ Dr. Erskine Palmer. Permission(Reusing this file): PD-USGov-HHS-CDC (None - This image is in the public domain and thus free of any copyright restrictions. As a matter of courtesy we request that the content provider be credited and notified in any public or private usage of this image.).

Description: Español: Mauro Zernotti, Médico Clínico, Sobre los grupos de riesgo de la Gripe A (H1N1). Date: 2 June 2016. Source: Own work. Author: María Antonieta Cacciavillani.

Description: Colorized transmission electron micrograph of negatively stained SW31 (swine strain) influenza virus particles. Credit: NIAID. Date: 29 July 2014, 11:56. Source: Swine Flu Strain Virus Particles. Author: NIAID.

Description: English: Transmission of Equine Influenza Virus (EIV). Droplet infection is an important mode of transmission. Transmission between animals includes crowded housing practices, non-vaccination, young horses of 1–5 years and international trade. Dog gets EIV by consuming infected dead horse meat. Date: 6 September 2018. Source: https://www.frontiersin.org/articles/10.3389/fmicb.2018.01941/full. Author: Raj K. Singh, Kuldeep Dhama, Kumaragurubaran Karthik, Rekha Khandia, Ashok Munjal, Sandip K. Khurana, Sandip Chakraborty, Yashpal S. Malik, Nitin Virmani, Rajendra Singh, Bhupendra N. Tripathi, Muhammad Munir, and Johannes H. van der Kolk.

: All images in this article were uploaded in the JPEG format even though it consists of non-photographic data. This information could be stored more efficiently or accurately in the PNG or SVG format. If possible, please upload a PNG or SVG version of this image without compression artifacts, derived from a non-JPEG source (or with existing artifacts removed). After doing so, please tag the JPEG version with {{Superseded|NewImage.ext}} and remove this tag. This tag should not be applied to photographs or scans. For more information, see {{BadJPEG}}.:. Description: English: Dimer of the Influenzavirus A non-structural protein 1 from A/Vietnam/1203/2004(H5N1). Date: 1 December 2008. Source: http://www.rcsb.org/pdb/explore/images.do?structureId=3F5T. Author: Image from the RCSB PDB (www.rcsb.org) of PDB ID 3F5T, by Z. A. Bornholdt, B. V. Prasad: X-ray structure of NS1 from a highly pathogenic H5N1 influenza virus. In: Nature. Band 456, Nummer 7224, Dezember 2008, ISSN 1476-4687, S. 985–988, doi:10.1038/nature07444, PMID 18987632, PMC 2798118.

Description: English: Influenza A virus. Date: 1 March 2021. Source: [1]. Author: Hi Eun Jung and Heung Kyu Lee.

Description: English: Phylogenetic analysis of hemagglutinin (HA) genes nucleotide sequences from 57 Equine Influenza Viruses (EIVs). The maximum likelihood tree was constructed using stringent T92 + G algorithm which was identified using the find best DNA/protein model tool available in MEGA 6. The reliability of the trees was assessed by bootstrap with 1,000 replications with cut off at 50 are shown in the tree. The phylogram depicts five major clusters of global EIVs. Phylogenetic group's viz., Florida sub-lineage clade 1, Florida sub-lineage clade 2, American, Eurasian and Pre-divergent, are mentioned by bars on the right. The major mutations (I179V and A144V) observed in the Clade 2 viruses of Florida sublineage in recent isolates have been denoted by solid dots. Date: 6 September 2018. Source: https://www.frontiersin.org/articles/10.3389/fmicb.2018.01941/full. Author: Raj K. Singh, Kuldeep Dhama, Kumaragurubaran Karthik, Rekha Khandia, Ashok Munjal, Sandip K. Khurana, Sandip Chakraborty, Yashpal S. Malik, Nitin Virmani, Rajendra Singh, Bhupendra N. Tripathi, Muhammad Munir, and Johannes H. van der Kolk.

Description: Colorized transmission electron micrograph of negatively stained SW31 (swine strain) influenza virus particles. Credit: NIAID. Date: 31 July 2014, 10:17. Source: Swine Flu Strain Virus Particles. Author: NIAID.

Description: English: Neuraminidase tetramer + 4-4 Fab HC and LC (Mouse) + NAG (= N-acetyl glucosamine, green) + sugars (green) + 4 Ca (red), Influenza A virus. Date: 19 May 2016 (upload to Wikimedia Commons), 23 July 2005 (deposition at PDB). Source: http://www.rcsb.org/pdb/explore/explore.do?structureId=2aep. Author: Deposition authors: Venkatramani, L., Bochkareva, E., Lee, J.T., Gulati, U., Laver, W.G., Bochkarev, A., Air, G.M.; visualization author: User:Astrojan.

Description: English: Influenza A and B viruses. (A) Schematic of the eight viral RNA (vRNA) gene segments that comprise the influenza A and B genomes. The 5′ and 3′ untranslated regions (UTRs), which contain the viral promoters, are represented with a line, and the box corresponds to the coding region within each vRNA. (B) Diagram of the viral mRNAs that are transcribed from the IAV (left) and IBV (right) vRNA templates. Boxes indicate the viral gene product encoded by each mRNA and the dashed lines show the alternative splicing of the IAV M and NS transcripts, as well as the IBV NS transcript. Red circles represent the 5′ M7pppG cap, black lines denote the 10–13 nucleotide, host-derived primers that are obtained by the cap-snatching mechanism of the viral polymerase. A(n) corresponds to the 3′ poly-A tail produced by reiterative stuttering of the viral polymerase. The smaller mRNAs (empty boxes) represent transcripts that encode nonessential accessory proteins found in many strains, whereas those that are less prevalent (PB2-S1, M42, and NS3) are not illustrated (6–11). (C) Diagram of an influenza A or B virus. The viral membrane proteins HA, NA, and M2 are shown, along with the eight viral ribonucleoproteins (vRNPs), and the matrix protein M1 that supports the viral envelope. To highlight the vRNP components, the illustration beneath the virus is not to scale. A single vRNA gene segment is shown wrapped around multiple nucleoprotein (NP) copies with the conserved promoter regions in the 5′ and 3′ UTRs forming a helical hairpin, which is bound by a single heterotrimeric viral RNA-dependent RNA polymerase (PB1, PB2, and PA). (D) Top view of an influenza virus cross-section showing the vRNP “1 + 7” configuration. vRNPs are depicted with black circles as it is not known if the positioning of a particular vRNP is conserved or interchangeable. Date: 20 July 2018. Source: https://www.frontiersin.org/articles/10.3389/fimmu.2018.01581/full. Author: Dan Dou, Rebecca Revol, Henrik Östbye, Hao Wang, and Robert Daniels.

Description: English: Receptor-mediated cell entry of IAVs. (A) Diagram of a bi-antennary N-linked glycan. The terminal sialic acid residues are displayed with an α-2,3 linkage, as well as an α-2,6 linkage, to illustrate the “linear” and “bent” presentations. (B) Illustration of IAV cell entry. (i) IAVs initiate cell entry by using the HA receptor-binding domain (located in the HA1 region) to associate with sialylated glycoconjugates on a host “receptor.” Binding to the “receptor” triggers endocytosis. (ii) The virus then traffics to the endosome where the lower pH facilitates a conformational change in HA, exposing the fusion peptide (located in the HA2 region) for insertion into the endosomal membrane. (iii) The HA pre-hairpin conformation begins to collapse, forming a six-helix bundle that promotes hemifusion of the viral envelop with the endosomal membrane. At some point, the M2 channel opens to release the viral ribonucleoproteins (vRNPs) from M1 by acidifying the viral interior. (iv) HA further collapses into a trimer of hairpins to promote the formation of the fusion pore, which (v) releases the vRNPs into the cytosol. (vi) The exposed nuclear localization signals (NLS) on the vRNPs are recognized by the adaptor protein importin-α, leading to the recruitment of importin-β that (vii) facilitates the transport through the nuclear pore complex (NPC) and into the nucleus. Date: 20 July 2018. Source: https://www.frontiersin.org/articles/10.3389/fimmu.2018.01581/full. Author: imageDan Dou, Rebecca Revol, Henrik Östbye, Hao Wang, and Robert Daniels.

Description: English: Replication and pathogenesis of Equine Influenza Virus (EIV). EIV damages the upper and lower respiratory tract's ciliated epithelial cells thereby causes inability to clear foreign substances. Spike glycoprotein HA fastens to the receptors present on the respiratory epithelial cells and it enters the cells by endocytosis. After endocytosis, EIV undergoes fusion and uncoating. Opening of M2 channel leads to proton entry and subsequent release of viral RNA followed by synthesis of viral structures leading to assembly of EIV. EIV is released from the infected cells by the process of budding. Date: 6 September 2018. Source: https://www.frontiersin.org/articles/10.3389/fmicb.2018.01941/full. Author: Raj K. Singh, Kuldeep Dhama, Kumaragurubaran Karthik, Rekha Khandia, Ashok Munjal, Sandip K. Khurana, Sandip Chakraborty, Yashpal S. Malik, Nitin Virmani, Rajendra Singh, Bhupendra N. Tripathi, Muhammad Munir, and Johannes H. van der Kolk.

Description: English: This digitally-colorized, negative-stained transmission electron microscopic (TEM) image depicted a number of Influenza A virions. Date: 1976. Source: https://phil.cdc.gov/Details.aspx?pid=11702. Author: F A Murphy.

Description: English: Replacing A/WSN/22 region of Influenza A genome - which encodes for Hemagglutinin (HA) - for the sequence of Renilla luciferase. Infected cells will show luminiscence. Date: 28 June 2011. Source: Own work. Author: Albert.caballeria.

Description: English: Transcription of the complimentary RNA (cRNA) and viral RNA (vRNA) by the heterotrimeric viral RNA-dependent RNA polymerase (PB2, PB1, and PA). (A) The viral polymerase initiates transcription of the positive-sense cRNA upon base-pairing of ATP and GTP with the complimentary nucleotides in the 3′ end of the vRNA. The subsequent formation of the A-G dinucleotide is followed by elongation of the cRNA transcript. Nucleoprotein (NP) molecules successively bind to the cRNA as it exits the polymerase, promoting cRNP assembly. cRNP formation is completed upon the termination of transcription and with the binding of a newly synthesized viral polymerase (yellow outline). (B) vRNA transcription proceeds in a similar manner as cRNA synthesis. Recent structures support a model where (i) ATP and GTP base pair to the nucleotides located 4 and 5 bases from the cRNA 3′ end, and there form a dinucleotide, which then disassociates and reanneals with the bases at positions 1 and 2. (ii) Alternatively, ATP and GTP could bind directly to the terminal nucleotides and form a dinucleotide. Both mechanisms would position the dinucleotide at the cRNA 3′ end, which is necessary to transcribe a full-length vRNA. Similar to cRNP formation, multiple NPs and a viral polymerase bind to the newly transcribed vRNA to produce a new viral ribonucleoprotein (vRNP). Date: 20 July 2018. Source: https://www.frontiersin.org/articles/10.3389/fimmu.2018.01581/full. Author: imageDan Dou, Rebecca Revol, Henrik Östbye, Hao Wang, and Robert Daniels.

Description: Colorized transmission electron micrograph of negatively stained SW31 (swine strain) influenza virus particles. Credit: NIAID. Date: 31 July 2014, 10:17. Source: Swine Flu Strain Virus Particles. Author: NIAID.

Description: English: This negatively-stained transmission electron microscopic (TEM) image revealed the presence of a number of Hong Kong Flu virus virions, the H3N2 subtype of the Influenza A virus. Note the proteinaceous coat, or capsid, surrounding each virion, and the hemagglutinin-neuraminidase spikes, which differ in terms of their molecular make-up from strain to strain. Date: 1974. Source: https://phil.cdc.gov/Details.aspx?pid=10245. Author: CDC/ Dr. Fred Murphy.

Summary.mw-parser-output table.commons-file-information-table,.mw-parser-output.fileinfotpl-type-information{border:1px solid #a2a9b1;background-color:#f8f9fa;padding:5px;font-size:95%;border-spacing:2px;box-sizing:border-box;margin:0;width:100%}.mw-parser-output table.commons-file-information-table>tbody>tr,.mw-parser-output.fileinfotpl-type-information>tbody>tr{vertical-align:top}.mw-parser-output table.commons-file-information-table>tbody>tr>td,.mw-parser-output table.commons-file-information-table>tbody>tr>th,.mw-parser-output.fileinfotpl-type-information>tbody>tr>td,.mw-parser-output.fileinfotpl-type-information>tbody>tr>th{padding:4px}.mw-parser-output.fileinfo-paramfield{background:#ccf;text-align:right;padding-right:0.4em;width:15%;font-weight:bold}.mw-parser-output.commons-file-information-table+table.commons-file-information-table,.mw-parser-output.commons-file-information-table+div.commons-file-information-table>table{border-top:0;padding-top:0;margin-top:-8px}@media only screen and (max-width:719px){.mw-parser-output table.commons-file-information-table,.mw-parser-output.commons-file-information-table.fileinfotpl-type-information{border-spacing:0;padding:0;word-break:break-word;width:100%!important}.mw-parser-output.commons-file-information-table>tbody,.mw-parser-output.fileinfotpl-type-information>tbody{display:block}.mw-parser-output.commons-file-information-table>tbody>tr>td,.mw-parser-output.commons-file-information-table>tbody>tr>th,.mw-parser-output.fileinfotpl-type-information>tbody>tr>td,.mw-parser-output.fileinfotpl-type-information>tbody>tr>th{padding:0.2em 0.4em;text-align:left;text-align:start}.mw-parser-output.commons-file-information-table>tbody>tr,.mw-parser-output.fileinfotpl-type-information>tbody>tr{display:flex;flex-direction:column}.mw-parser-output.commons-file-information-table+table.commons-file-information-table,.mw-parser-output.commons-file-information-table+div.commons-file-information-table>table{margin-top:-1px}.mw-parser-output.fileinfo-paramfield{box-sizing:border-box;flex:1 0 100%;width:100%}} Description: Antigenic drift is the process by which the flu virus genetically mutates, producing new virus strains that may not be recognozed by the body's immune system. Credit: NIAID. Date: 21 October 2010, 13:31. Source: Antigenic Drift of the Flu Virus. Author: NIAID.

Description: Español: Mauro Zernotti, Médico Clínico, Sobre la gripe A (H1N1). Date: 2 June 2016. Source: Own work. Author: María Antonieta Cacciavillani.

Description: Genetic relationships among human and swine influenza viruses, 1918-2009. Red arrows indicate human influenza virus lineages, black arrows swine influenza virus lineages, and gray arrows exportation of one or more genes from the avian influenza A virus gene pool. Horizontal bars shown inside the virus represent each of the eight virus genes, abbreviated PB2, PB1, PA, HA, NP, NA, M and NS. Credit: NIAID. Date: 6 February 2012, 10:21. Source: Evolution of Flu Viruses, 1918-2009. Author: NIAID.

Description: In order to infect a healthy cell, a flu virus must enter the cell (upper left) and empty viral genes into it. First, the virus binds to the cell. Then it becomes enveloped inside a bubble called an endosome as it gets taken into the cell. It is acidic inside the endosome--more acidic than the interior of the virus it contains. This pH difference serves as a signal to the virus that it is inside the cell, so it is time to release the viral genes (shown as orange squiggles). It is the M2 proton channel that helps the virus sense this difference in acidity and trigger the release of viral genes into the cell. Since the cell cannot tell the difference between its own genes and those of the virus, it gets tricked into making copies of the virus which can eventually go on to infect other cells. Check out the NSF Discovery to learn more. Credit: Nicolle Rager Fuller, National Science Foundation Visit NSF’s Multimedia Gallery, at www.nsf.gov/news/mmg, for more images, and for video. Date: 31 January 2012, 13:45. Source: Flu Virus. Author: National Science Foundation.

All images in this article were uploaded in the JPEG format even though it consists of non-photographic data. This information could be stored more efficiently or accurately in the PNG or SVG format. If possible, please upload a PNG or SVG version of this image without compression artifacts, derived from a non-JPEG source (or with existing artifacts removed). After doing so, please tag the JPEG version with {{Superseded|NewImage.ext}} and remove this tag. This tag should not be applied to photographs or scans. For more information, see {{BadJPEG}}. Description: English: RNA-binding protein in the virions of influenzavirus A. Date: 1 March 2013. Source: http://www.rcsb.org/pdb/explore/explore.do?structureId=3ZDP. Author: Image from the RCSB PDB (www.rcsb.org) of PDB ID 3ZDP, by S. Chenavas, L. F. Estrozi, A. Slama-Schwok, B. Delmas, C. Di Primo, F. Baudin, X. Li, T. Crépin, R. W. Ruigrok: Monomeric nucleoprotein of influenza A virus. In: PLoS pathogens. Band 9, Nummer 3, März 2013, ISSN 1553-7374, S. e1003275, doi:10.1371/journal.ppat.1003275, PMID 23555270, PMC 3610751.