Avian influenza causes
|
Avian influenza Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Avian influenza causes On the Web |
|
American Roentgen Ray Society Images of Avian influenza causes |
|
Risk calculators and risk factors for Avian influenza causes |
For more details about the avian influenza transmission, replication, and mechanism of infection in humans, click here
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Yazan Daaboul, M.D.
Overview
Avian influenza is caused by influenza A virus. Neither influenza B nor influenza C causes avian influenza. Influenza belongs to the Orthomyxoviridae family. Influenza is an enveloped, pleomorphic (spherical and filamentous forms) virus that contains a linear, segmented (8 segments), negative-sense, single-stranded RNA genome. The genome is composed of 8 segmented genes that encode 11 proteins.
Cause of Avian Influenza
Avian influenza is caused by influenza A virus. Neither influenza B nor influenza C causes avian influenza.
Family
- The influenza virus belongs to the Orthomyxoviridae family.
Genome
- The influenza A virus contains linear, segmented, negative-sense, single-stranded RNA.
- The RNA genome is segmented into 8 distinct segments.
- The total genomic length is approximately 13,000 nucleotides (range from 12,000 to 15,000).
- The genome is composed of 8 genes that encode 11 proteins.
The genome of influenza A consists of 8 gene segments, which encode 11 proteins[1]:
- Hemagglutinin (HA): Surface protein that acts as a receptor binding site. HA is targeted by host antibodies to neutralize the virus.[1][2][3]
- Neuraminidase (NA): Cleaves progeny virions from host cell receptors.[1]
- Polymerase proteins: PB1, PB2, PA, and PB1-F2. These proteins form the polymerase complex. Together with the NP protein, form the ribonucleoprotein (RNP) complex to induce replication and transcription. Additionally, PB1-F2 has a role in inducing apoptosis.[1][4]
- Nucleoprotein (NP): Together with the polymerase proteins, NP forms the RNP complex to induce replication and transcription.[1]
- Non-structural proteins: NS1 and NS2. NS1 processes mRNA and helps the virus evade the host immune responses. NS2 controls the exporting process of RNP from the host nucleus.[1]
- Matrix proteins: M1 and M2. M1 has a role in viral assembly. M2 controls pH in the Golgi body.[1]
Morphology
- The influenza virus contains an envelope.
- The influenza virus is pleomorphic with spherical and filamentous forms with particles that are approximately 80 nm to 120 nm in diameter.
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Korteweg C, Gu J (2008). "Pathology, molecular biology, and pathogenesis of avian influenza A (H5N1) infection in humans". Am J Pathol. 172 (5): 1155–70. doi:10.2353/ajpath.2008.070791. PMC 2329826. PMID 18403604.
- ↑ Zhou J, Law HK, Cheung CY, Ng IH, Peiris JS, Lau YL (2006). "Functional tumor necrosis factor-related apoptosis-inducing ligand production by avian influenza virus-infected macrophages". J Infect Dis. 193 (7): 945–53. doi:10.1086/500954. PMID 16518756.
- ↑ de Jong MD, Tran TT, Truong HK, Vo MH, Smith GJ, Nguyen VC; et al. (2005). "Oseltamivir resistance during treatment of influenza A (H5N1) infection". N Engl J Med. 353 (25): 2667–72. doi:10.1056/NEJMoa054512. PMID 16371632.
- ↑ Hatta M, Gao P, Halfmann P, Kawaoka Y (2001). "Molecular basis for high virulence of Hong Kong H5N1 influenza A viruses". Science. 293 (5536): 1840–2. doi:10.1126/science.1062882. PMID 11546875.