Current knowledge on PB1-F2 of influenza A viruses

Krumbholz, Andi; Philipps, Anja; Oehring, H; Schwarzer, Katja; Eitner, Annett; Wutzler, Peter; Zell, Roland

doi:10.1007/s00430-010-0176-8

Cited by 80 publications

(73 citation statements)

References 37 publications

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“…The PB1-F2, which is expressed from a ϩ1 reading frame of the viral RNA polymerase subunit PB1 (8), is able to induce apoptosis and promote inflammation (24) and has been shown to be a virulence factor and promote secondary bacterial infections (34). However, the 2009 pH1N1 viruses do not express full-length PB1-F2 because they possess three stop codons at amino acid positions 12, 58, and 88 in the PB1-F2 reading frame.…”

Section: Discussionmentioning

confidence: 99%

2009 Pandemic H1N1 Influenza Virus Causes Disease and Upregulation of Genes Related to Inflammatory and Immune Responses, Cell Death, and Lipid Metabolism in Pigs

Belisle

Mosier

et al. 2011

J Virol

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Section: Discussionmentioning

confidence: 99%

2009 Pandemic H1N1 Influenza Virus Causes Disease and Upregulation of Genes Related to Inflammatory and Immune Responses, Cell Death, and Lipid Metabolism in Pigs

Belisle

Mosier

et al. 2011

J Virol

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“…Exceptions to these generalizations abound. 72,143,174 Insertion of genes for the full-length protein into viruses with truncated forms does not necessarily enhance virulence, calling into question the protein's role as a virulence factor. Similarly in swine, most but not all swine triple reassortant H3N2 viruses express full-length PB1-F2 proteins, but in vitro and in vivo studies have not consistently associated the presence of these proteins with increased virulence.…”

Section: Pb1-f2mentioning

confidence: 99%

Influenza A Virus Infections in Swine

Janke

2013

Vet Pathol

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Influenza has been recognized as a respiratory disease in swine since its first appearance concurrent with the 1918 ''Spanish flu'' human pandemic. All influenza viruses of significance in swine are type A, subtype H1N1, H1N2, or H3N2 viruses. Influenza viruses infect epithelial cells lining the surface of the respiratory tract, inducing prominent necrotizing bronchitis and bronchiolitis and variable interstitial pneumonia. Cell death is due to direct virus infection and to insult directed by leukocytes and cytokines of the innate immune system. The most virulent viruses consistently express the following characteristics of infection: (1) higher or more prolonged virus replication, (2) excessive cytokine induction, and (3) replication in the lower respiratory tract. Nearly all the viral proteins contribute to virulence. Pigs are susceptible to infection with both human and avian viruses, which often results in gene reassortment between these viruses and endemic swine viruses. The receptors on the epithelial cells lining the respiratory tract are major determinants of infection by influenza viruses from other hosts. The polymerases, especially PB2, also influence cross-species infection. Methods of diagnosis and characterization of influenza viruses that infect swine have improved over the years, driven both by the availability of new technologies and by the necessity of keeping up with changes in the virus. Testing of oral fluids from pigs for virus and antibody is a recent development that allows efficient sampling of large numbers of animals.Keywords influenza virus, swine, pathogenesis, cytokines, apoptosis, virulence, cross-species infection, hemagglutinin, receptors, polymerases, diagnosisThe evolution and epidemiology of influenza A virus (IAV) infections in swine have been integrally tied to the segmented nature of the genome of the virus, which facilitates gene reassortment, and to the adaptability of these genes through mutation, which sometimes facilitates replication in a new host. 8,19,77,85,89 Influenza was first recognized as a respiratory disease entity in swine during the 1918 human Spanish flu pandemic. 67 The virus was not isolated until 1931, when nasal discharge from pigs was inoculated into ferrets and subsequently into embryonated chicken eggs. 129 In 1933, a similar virus was recovered from humans with this technique. 131 The viruses were essentially identical and served as the prototype for type A subtype H1N1 influenza viruses.All influenza viruses of significance that infect swine are type A viruses, defined by the highly conserved internal nucleoproteins and matrix proteins. Influenza A virus subtypes are based on the external hemagglutinin (HA) and neuraminidase (NA) proteins. The predominant viruses in swine populations in different parts of the world may have genes of different origin, even though the subtypes may be similar. 10,73,171 The original classic H1N1 swine influenza virus, which remained the predominant influenza virus in North American swine populations for nearl...

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“…The PB1 gene also encodes the PB1-F2 protein, which affects innate immune responses and the regulation of apoptosis in virusinfected cells (30,31). The full-length PB1-F2 protein encompasses 89 amino acids; however, many influenza A viruses, including some A(H7N9) viruses, encode premature stop codons, resulting in shorter PB1-F2 proteins whose contributions to virulence are not fully understood.…”

Section: Figmentioning

confidence: 99%