scholarly journals Role of Quail in the Interspecies Transmission of H9 Influenza A Viruses: Molecular Changes on HA That Correspond to Adaptation from Ducks to Chickens

2003 ◽  
Vol 77 (5) ◽  
pp. 3148-3156 ◽  
Author(s):  
Daniel R. Perez ◽  
Wilina Lim ◽  
Jon P. Seiler ◽  
Guan Yi ◽  
Malik Peiris ◽  
...  
Keyword(s):  
Influenza A ◽  
Reverse Genetics ◽  
Influenza Viruses ◽  
Interspecies Transmission ◽  
Influenza A Viruses ◽  
Species Barrier ◽  
Ha Gene ◽  
Novel Variants ◽  
Efficient Replication

ABSTRACT H9 influenza viruses have become endemic in land-based domestic poultry in Asia and have sporadically crossed to pigs and humans. To understand the molecular determinants of their adaptation to land-based birds, we tested the replication and transmission of several 1970s duck H9 viruses in chickens and quail. Quail were more susceptible than chickens to these viruses, and generation of recombinant H9 viruses by reverse genetics showed that changes in the HA gene are sufficient to initiate efficient replication and transmission in quail. Seven amino acid positions on the HA molecule corresponded to adaptation to land-based birds. In quail H9 viruses, the pattern of amino acids at these seven positions is intermediate between those of duck and chicken viruses; this fact may explain the susceptibility of quail to duck H9 viruses. Our findings suggest that quail provide an environment in which the adaptation of influenza viruses from ducks generates novel variants that can cross the species barrier.

scholarly journals Wild Birds in Live Birds Markets: Potential Reservoirs of Enzootic Avian Influenza Viruses and Antimicrobial Resistant Enterobacteriaceae in Northern Egypt

Pathogens ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 196 ◽  
Author(s):  
Nehal M. Nabil ◽  
Ahmed M. Erfan ◽  
Maram M. Tawakol ◽  
Naglaa M. Haggag ◽  
Mahmoud M. Naguib ◽  
...  
Keyword(s):  
Influenza A ◽  
Migratory Birds ◽  
Wild Birds ◽  
Influenza Viruses ◽  
Northern Coast ◽  
Influenza A Viruses ◽  
E Coli ◽  
Ha Gene ◽  
Live Bird

Wild migratory birds are often implicated in the introduction, maintenance, and global dissemination of different pathogens, such as influenza A viruses (IAV) and antimicrobial-resistant (AMR) bacteria. Trapping of migratory birds during their resting periods at the northern coast of Egypt is a common and ancient practice performed mainly for selling in live bird markets (LBM). In the present study, samples were collected from 148 wild birds, representing 14 species, which were being offered for sale in LBM. All birds were tested for the presence of AIV and enterobacteriaceae. Ten samples collected from Northern Shoveler birds (Spatula clypeata) were positive for IAV and PCR sub-typing and pan HA/NA sequencing assays detected H5N8, H9N2, and H6N2 viruses in four, four, and one birds, respectively. Sequencing of the full haemagglutinin (HA) gene revealed a high similarity with currently circulating IAV in Egypt. From all the birds, E. coli was recovered from 37.2% and Salmonella from 20.2%, with 66–96% and 23–43% isolates being resistant to at least one of seven selected critically important antimicrobials (CIA), respectively. The presence of enzootic IAV and the wide prevalence of AMR enterobacteriaceae in wild birds highlight the potential role of LBM in the spread of different pathogens from and to wild birds. Continued surveillance of both AIV and antimicrobial-resistant enterobacteriaceae in wild birds’ habitats is urgently needed.

scholarly journals Influenza A viruses of avian origin circulating in pigs and other mammals.

2014 ◽  
Vol 61 (3) ◽  
Author(s):  
Kinga Urbaniak ◽  
Andrzej Kowalczyk ◽  
Iwona Markowska-Daniel
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Mammalian Species ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
Interspecies Transmission ◽  
Influenza A Viruses ◽  
Avian Influenza Viruses ◽  
Species Barrier ◽  
New Host

Influenza A viruses (IAVs) are zoonotic agents, capable of crossing the species barriers. Nowadays, they still constitute a great challenge worldwide. The natural reservoir of all influenza A viruses are wild aquatic birds, despite the fact they have been isolated from a number of avian and mammalian species, including humans. Even when influenza A viruses are able to get into another than waterfowl population, they are often unable to efficiently adapt and transmit between individuals. Only in rare cases, these viruses are capable of establishing a new lineage. To succeed a complete adaptation and further transmission between species, influenza A virus must overcome a species barrier, including adaptation to the receptors of a new host, which would allow the virus-cell binding, virus replication and, then, animal-to-animal transmission. For many years, pigs were thought to be intermediate host for adaptation of avian influenza viruses to humans, because of their susceptibility to infection with both, avian and human influenza viruses, which supported hypothesis of pigs as a 'mixing vessel'. In this review, the molecular factors necessary for interspecies transmission are described, with special emphasis on adaptation of avian influenza viruses to the pig population. In addition, this review gives the information about swine influenza viruses circulating around the world with special emphasis on Polish strains.

scholarly journals An R195K Mutation in the PA-X Protein Increases the Virulence and Transmission of Influenza A Virus in Mammalian Hosts

2020 ◽  
Vol 94 (11) ◽  
Author(s):  
Yipeng Sun ◽  
Zhe Hu ◽  
Xuxiao Zhang ◽  
Mingyue Chen ◽  
Zhen Wang ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Reverse Genetics ◽  
Inflammatory Responses ◽  
Gene Segment ◽  
Genetic Alterations ◽  
Influenza Viruses ◽  
Interspecies Transmission ◽  
Adaptive Mutation ◽  
Human Origin

ABSTRACT In the 21st century, the emergence of H7N9 and H1N1/2009 influenza viruses, originating from animals and causing severe human infections, has prompted investigations into the genetic alterations required for cross-species transmission. We previously found that replacement of the human-origin PA gene segment in avian influenza virus (AIV) could overcome barriers to cross-species transmission. Recently, it was reported that the PA gene segment encodes both the PA protein and a second protein, PA-X. Here, we investigated the role of PA-X. We found that an H9N2 avian influenza reassortant virus bearing a human-origin H1N1/2009 PA gene was attenuated in mice after the loss of PA-X. Reverse genetics analyses of PA-X substitutions conserved in human influenza viruses indicated that R195K, K206R, and P210L substitutions conferred significantly increased replication and pathogenicity on H9N2 virus in mice and ferrets. PA-X R195K was present in all human H7N9 and H1N1/2009 viruses and predominated in human H5N6 viruses. Compared with PA-X 195R, H7N9 influenza viruses bearing PA-X 195K showed increased replication and transmission in ferrets. We further showed that PA-X 195K enhanced lung inflammatory responses, potentially due to decreased host shutoff function. A competitive transmission study in ferrets indicated that 195K provides a replicative advantage over 195R in H1N1/2009 viruses. In contrast, PA-X 195K did not influence the virulence of H9N2 AIV in chickens, suggesting that the effects of the substitution were mammal specific. Therefore, future surveillance efforts should scrutinize this region of PA-X because of its potential impact on cross-species transmission of influenza viruses. IMPORTANCE Four influenza pandemics in humans (the Spanish flu of 1918 [H1N1], the Asian flu of 1957 [H2N2], the Hong Kong flu of 1968 [H3N2], and the swine origin flu of 2009 [H1N1]) are all proposed to have been caused by avian or swine influenza viruses that acquired virulence factors through adaptive mutation or reassortment with circulating human viruses. Currently, influenza viruses circulating in animals are repeatedly transmitted to humans, posing a significant threat to public health. However, the molecular properties accounting for interspecies transmission of influenza viruses remain unclear. In the present study, we demonstrated that PA-X plays an important role in cross-species transmission of influenza viruses. At least three human-specific amino acid substitutions in PA-X dramatically enhanced the adaptation of animal influenza viruses in mammals. In particular, PA-X 195K might have contributed to cross-species transmission of H7N9, H5N6, and H1N1/2009 viruses from animal reservoirs to humans.

scholarly journals Viral Factors Important for Efficient Replication of Influenza A Viruses in Cells of the Central Nervous System

2019 ◽  
Vol 93 (11) ◽  
Author(s):  
Jurre Y. Siegers ◽  
Marco W. G. van de Bildt ◽  
Zhanmin Lin ◽  
Lonneke M. Leijten ◽  
Rémon A. M. Lavrijssen ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Influenza A ◽  
H5n1 Virus ◽  
Influenza Viruses ◽  
Virus Infections ◽  
Influenza A Viruses ◽  
Cns Disease ◽  
Efficient Replication ◽  
Hpai H5n1 ◽  
In Cells

ABSTRACTCentral nervous system (CNS) disease is one of the most common extrarespiratory tract complications of influenza A virus infections. Remarkably, zoonotic H5N1 virus infections are more frequently associated with CNS disease than seasonal or pandemic influenza viruses. Little is known about the interaction between influenza A viruses and cells of the CNS; therefore, it is currently unknown which viral factors are important for efficient replication. Here, we determined the replication kinetics of a seasonal, pandemic, zoonotic, and lab-adapted influenza A virus in human neuron-like (SK-N-SH) and astrocyte-like (U87-MG) cells and primary mouse cortex neurons. In general, highly pathogenic avian influenza (HPAI) H5N1 virus replicated most efficiently in all cells, which was associated with efficient attachment and infection. Seasonal H3N2 and to a lesser extent pandemic H1N1 virus replicated in a trypsin-dependent manner in SK-N-SH but not in U87-MG cells. In the absence of trypsin, only HPAI H5N1 and WSN viruses replicated. Removal of the multibasic cleavage site (MBCS) from HPAI H5N1 virus attenuated, but did not abrogate, replication. Taken together, our results showed that the MBCS and, to a lesser extent, the ability to attach are important determinants for efficient replication of HPAI H5N1 virus in cells of the CNS. This suggests that both an alternative hemagglutinin (HA) cleavage mechanism and preference for α-2,3-linked sialic acids allowing efficient attachment contribute to the ability of influenza A viruses to replicate efficiently in cells of the CNS. This study further improves our knowledge on potential viral factors important for the neurotropic potential of influenza A viruses.IMPORTANCECentral nervous system (CNS) disease is one of the most common extrarespiratory tract complications of influenza A virus infections, and the frequency and severity differ between seasonal, pandemic, and zoonotic influenza viruses. However, little is known about the interaction of these viruses with cells of the CNS. Differences among seasonal, pandemic, and zoonotic influenza viruses in replication efficacy in CNS cells,in vitro, suggest that the presence of an alternative HA cleavage mechanism and ability to attach are important viral factors. Identifying these viral factors and detailed knowledge of the interaction between influenza virus and CNS cells are important to prevent and treat this potentially lethal CNS disease.

scholarly journals The neuraminidase and matrix genes of the 2009 pandemic influenza H1N1 virus cooperate functionally to facilitate efficient replication and transmissibility in pigs

2012 ◽  
Vol 93 (6) ◽  
pp. 1261-1268 ◽  
Author(s):  
Wenjun Ma ◽  
Qinfang Liu ◽  
Bhupinder Bawa ◽  
Chuanling Qiao ◽  
Wenbao Qi ◽  
...  
Keyword(s):  
Influenza A ◽  
H1n1 Virus ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
Pandemic H1n1 ◽  
Efficient Replication ◽  
Pandemic Influenza H1n1 ◽  
The Right ◽  
Six Genes

The 2009 pandemic H1N1 virus (pH1N1) contains neuraminidase (NA) and matrix (M) genes from Eurasian avian-like swine influenza viruses (SIVs), with the remaining six genes from North American triple-reassortant SIVs. To characterize the role of the pH1N1 NA and M genes in pathogenesis and transmission, their impact was evaluated in the background of an H1N1 triple-reassortant (tr1930) SIV in which the HA (H3) and NA (N2) of influenza A/swine/Texas/4199-2/98 virus were replaced with those from the classical H1N1 A/swine/Iowa/15/30 (1930) virus. The laboratory-adapted 1930 virus did not shed nor transmit in pigs, but tr1930 was able to shed in infected pigs. The NA, M or both genes of the tr1930 virus were then substituted by those of pH1N1. The resulting virus with both NA and M from pH1N1 grew to significantly higher titre in cell cultures than the viruses with single NA or M from pH1N1. In a pig model, only the virus containing both NA and M from pH1N1 was transmitted to and infected sentinels, whereas the viruses with single NA or M from pH1N1 did not. These results demonstrate that the right combination of NA and M genes is critical for the replication and transmissibility of influenza viruses in pigs.

scholarly journals Strain-dependent effects of PB1-F2 of triple-reassortant H3N2 influenza viruses in swine

2012 ◽  
Vol 93 (10) ◽  
pp. 2204-2214 ◽  
Author(s):  
Lindomar Pena ◽  
Amy L. Vincent ◽  
Crystal L. Loving ◽  
Jamie N. Henningson ◽  
Kelly M. Lager ◽  
...  
Keyword(s):  
Virus Replication ◽  
Influenza A ◽  
Reverse Genetics ◽  
Influenza Viruses ◽  
Dependent Manner ◽  
Lung Pathology ◽  
Influenza A Viruses ◽  
Virus Shedding ◽  
The Impact ◽  
Strain Dependent

The PB1-F2 protein of the influenza A viruses (IAVs) can act as a virulence factor in mice. Its contribution to the virulence of IAV in swine, however, remains largely unexplored. In this study, we chose two genetically related H3N2 triple-reassortant IAVs to assess the impact of PB1-F2 in virus replication and virulence in pigs. Using reverse genetics, we disrupted the PB1-F2 ORF of A/swine/Wisconsin/14094/99 (H3N2) (Sw/99) and A/turkey/Ohio/313053/04 (H3N2) (Ty/04). Removing the PB1-F2 ORF led to increased expression of PB1-N40 in a strain-dependent manner. Ablation of the PB1-F2 ORF (or incorporation of the N66S mutation in the PB1-F2 ORF, Sw/99 N66S) affected the replication in porcine alveolar macrophages of only the Sw/99 KO (PB1-F2 knockout) and Sw/99 N66S variants. The Ty/04 KO strain showed decreased virus replication in swine respiratory explants, whereas no such effect was observed in Sw/99 KO, compared with the wild-type (WT) counterparts. In pigs, PB1-F2 did not affect virus shedding or viral load in the lungs for any of these strains. Upon necropsy, PB1-F2 had no effect on the lung pathology caused by Sw/99 variants. Interestingly, the Ty/04 KO-infected pigs showed significantly increased lung pathology at 3 days post-infection compared with pigs infected with the Ty/04 WT strain. In addition, the pulmonary levels of interleukin (IL)-6, IL-8 and gamma interferon were regulated differentially by the expression of PB1-F2. Taken together, these results indicate that PB1-F2 modulates virus replication, virulence and innate immune responses in pigs in a strain-dependent fashion.

scholarly journals Independence of Evolutionary and Mutational Rates after Transmission of Avian Influenza Viruses to Swine

1999 ◽  
Vol 73 (3) ◽  
pp. 1878-1884 ◽  
Author(s):  
J. Stech ◽  
X. Xiong ◽  
C. Scholtissek ◽  
R. G. Webster
Keyword(s):  
New York ◽  
Avian Influenza ◽  
Influenza A ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
Mutation Rates ◽  
Influenza A Viruses ◽  
Species Barrier ◽  
H1n1 Strain ◽  
Serologic Evidence

ABSTRACT In 1979, an H1N1 avian influenza virus crossed the species barrier, establishing a new lineage in European swine. Because there is no direct or serologic evidence of previous H1N1 strains in these pigs, these isolates provide a model for studying early evolution of influenza viruses. The evolutionary rates of both the coding and noncoding changes of the H1N1 swine strains are higher than those of human and classic swine influenza A viruses. In addition, early H1N1 swine isolates show a marked plaque heterogeneity that consistently appears after a few passages. The presence of a mutator mutation was postulated (C. Scholtissek, S. Ludwig, and W. M. Fitch, Arch. Virol. 131:237–250, 1993) to account for these observations and the successful establishment of an avian H1N1 strain in swine. To address this question, we calculated the mutation rates of A/Mallard/New York/6750/78 (H2N2) and A/Swine/Germany/2/81 (H1N1) by using the frequency of amantadine-resistant mutants. To account for the inherent variability of estimated mutation rates, we used a probabilistic model for the statistical analysis. The resulting estimated mutation rates of the two strains were not significantly different. Therefore, an increased mutation rate due to the presence of a mutator mutation is unlikely to have led to the successful introduction of avian H1N1 viruses in European swine.

scholarly journals Establishment of Vero cell RNA polymerase I-driven reverse genetics for Influenza A virus and its application for pandemic (H1N1) 2009 influenza virus vaccine production

2013 ◽  
Vol 94 (6) ◽  
pp. 1230-1235 ◽  
Author(s):  
Min-Suk Song ◽  
Yun Hee Baek ◽  
Philippe Noriel Q. Pascua ◽  
Hyeok-il Kwon ◽  
Su-Jin Park ◽  
...  
Keyword(s):  
Vero Cell ◽  
Influenza A ◽  
Reverse Genetics ◽  
Vero Cells ◽  
Influenza Virus Vaccine ◽  
Influenza Viruses ◽  
Vaccine Production ◽  
Influenza A Viruses ◽  
Alternative Means ◽  
Polymerase I

The constant threat of newly emerging influenza viruses with pandemic potential requires the need for prompt vaccine production. Here, we utilized the Vero cell polymerase I (PolI) promoter, rather than the commonly used human PolI promoter, in an established reverse-genetics system to rescue viable influenza viruses in Vero cells, an approved cell line for human vaccine production. The Vero PolI promoter was more efficient in Vero cells and demonstrated enhanced transcription levels and virus rescue rates commensurate with that of the human RNA PolI promoter in 293T cells. These results appeared to be associated with more efficient generation of A(H1N1)pdm09- and H5N1-derived vaccine seed viruses in Vero cells, whilst the rescue rates in 293T cells were comparable. Our study provides an alternative means for improving vaccine preparation by using a novel reverse-genetics system for generating influenza A viruses.

scholarly journals Sialic Acid Species as a Determinant of the Host Range of Influenza A Viruses

2000 ◽  
Vol 74 (24) ◽  
pp. 11825-11831 ◽  
Author(s):  
Yasuo Suzuki ◽  
Toshihiro Ito ◽  
Takashi Suzuki ◽  
Robert E. Holland ◽  
Thomas M. Chambers ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Viral Replication ◽  
Influenza A ◽  
Lectin Binding ◽  
Influenza Viruses ◽  
Influenza A Viruses ◽  
Acetylneuraminic Acid ◽  
Human Viruses ◽  
Immunohistochemical Analyses

ABSTRACT The distribution of sialic acid (SA) species varies among animal species, but the biological role of this variation is largely unknown. Influenza viruses differ in their ability to recognize SA-galactose (Gal) linkages, depending on the animal hosts from which they are isolated. For example, human viruses preferentially recognize SA linked to Gal by the α2,6(SAα2,6Gal) linkage, while equine viruses favor SAα2,3Gal. However, whether a difference in relative abundance of specific SA species (N-acetylneuraminic acid [NeuAc] andN-glycolylneuraminic acid [NeuGc]) among different animals affects the replicative potential of influenza viruses is uncertain. We therefore examined the requirement for the hemagglutinin (HA) for support of viral replication in horses, using viruses whose HAs differ in receptor specificity. A virus with an HA recognizing NeuAcα2,6Gal but not NeuAcα2,3Gal or NeuGcα2,3Gal failed to replicate in horses, while one with an HA recognizing the NeuGcα2,3Gal moiety replicated in horses. Furthermore, biochemical and immunohistochemical analyses and a lectin-binding assay demonstrated the abundance of the NeuGcα2,3Gal moiety in epithelial cells of horse trachea, indicating that recognition of this moiety is critical for viral replication in horses. Thus, these results provide evidence of a biological effect of different SA species in different animals.

scholarly journals Influenza A Viruses Control Expression of Proviral Human p53 Isoforms p53β and Δ133p53α

2012 ◽  
Vol 86 (16) ◽  
pp. 8452-8460 ◽  
Author(s):  
Olivier Terrier ◽  
Virginie Marcel ◽  
Gaëlle Cartet ◽  
David P. Lane ◽  
Bruno Lina ◽  
...  
Keyword(s):  
Virus Infection ◽  
Cell Fate ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
Influenza Viruses ◽  
Lung Epithelial Cells ◽  
Dependent Manner ◽  
Influenza A Viruses ◽  
P53 Isoforms

Previous studies have described the role of p53 isoforms, including p53β and Δ133p53α, in the modulation of the activity of full-length p53, which regulates cell fate. In the context of influenza virus infection, an interplay between influenza viruses and p53 has been described, with p53 being involved in the antiviral response. However, the role of physiological p53 isoforms has never been explored in this context. Here, we demonstrate that p53 isoforms play a role in influenza A virus infection by using silencing and transient expression strategies in human lung epithelial cells. In addition, with the help of a panel of different influenza viruses from different subtypes, we also show that infection differentially regulates the expressions of p53β and Δ133p53α. Altogether, our results highlight the role of p53 isoforms in the viral cycle of influenza A viruses, with p53β and Δ133p53α acting as regulators of viral production in a p53-dependent manner.

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