scholarly journals Dynamic changes in host gene expression associated with H5N8 avian influenza virus infection in mice

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Su-Jin Park ◽  
Mukesh Kumar ◽  
Hyeok-il Kwon ◽  
Rak-Kyun Seong ◽  
Kyudong Han ◽  
...  

Abstract Emerging outbreaks of newly found, highly pathogenic avian influenza (HPAI) A(H5N8) viruses have been reported globally. Previous studies have indicated that H5N8 pathogenicity in mice is relatively moderate compared with H5N1 pathogenicity. However, detailed mechanisms underlying avian influenza pathogenicity are still undetermined. We used a high-throughput RNA-seq method to analyse host and pathogen transcriptomes in the lungs of mice infected with A/MD/Korea/W452/2014 (H5N8) and A/EM/Korea/W149/2006 (H5N1) viruses. Sequenced numbers of viral transcripts and expression levels of host immune-related genes at 1 day post infection (dpi) were higher in H5N8-infected than H5N1-infected mice. Dual sequencing of viral transcripts revealed that in contrast to the observations at 1 dpi, higher number of H5N1 genes than H5N8 genes was sequenced at 3 and 7 dpi, which is consistent with higher viral titres and virulence observed in infected lungs in vivo. Ingenuity pathway analysis revealed a more significant upregulation of death receptor signalling, driven by H5N1 than with H5N8 infection at 3 and 7 dpi. Early induction of immune response-related genes may elicit protection in H5N8-infected mice, which correlates with moderate pathogenicity in vivo. Collectively, our data provide new insight into the underlying mechanisms of the differential pathogenicity of avian influenza viruses.

2007 ◽  
Vol 81 (21) ◽  
pp. 11612-11619 ◽  
Author(s):  
Erica Spackman ◽  
David E. Swayne ◽  
David L. Suarez ◽  
Dennis A. Senne ◽  
Janice C. Pedersen ◽  
...  

ABSTRACT Wild-bird surveillance in North America for avian influenza (AI) viruses with a goal of early identification of the Asian H5N1 highly pathogenic AI virus has identified at least six low-pathogenicity H5N1 AI viruses between 2004 and 2006. The hemagglutinin (HA) and neuraminidase (NA) genes from all 6 H5N1 viruses and an additional 38 North American wild-bird-origin H5 subtype and 28 N1 subtype viruses were sequenced and compared with sequences available in GenBank by phylogenetic analysis. Both HA and NA were phylogenetically distinct from those for viruses from outside of North America and from those for viruses recovered from mammals. Four of the H5N1 AI viruses were characterized as low pathogenicity by standard in vivo pathotyping tests. One of the H5N1 viruses, A/MuteSwan/MI/451072-2/06, was shown to replicate to low titers in chickens, turkeys, and ducks. However, transmission of A/MuteSwan/MI/451072-2/06 was more efficient among ducks than among chickens or turkeys based on virus shed. The 50% chicken infectious dose for A/MuteSwan/MI/451072-2/06 and three other wild-waterfowl-origin H5 viruses were also determined and were between 105.3 and 107.5 50% egg infective doses. Finally, seven H5 viruses representing different phylogenetic clades were evaluated for their antigenic relatedness by hemagglutination inhibition assay, showing that the antigenic relatedness was largely associated with geographic origin. Overall, the data support the conclusion that North American H5 wild-bird-origin AI viruses are low-pathogenicity wild-bird-adapted viruses and are antigenically and genetically distinct from the highly pathogenic Asian H5N1 virus lineage.


2016 ◽  
Vol 90 (23) ◽  
pp. 10936-10944 ◽  
Author(s):  
Xiangjie Sun ◽  
Jessica A. Belser ◽  
Joanna A. Pulit-Penaloza ◽  
Hui Zeng ◽  
Amanda Lewis ◽  
...  

ABSTRACTAvian influenza A H7 viruses have caused multiple outbreaks in domestic poultry throughout North America, resulting in occasional infections of humans in close contact with affected birds. In early 2016, the presence of H7N8 highly pathogenic avian influenza (HPAI) viruses and closely related H7N8 low-pathogenic avian influenza (LPAI) viruses was confirmed in commercial turkey farms in Indiana. These H7N8 viruses represent the first isolation of this subtype in domestic poultry in North America, and their virulence in mammalian hosts and the potential risk for human infection are largely unknown. In this study, we assessed the ability of H7N8 HPAI and LPAI viruses to replicatein vitroin human airway cells andin vivoin mouse and ferret models. Both H7N8 viruses replicated efficientlyin vitroandin vivo, but they exhibited substantial differences in disease severity in mammals. In mice, while the H7N8 LPAI virus largely remained avirulent, the H7N8 HPAI virus exhibited greater infectivity, virulence, and lethality. Both H7N8 viruses replicated similarly in ferrets, but only the H7N8 HPAI virus caused moderate weight loss, lethargy, and mortality. The H7N8 LPAI virus displayed limited transmissibility in ferrets placed in direct contact with an inoculated animal, while no transmission of H7N8 HPAI virus was detected. Our results indicate that the H7N8 avian influenza viruses from Indiana are able to replicate in mammals and cause severe disease but with limited transmission. The recent appearance of H7N8 viruses in domestic poultry highlights the need for continued influenza surveillance in wild birds and close monitoring of the potential risk to human health.IMPORTANCEH7 influenza viruses circulate in wild birds in the United States, but when the virus emerges in domestic poultry populations, the frequency of human exposure and the potential for human infections increases. An H7N8 highly pathogenic avian influenza (HPAI) virus and an H7N8 low-pathogenic avian influenza (LPAI) virus were recently isolated from commercial turkey farms in Indiana. To determine the risk that these influenza viruses pose to humans, we assessed their pathogenesis and transmissionin vitroand in mammalian models. We found that the H7N8 HPAI virus exhibited enhanced virulence, and although transmission was only observed with the H7N8 LPAI virus, the ability of this H7 virus to transmit in a mammalian host and quickly evolve to a more virulent strain is cause for concern. Our findings offer important insight into the potential for emerging H7 avian influenza viruses to acquire the ability to cause disease and transmit among mammals.


2021 ◽  
Vol 12 ◽  
Author(s):  
Albert Perlas ◽  
Jordi Argilaguet ◽  
Kateri Bertran ◽  
Raúl Sánchez-González ◽  
Miquel Nofrarías ◽  
...  

Highly pathogenic avian influenza viruses (HPAIVs) cause severe systemic disease and high mortality rates in chickens, leading to a huge economic impact in the poultry sector. However, some chickens are resistant to the disease. This study aimed at evaluating the mechanisms behind HPAIV disease resistance. Chickens of different breeds were challenged with H7N1 HPAIV or clade 2.3.4.4b H5N8 HPAIV, euthanized at 3 days post-inoculation (dpi), and classified as resistant or susceptible depending on the following criteria: chickens that presented i) clinical signs, ii) histopathological lesions, and iii) presence of HPAIV antigen in tissues were classified as susceptible, while chickens lacking all these criteria were classified as resistant. Once classified, we performed RNA-Seq from lung and spleen samples in order to compare the transcriptomic signatures between resistant and susceptible chickens. We identified minor transcriptomic changes in resistant chickens in contrast with huge alterations observed in susceptible chickens. Interestingly, six differentially expressed genes were downregulated in resistant birds and upregulated in susceptible birds. Some of these genes belong to the NF-kappa B and/or mitogen-activated protein kinase signaling pathways. Among these six genes, the serine protease-encoding gene PLAU was of particular interest, being the most significantly downregulated gene in resistant chickens. Expression levels of this protease were further validated by RT-qPCR in a larger number of experimentally infected chickens. Furthermore, HPAIV quasi-species populations were constructed using 3 dpi oral swabs. No substantial changes were found in the viral segments that interact with the innate immune response and with the host cell receptors, reinforcing the role of the immune system of the host in the clinical outcome. Altogether, our results suggest that an early inactivation of important host genes could prevent an exaggerated immune response and/or viral replication, conferring resistance to HPAIV in chickens.


2020 ◽  
Vol 21 (7) ◽  
pp. 2353
Author(s):  
Marcel Gischke ◽  
Reiner Ulrich ◽  
Olanrewaju I. Fatola ◽  
David Scheibner ◽  
Ahmed H. Salaheldin ◽  
...  

Highly pathogenic (HP) avian influenza viruses (AIVs) are naturally restricted to H5 and H7 subtypes with a polybasic cleavage site (CS) in hemagglutinin (HA) and any AIV with an intravenous pathogenicity index (IVPI) ≥ 1.2. Although only a few non-H5/H7 viruses fulfill the criteria of HPAIV; it remains unclear why these viruses did not spread in domestic birds. In 2012, a unique H4N2 virus with a polybasic CS 322PEKRRTR/G329 was isolated from quails in California which, however, was avirulent in chickens. This is the only known non-H5/H7 virus with four basic amino acids in the HACS. Here, we investigated the virulence of this virus in chickens after expansion of the polybasic CS by substitution of T327R (322PEKRRRR/G329) or T327K (322PEKRRKR/G329) with or without reassortment with HPAIV H5N1 and H7N7. The impact of single mutations or reassortment on virus fitness in vitro and in vivo was studied. Efficient cell culture replication of T327R/K carrying H4N2 viruses increased by treatment with trypsin, particularly in MDCK cells, and reassortment with HPAIV H5N1. Replication, virus excretion and bird-to-bird transmission of H4N2 was remarkably compromised by the CS mutations, but restored after reassortment with HPAIV H5N1, although not with HPAIV H7N7. Viruses carrying the H4-HA with or without R327 or K327 mutations and the other seven gene segments from HPAIV H5N1 exhibited high virulence and efficient transmission in chickens. Together, increasing the number of basic amino acids in the H4N2 HACS was detrimental for viral fitness particularly in vivo but compensated by reassortment with HPAIV H5N1. This may explain the absence of non-H5/H7 HPAIV in poultry.


2008 ◽  
Vol 52 (11) ◽  
pp. 3889-3897 ◽  
Author(s):  
Natalia A. Ilyushina ◽  
Alan Hay ◽  
Neziha Yilmaz ◽  
Adrianus C. M. Boon ◽  
Robert G. Webster ◽  
...  

ABSTRACT We studied the effects of a neuraminidase inhibitor (oseltamivir) and an inhibitor of influenza virus polymerases (ribavirin) against two highly pathogenic H5N1 influenza viruses. In vitro, A/Vietnam/1203/04 virus (clade 1) was highly susceptible to oseltamivir carboxylate (50% inhibitory concentration [IC50] = 0.3 nM), whereas A/Turkey/15/06 virus (clade 2.2) had reduced susceptibility (IC50 = 5.5 nM). In vivo, BALB/c mice were treated with oseltamivir (1, 10, 50, or 100 mg/kg of body weight/day), ribavirin (37.5, 55, or 75 mg/kg/day), or the combination of both drugs for 8 days, starting 4 h before virus inoculation. Monotherapy produced a dose-dependent antiviral effect against the two H5N1 viruses in vivo. Three-dimensional analysis of the drug-drug interactions revealed that oseltamivir and ribavirin interacted principally in an additive manner, with several exceptions of marginal synergy or marginal antagonism at some concentrations. The combination of ribavirin at 37.5 mg/kg/day and oseltamivir at 1 mg/kg/day and the combination of ribavirin at 37.5 mg/kg/day and oseltamivir at 10 mg/kg/day were synergistic against A/Vietnam/1203/04 and A/Turkey/15/06 viruses, respectively. These optimal oseltamivir-ribavirin combinations significantly inhibited virus replication in mouse organs, prevented the spread of H5N1 viruses beyond the respiratory tract, and abrogated the cytokine response (P < 0.01). Importantly, we observed clear differences between the efficacies of the drug combinations against two H5N1 viruses: higher doses were required for the protection of mice against A/Turkey/15/06 virus than for the protection of mice against A/Vietnam/1203/04 virus. Our preliminary results suggest that oseltamivir-ribavirin combinations can have a greater or lesser antiviral effect than monotherapy, depending on the H5N1 virus and the concentrations used.


2015 ◽  
Vol 90 (1) ◽  
pp. 400-411 ◽  
Author(s):  
El-Sayed M. Abdelwhab ◽  
Jutta Veits ◽  
Kerstin Tauscher ◽  
Mario Ziller ◽  
Jens P. Teifke ◽  
...  

ABSTRACT In 1999, after circulation for a few months in poultry in Italy, low-pathogenic (LP) avian influenza (AI) H7N1 virus mutated into a highly pathogenic (HP) form by acquisition of a unique multibasic cleavage site (mCS), PEIPKGSRVRR*GLF (asterisk indicates the cleavage site), in the hemagglutinin (HA) and additional alterations with hitherto unknown biological function. To elucidate these virulence-determining alterations, recombinant H7N1 viruses carrying specific mutations in the HA of LPAI A/chicken/Italy/473/1999 virus (Lp) and HPAI A/chicken/Italy/445/1999 virus (Hp) were generated. Hp with a monobasic CS or carrying the HA of Lp induced only mild or no disease in chickens, thus resembling Lp. Conversely, Lp with the HA of Hp was as virulent and transmissible as Hp. While Lp with a multibasic cleavage site (Lp_CS445) was less virulent than Hp, full virulence was exhibited when HA2 was replaced by that of Hp. In HA2, three amino acid differences consistently detected between LP and HP H7N1 viruses were successively introduced into Lp_CS445. Q450L in the HA2 stem domain increased virulence and transmission but was detrimental to replication in cell culture, probably due to low-pH activation of HA. A436T and/or K536R restored viral replication in vitro and in vivo . Viruses possessing A436T and K536R were observed early in the HPAI outbreak but were later superseded by viruses carrying all three mutations. Together, besides the mCS, stepwise mutations in HA2 increased the fitness of the Italian H7N1 virus in vivo . The shift toward higher virulence in the field was most likely gradual with rapid optimization. IMPORTANCE In 1999, after 9 months of circulation of low-pathogenic (LP) avian influenza virus (AIV), a devastating highly pathogenic (HP) H7N1 AIV emerged in poultry, marking the largest epidemic of AIV reported in a Western country. The HPAIV possessed a unique multibasic cleavage site (mCS) complying with the minimum motif for HPAIV. The main finding in this report is the identification of three mutations in the HA2 domain that are required for replication and stability, as well as for virulence, transmission, and tropism of H7N1 in chickens. In addition to the mCS, Q450L was required for full virulence and transmissibility of the virus. Nonetheless, it was detrimental to virus replication and required A436T and/or K536R to restore replication, systemic spread, and stability. These results are important for better understanding of the evolution of highly pathogenic avian influenza viruses from low-pathogenic precursors.


2017 ◽  
Vol 22 (9) ◽  
Author(s):  
François-Xavier Briand ◽  
Audrey Schmitz ◽  
Katell Ogor ◽  
Aurélie Le Prioux ◽  
Cécile Guillou-Cloarec ◽  
...  

Several new highly pathogenic (HP) H5 avian influenza virus (AIV) have been detected in poultry farms from south-western France since November 2015, among which an HP H5N1. The zoonotic potential and origin of these AIVs immediately became matters of concern. One virus of each subtype H5N1 (150169a), H5N2 (150233) and H5N9 (150236) was characterised. All proved highly pathogenic for poultry as demonstrated molecularly by the presence of a polybasic cleavage site in their HA protein – with a sequence (HQRRKR/GLF) previously unknown among avian H5 HPAI viruses – or experimentally by the in vivo demonstration of an intravenous pathogenicity index of 2.9 for the H5N1 HP isolate. Phylogenetic analyses based on the full genomes obtained by NGS confirmed that the eight viral segments of the three isolates were all part of avian Eurasian phylogenetic lineage but differed from the Gs/Gd/1/96-like lineage. The study of the genetic characteristics at specific amino acid positions relevant for modulating the adaptation to and the virulence for mammals showed that presently, these viruses possess most molecular features characteristic of AIV and lack some major characteristics required for efficient respiratory transmission to or between humans. The three isolates are therefore predicted to have no significant pandemic potential.


2022 ◽  
pp. 088532822110632
Author(s):  
Junfang Liu ◽  
Minhong Su ◽  
Xin Chen ◽  
Zhongli Li ◽  
Zekui Fang ◽  
...  

Monitoring the infection behavior of avian influenza viruses is crucial for understanding viral pathogenesis and preventing its epidemics among people. A number of viral labeling methods have been utilized for tracking viral infection process, but most of them are laborious or decreasing viral activity. Herein we explored a lipid biosynthetic labeling strategy for dynamical tracking the infection of H5N1 pseudotype virus (H5N1p) in host. Biotinylated lipids (biotinyl Cap-PE) were successfully incorporated into viral envelope when it underwent budding process by taking advantage of host cell-derived lipid metabolism. Biotin-H5N1p virus was effectively in situ–labeled with streptavidin-modified near-infrared quantum dots (NIR SA-QDs) using streptavidin-biotin conjugation with well-preserved virus activities. Dual-labeled imaging obviously shows that H5N1p viruses are primarily taken up in host cells via clathrin-mediated endocytosis. In animal models, Virus-conjugated NIR QDs displayed extraordinary photoluminescence, superior stability, and tissue penetration in lung, allowing us to long-term monitor respiratory viral infection in a noninvasive manner. Importantly, the co-localization of viral hemagglutinin protein and QDs in infected lung further conformed the dynamic infection process of virus in vivo. Hence, this in situ QD-labeling strategy based on cell natural biosynthesis provides a brand-new and reliable tool for noninvasion visualizing viral infection in body in a real-time manner.


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