scholarly journals Influenza Virus Infections and Cellular Kinases

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 171 ◽  
Author(s):  
Robert Meineke ◽  
Guus Rimmelzwaan ◽  
Husni Elbahesh

Influenza A viruses (IAVs) are a major cause of respiratory illness and are responsible for yearly epidemics associated with more than 500,000 annual deaths globally. Novel IAVs may cause pandemic outbreaks and zoonotic infections with, for example, highly pathogenic avian influenza virus (HPAIV) of the H5N1 and H7N9 subtypes, which pose a threat to public health. Treatment options are limited and emergence of strains resistant to antiviral drugs jeopardize this even further. Like all viruses, IAVs depend on host factors for every step of the virus replication cycle. Host kinases link multiple signaling pathways in respond to a myriad of stimuli, including viral infections. Their regulation of multiple response networks has justified actively targeting cellular kinases for anti-cancer therapies and immune modulators for decades. There is a growing volume of research highlighting the significant role of cellular kinases in regulating IAV infections. Their functional role is illustrated by the required phosphorylation of several IAV proteins necessary for replication and/or evasion/suppression of the innate immune response. Identified in the majority of host factor screens, functional studies further support the important role of kinases and their potential as host restriction factors. PKC, ERK, PI3K and FAK, to name a few, are kinases that regulate viral entry and replication. Additionally, kinases such as IKK, JNK and p38 MAPK are essential in mediating viral sensor signaling cascades that regulate expression of antiviral chemokines and cytokines. The feasibility of targeting kinases is steadily moving from bench to clinic and already-approved cancer drugs could potentially be repurposed for treatments of severe IAV infections. In this review, we will focus on the contribution of cellular kinases to IAV infections and their value as potential therapeutic targets.

2019 ◽  
Vol 4 (2) ◽  
pp. 96 ◽  
Author(s):  
David W. Smith ◽  
Ian G. Barr ◽  
Richmond Loh ◽  
Avram Levy ◽  
Simone Tempone ◽  
...  

Australia was previously believed to be free of enzootic swine influenza viruses due strict quarantine practices and use of biosecure breeding facilities. The first proven Australian outbreak of swine influenza occurred in Western Australian in 2012, revealing an unrecognized zoonotic risk, and a potential future pandemic threat. A public health investigation was undertaken to determine whether zoonotic infections had occurred and to reduce the risk of further transmission between humans and swine. A program of monitoring, testing, treatment, and vaccination was commenced, and a serosurvey of workers was also undertaken. No acute infections with the swine influenza viruses were detected. Serosurvey results were difficult to interpret due to previous influenza infections and past and current vaccinations. However, several workers had elevated haemagglutination inhibition (HI) antibody levels to the swine influenza viruses that could not be attributed to vaccination or infection with contemporaneous seasonal influenza A viruses. However, we lacked a suitable control population, so this was inconclusive. The experience was valuable in developing better protocols for managing outbreaks at the human–animal interface. Strict adherence to biosecurity practices, and ongoing monitoring of swine and their human contacts is important to mitigate pandemic risk. Strain specific serological assays would greatly assist in identifying zoonotic transmission.


mBio ◽  
2017 ◽  
Vol 8 (3) ◽  
Author(s):  
Shu-Ming Kuo ◽  
Chi-Jene Chen ◽  
Shih-Cheng Chang ◽  
Tzu-Jou Liu ◽  
Yi-Hsiang Chen ◽  
...  

ABSTRACT Avian influenza A viruses generally do not replicate efficiently in human cells, but substitution of glutamic acid (Glu, E) for lysine (Lys, K) at residue 627 of avian influenza virus polymerase basic protein 2 (PB2) can serve to overcome host restriction and facilitate human infectivity. Although PB2 residue 627 is regarded as a species-specific signature of influenza A viruses, host restriction factors associated with PB2627E have yet to be fully investigated. We conducted immunoprecipitation, followed by differential proteomic analysis, to identify proteins associating with PB2627K (human signature) and PB2627E (avian signature) of influenza A/WSN/1933(H1N1) virus, and the results indicated that Tu elongation factor, mitochondrial (TUFM), had a higher binding affinity for PB2627E than PB2627K in transfected human cells. Stronger binding of TUFM to avian-signature PB2590G/591Q and PB2627E in the 2009 swine-origin pandemic H1N1 and 2013 avian-origin H7N9 influenza A viruses was similarly observed. Viruses carrying avian-signature PB2627E demonstrated increased replication in TUFM-deficient cells, but viral replication decreased in cells overexpressing TUFM. Interestingly, the presence of TUFM specifically inhibited the replication of PB2627E viruses, but not PB2627K viruses. In addition, enhanced levels of interaction between TUFM and PB2627E were noted in the mitochondrial fraction of infected cells. Furthermore, TUFM-dependent autophagy was reduced in TUFM-deficient cells infected with PB2627E virus; however, autophagy remained consistent in PB2627K virus-infected cells. The results suggest that TUFM acts as a host restriction factor that impedes avian-signature influenza A virus replication in human cells in a manner that correlates with autophagy. IMPORTANCE An understanding of the mechanisms that influenza A viruses utilize to shift host tropism and the identification of host restriction factors that can limit infection are both critical to the prevention and control of emerging viruses that cross species barriers to target new hosts. Using a proteomic approach, we revealed a novel role for TUFM as a host restriction factor that exerts an inhibitory effect on avian-signature PB2627E influenza virus propagation in human cells. We further found that increased TUFM-dependent autophagy correlates with the inhibitory effect on avian-signature influenza virus replication and may serve as a key intrinsic mechanism to restrict avian influenza virus infection in humans. These findings provide new insight regarding the TUFM mitochondrial protein and may have important implications for the development of novel antiviral strategies. IMPORTANCE An understanding of the mechanisms that influenza A viruses utilize to shift host tropism and the identification of host restriction factors that can limit infection are both critical to the prevention and control of emerging viruses that cross species barriers to target new hosts. Using a proteomic approach, we revealed a novel role for TUFM as a host restriction factor that exerts an inhibitory effect on avian-signature PB2627E influenza virus propagation in human cells. We further found that increased TUFM-dependent autophagy correlates with the inhibitory effect on avian-signature influenza virus replication and may serve as a key intrinsic mechanism to restrict avian influenza virus infection in humans. These findings provide new insight regarding the TUFM mitochondrial protein and may have important implications for the development of novel antiviral strategies.


2019 ◽  
Vol 147 ◽  
Author(s):  
Jiajun Yang ◽  
Hao Li ◽  
Liyuan Jia ◽  
Xianchun Lan ◽  
Yuhui Zhao ◽  
...  

Abstract In the human population, influenza A viruses are associated with acute respiratory illness and are responsible for millions of deaths annually. Avian and human influenza viruses typically have a different α2-3- and α2-6-linked sialic acid (SA) binding preference. Only a few amino acid changes in the haemagglutinin on the surface of avian influenza viruses (AIV) can cause a switch from avian to human receptor specificity, and the individuals with pathognostic chronic diseases might be more susceptible to AIV due to the decreased expression level of terminal α2-3-linked SA in their saliva. Here, using lectin and virus histochemical staining, we observed the higher expression levels of α2-3/6-linked SA influenza virus receptors in the airway of HBV-transgenic mice compared with that of control mice due to the significant decrease in control mice during ageing, which imply that this is also a risk factor for individuals with pathognostic chronic diseases susceptible to influenza viruses. Our findings will help understand the impact on influenza virus pathogenesis and transmission.


2017 ◽  
Vol 91 (7) ◽  
Author(s):  
Benjamin E. Nilsson ◽  
Aartjan J. W. te Velthuis ◽  
Ervin Fodor

ABSTRACT The RNA genome of influenza A viruses is transcribed and replicated by the viral RNA-dependent RNA polymerase, composed of the subunits PA, PB1, and PB2. High-resolution structural data revealed that the polymerase assembles into a central polymerase core and several auxiliary highly flexible, protruding domains. The auxiliary PB2 cap-binding and the PA endonuclease domains are both involved in cap snatching, but the role of the auxiliary PB2 627 domain, implicated in host range restriction of influenza A viruses, is still poorly understood. In this study, we used structure-guided truncations of the PB2 subunit to show that a PB2 subunit lacking the 627 domain accumulates in the cell nucleus and assembles into a heterotrimeric polymerase with PB1 and PA. Furthermore, we showed that a recombinant viral polymerase lacking the PB2 627 domain is able to carry out cap snatching, cap-dependent transcription initiation, and cap-independent ApG dinucleotide extension in vitro, indicating that the PB2 627 domain of the influenza virus RNA polymerase is not involved in core catalytic functions of the polymerase. However, in a cellular context, the 627 domain is essential for both transcription and replication. In particular, we showed that the PB2 627 domain is essential for the accumulation of the cRNA replicative intermediate in infected cells. Together, these results further our understanding of the role of the PB2 627 domain in transcription and replication of the influenza virus RNA genome. IMPORTANCE Influenza A viruses are a major global health threat, not only causing disease in both humans and birds but also placing significant strains on economies worldwide. Avian influenza A virus polymerases typically do not function efficiently in mammalian hosts and require adaptive mutations to restore polymerase activity. These adaptations include mutations in the 627 domain of the PB2 subunit of the viral polymerase, but it still remains to be established how these mutations enable host adaptation on a molecular level. In this report, we characterize the role of the 627 domain in polymerase function and offer insights into the replication mechanism of influenza A viruses.


2015 ◽  
Vol 89 (10) ◽  
pp. 5406-5418 ◽  
Author(s):  
Henan Zhu ◽  
Joseph Hughes ◽  
Pablo R. Murcia

ABSTRACTInfluenza A viruses (IAVs) are maintained mainly in wild birds, and despite frequent spillover infections of avian IAVs into mammals, only a small number of viruses have become established in mammalian hosts. A new H3N2 canine influenza virus (CIV) of avian origin emerged in Asia in the mid-2000s and is now circulating in dog populations of China and South Korea, and possibly in Thailand. The emergence of CIV provides new opportunities for zoonotic infections and interspecies transmission. We examined 14,764 complete IAV genomes together with all CIV genomes publicly available since its first isolation until 2013. We show that CIV may have originated as early as 1999 as a result of segment reassortment among Eurasian and North American avian IAV lineages. We also identified amino acid changes that might have played a role in CIV emergence, some of which have not been previously identified in other cross-species jumps. CIV evolves at a lower rate than H3N2 human influenza viruses do, and viral phylogenies exhibit geographical structure compatible with high levels of local transmission. We detected multiple intrasubtypic and heterosubtypic reassortment events, including the acquisition of the NS segment of an H5N1 avian influenza virus that had previously been overlooked. In sum, our results provide insight into the adaptive changes required by avian viruses to establish themselves in mammals and also highlight the potential role of dogs to act as intermediate hosts in which viruses with zoonotic and/or pandemic potential could originate, particularly with an estimated dog population of ∼700 million.IMPORTANCEInfluenza A viruses circulate in humans and animals. This multihost ecology has important implications, as past pandemics were caused by IAVs carrying gene segments of both human and animal origin. Adaptive evolution is central to cross-species jumps, and this is why understanding the evolutionary processes that shape influenza A virus genomes is key to elucidating the mechanisms underpinning viral emergence. An avian-origin canine influenza virus (CIV) has recently emerged in dogs and is spreading in Asia. We reconstructed the evolutionary history of CIV and show that it originated from both Eurasian and North American avian lineages. We also identified the mutations that might have been responsible for the cross-species jump. Finally, we provide evidence of multiple reassortment events between CIV and other influenza viruses (including an H5N1 avian virus). This is a cause for concern, as there is a large global dog population to which humans are highly exposed.


2017 ◽  
Vol 92 (2) ◽  
Author(s):  
Barbara M. Waring ◽  
Louisa E. Sjaastad ◽  
Jessica K. Fiege ◽  
Elizabeth J. Fay ◽  
Ismarc Reyes ◽  
...  

ABSTRACTInfluenza A virus drives significant morbidity and mortality in humans and livestock. Annual circulation of the virus in livestock and waterfowl contributes to severe economic disruption and increases the risk of zoonotic transmission of novel strains into the human population, where there is no preexisting immunity. Seasonal vaccinations in humans help prevent infection and can reduce symptoms when infection does occur. However, current vaccination regimens available for livestock are limited in part due to safety concerns regarding reassortment/recombination with circulating strains. Therefore, inactivated vaccines are used instead of the more immunostimulatory live attenuated vaccines. MicroRNAs (miRNAs) have been used previously to generate attenuated influenza A viruses for use as a vaccine. Here, we systematically targeted individual influenza gene mRNAs using the same miRNA to determine the segment(s) that yields maximal attenuation potential. This analysis demonstrated that targeting of NP mRNA most efficiently ablates replication. We further increased the plasticity of miRNA-mediated attenuation of influenza A virus by exploiting a miRNA, miR-21, that is ubiquitously expressed across influenza-susceptible hosts. In order to construct this targeted virus, we used CRISPR/Cas9 to eliminate the universally expressed miR-21 from MDCK cells. miR-21-targeted viruses were attenuated in human, mouse, canine, and avian cells and drove protective immunity in mice. This strategy has the potential to enhance the safety of live attenuated vaccines in humans and zoonotic reservoirs.IMPORTANCEInfluenza A virus circulates annually in both avian and human populations, causing significant morbidity, mortality, and economic burden. High incidence of zoonotic infections greatly increases the potential for transmission to humans, where no preexisting immunity or vaccine exists. There is a critical need for new vaccine strategies to combat emerging influenza outbreaks. MicroRNAs were used previously to attenuate influenza A viruses. We propose the development of a novel platform to produce live attenuated vaccines that are highly customizable, efficacious across a broad species range, and exhibit enhanced safety over traditional vaccination methods. This strategy exploits a microRNA that is expressed abundantly in influenza virus-susceptible hosts. By eliminating this ubiquitous microRNA from a cell line, targeted viruses that are attenuated across susceptible strains can be generated. This approach greatly increases the plasticity of the microRNA targeting approach and enhances vaccine safety.


2021 ◽  
Vol 2 (2) ◽  
pp. 1-15
Author(s):  
Rehan Zafar Paracha ◽  
Fahed Parvaiz ◽  
Babar Aslam ◽  
Ayesha Obaid ◽  
Sidra Qureshi ◽  
...  

Viral infections are the cause of serious infirmities in humans and kill millions of people every year. Management of viral diseases is one of the challenges faced by the whole world which needs improvement in prevention and treatment options. Complete understanding of the consequences of viral proteins interaction network on host physiology is essential. Towards this goal, deciphering viral protein-protein interactions is one of the perspective which can help in our understanding about the basis of viral pathogenesis and the development of new antivirals. Indeed, viral infection network based on viral-viral proteins will provide an elusive and investigative framework to articulate rationalize drug discovery based on proteomics scale of viruses. In this study, proteomics a collection of viral-viral protein interactions reporting different studies of Hepatitis C virus, Influenza A virus, Dengue virus and SARS Coronavirus. Our effort of protein-interactions was focused on different studies reporting interactions between viral proteins encoded by the viruses under study. The study is integrated with a broad and original literature-curated data of viral-viral protein (197 non-redundant) interactions.


2015 ◽  
Vol 89 (12) ◽  
pp. 6218-6226 ◽  
Author(s):  
Martha I. Nelson ◽  
Jered Stratton ◽  
Mary Lea Killian ◽  
Alicia Janas-Martindale ◽  
Amy L. Vincent

ABSTRACTThe diversity of influenza A viruses in swine (swIAVs) presents an important pandemic threat. Knowledge of the human-swine interface is particularly important for understanding how viruses with pandemic potential evolve in swine hosts. Through phylogenetic analysis of contemporary swIAVs in the United States, we demonstrate that human-to-swine transmission of pandemic H1N1 (pH1N1) viruses has occurred continuously in the years following the 2009 H1N1 pandemic and has been an important contributor to the genetic diversity of U.S. swIAVs. Although pandemic H1 and N1 segments had been largely removed from the U.S. swine population by 2013 via reassortment with other swIAVs, these antigens reemerged following multiple human-to-swine transmission events during the 2013-2014 seasonal epidemic. These findings indicate that the six internal gene segments from pH1N1 viruses are likely to be sustained long term in the U.S. swine population, with periodic reemergence of pandemic hemagglutinin (HA) and neuraminidase (NA) segments in association with seasonal pH1N1 epidemics in humans. Vaccinating U.S. swine workers may reduce infection of both humans and swine and in turn limit the role of humans as sources of influenza virus diversity in pigs.IMPORTANCESwine are important hosts in the evolution of influenza A viruses with pandemic potential. Here, we analyze influenza virus sequence data generated by the U.S. Department of Agriculture's national surveillance system to identify the central role of humans in the reemergence of pandemic H1N1 (pH1N1) influenza viruses in U.S. swine herds in 2014. These findings emphasize the important role of humans as continuous sources of influenza virus diversity in swine and indicate that influenza viruses with pandemic HA and NA segments are likely to continue to reemerge in U.S. swine in association with seasonal pH1N1 epidemics in humans.


2020 ◽  
Vol 94 (23) ◽  
Author(s):  
Jingwei Song ◽  
Honglei Sun ◽  
Haoran Sun ◽  
Zhimin Jiang ◽  
Junda Zhu ◽  
...  

ABSTRACT Avian influenza virus (AIV) can cross species barriers to infect humans and other mammals. However, these species-cross transmissions are most often dead-end infections due to host restriction. Current research about host restriction focuses mainly on the barriers of cell membrane, nuclear envelope, and host proteins; whether microRNAs (miRNAs) play a role in host restriction is largely unknown. In this study, we used porcine alveolar macrophage (PAM) cells as a model to elucidate the role of miRNAs in host range restriction. During AIV infection, 40 dysregulation expressed miRNAs were selected in PAM cells. Among them, two Sus scrofa (ssc; swine) miRNAs, ssc-miR-221-3p and ssc-miR-222, could inhibit the infection and replication of AIV in PAM cells by directly targeting viral genome and inducing cell apoptosis via inhibiting the expression of anti-apoptotic protein HMBOX1. Avian but not swine influenza virus caused upregulated expressions of ssc-miR-221-3p and ssc-miR-222 in PAM cells. We further found that NF-κB P65 was more effectively phosphorylated upon AIV infection and that P65 functioned as a transcription activator to regulate the AIV-induced expression of miR-221-3p/222. Importantly, we found that ssc-miR-221-3p and ssc-miR-222 could also be specifically upregulated upon AIV infection in newborn pig tracheal epithelial (NPTr) cells and also exerted anti-AIV function. In summary, our study indicated that miRNAs act as a host barrier during cross-species infection of influenza A virus. IMPORTANCE The host range of an influenza A virus is determined by species-specific interactions between virus and host cell factors. Host miRNAs can regulate influenza A virus replication; however, the role of miRNAs in host species specificity is unclear. Here, we show that the induced expression of ssc-miR-221-3p and ssc-miR-222 in swine cells is modulated by NF-κB P65 phosphorylation in response to AIV infection but not swine influenza virus infection. ssc-miR-221-3p and ssc-miR-222 exerted antiviral function via targeting viral RNAs and causing apoptosis by inhibiting the expression of HMBOX1 in host cells. These findings uncover miRNAs as a host range restriction factor that limits cross-species infection of influenza A virus.


2019 ◽  
Vol 32 (1) ◽  
pp. 15-20
Author(s):  
Oliver Gittins ◽  
Llorenç Grau-Roma ◽  
Rosa Valle ◽  
Francesc Xavier Abad ◽  
Miquel Nofrarías ◽  
...  

AbstractTo evaluate how avian influenza virus (AIV) circulates among the avifauna of the Antarctic and sub-Antarctic islands, we surveyed 14 species of birds from Marion, Livingston and Gough islands. A competitive enzyme-linked immunosorbent assay was carried out on the sera of 147 birds. Quantitative reverse transcription polymerase chain reaction was used to detect the AIV genome from 113 oropharyngeal and 122 cloacal swabs from these birds. The overall seroprevalence to AIV infection was 4.8%, with the only positive results coming from brown skuas (Catharacta antarctica) (4 out of 18, 22%) and southern giant petrels (Macronectes giganteus) (3 out of 24, 13%). Avian influenza virus antibodies were detected in birds sampled from Marion and Gough islands, with a higher seroprevalence on Marion Island (P = 0.014) and a risk ratio of 11.29 (95% confidence interval: 1.40–91.28) compared to Gough Island. The AIV genome was not detected in any of the birds sampled. These results confirm that AIV strains are uncommon among Antarctic and sub-Antarctic predatory seabirds, but they may suggest that scavenging seabirds are the main avian reservoirs and spreaders of this virus in the Southern Ocean. Further studies are necessary to determine the precise role of these species in the epidemiology of AIV.


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