scholarly journals Novel Approach to the Development of Effective H5N1 Influenza A Virus Vaccines: Use of M2 Cytoplasmic Tail Mutants

2007 ◽  
Vol 82 (5) ◽  
pp. 2486-2492 ◽  
Author(s):  
Tokiko Watanabe ◽  
Shinji Watanabe ◽  
Jin Hyun Kim ◽  
Masato Hatta ◽  
Yoshihiro Kawaoka
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Cytoplasmic Tail ◽  
Influenza Viruses ◽  
Wild Type Virus ◽  
Highly Pathogenic ◽  
Live Attenuated Vaccines ◽  
H5n1 Influenza ◽  
Pathogenic H5n1

ABSTRACT Outbreaks of highly pathogenic H5N1 influenza viruses in avian species began in Asia and have since spread to other continents. Concern regarding the pandemic potential of these viruses in humans is clearly warranted, and there is an urgent need to develop effective vaccines against them. Previously, we and others demonstrated that deletions of the M2 cytoplasmic tail caused a growth defect in A/WSN/33 (H1N1) influenza A virus in vitro (K. Iwatsuki-Horimoto, T. Horimoto, T. Noda, M. Kiso, J. Maeda, S. Watanabe, Y. Muramoto, K. Fujii, and Y. Kawaoka, J. Virol. 80:5233-5240, 2006; M. F. McCown and A. Pekosz, J. Virol. 79:3595-3605, 2005; M. F. McCown and A. Pekosz, J. Virol. 80:8178-8189, 2006). We therefore tested the feasibility of using M2 tail mutants as live attenuated vaccines against H5N1 virus. First we generated a series of highly pathogenic H5N1 (A/Vietnam/1203/04 [VN1203]) M2 cytoplasmic tail deletion mutants and examined their growth properties in vitro and in vivo. We found that one mutant, which contains an 11-amino-acid deletion from the C terminus (M2del11 virus), grew as well as the wild-type virus but replicated in mice less efficiently. We then generated a recombinant VN1203M2del11 virus whose hemagglutinin (HA) gene was modified by replacing sequences at the cleavage site with those of an avirulent type of HA (M2del11-HAavir virus). This M2del11-HAavir virus protected mice against challenge with lethal doses of homologous (VN1203; clade 1) and antigenically distinct heterologous (A/Indonesia/7/2005; clade 2) H5N1 viruses. Our results suggest that M2 cytoplasmic tail mutants have potential as live attenuated vaccines against H5N1 influenza viruses.

scholarly journals Characterization of a Highly Pathogenic H5N1 Avian Influenza A Virus Isolated from Duck Meat

2002 ◽  
Vol 76 (12) ◽  
pp. 6344-6355 ◽  
Author(s):  
Terrence M. Tumpey ◽  
David L. Suarez ◽  
Laura E. L. Perkins ◽  
Dennis A. Senne ◽  
Jae-gil Lee ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Hong Kong ◽  
Influenza A Virus ◽  
Influenza A ◽  
Infectious Virus ◽  
Influenza Viruses ◽  
H5n1 Influenza Virus ◽  
Highly Pathogenic ◽  
H5n1 Influenza ◽  
Pathogenic H5n1

ABSTRACT Since the 1997 H5N1 influenza virus outbreak in humans and poultry in Hong Kong, the emergence of closely related viruses in poultry has raised concerns that additional zoonotic transmissions of influenza viruses from poultry to humans may occur. In May 2001, an avian H5N1 influenza A virus was isolated from duck meat that had been imported to South Korea from China. Phylogenetic analysis of the hemagglutinin (HA) gene of A/Duck/Anyang/AVL-1/01 showed that the virus clustered with the H5 Goose/Guandong/1/96 lineage and 1997 Hong Kong human isolates and possessed an HA cleavage site sequence identical to these isolates. Following intravenous or intranasal inoculation, this virus was highly pathogenic and replicated to high titers in chickens. The pathogenesis of DK/Anyang/AVL-1/01 virus in Pekin ducks was further characterized and compared with a recent H5N1 isolate, A/Chicken/Hong Kong/317.5/01, and an H5N1 1997 chicken isolate, A/Chicken/Hong Kong/220/97. Although no clinical signs of disease were observed in H5N1 virus-inoculated ducks, infectious virus could be detected in lung tissue, cloacal, and oropharyngeal swabs. The DK/Anyang/AVL-1/01 virus was unique among the H5N1 isolates in that infectious virus and viral antigen could also be detected in muscle and brain tissue of ducks. The pathogenesis of DK/Anyang/AVL-1/01 virus was characterized in BALB/c mice and compared with the other H5N1 isolates. All viruses replicated in mice, but in contrast to the highly lethal CK/HK/220/97 virus, DK/Anyang/AVL-1/01 and CK/HK/317.5/01 viruses remained localized to the respiratory tract. DK/Anyang/AVL-1/01 virus caused weight loss and resulted in 22 to 33% mortality, whereas CK/HK/317.5/01-infected mice exhibited no morbidity or mortality. The isolation of a highly pathogenic H5N1 influenza virus from poultry indicates that such viruses are still circulating in China and may present a risk for transmission of the virus to humans.

scholarly journals Are Ducks Contributing to the Endemicity of Highly Pathogenic H5N1 Influenza Virus in Asia?

2005 ◽  
Vol 79 (17) ◽  
pp. 11269-11279 ◽  
Author(s):  
K. M. Sturm-Ramirez ◽  
D. J. Hulse-Post ◽  
E. A. Govorkova ◽  
J. Humberd ◽  
P. Seiler ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Virus Disease ◽  
Influenza Viruses ◽  
H5n1 Influenza Virus ◽  
Highly Pathogenic ◽  
Main Site ◽  
H5n1 Influenza ◽  
Pathogenic H5n1 ◽  
Virus Isolates

ABSTRACT Wild waterfowl are the natural reservoir of all influenza A viruses, and these viruses are usually nonpathogenic in these birds. However, since late 2002, H5N1 outbreaks in Asia have resulted in mortality among waterfowl in recreational parks, domestic flocks, and wild migratory birds. The evolutionary stasis between influenza virus and its natural host may have been disrupted, prompting us to ask whether waterfowl are resistant to H5N1 influenza virus disease and whether they can still act as a reservoir for these viruses. To better understand the biology of H5N1 viruses in ducks and attempt to answer this question, we inoculated juvenile mallards with 23 different H5N1 influenza viruses isolated in Asia between 2003 and 2004. All virus isolates replicated efficiently in inoculated ducks, and 22 were transmitted to susceptible contacts. Viruses replicated to higher levels in the trachea than in the cloaca of both inoculated and contact birds, suggesting that the digestive tract is not the main site of H5N1 influenza virus replication in ducks and that the fecal-oral route may no longer be the main transmission path. The virus isolates' pathogenicities varied from completely nonpathogenic to highly lethal and were positively correlated with tracheal virus titers. Nevertheless, the eight virus isolates that were nonpathogenic in ducks replicated and transmitted efficiently to naïve contacts, suggesting that highly pathogenic H5N1 viruses causing minimal signs of disease in ducks can propagate silently and efficiently among domestic and wild ducks in Asia and that they represent a serious threat to human and veterinary public health.

scholarly journals Natural Variation Can Significantly Alter the Sensitivity of Influenza A (H5N1) Viruses to Oseltamivir

2006 ◽  
Vol 50 (11) ◽  
pp. 3809-3815 ◽  
Author(s):  
M. A. Rameix-Welti ◽  
F. Agou ◽  
P. Buchy ◽  
S. Mardy ◽  
J. T. Aubin ◽  
...  
Keyword(s):  
Influenza A ◽  
Influenza Pandemic ◽  
Fold Increase ◽  
Influenza Viruses ◽  
Control Measures ◽  
Inhibition Assay ◽  
Highly Pathogenic ◽  
H5n1 Influenza ◽  
The Impact

ABSTRACT Geographic spread of highly pathogenic avian H5N1 influenza viruses may give rise to an influenza pandemic. During the first months of a pandemic, control measures would rely mainly on antiviral drugs, such as the neuraminidase (NA) inhibitors oseltamivir and zanamivir. In this study, we compare the sensitivities to oseltamivir of the NAs of several highly pathogenic H5N1 viruses isolated in Asia from 1997 to 2005. The corresponding 50% inhibitory concentrations were determined using a standard in vitro NA inhibition assay. The Km for the substrate and the affinity for the inhibitor (Ki ) of NA were determined for a 1997 and a 2005 virus, using an NA inhibition assay on cells transiently expressing the viral enzyme. Our data show that the sensitivities of the NAs of H5N1 viruses isolated in 2004 and 2005 to oseltamivir are about 10-fold higher than those of earlier H5N1 viruses or currently circulating H1N1 viruses. Three-dimensional modeling of the N1 protein predicted that Glu248Gly and Tyr252His changes could account for increased sensitivity. Our data indicate that genetic variation in the absence of any drug-selective pressure may result in significant variations in sensitivity to anti-NA drugs. Although the clinical relevance of a 10-fold increase in the sensitivity of NA to oseltamivir needs to be investigated further, the possibility that sensitivity to anti-NA drugs could increase (or possibly decrease) significantly, even in the absence of treatment, underscores the need for continuous evaluation of the impact of genetic drift on this parameter, especially for influenza viruses with pandemic potential.

scholarly journals Differential Contribution of PB1-F2 to the Virulence of Highly Pathogenic H5N1 Influenza A Virus in Mammalian and Avian Species

2011 ◽  
Vol 7 (8) ◽  
pp. e1002186 ◽  
Author(s):  
Mirco Schmolke ◽  
Balaji Manicassamy ◽  
Lindomar Pena ◽  
Troy Sutton ◽  
Rong Hai ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Avian Species ◽  
Highly Pathogenic ◽  
H5n1 Influenza ◽  
Pathogenic H5n1 ◽  
Differential Contribution

scholarly journals Host Genetic Variation Affects Resistance to Infection with a Highly Pathogenic H5N1 Influenza A Virus in Mice

2009 ◽  
Vol 83 (20) ◽  
pp. 10417-10426 ◽  
Author(s):  
Adrianus C. M. Boon ◽  
Jennifer deBeauchamp ◽  
Anna Hollmann ◽  
Jennifer Luke ◽  
Malak Kotb ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
H5n1 Virus ◽  
Lethal Dose ◽  
Influenza Virus Infection ◽  
Virus Titer ◽  
Influenza Viruses ◽  
Highly Pathogenic ◽  
H5n1 Influenza ◽  
Pathogenic H5n1

ABSTRACT Despite the prevalence of H5N1 influenza viruses in global avian populations, comparatively few cases have been diagnosed in humans. Although viral factors almost certainly play a role in limiting human infection and disease, host genetics most likely contribute substantially. To model host factors in the context of influenza virus infection, we determined the lethal dose of a highly pathogenic H5N1 virus (A/Hong Kong/213/03) in C57BL/6J and DBA/2J mice and identified genetic elements associated with survival after infection. The lethal dose in these hosts varied by 4 logs and was associated with differences in replication kinetics and increased production of proinflammatory cytokines CCL2 and tumor necrosis factor alpha in susceptible DBA/2J mice. Gene mapping with recombinant inbred BXD strains revealed five loci or Qivr (quantitative trait loci for influenza virus resistance) located on chromosomes 2, 7, 11, 15, and 17 associated with resistance to H5N1 virus. In conjunction with gene expression profiling, we identified a number of candidate susceptibility genes. One of the validated genes, the hemolytic complement gene, affected virus titer 7 days after infection. We conclude that H5N1 influenza virus-induced pathology is affected by a complex and multigenic host component.

scholarly journals Oseltamivir-Ribavirin Combination Therapy for Highly Pathogenic H5N1 Influenza Virus Infection in Mice

2008 ◽  
Vol 52 (11) ◽  
pp. 3889-3897 ◽  
Author(s):  
Natalia A. Ilyushina ◽  
Alan Hay ◽  
Neziha Yilmaz ◽  
Adrianus C. M. Boon ◽  
Robert G. Webster ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza Virus Infection ◽  
Antiviral Effect ◽  
Influenza Viruses ◽  
Oseltamivir Carboxylate ◽  
Highly Pathogenic ◽  
H5n1 Influenza ◽  
Pathogenic H5n1

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.

scholarly journals Susceptibility of Highly Pathogenic H5N1 Influenza Viruses to the Neuraminidase Inhibitor Oseltamivir Differs In Vitro and in a Mouse Model

2009 ◽  
Vol 53 (7) ◽  
pp. 3088-3096 ◽  
Author(s):  
Elena A. Govorkova ◽  
Natalia A. Ilyushina ◽  
Jennifer L. McClaren ◽  
Tri S. P. Naipospos ◽  
Bounlom Douangngeun ◽  
...  
Keyword(s):  
Antiviral Treatment ◽  
Influenza Viruses ◽  
Oseltamivir Carboxylate ◽  
In Vitro Susceptibility ◽  
Highly Pathogenic ◽  
Proinflammatory Mediators ◽  
H5n1 Influenza ◽  
Pathogenic H5n1

ABSTRACT While the neuraminidase (NA) inhibitor oseltamivir is currently our first line of defense against a pandemic threat, there is little information about whether in vitro testing can predict the in vivo effectiveness of antiviral treatment. Using a panel of five H5N1 influenza viruses (H5 clades 1 and 2), we determined that four viruses were susceptible to the drug in vitro (mean 50% inhibitory concentration [IC50], 0.1 to 4.9 nM), and A/Turkey/65-1242/06 virus was slightly less susceptible (mean IC50, 10.8 nM). Two avian viruses showed significantly greater NA enzymatic activity (V max) than the human viruses, and the five viruses varied in their affinity for the NA substrate MUNANA (Km , 64 to 300 μM) and for oseltamivir carboxylate (Ki , 0.1 to 7.9 nM). The protection of mice provided by a standard oseltamivir regimen (20 mg/kg/day for 5 days) also varied among the viruses used. We observed (i) complete protection against the less virulent A/chicken/Jogjakarta/BBVET/IX/04 virus; (ii) moderate protection (60 to 80% survival) against three viruses, two of which are neurotropic; and (iii) no protection against A/Turkey/65-1242/06 virus, which induced high pulmonary expression of proinflammatory mediators (interleukin-1α [IL-1α], IL-6, alpha interferon, and monocyte chemotactic protein 1) and contained a minor subpopulation of drug-resistant clones (I117V and E119A NA mutations). We found no correlation between in vitro susceptibility and in vivo protection (Spearman rank correlation coefficient ρ = −0.1; P > 0.05). Therefore, the in vivo efficacy of oseltamivir against highly pathogenic H5N1 influenza viruses cannot be reliably predicted by susceptibility testing, and more prognostic ways to evaluate anti-influenza compounds must be developed. Multiple viral and host factors modulate the effectiveness of NA inhibitor regimens against such viruses and new, more consistently effective treatment options, including combination therapies, are needed.

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