scholarly journals Seasonal and Pandemic Human Influenza Viruses Attach Better to Human Upper Respiratory Tract Epithelium than Avian Influenza Viruses

2010 ◽  
Vol 176 (4) ◽  
pp. 1614-1618 ◽  
Author(s):  
Debby van Riel ◽  
Michael A. den Bakker ◽  
Lonneke M.E. Leijten ◽  
Salin Chutinimitkul ◽  
Vincent J. Munster ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Respiratory Tract ◽  
Influenza Viruses ◽  
Upper Respiratory Tract ◽  
Human Influenza ◽  
Avian Influenza Viruses ◽  
Upper Respiratory

scholarly journals Pathogenicity and Transmissibility of North American H7 Low Pathogenic Avian Influenza Viruses in Chickens and Turkeys

Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 163 ◽  
Author(s):  
Ishita Roy Chowdhury ◽  
Sai Yeddula ◽  
Shin-Hee Kim
Keyword(s):  
Avian Influenza ◽  
Respiratory Tract ◽  
Broiler Chickens ◽  
Influenza Viruses ◽  
Upper Respiratory Tract ◽  
Pathogenic Avian Influenza ◽  
Recent Emergence ◽  
Specific Pathogen ◽  
Upper Respiratory ◽  
Low Pathogenic Avian Influenza

Low pathogenic avian influenza (LPAI) viruses can silently circulate in poultry and wild aquatic birds and potentially mutate into highly pathogenic avian influenza (HPAI) viruses. In the U.S., recent emergence and spread of H7N8 and H7N9 HPAI viruses not only caused devastating losses to domestic poultry but also underscored the capability of LPAI viruses to mutate into HPAI viruses. Therefore, in this study, we evaluated pathogenicity and transmissibility of H7N8 and H7N9 LPAI viruses (the progenitors of HPAI viruses) in chickens and turkeys. We also included H7N2 isolated from an outbreak of LPAI in commercial chickens. H7 viruses replicated more efficiently in the respiratory tract than in the gastrointestinal tract, suggesting that their replication is restricted to the upper respiratory tract. Specifically, H7N2 replicated most efficiently in two-week-old chickens and turkeys. In contrast, H7N8 replicated least efficiently in those birds. Further, replication of H7N2 and H7N9 was restricted in the upper respiratory tract of four-week-old specific-pathogen-free (SPF) and broiler chickens. Despite their restricted replication, the two viruses efficiently transmitted from infected to naïve birds by direct contact, leading to seroconversion of contacted chickens. Our findings suggest the importance of continuous monitoring and surveillance of LPAI viruses in the fields.

scholarly journals Insights into the Acquisition of Virulence of Avian Influenza Viruses during a Single Passage in Ferrets

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 915
Author(s):  
Butler ◽  
Middleton ◽  
Haining ◽  
Layton ◽  
Rockman ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Respiratory Tract ◽  
Severe Disease ◽  
Influenza Viruses ◽  
Mammalian Host ◽  
Upper Respiratory Tract ◽  
Avian Influenza Viruses ◽  
Single Passage ◽  
H5n1 Isolate ◽  
High Pathogenicity

Circulating avian influenza viruses pose a significant threat, with human infections occurring infrequently but with potentially severe consequences. To examine the dynamics and locale of the adaptation process of avian influenza viruses when introduced to a mammalian host, we infected ferrets with H5N1 viruses. As expected, all ferrets infected with the human H5N1 isolate A/Vietnam/1203/2004 showed severe disease and virus replication outside the respiratory tract in multiple organs including the brain. In contrast infection of ferrets with the avian H5N1 virus A/Chicken/Laos/Xaythiani26/2006 showed a different collective pattern of infection; many ferrets developed and cleared a mild respiratory infection but a subset (25–50%), showed extended replication in the upper respiratory tract and developed infection in distal sites. Virus from these severely infected ferrets was commonly found in tissues that included liver and small intestine. In most instances the virus had acquired the common virulence substitution PB2 E627K but, in one case, a previously unidentified combination of two amino acid substitutions at PB2 S489P and NP V408I, which enhanced polymerase activity, was found. We noted that virus with high pathogenicity adaptations could be dominant in an extra-respiratory site without being equally represented in the nasal wash. Further ferret passage of these mutated viruses resulted in high pathogenicity in all ferrets. These findings illustrate the remarkable ability of avian influenza viruses that avoid clearance in the respiratory tract, to mutate towards a high pathogenicity phenotype during just a single passage in ferrets and also indicate a window of less than 5 days in which treatment may curtail systemic infection.

scholarly journals Constitutively Expressed IFITM3 Protein in Human Endothelial Cells Poses an Early Infection Block to Human Influenza Viruses

2016 ◽  
Vol 90 (24) ◽  
pp. 11157-11167 ◽  
Author(s):  
Xiangjie Sun ◽  
Hui Zeng ◽  
Amrita Kumar ◽  
Jessica A. Belser ◽  
Taronna R. Maines ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Influenza Virus ◽  
Virus Infection ◽  
Avian Influenza ◽  
Influenza Virus Infection ◽  
Influenza Viruses ◽  
Human Influenza ◽  
Avian Influenza Viruses ◽  
Human Influenza Virus ◽  
Pulmonary Endothelial Cells

ABSTRACTA role for pulmonary endothelial cells in the orchestration of cytokine production and leukocyte recruitment during influenza virus infection, leading to severe lung damage, has been recently identified. As the mechanistic pathway for this ability is not fully known, we extended previous studies on influenza virus tropism in cultured human pulmonary endothelial cells. We found that a subset of avian influenza viruses, including potentially pandemic H5N1, H7N9, and H9N2 viruses, could infect human pulmonary endothelial cells (HULEC) with high efficiency compared to human H1N1 or H3N2 viruses. In HULEC, human influenza viruses were capable of binding to host cellular receptors, becoming internalized and initiating hemifusion but failing to uncoat the viral nucleocapsid and to replicate in host nuclei. Unlike numerous cell types, including epithelial cells, we found that pulmonary endothelial cells constitutively express a high level of the restriction protein IFITM3 in endosomal compartments. IFITM3 knockdown by small interfering RNA (siRNA) could partially rescue H1N1 virus infection in HULEC, suggesting IFITM3 proteins were involved in blocking human influenza virus infection in endothelial cells. In contrast, selected avian influenza viruses were able to escape IFITM3 restriction in endothelial cells, possibly by fusing in early endosomes at higher pH or by other, unknown mechanisms. Collectively, our study demonstrates that the human pulmonary endothelium possesses intrinsic immunity to human influenza viruses, in part due to the constitutive expression of IFITM3 proteins. Notably, certain avian influenza viruses have evolved to escape this restriction, possibly contributing to virus-induced pneumonia and severe lung disease in humans.IMPORTANCEAvian influenza viruses, including H5N1 and H7N9, have been associated with severe respiratory disease and fatal outcomes in humans. Although acute respiratory distress syndrome (ARDS) and progressive pulmonary endothelial damage are known to be present during severe human infections, the role of pulmonary endothelial cells in the pathogenesis of avian influenza virus infections is largely unknown. By comparing human seasonal influenza strains to avian influenza viruses, we provide greater insight into the interaction of influenza virus with human pulmonary endothelial cells. We show that human influenza virus infection is blocked during the early stages of virus entry, which is likely due to the relatively high expression of the host antiviral factors IFITMs (interferon-induced transmembrane proteins) located in membrane-bound compartments inside cells. Overall, this study provides a mechanism by which human endothelial cells limit replication of human influenza virus strains, whereas avian influenza viruses overcome these restriction factors in this cell type.

scholarly journals Prevention and Treatment of Influenza, Influenza-Like Illness, and Common Cold by Herbal, Complementary, and Natural Therapies

2016 ◽  
Vol 22 (1) ◽  
pp. 166-174 ◽  
Author(s):  
Haider Abdul-Lateef Mousa
Keyword(s):  
Respiratory Tract ◽  
Respiratory Tract Infections ◽  
Influenza Viruses ◽  
Carnosic Acid ◽  
Upper Respiratory Tract ◽  
H5n1 Influenza ◽  
Prevention And Treatment ◽  
Upper Respiratory ◽  
Tract Infections ◽  
Viral Respiratory

In recent years viral respiratory tract infections, especially influenza viruses, have had a major impact on communities worldwide as a result of unavailability of effective treatment or vaccine. The frequent alterations in the antigenic structures of respiratory viruses, particularly for RNA viruses, pose difficulties in production of effective vaccines. The unavailability of optimal medication and shortage of effective vaccines suggests the requirement for alternative natural therapies. Several herbal remedies were used for prevention and treatment viral respiratory illnesses. Among those that were found effective included maoto, licorice roots, antiwei, North American ginseng, berries, Echinacea, plants extracted carnosic acid, pomegranate, guava tea, and Bai Shao. There is scientific evidence regarding the effectiveness of several complementary therapies for colds. Oral zinc may reduce the length and severity of a cold. Taking vitamin C supplements on a regular basis only slightly reduces the length and severity of colds. Probiotics were found better than placebo in reducing the number episodes of acute upper respiratory tract infections, the rate of episodes of acute upper respiratory tract infection and reducing antibiotic use. Alkaline diets or drinks might have antiviral properties as in vitro studies demonstrated inactivation effect of alkaline medium on respiratory virus. Earthing might have a natural anti-inflammatory effect for human body. It is now accepted that an overwhelming inflammatory response is the cause of human deaths from avian H5N1 influenza infection. Earthing accelerates immune response following vaccination, as demonstrated by increases of gamma globulin concentration. No in vivo or clinical studies were found that investigate the role of alkalization or earthing on respiratory viral infections. Thus, future studies are recommended to reveal any potential curative effects.

The potential of neuraminidase as an antigen for nasal vaccines to increase cross-protection against influenza viruses

2021 ◽  
Author(s):  
Atsushi Kawai ◽  
Yasuyuki Yamamoto ◽  
Takuto Nogimori ◽  
Kohei Takeshita ◽  
Takuya Yamamoto ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Influenza Viruses ◽  
Cross Protection ◽  
Influenza Vaccines ◽  
Upper Respiratory Tract ◽  
Specific Antibodies ◽  
Intranasal Immunization ◽  
Wide Range ◽  
Heterologous Virus ◽  
Upper Respiratory

Despite the availability of vaccines that efficiently reduce the severity of clinical symptoms, influenza viruses still cause substantial morbidity and mortality worldwide. In this regard, nasal influenza vaccines—because they induce virus-specific IgA—may be more effective than traditional parenteral formulations in preventing infection of the upper respiratory tract. In addition, the neuraminidase (NA) of influenza virus has shown promise as a vaccine antigen to confer broad cross-protection, in contrast to hemagglutinin (HA), the target of most current vaccines, which undergoes frequent antigenic changes leading to vaccine ineffectiveness against mismatched heterologous strains. However, the usefulness of NA as an antigen for nasal vaccines is unclear. Here, we compared NA and HA as antigens for nasal vaccines in mice. Intranasal immunization with recombinant NA (rNA) plus adjuvant protected mice against not only homologous but also heterologous virus challenge in the upper respiratory tract, whereas intranasal immunization with rHA failed to protect against heterologous challenge. In addition, intranasal immunization with rNA, but not rHA, conferred cross-protection even in the absence of adjuvant in virus infection–experienced mice; this strong cross-protection was due to the broader binding capacity of NA-specific antibodies to heterologous virus. Furthermore, the NA-specific IgA in the upper respiratory tract that was induced through rNA intranasal immunization recognized more epitopes than did the NA-specific IgG and IgA in plasma, again increasing cross-protection. Together, our findings suggest the potential of NA as an antigen for nasal vaccines to provide broad cross-protection against both homologous and heterologous influenza viruses. IMPORTANCE Because mismatch between vaccine strains and epidemic strains cannot always be avoided, the development of influenza vaccines that induce broad cross-protection against antigenically mismatched heterologous strains is needed. Although the importance of NA-specific antibodies to cross-protection in humans and experimental animals is becoming clear, the potential of NA as an antigen for providing cross-protection through nasal vaccines is unknown. We show here that intranasal immunization with NA confers broad cross-protection in the upper respiratory tract, where virus transmission is initiated, by inducing NA-specific IgA that recognizes a wide range of epitopes. These data shed new light on NA-based nasal vaccines as powerful anti-influenza tools that confer broad cross-protection.

scholarly journals Human and Avian Influenza Viruses Target Different Cells in the Lower Respiratory Tract of Humans and Other Mammals

2007 ◽  
Vol 171 (4) ◽  
pp. 1215-1223 ◽  
Author(s):  
Debby van Riel ◽  
Vincent J. Munster ◽  
Emmie de Wit ◽  
Guus F. Rimmelzwaan ◽  
Ron A.M. Fouchier ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Respiratory Tract ◽  
Lower Respiratory Tract ◽  
Influenza Viruses ◽  
Avian Influenza Viruses
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