H1N1 Influenza Virus Research Articles

Monoclonal antibody against H1N1 influenza virus hemagglutinin cross reacts with hnRNPA1 and hnRNPA2/B1.

Following influenza A vaccination, certain individuals exhibit adverse reactions in the nervous system, which causes a problem with the safety of the influenza A vaccine. However, to the best of our knowledge, the underlying mechanism of this is unknown. The present study revealed that a monoclonal antibody (H1-84mAb) against the H1N1 influenza virus hemagglutinin (HA) protein cross-reacted with an antigen from brain tissue. Total brain tissue protein was immunoprecipitated with this cross-reactive antibody, and mass spectrometry revealed that the bound antigens were heterogeneous nuclear ribonucleoprotein (hnRNP) A1 and hnRNPA2/B1. Subsequently, the two proteins were expressed in bacteria and it was demonstrated that H1-84mAb bound to hnRNPA1 and hnRNPA2/B1. These two proteins were expressed in three segments and the cross-reactivity of H1-84mAb with the glycine (Gly)-rich domains of hnRNPA1 (195aa-320aa) and hnRNPA2/B1 (202aa-349aa) was determined using ELISA blocking experiments. It was concluded that the Gly-rich domains of these two proteins are heterophilic antigens that cross-react with influenza virus HA. The association between the heterophilic antigen Gly-rich domains and the safety of influenza A vaccines remains to be investigated.

H9N2 Influenza Virus Infections in Human Cells Require a Balance between Neuraminidase Sialidase Activity and Hemagglutinin Receptor Affinity.

Some avian influenza (AI) viruses have a deletion of up to 20 to 30 amino acids in their neuraminidase (NA) stalk. This has been associated with changes in virus replication and host range. Currently prevalent H9N2 AI viruses have only a 2- or 3-amino-acid deletion, and such deletions were detected in G1 and Y280 lineage viruses, respectively. The effect of an NA deletion on the H9N2 phenotype has not been fully elucidated. In this study, we isolated G1 mutants that carried an 8-amino-acid deletion in their NA stalk. To systematically analyze the effect of NA stalk length and concomitant (de)glycosylation on G1 replication and host range, we generated G1 viruses that had various NA stalk lengths and that were either glycosylated or not glycosylated. The stalk length was correlated with NA sialidase activity, using low-molecular-weight substrates, and with virus elution efficacy from erythrocytes. G1 virus replication in avian cells and eggs was positively correlated with the NA stalk length but was negatively correlated in human cells and mice. NA stalk length modulated G1 virus entry into host cells, with shorter stalks enabling more efficient G1 entry into human cells. However, with a hemagglutinin (HA) with a higher α2,6-linked sialylglycan affinity, the effect of NA stalk length on G1 virus infection was reversed, with shorter NA stalks reducing virus entry into human cells. These results indicate that a balance between HA binding affinity and NA sialidase activity, modulated by NA stalk length, is required for optimal G1 virus entry into human airway cells.IMPORTANCE H9N2 avian influenza (AI) virus, one of the most prevalent AI viruses, has caused repeated poultry and human infections, posing a huge public health risk. The H9N2 virus has diversified into multiple lineages, with the G1 lineage being the most prevalent worldwide. In this study, we isolated G1 variants carrying an 8-amino-acid deletion in their NA stalk, which is, to our knowledge, the longest deletion found in H9N2 viruses in the field. The NA stalk length was found to modulate G1 virus entry into host cells, with the effects being species specific and dependent on the corresponding HA binding affinity. Our results suggest that, in nature, H9N2 G1 viruses balance their HA and NA functions by the NA stalk length, leading to the possible association of host range and virulence in poultry and mammals during the evolution of G1 lineage viruses.

Reusable surface plasmon resonance biosensor chip for the detection of H1N1 influenza virus

We developed a reusable magnetic surface plasmon resonance (SPR) sensor chip for detecting various target molecules repeatedly in a conventional SPR system. Here, ferromagnetic patterns on a SPR sensor chip were utilized to trap a layer of magnetic particles, and they were utilized as a solid substrate for SPR sensing in a conventional SPR system. After a sensing experiment, the used magnetic particles were removed by external magnetic fields, and a new layer of magnetic particles was immobilized to the SPR sensor chip for additional sensing measurements. Since magnetic particles were trapped on the ferromagnetic patterns, we could use our reusable SPR chip for SPR sensing measurements in a traditional SPR system without any applied magnetic fields. Significantly, ferromagnetic patterns on the sensor chip surface deflected the strong external fields, so that the large aggregation of magnetic particles on the sensor surface was reduced. We demonstrated using a single reusable SPR sensor chip to measure the nucleoprotein (NP) of H1N1 influenza virus solution ranging repeatedly for more than 7 times without significant signal degradation. Also, different target molecules could be repeatedly measured in a single SPR chip. Since our reusable SPR sensor chip can be repeatedly used in a conventional SPR system without any chemical processes for refreshment, the cost for SPR sensing should be significantly reduced. In this case, our reusable SPR sensor chip can be a major breakthrough and can be used for versatile practical applications of SPR sensors.

APLIKASI FILOGENETIK DI DUNIA BIOLOGI KESEHATAN: MELACAK PANDEMI PATOGEN

Phylogenetics is known as a study related to biological science. Phylogenetics provides facilities in the fields of human epidemiology, ecology, and evolutionary biology. In evolutionary science, this field of science is used to integrate spatial data in detecting the journey of living things over time. In health biology, the development of this science is also used to detect the spread of disease/pathogens from a region to the global direction. Phylogenetic analysis is able to describe the origin of the disease, the pattern of distribution, and speciation. In the pandemic analysis, several diseases that have been analyzed are the Chikungunya virus outbreak in 2007, Ebola and H3N2 influenza virus in 2014, and the SARS-CoV-2 virus in 2020. The study results reveal that the SARS-CoV-2 virus has three variants of lineage groups, namely types A, B, and C. The Covid-19 virus type A was first discovered in Wuhan City, China. Meanwhile, the type A virus mutation is seen in the United States and most of these viruses have also been found in corona positive patients from Australia. The Covid-19 type B virus was detected in patients living in East Asia, while the Covid-19 type was concentrated in the European region.

Immune-engineered H7N9 influenza hemagglutinin improves protection against viral influenza virus challenge

ABSTRACT The influenza hemagglutinin (HA) isolated from avian H7N9 influenza virus strains elicit weak immune responses. This low immunogenicity may be due to a regulatory T cell (Treg)–stimulating epitopes in HA from the H7N9 isolate A/Anhui/1/2013 (Anh/13). In this report, this Treg stimulating sequence was removed from the wild-type (WT) H7 HA amino acid sequence and replaced with a conserved CD4 + T cell stimulating sequences from human seasonal H3N2 strains and designed OPT1 H7 HA. The effectiveness of this optimized H7 HA protein was determined using a humanized mouse (HLA-DR3) expressing the human leukocyte antigen (HLA) DR3 allele. HLA-DR3 mice were pre-immunized by infecting with H3N2 influenza virus, A/Hong Kong/4108/2014 and then vaccinated intramuscularly with either the WT H7 HA from Anh/13 or the OPT1 H7 HA antigen without adjuvant. The OPT1 H7 HA vaccination group elicited higher H7 HA-specific IgG titers that resulted in a lower mortality, weight loss, and lung viral titer following lethal challenge with the H7N9 Anh/13 influenza virus compared to WT-vaccinated mice. Overall, T-cell epitope-engineered vaccines can improve the immunogenicity of H7 HA antigens resulting in enhanced survival and lower morbidity against H7N9 influenza virus challenge.

Analysis on genetic characteristics of H9N2 avian influenza virus isolated from human infection and external environment in Gansu province

Objective: To analyze the genomic characteristics of human infection with H9N2 avian influenza virus in Gansu province. Methods: The etiological analysis was conducted for human infection with H9N2 avian influenza virus detected in influenza like illness cases in northwestern China in 2016. Molecular bioinformatics Mega 7.0 software was used to analyze the full genomic sequences of the viral isolate. Results: The gene fragments of HA, NA, MP, NP, NS, PA, PB1 and PB2 of the isolate were highly similar (>90%) to those of H9N2 avian influenza virus strain isolated in external environment in Gansu from 2014 to 2019. The HA gene belonged to BJ/94-like branch, PB2 and MP belonged to G1/97-like branch, and the PB1, PA, NS, and NP genes belonged to F/98-like branch. MP and PB2 were closely related to H7N9, H10N8 and H5N6 viruses. Amino acid sequence alignment showed that the HA cleavage site was arranged in PSRSSR ↓ GLF, H183N and Q226L mutated which included 7 HA glycosylated sites; 62-64 sites of NA absented 3 amino acids (ITE); and M2-31N, NS1-42S, PA-356R, and PA-409N mutated. Conclusions: Apparently, this case of human infection with human infection with H9N2 avian influenza virus was an incidental. However, the isolates of H9N2 influenza virus in external environment of Gansu had a series of mammalian adaptive molecular markers, suggesting that the risk of human infection is higher. It is necessary to strengthen the surveillance by multi departments to deal with influenza pandemic.

Anti-influenza H7 human antibody targets antigenic site in hemagglutinin head domain interface.

Although broadly protective, stem-targeted Abs against the influenza A virus hemagglutinin (HA) have been well studied, very limited information is available on Abs that broadly recognize the head domain. We determined the crystal structure of the HA protein of the avian H7N9 influenza virus in complex with a pan-H7, non-neutralizing, protective human Ab. The structure revealed a B cell epitope in the HA head domain trimer interface (TI). This discovery of a second major protective TI epitope supports a model in which uncleaved HA trimers exist on the surface of infected cells in a highly dynamic state that exposes hidden HA head domain features.

Safety and immunogenicity of an alum-adjuvanted whole-virion H7N9 influenza vaccine: a randomized, blinded, clinical trial

ObjectivesA case of H7N9 influenza virus infection was first identified in China in 2013. This virus is considered to have high pandemic potential. Here we developed an H7N9 influenza vaccine containing an aluminium adjuvant and evaluated the safety and immunogenicity of the vaccine. MethodsFrom October 2017 through August 2018 we conducted a randomized, double-blinded, single-centre phase I clinical trial in China among 360 participants aged ≥12 years. All participants received two doses of the vaccine (7.5, 15 or 30 μg haemagglutinin antigen) or placebo at an interval of 21 days. Adverse event data were collected for 30 days after vaccination. Serum samples were collected on days 0, 21 and 42 for the haemagglutinin inhibition (HI) antibody assay. ResultsA total of 347 participants (347/360, 96.4%) completed the study. The proportions of vaccine-related adverse events after one injection were 56.7% (34/60) in the 7.5-μg group, 86.7% (52/60) in the 15-μg group and 86.7% (52/60) in the 30-μg group. The proportions of adverse events after two injections were less than those reported after the first dose. None of the serious adverse events were related to the vaccine. After receiving two doses of the 7.5-μg vaccine, the proportion of participants achieving an HI titre of ≥40 was 98.2% (55/56, 95%CI 72.3~100.0%), with a geometric mean titre (GMT) of 192.6 (95%CI 162.9~227.8). ConclusionsThe alum-adjuvanted H7N9 whole-virion inactivated vaccine was safe and strongly immunogenic in a population aged ≥12 years.

Integrated Analysis of microRNA-mRNA Expression in Mouse Lungs Infected With H7N9 Influenza Virus: A Direct Comparison of Host-Adapting PB2 Mutants.

MicroRNAs (miRNAs) are important regulators involved in the antiviral response to influenza virus infection, however, an analytical comparison of miRNA and mRNA expression changes induced by several H7N9 host-adapting PB2 mutants remains undone. Here, miRNA microarray and transcriptome sequencing of BALB/c mouse lungs infected with A/Anhui/1/2013 (H7N9) [hereafter referred to as H7N9/AH1-PB2-627K(WT)] and mutant variants with PB2 amino acid substitutions (avian-like H7N9/AH1-PB2-627E and mammalian-adapted H7N9/AH1-PB2-627E/701N) were directly compared. The results showed that influenza virus infection induced dysregulation of numerous host cell processes. In a miRNA-mRNA network associated with immunity, changes in the expression of 38 miRNAs and 58 mRNAs were detected following influenza virus infection. Notably, the miRNAs of mmu-miR-188-5p, mmu-miR-511-5p, mmu-miR-483-5p, and mmu-miR-690 were specifically associated with the replication of the avian-like virus H7N9/AH1-PB2-627E. Likewise, the miRNAs of mmu-miR-691, mmu-miR-329-3p, and mmu-miR-144-3p were specifically associated with the mammalian-adapted virus H7N9/AH1-PB2-627E/701N. Finally, the miRNAs of mmu-miR-98-5p, mmu-miR-103-3p, mmu-miR-199a-5p, and mmu-miR-378a-3p were specifically associated with H7N9/AH1-PB2-627K(WT) virus replication. This is the first report of comparative integration analysis of miRNA-mRNA expression of these three H7N9 influenza viruses with different host-adapting PB2 mutations. Our results highlight potential miRNAs of importance in influenza virus pathogenesis.

Sensitive detection of virus with broad dynamic range based on highly bright quantum dot-embedded nanoprobe and magnetic beads

As virus spread can lead to severe epidemics and pandemics associated with high mortality, it is necessary to have a highly sensitive detection method for viruses. Although various detection methods have been developed so far, current methods in detecting a virus require preprocessing and involve quite intricate processes of low sensitivity. Here, we have developed a virus detection method with a broad dynamic range and high sensitivity, based on immuno-complex formation between quantum dot (QD)-embedded silica nanoparticles (QD2) and magnetic beads. The multiple QD- containing QD2s showed 500 times stronger photoluminescence than individual QDs. When biotin was immobilized as a ligand, streptavidin was detected in a range of 10zM to 10nM. The clinical applicability of the QD2-based system was examined using the avian virus (i.e., H1N1 influenza virus), and it showed a detection range of 4.76×10−4< span class="xps_thinspace"> ∼3.2 hemagglutination unit/mL. This result is comparable to the polymerase chain reaction method, and is approximately 2100 times more sensitive than the conventional hemagglutination method. Since the QD2-based system could detect target molecules with high sensitivity without requiring an amplification step, it can be applied in various biomedical and clinical fields.

H9N2 swine influenza virus infection-induced damage is mediated by TRPM2 channels in mouse pulmonary microvascular endothelial cells

Oxidative stress is implicated in the pathogenesis of influenza virus infection. Increasing evidences show that transient receptor potential melastatin 2 (TRPM2), a Ca2+-permeable non-selective cation channel, plays an important role in the pathomechanism of reactive oxygen species (ROS)-coupled diseases. The present study investigated the role of TRPM2 in pulmonary microvascular endothelial cells (PMVECs) during H9N2 influenza virus infection. We knocked down TRPM2 in PMVECs using TRPM2 shRNA lentiviral particles. Subsequently, we utilized enzyme-linked immunosorbent assay and flow cytometry to compare ROS levels, DNA damage, mitochondrial integrity, apoptosis, and inflammatory factors between control and TRPM2-knockdown PMVECs following H9N2 influenza virus infection. Inhibition of TRPM2 channels reduced H9N2 virus-induced intracellular ROS production, decreased DNA damage, and inhibited H9N2-induced cellular apoptosis. This study shows that the inhibition of TRPM2 channels may protect PMVECs from the damage caused by H9N2 virus infection. Our results highlight the importance of TRPM2 in modulating ROS production, apoptosis, mitochondrial dysfunction, cytokine expression, and DNA damage in H9N2 virus-infected PMVECs, and suggest that TRPM2 may be a potential antiviral target.

H1N1 Influenza Virus in Patients With Cystic Fibrosis: A Literature Review Examining Both Disease Entities and Their Association in Light of the 2009 Pandemic.

The novel coronavirus (COVID-19) that is challenging the health sector and negatively impacting the global economy takes us back to the 2009 influenza A (H1N1) virus pandemic that brought the world to a standstill. In 2009, H1N1 became a significant health concern for several months. It mainly affected people under the age of 65 hyears who had no prior immunity, including children. Among the high-risk populations were pregnant patients and those with chronic cardiac, pulmonary, or respiratory diseases. These patients were at risk of developing severe pneumonia and respiratory complications. Cystic fibrosis (CF) represents a form of severe chronic lung disease in young adults and is the major fatal hereditary disorder of Caucasians in the United States. An online search of PubMed and Google Scholar was conducted to find relevant literature that explicitly examines patients with CF and H1N1.

Serie de casos de COVID-19: presentaciones atípicas de la enfermedad

the objective of this work is to present a series of cases of COVID-19 with atypical manifestations of the disease. The cases were evaluated by an interdisciplinary team of health personnel from a fourth-level clinic in Barranquilla, Colombia, and the data was subsequently taken from the clinical history of each patient. Three cases were evaluated, initially the first case with torpid evolution, coinfection with H1N1 influenza virus, however, with satisfactory outcome, and cases two and three with gastrointestinal manifestations as disease debut, with satisfactory evolution. The SARS-CoV-2 pandemic takes more lives every day, so it is necessary to describe the cases and their diverse variety of presentation, to identify the infected and take both therapeutic and preventive measures. To prevent the spread of the disease and achieve its control.

The Impact of Excessive Cytokine Production in the Body, Particularly in the Context of Virus Infection

SARS -CoV-2; covid-19 and multiple influenza forms such as H5N1 influenza virus can be lethal to humans due to an overreaction...

Replication of a Dog-Origin H6N1 Influenza Virus in Cell Culture and Mice.

The world’s first natural avian-origin H6N1 influenza A virus infection case in dogs was confirmed in Taiwan in 2014. The H6N1 virus in chickens has been endemic in Taiwan since 1972. Whether the dog H6N1 virus has interspecies transmission potential is the key issue we aim to understand. Following one virus passage in embryonated eggs and two further passages in MDCK cells, we obtained two virus derivatives, E01EE (PB1 739E and PB2 627E) and E01GK (PB1 739G and PB2 627K), respectively. The pathogenicity of E01EE and E01GK was investigated using plaque assay, growth dynamic analysis and cell viability quantification in cells from different animal species. The impact of amino acid mutation on PB1 739 and PB2 627 on viral ribonucleoprotein (RNP) activity was also analyzed. Further mouse infection experiments were performed. The results showed that both E01EE and E01GK decreased cell relative viability of canine MDCK cells, human A549 cells and chicken DF1 cells. E01Gk caused greater cellular harm in MDCK and A549 cells and had significantly higher virus titers in all of the cells compared to E01EE. The PB2 627K but not PB1 739G was the critical mutation that influenced the viral RNP activity. Both E01EE and E01GK caused mice pneumonia and considerable virus shedding, especially E01GK. This report verifies PB2 E627K mutation in virulence and spotlights the potential for the dog H6N1 virus to extend interspecies transmission.

The possible impairment of respiratory-related neural loops may be associated with the silent pneumonia induced by SARS-CoV-2.

As compared to many other viral pulmonary infections, there existed several peculiar manifestations in the COVID‐19 patients, including the “silence” of pneumonia in both mild and severe cases and a long intensive care unit stay for those requiring invasive mechanical ventilation. Similar silent pneumonia has been documented in the infectioninduced by H5N1 influenza virus HK483 and was found to result from the direct attack of the virus on the bronchopulmonary C‐fibers at the early stage and the final infection in the brainstem at the late stage. The long stay of critical patients in the intensive care unit is possibly due to the depression of central respiratory drive, which resulted in the failure to wean from the mechanic ventilation. Carotid and aortic bodies and bronchopulmonary C‐fibers are two key peripheral components responsible for the chemosensitive responses in the respiratory system, while triggering respiratory reflexes depends predominantly on the putative chemosensitive neurons located in the pontomedullary nuclei. In view of the findings for the H5N1 influenza virus, the silence of pneumonia induced by SARS‐CoV‐2 may be due to the possible impairment of peripheral chemosensitive reflexes as well as the damage to the respiratory‐related central neurons.

Host DNA released by NETosis in neutrophils exposed to seasonal H1N1 and highly pathogenic H5N1 influenza viruses

BackgroundNeutrophil is of the most abundant number in human immune system. During acute influenza virus infection, neutrophils are already active in the early phase of inflammation - a time in which clinical biopsy or autopsy material is not readily available. However, the role of neutrophil in virus infection is not well understood. Here, we studied the role of neutrophil in host defense during influenza A virus infection, specifically assessing if it contributes to the differential pathogenesis in H5N1 disease.MethodsNeutrophils were freshly isolated from healthy volunteers and subjected to direct influenza H1N1 and H5N1 virus infection in vitro. The ability of the naïve neutrophils to infiltrate from the basolateral to the apical phase of the influenza virus infected alveolar epithelium was assessed. The viral replication, innate immune responses and Neutrophil extracellular trap (NET) formation of neutrophils upon influenza virus infection were evaluated.ResultsOur results demonstrated that influenza virus infected alveolar epithelium allowed neutrophil transmigration. Significantly more neutrophils migrated across the H5N1 influenza virus infected the epithelium than the counterpart infected by the seasonal influenza H1N1 virus infected. Neutrophils were equally susceptible to H5N1 and H1N1 virus infection with similar viral gene transcription. Productive replication was observed in H5N1 infected neutrophils. H5N1 induced higher cytokine and chemokine gene transcription than H1N1 infected neutrophils, including TNF-α, IFN-β, CXCL10, MIP-1α and IL-8. This inferred a more intense inflammatory response posed by H5N1 than H1N1 virus. Strikingly, NADPH oxidase-independent NET formation was only observed in H1N1 infected neutrophils at 6 hpi while no NET formation was observed upon H5N1 infection.ConclusionOur data is the first to demonstrate that NET formation is abrogated in H5N1 influenza virus infection and might contribute to the severity of H5N1 disease.

Insights from investigating the interactions of natural product inhibitors with neuraminidase of the 2009 H1N1 influenza virus

Insights from investigating the interactions of natural product inhibitors with neuraminidase of the 2009 H1N1 influenza virus

Enhanced Potency of a Broad H7N9-Neutralizing Antibody HNIgGA6 Through Structure-Based Design.

H7N9 influenza virus was first isolated in 2013 and has caused five epidemic waves among humans to date. Treatment opinions are currently limited. Previously, we characterized a human neutralizing antibody, HNIgGA6, by isolating rearranged heavy- and light-chain genes from convalescent patients. The mAb disrupts viral attachment to the cellular receptor by directly interposing into the receptor binding site (RBS) and broadly neutralizing divergent H7N9 strains. To increase the protective efficacy of HNIgGA6, we employed a structure-based design to enhance its binding affinity and neutralization potency. When the serine at position 28 on light-chain complementarity-determining region 1 (LCDR1) was substituted by a histidine, compared to HNIgGA6, the mutated antibody showed an approximately three-fold increase in HA-binding affinity and 10-fold enhancement in neutralization potency in vitro. Importantly, the S28H variant also exhibited broad H7N9-neutralizing activity. When administered to BALB/c mice, mAb S28H showed enhanced potency in inhibiting the pulmonary virus titre and reducing lung lesions and resulted in better protection of the animals than did the original antibody.

Regulatory consideration on preparation and clinical use of COVID-19 convalescent plasma

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease (COVID-19), spreading from Wuhan to worldwide has been emerged since December 2019. Although scientists and researchers have been racing to develop specific therapeutic agents or vaccines against SARS-CoV-2 since the identification of the agent, either a drug or a vaccine has not been approved to treat or to prevent COVID-19 up to date. On the base of historical experiences, Convalescent Plasma (CP), a passive antibody therapy, has been evaluated as a hopeful and potential therapeutic option since the beginning of the COVID-19 outbreak. Immune plasma had been used previously for the treatment of H1N1 influenza virus, SARS-CoV-1 and MERS-CoV epidemics successfully. In this scope competent authorities are responsible to set up certain principles and criteria for the collection and clinical use of COVID-19 Convalescent Plasma (CCP). This document has been prepared to aid both for the convalescent plasma suppliers and the clinicians. The first part encompasses the supply of CCP and the second part lead the clinical use of CCP for the treatment of patients with severe COVID-19 infection.Turkish Ministry of Health developed a guide on collection and clinical use of CCP and created a web-based monitoring system to follow-up the patients treated with convalescent plasma in universal. This follow-up process is thought to be crucial for the creation and development of current and future treatment modalities. This guide would be a pathfinder for clinicians and/or institutions those eager to conduct CCP treatment more effectively.