Susanne C Duwe, Barbara Schmidt, Barbara C Gärtner, Jörg Timm, Ortwin Adams, Helmut Fickenscher, Michaela Schmidtke
Influenza viruses of types A and B attack 5-10% of adults and 20-30% of children, thereby causing millions of acute respiratory infections in Germany annually. A significant number of these infections are associated with complications such as pneumonia and bacterial superinfections that need hospitalization and might lead to death. In addition to vaccines, drugs were developed that might support influenza prevention and that can be used to treat influenza patients. The timely application of anti-influenza drugs can inhibit virus replication, help reduce and shorten the symptoms, and prevent death as well as virus transmission...
2021: GMS Infectious Diseases
Mari Toña Juárez-Méndez, Rocío Borges-Argáez, Guadalupe Ayora-Talavera, Sigfredo Edmundo Escalante-Rebolledo, Fabiola Escalante-Erosa, Mirbella Cáceres-Farfán
Influenza viral proteins Haemagglutinin (HA) and Neuraminidase (NA) are important targets for antiviral design. We analyzed for the first time the anti-HA activity and the NA inhibitory activity of extracts and their fractions from Diospyros anisandra on the influenza AH1N1pdm09 virus. The n -hexane fruit extract exhibited HA inhibitory (HAI) activity, and fraction F3 inhibited the hemagglutination from 12.5 up to 100 μg/ml. Gas chromatography-mass spectrometry analysis (GC-MS) on fraction F3, and the n -hexane fruit extract, identified six compounds that were individually evaluated...
June 10, 2021: Natural Product Research
Intan M W Dewi, Cristina Cunha, Martin Jaeger, Mark S Gresnigt, Marina E Gkountzinopoulou, Fadel M Garishah, Cláudio Duarte-Oliveira, Cláudia F Campos, Lore Vanderbeke, Agustin Resendiz Sharpe, Roger J Brüggemann, Paul E Verweij, Katrien Lagrou, Greetje Vande Velde, Quirijn de Mast, Leo A B Joosten, Mihai G Netea, Andre J A M van der Ven, Joost Wauters, Agostinho Carvalho, Frank L van de Veerdonk
Influenza-associated pulmonary aspergillosis (IAPA) has been reported increasingly since the advent of use of neuraminidase (NA) inhibitors following the 2009 influenza pandemic. We hypothesize that blocking host NA modulates the immune response against Aspergillus fumigatus . We demonstrate that NA influences the host response against A. fumigatus in vitro and that oseltamivir increases the susceptibility of mice to pulmonary aspergillosis. Oseltamivir impairs the mouse splenocyte and human peripheral blood mononuclear cell (PBMC) killing capacity of A...
May 18, 2021: Cell reports medicine
Tanya R McKitrick, Steffen M Bernard, Alexander J Noll, Bernard C Collins, Christoffer K Goth, Alyssa M McQuillan, Jamie Heimburg-Molinaro, Brantley R Herrin, Ian A Wilson, Max D Cooper, Richard D Cummings
The terminal galactose residues of N- and O-glycans in animal glycoproteins are often sialylated and/or fucosylated, but sulfation, such as 3-O-sulfated galactose (3-O-SGal), represents an additional, but poorly understood modification. To this end, we have developed a novel sea lamprey variable lymphocyte receptor (VLR) termed O6 to explore 3-O-SGal expression. O6 was engineered as a recombinant murine IgG chimera and its specificity and affinity to the 3-O-SGal epitope was defined using a variety of approaches, including glycan and glycoprotein microarray analyses, isothermal calorimetry, ligand-bound crystal structure, FACS, and immunohistochemistry of human tissue macroarrays...
June 3, 2021: Communications Biology
Hongqian Zhao, Siyuan Jiang, Zhifan Ye, Hongxi Zhu, Baichun Hu, Peipei Meng, Yanmei Hu, Huicong Zhang, Kuanglei Wang, Jun Wang, Yongshou Tian
Neuraminidase (NA) inhibitors play a prime role in treating influenza. However, a variety of viruses containing mutant NAs have developed severe drug resistance towards NA inhibitors, so it is of crucial significance to solve this problem. Encouraged by urea-containing compound 12 disclosed by our lab, we designed a series of oseltamivir derivatives bearing hydrazide fragment for targeting the 150 cavity. Among the synthesized compounds, compound 17a showed 8.77-fold, 4.12-fold, 203-fold and 6.23-fold more potent activity than oseltamivir carboxylate against NAs from H5N1, H1N1, H5N1-H274Y, H1N1-H274Y, respectively...
May 23, 2021: European Journal of Medicinal Chemistry
Quyen-Thi Nguyen, Young-Ki Choi
Traditional influenza vaccines generate strain-specific antibodies which cannot provide protection against divergent influenza virus strains. Further, due to frequent antigenic shifts and drift of influenza viruses, annual reformulation and revaccination are required in order to match circulating strains. Thus, the development of a universal influenza vaccine (UIV) is critical for long-term protection against all seasonal influenza virus strains, as well as to provide protection against a potential pandemic virus...
May 24, 2021: Viruses
Kobporn Boonnak, Chayasin Mansanguan, Dennis Schuerch, Usa Boonyuen, Hatairat Lerdsamran, Kultida Jiamsomboon, Fanny Sae Wang, Arun Huntrup, Jarunee Prasertsopon, Nathamon Kosoltanapiwat, Pilaipan Puthavathana
Influenza viruses continue to be a major public health threat due to the possible emergence of more virulent influenza virus strains resulting from dynamic changes in virus adaptability, consequent of functional mutations and antigenic drift in surface proteins, especially hemagglutinin (HA) and neuraminidase (NA). In this study, we describe the genetic and evolutionary characteristics of H1N1, H3N2, and influenza B strains detected in severe cases of seasonal influenza in Thailand from 2018 to 2019. We genetically characterized seven A/H1N1 isolates, seven A/H3N2 isolates, and six influenza B isolates...
May 25, 2021: Viruses
Jenna J Guthmiller, Henry A Utset, Patrick C Wilson
Antibodies are critical for providing protection against influenza virus infections. However, protective humoral immunity against influenza viruses is limited by the antigenic drift and shift of the major surface glycoproteins, hemagglutinin and neuraminidase. Importantly, people are exposed to influenza viruses throughout their life and tend to reuse memory B cells from prior exposure to generate antibodies against new variants. Despite this, people tend to recall memory B cells against constantly evolving variable epitopes or non-protective antigens, as opposed to recalling them against broadly neutralizing epitopes of hemagglutinin...
May 22, 2021: Viruses
Thuy-Tien Thi Trinh, Indira Tiwari, Kaliannan Durairaj, Bao Tuan Duong, Anh Thi Viet Nguyen, Hien Thi Tuong, Vui Thi Hoang, Duong Duc Than, SunJeong Nam, Seon-Ju Yeo, Hyun Park
Low-pathogenicity avian influenza viruses (LPAIV) introduced by migratory birds circulate in wild birds and can be transmitted to poultry. These viruses can mutate to become highly pathogenic avian influenza viruses causing severe disease and death in poultry. In March 2019, an H7N3 avian influenza virus-A/Spot-billed duck/South Korea/WKU2019-1/2019 (H7N3)-was isolated from spot-billed ducks in South Korea. This study aimed to evaluate the phylogenetic and mutational analysis of this isolate. Molecular analysis revealed that the genes for HA (hemagglutinin) and NA (neuraminidase) of this strain belonged to the Central Asian lineage, whereas genes for other internal proteins such as polymerase basic protein 1 (PB1), PB2, nucleoprotein, polymerase acidic protein, matrix protein, and non-structural protein belonged to that of the Korean lineage...
May 7, 2021: Viruses
Tainá Cavalcante, Mariana Medina Medeiros, Simon Ngao Mule, Giuseppe Palmisano, Beatriz Simonsen Stolf
Carbohydrates or glycans are ubiquitous components of the cell surface which play crucial biological and structural roles. Sialic acids (Sias) are nine-carbon atoms sugars usually present as terminal residues of glycoproteins and glycolipids on the cell surface or secreted. They have important roles in cellular communication and also in infection and survival of pathogens. More than 20 pathogens can synthesize or capture Sias from their hosts and incorporate them into their own glycoconjugates and derivatives...
2021: Frontiers in Cellular and Infection Microbiology
Yong Chong, Naoki Kawai, Naoki Tani, Takuma Bando, Yoshio Takasaki, Shizuo Shindo, Hideyuki Ikematsu
Although the virological and clinical efficacies of baloxavir for influenza and the post-treatment emergence of variant viruses have been reported in clinical trials, its efficacies have not been fully investigated in clinical settings. This prospective, observational investigator-initiated study was conducted during the 2019-2020 Japanese influenza season. In outpatients receiving baloxavir or oseltamivir, nasopharyngeal samples were obtained on day 1 before treatment and on the scheduled days 5 and 10 after treatment...
May 27, 2021: Antiviral Research
Tadanobu Takahashi, Yuuki Kurebayashi, Tadamune Otsubo, Kiyoshi Ikeda, Akira Minami, Takashi Suzuki
Visualization of virus-infected cells is usually performed by immunostaining with an antiviral antibody. On the other hand, we established an easy method for fluorescence (FL) imaging of cells infected with influenza A and B viruses and some paramyxoviruses without the need for cell fixation and an antiviral antibody. These viruses and the cells they have infected express the viral surface enzyme "neuraminidase" or "hemagglutinin-neuraminidase" that shows sialidase activity. Sialidase activity is fluorescently visualized by using a sialidase fluorogenic probe developed in our previous study...
2021: Methods in Molecular Biology
David F Zeigler, Emily Gage, Christopher H Clegg
Seasonal influenza vaccines are often ineffective because they elicit strain-specific antibody responses to mutation-prone sites on the hemagglutinin (HA) head. Vaccines that provide long-lasting immunity to conserved epitopes are needed. Recently, we reported a nanoparticle-based vaccine platform produced by solid-phase peptide synthesis (SPPS) for targeting linear and helical protein-based epitopes. Here, we illustrate its potential for building broadly protective influenza vaccines. Targeting known epitopes in the HA stem, neuraminidase (NA) active site, and M2 ectodomain (M2e) conferred 50-75% survival against 5LD50 influenza B and H1N1 challenge; combining stem and M2e antigens increased survival to 90%...
2021: PloS One
Piyumi Wijesekara, Ying Liu, Weitao Wang, Elizabeth K Johnston, Mara L G Sullivan, Rebecca E Taylor, Xi Ren
The cell-surface glycocalyx serves as a physiological barrier regulating cellular accessibility to macromolecules and other cells. Conventional glycocalyx characterization has largely been morphological rather than functional. Here, we demonstrated direct glycocalyx anchoring of DNA origami nanotiles and performed a comprehensive comparison with traditional origami targeting to the phospholipid bilayer (PLB) using cholesterol. While DNA nanotiles effectively accessed single-stranded DNA initiators anchored on the glycocalyx, their accessibility to the underlying PLB was only permitted by extended nanotile-to-initiator spacing or by enzymatic glycocalyx degradation using trypsin or pathogenic neuraminidase...
May 24, 2021: Nano Letters
Hyeran Kim, Hyunju Kang, Hye-Nan Kim, Hongki Kim, Jeong Moon, Kyeonghye Guk, Hwangseo Park, Dongeun Yong, Pan Kee Bae, Hyun Gyu Park, Eun-Kyung Lim, Taejoon Kang, Juyeon Jung
Influenza viruses are responsible for several pandemics and seasonal epidemics and pose a major public health threat. Even after a major outbreak, the emergence of drug-resistant influenza viruses can pose disease control problems. Here we report a novel 6E3 monoclonal antibody capable of recognizing and binding to the H275Y neuraminidase (NA) mutation, which has been associated with reduced susceptibility of influenza viruses to NA inhibitors. The 6E3 antibody had a KD of 72.74 μM for wild-type NA and 32...
May 11, 2021: Biosensors & Bioelectronics
Van Dam Lai, Jae Won Kim, Yoon Young Choi, Jeom-Joo Kim, Hyun-Hee So, Jongseo Mo
H9N2 Low-pathogenic avian influenza (LPAI) viruses have long been circulating in the world poultry industry, resulting in substantial economic losses. In addition to animal health consequences, viruses from specific lineages such as G1 and Y280 are also known to have the potential of causing a pandemic within the human population. In South Korea, after introducing inactivated H9N2 vaccines in 2007, there were no field outbreaks of H9N2 LPAI since 2009. However, in June 2020, a H9N2 virus was isolated from an outbreak in a Korean chicken farm...
May 20, 2021: Avian Pathology: Journal of the W.V.P.A
A V Mikurova, A V Rybina, V S Skvortsov
Several variants of models for predicting the IC50 values of inhibitors of influenza virus neuraminidase are presented for both individual strains and also for combinations of data for neuraminidases of several strains. They are based on the use of calculated energy contributions to the amount of change in the free energy of enzyme-inhibitor complexes. In contrast to previous works, aimed at the complex modeling, we added a procedure of comparison of the docking variants with one of the neuraminidase inhibitors, for which the structure of the complexes was determined experimentally...
2021: Biochemistry (Moscow) Supplement. Series B, Biomedical Chemistry
Yizhi Jiang, Yaqiong Tang, Christopher Hoover, Yuji Kondo, Dongping Huang, Damien Restagno, Bojing Shao, Liang Gao, J Michael McDaniel, Meixiang Zhou, Robert Silasi-Mansat, Samuel McGee, Miao Jiang, Xia Bai, Florea Lupu, Changgeng Ruan, Jamey D Marth, Depei Wu, Yue Han, Lijun Xia
The liver has recently been identified as a major organ for destruction of desialylated platelets. However, the underlying mechanism remains unclear. Kupffer cells, which are professional phagocytic cells in the liver, comprise the largest population of resident tissue macrophages in the body. Kupffer cells express a C-type lectin receptor, CLEC4F, that recognizes desialylated glycans with an unclear in vivo role in mediating platelet destruction. In this study, we generated a CLEC4F-deficient mouse model (Clec4f-/- ) and found that CLEC4F was specifically expressed by Kupffer cells...
May 15, 2021: Cell Death and Differentiation
Mandana Behbahani, Mohammad Moradi, Hassan Mohabatkar
Designing an effective vaccine against different subtypes of Influenza A virus is a critical issue in the field of medical biotechnology. At the current study, a novel potential multi-epitope vaccine candidate based on the neuraminidase proteins for seven subtypes of Influenza virus was designed, using the in silico approach. Potential linear B-cell and T-cell binding epitopes from each neuraminidase protein (N1, N2, N3, N4, N6, N7, N8) were predicted by in silico tools of epitope prediction. The selected epitopes were joined by three different linkers, and physicochemical properties, toxicity, and allergenecity were investigated...
2021: In Silico Pharmacology
Alexei Gorelik, Katalin Illes, S M Naimul Hasan, Bhushan Nagar, Mohammad T Mazhab-Jafari
The enzymes β-galactosidase (GLB1) and neuraminidase 1 (NEU1; sialidase 1) participate in the degradation of glycoproteins and glycolipids in the lysosome. To remain active and stable, they associate with PPCA [protective protein cathepsin A (CTSA)] into a high-molecular weight lysosomal multienzyme complex (LMC), of which several forms exist. Genetic defects in these three proteins cause the lysosomal storage diseases GM1-gangliosidosis/mucopolysaccharidosis IV type B, sialidosis, and galactosialidosis, respectively...
May 2021: Science Advances
Fetch more papers »
Fetching more papers... Fetching...
Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"