Characterization of Natural and Synthetic Sialoglycans Targeting the Hemagglutinin-Neuraminidase of Mumps Virus

The inhibition of surface viral glycoproteins offers great potential to hamper the attachment of viruses to the host cells surface and the spreading of viral infection. Mumps virus (MuV) is the etiological agent of the mumps infectious disease and causes a wide spectrum of mild to severe symptoms due to the inflammation of the salivary glands. Here we focus our attention on the hemagglutinin-neuraminidase (HN) isolated from MuV SBL-1 strain. We describe the molecular features of host sialoglycans recognition by HN protein by means of NMR, fluorescence assays and computational studies. Furthermore, we also describe the synthesis of a N-acetylneuraminic acid-derived thiotrisaccharide targeting the viral protein, and the corresponding 3D-complex. Our results provide the basis to improve the design and synthesis of potent viral hemagglutinin-neuraminidase inhibitors.

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Exploring the Effect of Structure-Based Scaffold Hopping on the Inhibition of Coxsackievirus A24v Transduction by Pentavalent N-Acetylneuraminic Acid Conjugates

International Journal of Molecular Sciences ◽

10.3390/ijms22168418 ◽

2021 ◽

Vol 22 (16) ◽

pp. 8418

Author(s):

Emil Johansson ◽

Rémi Caraballo ◽

Daniel L. Hurdiss ◽

Nitesh Mistry ◽

C. David Andersson ◽

...

Keyword(s):

Antiviral Agents ◽

Host Cells ◽

Scaffold Hopping ◽

Corneal Epithelial ◽

Acetylneuraminic Acid ◽

Design And Synthesis ◽

Coxsackievirus A24 Variant ◽

Human Corneal Epithelial Cells ◽

Eye Infection ◽

Coxsackievirus A24

Coxsackievirus A24 variant (CVA24v) is the primary causative agent of the highly contagious eye infection designated acute hemorrhagic conjunctivitis (AHC). It is solely responsible for two pandemics and several recurring outbreaks of the disease over the last decades, thus affecting millions of individuals throughout the world. To date, no antiviral agents or vaccines are available for combating this disease, and treatment is mainly supportive. CVA24v utilizes Neu5Ac-containing glycans as attachment receptors facilitating entry into host cells. We have previously reported that pentavalent Neu5Ac conjugates based on a glucose-scaffold inhibit CVA24v infection of human corneal epithelial cells. In this study, we report on the design and synthesis of scaffold-replaced pentavalent Neu5Ac conjugates and their effect on CVA24v cell transduction and the use of cryogenic electron microscopy (cryo-EM) to study the binding of these multivalent conjugates to CVA24v. The results presented here provide insights into the development of Neu5Ac-based inhibitors of CVA24v and, most significantly, the first application of cryo-EM to study the binding of a multivalent ligand to a lectin.

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Leishmania species: models of intracellular parasitism

Journal of Cell Science ◽

10.1242/jcs.112.18.2993 ◽

1999 ◽

Vol 112 (18) ◽

pp. 2993-3002 ◽

Cited By ~ 3

Author(s):

J. Alexander ◽

A.R. Satoskar ◽

D.G. Russell

Keyword(s):

Immune Response ◽

Wide Spectrum ◽

Cell Lineage ◽

Leishmania Species ◽

Host Cells ◽

Accessory Cell ◽

Intracellular Parasites ◽

Successful Infection ◽

Antigen Presenting

Leishmania species are obligate intracellular parasites of cells of the macrophage-dendritic cell lineage. Indeed, the ability to survive and multiply within macrophages is a feature of a surprising number of infectious agents of major importance to public health, including Mycobacterium tuberculosis, Mycobacterium leprae, Listeria monocytogenes, Salmonella typhimurium, Toxoplasma gondii and Trypanosoma cruzi. The relationship between such organisms and their host cells is particularly intriguing because, not only are macrophages capable of potent microbicidal activity, but in their antigen-presenting capacity they can orchestrate the developing immune response. Thus, to initiate a successful infection parasites must gain entry into macrophages, and also withstand or circumvent their killing and degradative functions. However, to sustain a chronic infection, parasites must also subvert macrophage-accessory-cell activities and ablate the development of protective immunity. The leishmanias produce a wide spectrum of disease in mice, and as such they have provided excellent models for studying problems associated with intracellular parasitism. In recent years, largely using these organisms, we have made enormous progress in elucidating the mechanisms by which successful intracellular infection occurs. Furthermore, characterization of immunological pathways that are responsible for resistance or susceptibility to Leishmania has given rise to the Th1/Th2 paradigm of cellular/humoral dominance of the immune response.

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Characterization of the Bacteriophage vB_EfaS-271 Infecting Enterococcus faecalis

International Journal of Molecular Sciences ◽

10.3390/ijms21176345 ◽

2020 ◽

Vol 21 (17) ◽

pp. 6345

Author(s):

Gracja Topka-Bielecka ◽

Sylwia Bloch ◽

Bożena Nejman-Faleńczyk ◽

Michał Grabski ◽

Agata Jurczak-Kurek ◽

...

Keyword(s):

Enterococcus Faecalis ◽

Burst Size ◽

Host Cells ◽

Mass Spectrometry Analysis ◽

Narrow Host Range ◽

Spectrometry Analysis ◽

Molecular Features ◽

Functional Features ◽

Microscopy Characterization

A newly isolated bacteriophage infecting Enterococcus faecalis strains has been characterized, including determination of its molecular features. This phage, named vB_EfaS-271, has been classified as a Siphoviridae member, according to electron microscopy characterization of the virions, composed of a 50 nm-diameter head and a long, flexible, noncontractable tail (219 × 12.5 nm). Analysis of the whole dsDNA genome of this phage showed that it consists of 40,197 bp and functional modules containing genes coding for proteins that are involved in DNA replication (including DNA polymerase/primase), morphogenesis, packaging and cell lysis. Mass spectrometry analysis allowed us to identify several phage-encoded proteins. vB_EfaS-271 reveals a relatively narrow host range, as it is able to infect only a few E. faecalis strains. On the other hand, it is a virulent phage (unable to lysogenize host cells), effectively and quickly destroying cultures of sensitive host bacteria, with a latent period as short as 8 min and burst size of approximately 70 phages per cell at 37 °C. This phage was also able to destroy biofilms formed by E. faecalis. These results contribute to our understanding of the biodiversity of bacteriophages, confirming the high variability among these viruses and indicating specific genetic and functional features of vB_EfaS-271.

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In Vitro Characterization of the Antibacterial Spectrum of Novel Bacterial Type II Topoisomerase Inhibitors of the Aminobenzimidazole Class

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.50.4.1228-1237.2006 ◽

2006 ◽

Vol 50 (4) ◽

pp. 1228-1237 ◽

Cited By ~ 56

Author(s):

Nagraj Mani ◽

Christian H. Gross ◽

Jonathan D. Parsons ◽

Brian Hanzelka ◽

Ute Müh ◽

...

Keyword(s):

Bacterial Resistance ◽

Wide Spectrum ◽

Dna Gyrase ◽

Antibacterial Activities ◽

Mechanisms Of Action ◽

Fluoroquinolone Resistance ◽

Topoisomerase Iv ◽

Low Frequencies

ABSTRACT Antibiotics with novel mechanisms of action are becoming increasingly important in the battle against bacterial resistance to all currently used classes of antibiotics. Bacterial DNA gyrase and topoisomerase IV (topoIV) are the familiar targets of fluoroquinolone and coumarin antibiotics. Here we present the characterization of two members of a new class of synthetic bacterial topoII ATPase inhibitors: VRT-125853 and VRT-752586. These aminobenzimidazole compounds were potent inhibitors of both DNA gyrase and topoIV and had excellent antibacterial activities against a wide spectrum of problematic pathogens responsible for both nosocomial and community-acquired infections, including staphylococci, streptococci, enterococci, and mycobacteria. Consistent with the novelty of their structures and mechanisms of action, antibacterial potency was unaffected by commonly encountered resistance phenotypes, including fluoroquinolone resistance. In time-kill assays, VRT-125853 and VRT-752586 were bactericidal against Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecalis, and Haemophilus influenzae, causing 3-log reductions in viable cells within 24 h. Finally, similar to the fluoroquinolones, relatively low frequencies of spontaneous resistance to VRT-125853 and VRT-752586 were found, a property consistent with their in vitro dual-targeting activities.

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Characterization of glycopeptides derived from the low-density lipoprotein of hen's egg yolk

Canadian Journal of Biochemistry ◽

10.1139/o68-147 ◽

1968 ◽

Vol 46 (8) ◽

pp. 983-988 ◽

Cited By ~ 6

Author(s):

J. Z. Augustyniak ◽

W. G. Martin

Keyword(s):

Low Density Lipoprotein ◽

Density Lipoprotein ◽

Egg Yolk ◽

Low Density ◽

Amide Nitrogen ◽

Acetylneuraminic Acid ◽

Hen’S Egg ◽

Terminal Amino ◽

Protein Moiety

Two glycopeptides (A and B) were isolated from pronase-digested vitellenin, the protein moiety of the low-density lipoprotein of hen's egg yolk. Aspartic acid was the only N-terminal amino acid of both glycopeptides but only A contained N-acetylneuraminic acid. A contained 55% hexose (mannose), 14% hexosamine, 12% N-acetylneuraminic acid, 0.71% amide nitrogen, and its molecular weight was 2.3 × 103. The corresponding values for B were 64, 17, 0.0, 0.75, and 2.0 × 103. Chemical analyses showed that B (and probably A) occurs in vitellenin with the heteropolysaccharide group bound N-glycosidically via the β-amide group of an asparaginyl residue. The indicated structure is R∙(NH)Asp∙Thr∙Ser∙(Ala, Gly, Val)∙Ile, where R, the heteropolysaccharide group, contains 2 hexosamine and 8 hexose residues.

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Differential Regulation of Inflammatory Cytokine Secretion by Human Dendritic Cells upon Chlamydia trachomatis Infection

Infection and Immunity ◽

10.1128/iai.72.12.7231-7239.2004 ◽

2004 ◽

Vol 72 (12) ◽

pp. 7231-7239 ◽

Cited By ~ 57

Author(s):

Ana Gervassi ◽

Mark R. Alderson ◽

Robert Suchland ◽

Jean François Maisonneuve ◽

Kenneth H. Grabstein ◽

...

Keyword(s):

Dendritic Cells ◽

Chlamydia Trachomatis ◽

Wide Spectrum ◽

Cytokine Secretion ◽

Host Cells ◽

Microbial Pathogens ◽

Potential Contribution ◽

Necrosis Factor Alpha ◽

Chlamydia Trachomatis Infection ◽

Tnf Α

ABSTRACT Chlamydia trachomatis is an obligate intracellular gram-negative bacterium responsible for a wide spectrum of diseases in humans. Both genital and ocular C. trachomatis infections are associated with tissue inflammation and pathology. Dendritic cells (DC) play an important role in both innate and adaptive immune responses to microbial pathogens and are a source of inflammatory cytokines. To determine the potential contribution of DC to the inflammatory process, human DC were infected with C. trachomatis serovar E or L2. Both C. trachomatis serovars were found to infect and replicate in DC. Upon infection, DC up-regulated the expression of costimulatory (B7-1) and cell adhesion (ICAM-1) molecules. Furthermore, chlamydial infection induced the secretion of interleukin-1β (IL-1β), IL-6, IL-8, IL-12p70, IL-18, and tumor necrosis factor alpha (TNF-α). The mechanisms involved in Chlamydia-induced IL-1β and IL-18 secretion differed from those of the other cytokines. Chlamydia-induced IL-1β and IL-18 secretion required infection with viable bacteria and was associated with the Chlamydia-induced activation of caspase-1 in infected host cells. In contrast, TNF-α and IL-6 secretion did not require that the Chlamydia be viable, suggesting that there are at least two mechanisms involved in the Chlamydia-induced cytokine secretion in DC. Interestingly, an antibody to Toll-like receptor 4 inhibited Chlamydia-induced IL-1β, IL-6, and TNF-α secretion. The data herein demonstrate that DC can be infected by human C. trachomatis serovars and that chlamydial components regulate the secretion of various cytokines in DC. Collectively, these data suggest that DC play a role in the inflammatory processes caused by chlamydial infections.

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Detection and characterization of mumps virus V protein

Virology ◽

10.1016/0042-6822(90)90400-l ◽

1990 ◽

Vol 178 (1) ◽

pp. 247-253 ◽

Cited By ~ 30

Author(s):

Kaoru Takeuchi ◽

Kiyoshi Tanabayashi ◽

Michiko Hishiyama ◽

Yasuko K. Yamada ◽

Akio Yamada ◽

...

Keyword(s):

Mumps Virus ◽

V Protein

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Characterization of Gnomoniopsis idaeicola, the Causal Agent of Canker and Wilting of Blackberry in Serbia

Plant Disease ◽

10.1094/pdis-03-18-0516-re ◽

2019 ◽

Vol 103 (2) ◽

pp. 249-258 ◽

Cited By ~ 1

Author(s):

Miloš Stevanović ◽

Danijela Ristić ◽

Svetlana Živković ◽

Goran Aleksić ◽

Ivana Stanković ◽

...

Keyword(s):

Disease Incidence ◽

Initial Step ◽

First Record ◽

Wide Distribution ◽

Causal Agent ◽

Control Measures ◽

Molecular Features ◽

Intraspecies Diversity ◽

Specific Symptoms

Blackberry cane diseases with the symptoms of necrosis, canker, and wilting are caused by several fungi worldwide. Surveys conducted from 2013 to 2016 in Serbia revealed the occurrence of Gnomoniopsis idaeicola, the causal agent of cane canker and wilting, which was found to be distributed in almost half of the surveyed orchards, in three blackberry cultivars, and with disease incidence of up to 80%. Wide distribution and high disease incidence suggest that G. idaeicola has been present in Serbia for some time. Out of 427 samples, a total of 65 G. idaeicola isolates were obtained (isolation rate of 34.19%). Reference isolates, originating from different localities, were conventionally and molecularly identified and characterized. G. idaeicola was detected in single and mixed infections with fungi from genera Paraconiothyrium, Colletotrichum, Diaporthe, Botryosphaeria, Botrytis, Septoria, Neofusicoccum, and Discostroma, and no diagnostically specific symptoms could be related directly to the G. idaeicola infection. In orchards solely infected with G. idaeicola, blackberry plant mortality was up to 40%, and yield loses were estimated at 50%. G. idaeicola isolates included in this study demonstrated intraspecies diversity in morphological, biological, pathogenic, and molecular features, which indicates that population in Serbia may be of different origin. This is the first record of a massive outbreak of G. idaeicola infection, illustrating its capability of harmful influence on blackberry production. This study represents the initial step in studying G. idaeicola as a new blackberry pathogen in Serbia, aiming at developing efficient control measures.

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Functional Characterization of a Redundant Plasmodium TRAP Family Invasin, TRAP-Like Protein, by Aldolase Binding and a Genetic Complementation Test

Eukaryotic Cell ◽

10.1128/ec.00089-08 ◽

2008 ◽

Vol 7 (6) ◽

pp. 1062-1070 ◽

Cited By ~ 39

Author(s):

Kirsten Heiss ◽

Hui Nie ◽

Sumit Kumar ◽

Thomas M. Daly ◽

Lawrence W. Bergman ◽

...

Keyword(s):

Functional Characterization ◽

Cell Entry ◽

Host Cells ◽

Complementation Test ◽

Type I ◽

Cycle Progression ◽

Targeted Gene Disruption ◽

Specific Host ◽

Host Cell Entry

ABSTRACT Efficient and specific host cell entry is of exquisite importance for intracellular pathogens. Parasites of the phylum Apicomplexa are highly motile and actively enter host cells. These functions are mediated by type I transmembrane invasins of the TRAP family that link an extracellular recognition event to the parasite actin-myosin motor machinery. We systematically tested potential parasite invasins for binding to the actin bridging molecule aldolase and complementation of the vital cytoplasmic domain of the sporozoite invasin TRAP. We show that the ookinete invasin CTRP and a novel, structurally related protein, termed TRAP-like protein (TLP), are functional members of the TRAP family. Although TLP is expressed in invasive stages, targeted gene disruption revealed a nonvital role during life cycle progression. This is the first genetic analysis of TLP, encoding a redundant TRAP family invasin, in the malaria parasite.

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Molecular Determinants of Soft Tissue Sarcoma Immunity: Targets for Immune Intervention

International Journal of Molecular Sciences ◽

10.3390/ijms22147518 ◽

2021 ◽

Vol 22 (14) ◽

pp. 7518

Author(s):

Marcella Tazzari ◽

Laura Bergamaschi ◽

Alessandro De Vita ◽

Paola Collini ◽

Marta Barisella ◽

...

Keyword(s):

Soft Tissue ◽

Malignant Tumors ◽

Soft Tissue Sarcomas ◽

Point Of View ◽

Molecular Features ◽

Molecular Determinants ◽

Genetic Landscape ◽

Current Therapies ◽

Cumulative Evidence

Soft tissue sarcomas (STSs) are a family of rare malignant tumors encompassing more than 80 histologies. Current therapies for metastatic STS, a condition that affects roughly half of patients, have limited efficacy, making innovative therapeutic strategies urgently needed. From a molecular point of view, STSs can be classified as translocation-related and those with a heavily rearranged genotype. Although only the latter display an increased mutational burden, molecular profiles suggestive of an “immune hot” tumor microenvironment are observed across STS histologies, and response to immunotherapy has been reported in both translocation-related and genetic complex STSs. These data reinforce the notion that immunity in STSs is multifaceted and influenced by both genetic and epigenetic determinants. Cumulative evidence indicates that a fine characterization of STSs at different levels is required to identify biomarkers predictive of immunotherapy response and to discover targetable pathways to switch on the immune sensitivity of “immune cold” tumors. In this review, we will summarize recent findings on the interplay between genetic landscape, molecular profiling and immunity in STSs. Immunological and molecular features will be discussed for their prognostic value in selected STS histologies. Finally, the local and systemic immunomodulatory effects of the targeted drugs imatinib and sunitinib will be discussed.

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