Lipid-mediated biosynthetic labeling strategy for in vivo dynamic tracing of avian influenza virus infection

Monitoring the infection behavior of avian influenza viruses is crucial for understanding viral pathogenesis and preventing its epidemics among people. A number of viral labeling methods have been utilized for tracking viral infection process, but most of them are laborious or decreasing viral activity. Herein we explored a lipid biosynthetic labeling strategy for dynamical tracking the infection of H5N1 pseudotype virus (H5N1p) in host. Biotinylated lipids (biotinyl Cap-PE) were successfully incorporated into viral envelope when it underwent budding process by taking advantage of host cell-derived lipid metabolism. Biotin-H5N1p virus was effectively in situ–labeled with streptavidin-modified near-infrared quantum dots (NIR SA-QDs) using streptavidin-biotin conjugation with well-preserved virus activities. Dual-labeled imaging obviously shows that H5N1p viruses are primarily taken up in host cells via clathrin-mediated endocytosis. In animal models, Virus-conjugated NIR QDs displayed extraordinary photoluminescence, superior stability, and tissue penetration in lung, allowing us to long-term monitor respiratory viral infection in a noninvasive manner. Importantly, the co-localization of viral hemagglutinin protein and QDs in infected lung further conformed the dynamic infection process of virus in vivo. Hence, this in situ QD-labeling strategy based on cell natural biosynthesis provides a brand-new and reliable tool for noninvasion visualizing viral infection in body in a real-time manner.

Download Full-text

Dynamic changes in host gene expression associated with H5N8 avian influenza virus infection in mice

Scientific Reports ◽

10.1038/srep16512 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 28

Author(s):

Su-Jin Park ◽

Mukesh Kumar ◽

Hyeok-il Kwon ◽

Rak-Kyun Seong ◽

Kyudong Han ◽

...

Keyword(s):

Avian Influenza ◽

Death Receptor ◽

Influenza Virus Infection ◽

Influenza Viruses ◽

Rna Seq ◽

Highly Pathogenic ◽

Underlying Mechanisms ◽

Immune Related Genes ◽

Insight Into

Abstract Emerging outbreaks of newly found, highly pathogenic avian influenza (HPAI) A(H5N8) viruses have been reported globally. Previous studies have indicated that H5N8 pathogenicity in mice is relatively moderate compared with H5N1 pathogenicity. However, detailed mechanisms underlying avian influenza pathogenicity are still undetermined. We used a high-throughput RNA-seq method to analyse host and pathogen transcriptomes in the lungs of mice infected with A/MD/Korea/W452/2014 (H5N8) and A/EM/Korea/W149/2006 (H5N1) viruses. Sequenced numbers of viral transcripts and expression levels of host immune-related genes at 1 day post infection (dpi) were higher in H5N8-infected than H5N1-infected mice. Dual sequencing of viral transcripts revealed that in contrast to the observations at 1 dpi, higher number of H5N1 genes than H5N8 genes was sequenced at 3 and 7 dpi, which is consistent with higher viral titres and virulence observed in infected lungs in vivo. Ingenuity pathway analysis revealed a more significant upregulation of death receptor signalling, driven by H5N1 than with H5N8 infection at 3 and 7 dpi. Early induction of immune response-related genes may elicit protection in H5N8-infected mice, which correlates with moderate pathogenicity in vivo. Collectively, our data provide new insight into the underlying mechanisms of the differential pathogenicity of avian influenza viruses.

Download Full-text

Distinct miRNA Profile of Cellular and Extracellular Vesicles Released from Chicken Tracheal Cells Following Avian Influenza Virus Infection

Vaccines ◽

10.3390/vaccines8030438 ◽

2020 ◽

Vol 8 (3) ◽

pp. 438

Author(s):

Kelsey O’Dowd ◽

Mehdi Emam ◽

Mohamed Reda El Khili ◽

Amin Emad ◽

Eveline M. Ibeagha-Awemu ◽

...

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Avian Influenza Virus ◽

Extracellular Vesicles ◽

Viral Infections ◽

Influenza Virus Infection ◽

Influenza Viruses ◽

Host Cells ◽

Control Group ◽

Antiviral Responses

Innate responses provide the first line of defense against viral infections, including the influenza virus at mucosal surfaces. Communication and interaction between different host cells at the early stage of viral infections determine the quality and magnitude of immune responses against the invading virus. The release of membrane-encapsulated extracellular vesicles (EVs), from host cells, is defined as a refined system of cell-to-cell communication. EVs contain a diverse array of biomolecules, including microRNAs (miRNAs). We hypothesized that the activation of the tracheal cells with different stimuli impacts the cellular and EV miRNA profiles. Chicken tracheal rings were stimulated with polyI:C and LPS from Escherichia coli 026:B6 or infected with low pathogenic avian influenza virus H4N6. Subsequently, miRNAs were isolated from chicken tracheal cells or from EVs released from chicken tracheal cells. Differentially expressed (DE) miRNAs were identified in treated groups when compared to the control group. Our results demonstrated that there were 67 up-regulated miRNAs, 157 down-regulated miRNAs across all cellular and EV samples. In the next step, several genes or pathways targeted by DE miRNAs were predicted. Overall, this study presented a global miRNA expression profile in chicken tracheas in response to avian influenza viruses (AIV) and toll-like receptor (TLR) ligands. The results presented predicted the possible roles of some DE miRNAs in the induction of antiviral responses. The DE candidate miRNAs, including miR-146a, miR-146b, miR-205a, miR-205b and miR-449, can be investigated further for functional validation studies and to be used as novel prophylactic and therapeutic targets in tailoring or enhancing antiviral responses against AIV.

Download Full-text

Host-derived lipids orchestrate pulmonary γδ T cell response to provide early protection against influenza virus infection

Nature Communications ◽

10.1038/s41467-021-22242-9 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Xiaohui Wang ◽

Xiang Lin ◽

Zihan Zheng ◽

Bingtai Lu ◽

Jun Wang ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Viral Infection ◽

Influenza Virus Infection ◽

Γδ T Cells ◽

T Cell Response ◽

Host Cells ◽

Interleukin 17 ◽

Γδ T Cell ◽

Innate Defense

AbstractInnate immunity is important for host defense by eliciting rapid anti-viral responses and bridging adaptive immunity. Here, we show that endogenous lipids released from virus-infected host cells activate lung γδ T cells to produce interleukin 17 A (IL-17A) for early protection against H1N1 influenza infection. During infection, the lung γδ T cell pool is constantly supplemented by thymic output, with recent emigrants infiltrating into the lung parenchyma and airway to acquire tissue-resident feature. Single-cell studies identify IL-17A-producing γδ T (Tγδ17) cells with a phenotype of TCRγδhiCD3hiAQP3hiCXCR6hi in both infected mice and patients with pneumonia. Mechanistically, host cell-released lipids during viral infection are presented by lung infiltrating CD1d+ B-1a cells to activate IL-17A production in γδ T cells via γδTCR-mediated IRF4-dependent transcription. Reduced IL-17A production in γδ T cells is detected in mice either lacking B-1a cells or with ablated CD1d in B cells. Our findings identify a local host-immune crosstalk and define important cellular and molecular mediators for early innate defense against lung viral infection.

Download Full-text

An amphiphilic dendrimer as a light-activable immunological adjuvant for in situ cancer vaccination

Nature Communications ◽

10.1038/s41467-021-25197-z ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Yongchao Wang ◽

Ningqiang Gong ◽

Chi Ma ◽

Yuxuan Zhang ◽

Hong Tan ◽

...

Keyword(s):

Near Infrared ◽

Infrared Light ◽

Immune Memory ◽

Toll Like Receptor ◽

Tumour Site ◽

Adjuvant Effect ◽

Cancer Vaccination ◽

Tumour Metastasis

AbstractImmunological adjuvants are essential for successful cancer vaccination. However, traditional adjuvants have some limitations, such as lack of controllability and induction of systemic toxicity, which restrict their broad application. Here, we present a light-activable immunological adjuvant (LIA), which is composed of a hypoxia-responsive amphiphilic dendrimer nanoparticle loaded with chlorin e6. Under irradiation with near-infrared light, the LIA not only induces tumour cell lysis and tumour antigen release, but also promotes the structural transformation of 2-nitroimidazole containing dendrimer to 2-aminoimidazole containing dendrimer which can activate dendritic cells via the Toll-like receptor 7-mediated signaling pathway. The LIA efficiently inhibits both primary and abscopal tumour growth and induces strong antigen-specific immune memory effect to prevent tumour metastasis and recurrence in vivo. Furthermore, LIA localizes the immunological adjuvant effect at the tumour site. We demonstrate this light-activable immunological adjuvant offers a safe and potent platform for in situ cancer vaccination.

Download Full-text

The Use of Lectins as Tools to Combat SARS-CoV-2

Current Pharmaceutical Design ◽

10.2174/1381612827666210830094743 ◽

2021 ◽

Vol 27 ◽

Author(s):

Daniela Martinez ◽

Diego Amaral ◽

David Markovitz ◽

Luciano Pinto

Keyword(s):

Viral Infection ◽

Host Cells ◽

Viral Fusion ◽

Cell Receptors ◽

First Case ◽

Mannose Binding ◽

New Treatments ◽

Viral Surface

Background: in december 2019, china announced the first case of an infection caused by an, until then, unknown virus: sars-cov-2. since then, researchers have been looking for viable alternatives for the treatment and/or cure of viral infection. among the possible complementary solutions are lectins, and proteins that are reversibly bound to different carbohydrates. the spike protein, present on the viral surface, can interact with different cell receptors: ace2, cd147, and dc-signr. since lectins have an affinity for different carbohydrates, the binding with the glycosylated cell receptors represents a possibility of preventing the virus from binding to the receptors of host cells. Objective: in this review we discuss the main lectins that are possible candidates for use in the treatment of covid-19, highlighting those that have already demonstrated antiviral activity in vivo and in vitro, including mannose-binding lectin, griffithsin, banlec, and others. we also aim to discuss the possible mechanism of action of lectins, which appears to occur through the mediation of viral fusion in host cells, by binding of lectins to glycosylated receptors found in human cells and/or binding of these proteins with the spike glycoprotein, present in virus surface.moreover, we also discuss the use of lectins in clinical practice. Conclusion: Even with the development of effective vaccines, new cases of viral infection with the same virus, or new outbreaks with different viruses can occur; so, the development of new treatments should not be discarded. moreover, the discussions made in this work are relevant regarding the anti-viral properties of lectins.

Download Full-text

The illustrated life cycle of Microbotryum on the host plant Silene latifolia

Botany ◽

10.1139/b10-061 ◽

2010 ◽

Vol 88 (10) ◽

pp. 875-885 ◽

Cited By ~ 44

Author(s):

Angela Maria Schäfer ◽

Martin Kemler ◽

Robert Bauer ◽

Dominik Begerow

Keyword(s):

Life Cycle ◽

Light And Electron Microscopy ◽

Laboratory Data ◽

Infection Process ◽

Host Cells ◽

Silene Latifolia ◽

Long Distance ◽

Biological Studies ◽

Plant Parasitic

The plant-parasitic genus Microbotryum (Pucciniomycotina) has been used as a model for various biological studies, but fundamental aspects of its life history have not been documented in detail. The smut fungus is characterized by a dimorphic life cycle with a haploid saprophytic yeast-like stage and a dikaryotic plant-parasitic stage, which bears the teliospores as dispersal agents. In this study, seedlings and flowers of Silene latifolia Poir. (Caryophyllaceae) were inoculated with teliospores or sporidial cells of Microbotryum lychnidis-dioicae (DC. ex Liro) G. Deml & Oberw. and the germination of teliospores, the infection process, and the proliferation in the host tissue were documented in vivo using light and electron microscopy. Although germination of the teliospore is crucial for the establishment of Microbotryum, basidium development is variable under natural conditions. In flowers, where the amount of nutrients is thought to be high, the fungus propagates as sporidia, and mating of compatible cells takes place only when flowers are withering and nutrients are decreasing. On cotyledons (i.e., nutrient-depleted conditions), conjugation occurs shortly after teliospore germination, often via intrapromycelial mating. After formation of an infectious hypha with an appressorium, the invasion of the host occurs by direct penetration of the epidermis. While the growth in the plant is typically intercellular, long distance proliferation seems mediated through xylem tracheary elements. At the beginning of the vegetation period, fungal cells were found between meristematic shoot host cells, indicating a dormant phase inside the plant. By using different microscopy techniques, many life stages of Microbotryum are illustrated for the first time, thereby allowing new interpretations of laboratory data.

Download Full-text

Highly Pathogenic Avian Influenza Virus Infection of Mallards with Homo- and Heterosubtypic Immunity Induced by Low Pathogenic Avian Influenza Viruses

PLoS ONE ◽

10.1371/journal.pone.0006706 ◽

2009 ◽

Vol 4 (8) ◽

pp. e6706 ◽

Cited By ~ 76

Author(s):

Sasan R. Fereidouni ◽

Elke Starick ◽

Martin Beer ◽

Hendrik Wilking ◽

Donata Kalthoff ◽

...

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Highly Pathogenic Avian Influenza ◽

Influenza Virus Infection ◽

Influenza Viruses ◽

Avian Influenza Viruses ◽

Highly Pathogenic ◽

Pathogenic Avian Influenza ◽

Heterosubtypic Immunity ◽

Pathogenic Avian Influenza Virus

Download Full-text

Characterization of Low-Pathogenicity H5N1 Avian Influenza Viruses from North America

Journal of Virology ◽

10.1128/jvi.01368-07 ◽

2007 ◽

Vol 81 (21) ◽

pp. 11612-11619 ◽

Cited By ~ 45

Author(s):

Erica Spackman ◽

David E. Swayne ◽

David L. Suarez ◽

Dennis A. Senne ◽

Janice C. Pedersen ◽

...

Keyword(s):

North America ◽

Avian Influenza ◽

North American ◽

Wild Bird ◽

Geographic Origin ◽

Influenza Viruses ◽

Highly Pathogenic ◽

Infectious Dose ◽

Antigenic Relatedness

ABSTRACT Wild-bird surveillance in North America for avian influenza (AI) viruses with a goal of early identification of the Asian H5N1 highly pathogenic AI virus has identified at least six low-pathogenicity H5N1 AI viruses between 2004 and 2006. The hemagglutinin (HA) and neuraminidase (NA) genes from all 6 H5N1 viruses and an additional 38 North American wild-bird-origin H5 subtype and 28 N1 subtype viruses were sequenced and compared with sequences available in GenBank by phylogenetic analysis. Both HA and NA were phylogenetically distinct from those for viruses from outside of North America and from those for viruses recovered from mammals. Four of the H5N1 AI viruses were characterized as low pathogenicity by standard in vivo pathotyping tests. One of the H5N1 viruses, A/MuteSwan/MI/451072-2/06, was shown to replicate to low titers in chickens, turkeys, and ducks. However, transmission of A/MuteSwan/MI/451072-2/06 was more efficient among ducks than among chickens or turkeys based on virus shed. The 50% chicken infectious dose for A/MuteSwan/MI/451072-2/06 and three other wild-waterfowl-origin H5 viruses were also determined and were between 105.3 and 107.5 50% egg infective doses. Finally, seven H5 viruses representing different phylogenetic clades were evaluated for their antigenic relatedness by hemagglutination inhibition assay, showing that the antigenic relatedness was largely associated with geographic origin. Overall, the data support the conclusion that North American H5 wild-bird-origin AI viruses are low-pathogenicity wild-bird-adapted viruses and are antigenically and genetically distinct from the highly pathogenic Asian H5N1 virus lineage.

Download Full-text

Tropism and Infectivity of a Seasonal A(H1N1) and a Highly Pathogenic Avian A(H5N1) Influenza Virus in Primary Differentiated Ferret Nasal Epithelial Cell Cultures

Journal of Virology ◽

10.1128/jvi.00080-19 ◽

2019 ◽

Vol 93 (10) ◽

Cited By ~ 6

Author(s):

Hui Zeng ◽

Cynthia S. Goldsmith ◽

Amrita Kumar ◽

Jessica A. Belser ◽

Xiangjie Sun ◽

...

Keyword(s):

Influenza Virus ◽

Virus Infection ◽

Avian Influenza ◽

H5n1 Virus ◽

H1n1 Virus ◽

Influenza Virus Infection ◽

Influenza Viruses ◽

Host Interactions ◽

Culture Model

ABSTRACTFerrets represent an invaluable animal model to study influenza virus pathogenesis and transmission. To further characterize this model, we developed a differentiated primary ferret nasal epithelial cell (FNEC) culture model for investigation of influenza A virus infection and virus-host interactions. This well-differentiated culture consists of various cell types, a mucociliary clearance system, and tight junctions, representing the nasal ciliated pseudostratified respiratory epithelium. Both α2,6-linked and α2,3-linked sialic acid (SA) receptors, which preferentially bind the hemagglutinin (HA) of human and avian influenza viruses, respectively, were detected on the apical surface of the culture with different cellular tropisms. In accordance with the distribution of SA receptors, we observed that a pre-2009 seasonal A(H1N1) virus infected both ciliated and nonciliated cells, whereas a highly pathogenic avian influenza (HPAI) A(H5N1) virus primarily infected nonciliated cells. Transmission electron microscopy revealed that virions were released from or associated with the apical membranes of ciliated, nonciliated, and mucin-secretory goblet cells. Upon infection, the HPAI A(H5N1) virus replicated to titers higher than those of the human A(H1N1) virus at 37°C; however, replication of the A(H5N1) virus was significantly attenuated at 33°C. Furthermore, we found that infection with the A(H5N1) virus induced higher expression levels of immune mediator genes and resulted in more cell damage/loss than with the human A(H1N1) virus. This primary differentiated FNEC culture model, recapitulating the structure of the nasal epithelium, provides a useful model to bridgein vivoandin vitrostudies of cellular tropism, infectivity, and pathogenesis of influenza viruses during the initial stages of infection.IMPORTANCEAlthough ferrets serve as an important model of influenza virus infection, much remains unknown about virus-host interactions in this species at the cellular level. The development of differentiated primary cultures of ferret nasal epithelial cells is an important step toward understanding cellular tropism and the mechanisms of influenza virus infection and replication in the airway milieu of this model. Using lectin staining and microscopy techniques, we characterized the sialic acid receptor distribution and the cellular composition of the culture model. We then evaluated the replication of and immune response to human and avian influenza viruses at relevant physiological temperatures. Our findings offer significant insight into this first line of defense against influenza virus infection and provide a model for the evaluation of emerging influenza viruses in a well-controlledin vitroenvironmental setting.

Download Full-text