scholarly journals Selection and Characterization of ssDNA Aptamers Targeting Largemouth Bass Virus Infected Cells With Antiviral Activities

2021 ◽  
Vol 12 ◽  
Author(s):  
Qing Yu ◽  
Mengmeng Li ◽  
Mingzhu Liu ◽  
Shuaishuai Huang ◽  
Gaoxue Wang ◽  
...  
Keyword(s):  
Largemouth Bass ◽  
Dissociation Constants ◽  
High Sensitivity ◽  
Molecular Probes ◽  
Host Cells ◽  
Target Cells ◽  
Antiviral Activities ◽  
Infected Cells

Largemouth bass virus (LMBV) is one of the most devastating viral pathogens in farmed Largemouth bass. Aptamers are novel molecule probes and have been widely applied in the field of efficient therapeutic and diagnostic agents development. LMBV-infected fathead minnow cells (LMBV-FHM) served as target cells in this study, and three DNA aptamers (LBVA1, LBVA2, and LBVA3) were generated against target cells by SELEX technology. The selected aptamers could specifically bind to LMBV-FHM cells, with rather high calculated dissociation constants (Kd) of 890.09, 517.22, and 249.31 nM for aptamers LBVA1, LBVA2, and LBVA3, respectively. Three aptamers displayed efficient antiviral activities in vitro. It indicates that the selected aptamers have great potentials in developing efficient anti-viruses treatments. The targets of aptamers LBVA1, LBVA2, and LBVA3 could be membrane proteins on host cells. The targets of aptamers (LBVA1, LBVA2, and LBVA3) come out on the cells surface at 8, 10, 8 h post-infection. As novel molecular probes for accurate recognition, aptamer LBVA3 could detect LMBV infection in vitro and in vivo, it indicates that the selected aptamers could be applied in the development of rapid detective technologies, which are characterized by high sensitivity, accuracy, and easy operation.

scholarly journals In vivo analysis of influenza A mRNA secondary structures identifies critical regulatory motifs

2019 ◽  
Vol 47 (13) ◽  
pp. 7003-7017 ◽  
Author(s):  
Lisa Marie Simon ◽  
Edoardo Morandi ◽  
Anna Luganini ◽  
Giorgio Gribaudo ◽  
Luis Martinez-Sobrido ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Influenza A ◽  
Host Cells ◽  
Messenger Rnas ◽  
Infected Cells ◽  
In Vivo Analysis ◽  
First Time ◽  
Negative Sense

AbstractThe influenza A virus (IAV) is a continuous health threat to humans as well as animals due to its recurring epidemics and pandemics. The IAV genome is segmented and the eight negative-sense viral RNAs (vRNAs) are transcribed into positive sense complementary RNAs (cRNAs) and viral messenger RNAs (mRNAs) inside infected host cells. A role for the secondary structure of IAV mRNAs has been hypothesized and debated for many years, but knowledge on the structure mRNAs adopt in vivo is currently missing. Here we solve, for the first time, the in vivo secondary structure of IAV mRNAs in living infected cells. We demonstrate that, compared to the in vitro refolded structure, in vivo IAV mRNAs are less structured but exhibit specific locally stable elements. Moreover, we show that the targeted disruption of these high-confidence structured domains results in an extraordinary attenuation of IAV replicative capacity. Collectively, our data provide the first comprehensive map of the in vivo structural landscape of IAV mRNAs, hence providing the means for the development of new RNA-targeted antivirals.

scholarly journals How Many Human Immunodeficiency Virus Type 1-Infected Target Cells Can a Cytotoxic T-Lymphocyte Kill?

2005 ◽  
Vol 79 (21) ◽  
pp. 13579-13586 ◽  
Author(s):  
W. David Wick ◽  
Otto O. Yang ◽  
Lawrence Corey ◽  
Steven G. Self
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Target Cells ◽  
Immunodeficiency Virus ◽  
Infected Cells ◽  
Hiv 1

ABSTRACT The antiviral role of CD8+ cytotoxic T lymphocytes (CTLs) in human immunodeficiency virus type 1 (HIV-1) infection is poorly understood. Specifically, the degree to which CTLs reduce viral replication by killing HIV-1-infected cells in vivo is not known. Here we employ mathematical models of the infection process and CTL action to estimate the rate that CTLs can kill HIV-1-infected cells from in vitro and in vivo data. Our estimates, which are surprisingly consistent considering the disparities between the two experimental systems, demonstrate that on average CTLs can kill from 0.7 to 3 infected target cells per day, with the variability in this figure due to epitope specificity or other factors. These results are compatible with the observed decline in viremia after primary infection being primarily a consequence of CTL activity and have interesting implications for vaccine design.

scholarly journals Deubiquitinating Function of Adenovirus Proteinase

2002 ◽  
Vol 76 (12) ◽  
pp. 6323-6331 ◽  
Author(s):  
Maxim Y. Balakirev ◽  
Michel Jaquinod ◽  
Arthur L. Haas ◽  
Jadwiga Chroboczek
Keyword(s):  
Structural Model ◽  
Proteolytic Processing ◽  
Host Cells ◽  
Cellular Proteins ◽  
Viral Gene ◽  
Cellular Processes ◽  
Infected Cells ◽  
Substrate Binding Sites

ABSTRACT The invasion strategy of many viruses involves the synthesis of viral gene products that mimic the functions of the cellular proteins and thus interfere with the key cellular processes. Here we show that adenovirus infection is accompanied by an increased ubiquitin-cleaving (deubiquitinating) activity in the host cells. Affinity chromatography on ubiquitin aldehyde (Ubal), which was designed to identify the deubiquitinating proteases, revealed the presence of adenovirus L3 23K proteinase (Avp) in the eluate from adenovirus-infected cells. This proteinase is known to be necessary for the processing of viral precursor proteins during virion maturation. We show here that in vivo Avp deubiquitinates a number of cellular proteins. Analysis of the substrate specificity of Avp in vitro demonstrated that the protein deubiquitination by this enzyme could be as efficient as proteolytic processing of viral proteins. The structural model of the Ubal-Avp interaction revealed some similarity between S1-S4 substrate binding sites of Avp and ubiquitin hydrolases. These results may reflect the acquisition of an advantageous property by adenovirus and may indicate the importance of ubiquitin pathways in viral infection.

scholarly journals The Triad Hsp60-miRNAs-Extracellular Vesicles in Brain Tumors: Assessing Its Components for Understanding Tumorigenesis and Monitoring Patients

2021 ◽  
Vol 11 (6) ◽  
pp. 2867
Author(s):  
Francesca Graziano ◽  
Domenico Gerardo Iacopino ◽  
Giacomo Cammarata ◽  
Gianluca Scalia ◽  
Claudia Campanella ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Extracellular Vesicles ◽  
Current Knowledge ◽  
Disease Status ◽  
Experimental Models ◽  
Host Cells ◽  
Target Cells ◽  
Original Cell

Brain tumors have a poor prognosis and progress must be made for developing efficacious treatments, but for this to occur their biology and interaction with the host must be elucidated beyond current knowledge. What has been learned from other tumors may be applied to study brain tumors, for example, the role of Hsp60, miRNAs, and extracellular vesicles (EVs) in the mechanisms of cell proliferation and dissemination, and resistance to immune attack and anticancer drugs. It has been established that Hsp60 increases in cancer cells, in which it occurs not only in the mitochondria but also in the cytosol and plasma-cell membrane and it is released in EVs into the extracellular space and in circulation. There is evidence suggesting that these EVs interact with cells near and far from their original cell and that this interaction has an impact on the functions of the target cell. It is assumed that this crosstalk between cancer and host cells favors carcinogenesis in various ways. We, therefore, propose to study the triad Hsp60-related miRNAs-EVs in brain tumors and have standardized methods for the purpose. These revealed that EVs with Hsp60 and related miRNAs increase in patients’ blood in a manner that reflects disease status. The means are now available to monitor brain tumor patients by measuring the triad and to dissect its effects on target cells in vitro, and in experimental models in vivo.

scholarly journals Human MAIT cells respond to and suppress HIV-1

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Chansavath Phetsouphanh ◽  
Prabhjeet Phalora ◽  
Carl-Philipp Hackstein ◽  
John Thornhill ◽  
Mee Ling Munier ◽  
...  
Keyword(s):  
Protective Role ◽  
Target Cells ◽  
Restriction Factors ◽  
Innate And Adaptive Immunity ◽  
Mait Cells ◽  
Infected Cells ◽  
Hiv 1 ◽  
Stimulation Of

Human MAIT cells sit at the interface between innate and adaptive immunity, are polyfunctional and are capable of killing pathogen infected cells via recognition of the Class IB molecule MR1. MAIT cells have recently been shown to possess an antiviral protective role in vivo and we therefore sought to explore this in relation to HIV-1 infection. There was marked activation of MAIT cells in vivo in HIV-1 infected individuals, which decreased following ART. Stimulation of THP1 monocytes with R5 tropic HIVBAL potently activated MAIT cells in vitro. This activation was dependent on IL-12 and IL-18 but was independent of the TCR. Upon activation, MAIT cells were able to up-regulate granzyme B, IFNg and HIV-1 restriction factors CCL3, 4 and 5. Restriction factors produced by MAIT cells inhibited HIV-1 infection of primary PBMCs and immortalized target cells in vitro. These data reveal MAIT cells to be an additional T cell population responding to HIV-1, with a potentially important role in controlling viral replication at mucosal sites.

scholarly journals A pomegranate peel extract as inhibitor of SARS-CoV-2 Spike binding to human ACE2 (in vitro): a promising source of novel antiviral drugs

2020 ◽  
Author(s):  
Annalisa Tito ◽  
Antonio Colantuono ◽  
Luciano Pirone ◽  
Emilia Pedone ◽  
Daniela Intartaglia ◽  
...  
Keyword(s):  
Host Cells ◽  
Pomegranate Peel ◽  
Angiotensin Converting Enzyme 2 ◽  
Innovative Therapies ◽  
Antiviral Activities ◽  
Pomegranate Peel Extract ◽  
Promising Source ◽  
Peel Extract

AbstractPlant extracts are rich in bioactive compounds, such as polyphenols, sesquiterpenes and triterpenes, with potential antiviral activities. As the dramatic outbreak of the pandemic COVID-19, caused by the SARS-CoV-2 virus, thousands of scientists are working tirelessly trying to understand the biology of this new virus and the disease pathophysiology, with the main goal to discover effective preventive treatments and therapeutic agents. Plant-derived secondary metabolites may play key roles in preventing and counteracting the rapid spread of SARS-CoV-2 infections by inhibiting the activity of several viral proteins, in particular those involved in the virus entry into the host cells and its replication. In this study, by using different in vitro approaches, we uncovered the role of a pomegranate peel extract in attenuating the interaction between the SARS-CoV-2 Spike glycoprotein and the human Angiotensin-Converting Enzyme 2 (ACE2) receptor, and in inhibiting the activity of the virus 3CL protease. Although further studies will be determinant to assess the efficacy of this extract in vivo, our results open up new promising opportunities to employ natural extracts for the development of effective and innovative therapies in the fight against SARS-CoV-2.

scholarly journals In Vitro Activities of Azithromycin and Ofloxacin againstChlamydia pneumoniae in a Continuous-Infection Model

1999 ◽  
Vol 43 (9) ◽  
pp. 2268-2272 ◽  
Author(s):  
Andrei Kutlin ◽  
Patricia M. Roblin ◽  
Margaret R. Hammerschlag
Keyword(s):  
Chlamydia Pneumoniae ◽  
In Vitro Study ◽  
Community Acquired Pneumonia ◽  
Host Cells ◽  
Infection Model ◽  
Chronic Infections ◽  
Adults And Children ◽  
Infected Cells

ABSTRACT Chlamydia pneumoniae is a well-established cause of community-acquired pneumonia and bronchitis in adults and children. Chronic infections with C. pneumoniae have been implicated in the development of atherosclerosis and other diseases in humans. Methods currently used for the culture and propagation ofC. pneumoniae are not analogous to the infection as it occurs in vivo. We have established a model of continuous C. pneumoniae infection in vitro. HEp-2 cells inoculated with CM-1 and TW-183 strains have been persistently infected for periods of over 1.5 and 2 years, respectively. The cultures were maintained without centrifugation or the addition of cycloheximide, fresh host cells, or chlamydia. We observed cycles of host cell lysis, detachment, and regrowth with both strains of C. pneumoniae. Continuous C. pneumoniae infections may more closely resemble the actual events as they occur in vivo and, therefore, may be a better model for the in vitro study of C. pneumoniae infection. When we used continuously infected cells to determine the effects of azithromycin and ofloxacin on C. pneumoniae propagation in vitro, we found that both drugs reduced but did not completely eliminate the organism. This may be an important observation, as the failure of antibiotic therapy against C. pneumoniae infection in humans has been described.

scholarly journals Pomegranate Peel Extract as an Inhibitor of SARS-CoV-2 Spike Binding to Human ACE2 Receptor (in vitro): A Promising Source of Novel Antiviral Drugs

2021 ◽  
Vol 9 ◽  
Author(s):  
Annalisa Tito ◽  
Antonio Colantuono ◽  
Luciano Pirone ◽  
Emilia Pedone ◽  
Daniela Intartaglia ◽  
...  
Keyword(s):  
Host Cells ◽  
Pomegranate Peel ◽  
Angiotensin Converting Enzyme 2 ◽  
Innovative Therapies ◽  
Antiviral Activities ◽  
Pomegranate Peel Extract ◽  
Promising Source ◽  
Peel Extract

Plant extracts are rich in bioactive compounds, such as polyphenols, sesquiterpenes, and triterpenes, which potentially have antiviral activities. As a consequence of the coronavirus disease 2019 pandemic, caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus, thousands of scientists have been working tirelessly trying to understand the biology of this new virus and the disease pathophysiology, with the main goal of discovering effective preventive treatments and therapeutic agents. Plant-derived secondary metabolites may play key roles in preventing and counteracting the rapid spread of SARS-CoV-2 infections by inhibiting the activity of several viral proteins, in particular those involved in the virus entry into the host cells and its replication. Using in vitro approaches, we investigated the role of a pomegranate peel extract (PPE) in attenuating the interaction between the SARS-CoV-2 Spike glycoprotein and the human angiotensin-converting enzyme 2 receptor, and on the activity of the virus 3CL protease. Although further studies will be determinant to assess the efficacy of this extract in vivo, our results opened new promising opportunities to employ natural extracts for the development of effective and innovative therapies in the fight against SARS-CoV-2.

scholarly journals Intracellular passage triggers a molecular response in Brucella abortus that increases its infectiousness

2021 ◽  
Author(s):  
Pamela Altamirano-Silva ◽  
Marlen Cordero-Serrano ◽  
Joselyn Méndez-Montoya ◽  
Carlos Chacón-Díaz ◽  
Caterina Guzmán-Verri ◽  
...  
Keyword(s):  
Brucella Abortus ◽  
Host Cells ◽  
Target Cells ◽  
Molecular Response ◽  
Two Component System ◽  
New Host ◽  
Type Iv ◽  
Infected Cells ◽  
Early Interaction

Brucella abortus is a facultative extracellular-intracellular pathogen that encounters a diversity of environments within the host cell. We report that bacteria extracted from infected cells at late stages (48 h post-infection) of the intracellular life cycle significantly increase their ability to multiply in new target cells. This increase depends on early interaction with the cell surface since bacteria become more adherent and penetrate more efficiently as compared to in vitro grown bacteria. At this late stage of infection, the bacterium locates within an autophagosome-like compartment, facing starving and acidic conditions. At this point, the two-component system BvrR/BvrS becomes activated, and the expression of the transcriptional regulator VjbR and the type IV secretion system VirB increased. Using bafilomycin to inhibit BvrR/BvrS activation and specific inhibitors for VjbR and VirB we showed that the BvrR/BvrS and VjbR systems correlate with the increased interaction with new host cells while the VirB system does not. Bacteria released from infected cells under natural conditions displayed the same phenotype as intracellular bacteria. We propose a model in which the B. abortus BvrR/BvrS system senses the transition from its replicative niche at the endoplasmic reticulum to the autophagosome-like exit compartment. This activation leads to the expression of VirB participating in the release of the bacterium from the cells and an increase in VjbR expression that results in a more efficient interaction with new host cells.

scholarly journals Siglec-9 defines and restrains a natural killer subpopulation highly cytotoxic to HIV-infected cells

2021 ◽  
Vol 17 (11) ◽  
pp. e1010034
Author(s):  
Opeyemi S. Adeniji ◽  
Leticia Kuri-Cervantes ◽  
Chenfei Yu ◽  
Ziyang Xu ◽  
Michelle Ho ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Nk Cells ◽  
Natural Killer ◽  
Immune Evasion ◽  
Neutralizing Antibodies ◽  
Target Cells ◽  
Inhibitory Receptor ◽  
Infected Cells

Siglec-9 is an MHC-independent inhibitory receptor expressed on a subset of natural killer (NK) cells. Siglec-9 restrains NK cytotoxicity by binding to sialoglycans (sialic acid-containing glycans) on target cells. Despite the importance of Siglec-9 interactions in tumor immune evasion, their role as an immune evasion mechanism during HIV infection has not been investigated. Using in vivo phenotypic analyses, we found that Siglec-9+ CD56dim NK cells, during HIV infection, exhibit an activated phenotype with higher expression of activating receptors and markers (NKp30, CD38, CD16, DNAM-1, perforin) and lower expression of the inhibitory receptor NKG2A, compared to Siglec-9- CD56dim NK cells. We also found that levels of Siglec-9+ CD56dim NK cells inversely correlate with viral load during viremic infection and CD4+ T cell-associated HIV DNA during suppressed infection. Using in vitro cytotoxicity assays, we confirmed that Siglec-9+ NK cells exhibit higher cytotoxicity towards HIV-infected cells compared to Siglec-9- NK cells. These data are consistent with the notion that Siglec-9+ NK cells are highly cytotoxic against HIV-infected cells. However, blocking Siglec-9 enhanced NK cells’ ability to lyse HIV-infected cells, consistent with the known inhibitory function of the Siglec-9 molecule. Together, these data support a model in which the Siglec-9+ CD56dim NK subpopulation is highly cytotoxic against HIV-infected cells even whilst being restrained by the inhibitory effects of Siglec-9. To harness the cytotoxic capacity of the Siglec-9+ NK subpopulation, which is dampened by Siglec-9, we developed a proof-of-concept approach to selectively disrupt Siglec/sialoglycan interactions between NK and HIV-infected cells. We achieved this goal by conjugating Sialidase to several HIV broadly neutralizing antibodies. These conjugates selectively desialylated HIV-infected cells and enhanced NK cells’ capacity to kill them. In summary, we identified a novel, glycan-based interaction that may contribute to HIV-infected cells’ ability to evade NK immunosurveillance and developed an approach to break this interaction.

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