scholarly journals Lassa Virus Cell Entry Reveals New Aspects of Virus-Host Cell Interaction

2016 ◽  
Vol 91 (4) ◽  
Author(s):  
Giulia Torriani ◽  
Clara Galan-Navarro ◽  
Stefan Kunz
Keyword(s):  
Host Cell ◽  
Viral Entry ◽  
Molecular Mechanisms ◽  
Cell Interaction ◽  
Cell Entry ◽  
Lassa Virus ◽  
Human Pathogen ◽  
Highly Pathogenic ◽  
Receptor Recognition ◽  
Host Cell Interaction

ABSTRACT Viral entry represents the first step of every viral infection and is a determinant for the host range and disease potential of a virus. Here, we review the latest developments on cell entry of the highly pathogenic Old World arenavirus Lassa virus, providing novel insights into the complex virus-host cell interaction of this important human pathogen. We will cover new discoveries on the molecular mechanisms of receptor recognition, endocytosis, and the use of late endosomal entry factors.

scholarly journals Down-regulation of TUFM impairs host cell interaction and virulence by Paracoccidioides brasiliensis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Caroline Maria Marcos ◽  
Gabrielle Tamer ◽  
Haroldo Cesar de Oliveira ◽  
Patricia Akemi Assato ◽  
Liliana Scorzoni ◽  
...  
Keyword(s):  
Host Cell ◽  
Molecular Mechanisms ◽  
Galleria Mellonella ◽  
Paracoccidioides Brasiliensis ◽  
Cell Interaction ◽  
Yeast Cells ◽  
Dimorphic Fungi ◽  
Phenotypic Differences ◽  
Macrophage Phagocytosis ◽  
Host Cell Interaction

AbstractThe genus Paracoccidioides consist of dimorphic fungi geographically limited to the subtropical regions of Latin America, which are responsible for causing deep systemic mycosis in humans. However, the molecular mechanisms by which Paracoccidioides spp. causes the disease remain poorly understood. Paracoccidioides spp. harbor genes that encode proteins involved in host cell interaction and mitochondrial function, which together are required for pathogenicity and mediate virulence. Previously, we identified TufM (previously known as EF-Tu) in Paracoccidioides brasiliensis (PbTufM) and suggested that it may be involved in the pathogenicity of this fungus. In this study, we examined the effects of downregulating PbTUFM using a silenced strain with a 55% reduction in PbTUFM expression obtained by antisense-RNA (aRNA) technology. Silencing PbTUFM yielded phenotypic differences, such as altered translation elongation, respiratory defects, increased sensitivity of yeast cells to reactive oxygen stress, survival after macrophage phagocytosis, and reduced interaction with pneumocytes. These results were associated with reduced virulence in Galleria mellonella and murine infection models, emphasizing the importance of PbTufM in the full virulence of P. brasiliensis and its potential as a target for antifungal agents against paracoccidioidomycosis.

Bacteriophages Associated with Turkey Coecums in Bluecomb-Infected and Healthy Birds

1969 ◽  
Vol 27 ◽  
pp. 226-227
Author(s):  
A. E. Ritchie
Keyword(s):  
Host Cell ◽  
Causal Relationship ◽  
Cell Cultures ◽  
Cell Interaction ◽  
Etiologic Agent ◽  
Viral Origin ◽  
Intestinal Contents ◽  
Host Cell Interaction

The cause of bluecomb disease in turkeys is unknown. Filtration of infective intestinal contents suggests a viral origin. To date, it has not been possible to isolate the etiologic agent in various cell cultures. The purpose of this work was to characterize as many virus-like entities as were recognizable in intestines of both healthy and bluecomb-infected turkeys. By a comparison of the viral populations it was hoped that some insight might be gained into the cause of this disease. Studies of turkey hemorraghic enteritis by Gross and Moore (Avian Dis. 11: 296-307, 1967) have suggested that a bacteriophage-host cell interaction may bear some causal relationship to that disease.

scholarly journals Why Does SARS-CoV-2 Infection Induce Autoantibody Production?

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 380
Author(s):  
Ales Macela ◽  
Klara Kubelkova
Keyword(s):  
Immune Response ◽  
Immune System ◽  
Host Cell ◽  
Critical Role ◽  
Cell Interaction ◽  
Immune Recognition ◽  
Autoantibody Production ◽  
Host Cell Interaction ◽  
Primary Virus

SARS-CoV-2 infection induces the production of autoantibodies, which is significantly associated with complications during hospitalization and a more severe prognosis in COVID-19 patients. Such a response of the patient’s immune system may reflect (1) the dysregulation of the immune response or (2) it may be an attempt to regulate itself in situations where the non-infectious self poses a greater threat than the infectious non-self. Of significance may be the primary virus-host cell interaction where the surface-bound ACE2 ectoenzyme plays a critical role. Here, we present a brief analysis of recent findings concerning the immune recognition of SARS-CoV-2, which, we believe, favors the second possibility as the underlying reason for the production of autoantibodies during COVID-19.

Kinetics and pattern of organelle exocytosis duringToxoplasma gondii/host-cell interaction

1993 ◽  
Vol 79 (5) ◽  
pp. 402-408 ◽  
Author(s):  
Jean Fran�ois Dubremetz ◽  
Abderrahim Achbarou ◽  
David Bermudes ◽  
Keith A. Joiner
Keyword(s):  
Host Cell ◽  
Cell Interaction ◽  
Host Cell Interaction

scholarly journals Significance of thiol-disulfide balance in SARS-CoV-2 infection

2021 ◽  
Vol 72 (3) ◽  
pp. 30-36
Author(s):  
Tatjana Simić
Keyword(s):  
Cell Surface ◽  
Host Cell ◽  
Protein Interactions ◽  
Viral Entry ◽  
Molecular Mechanisms ◽  
Alkylating Agents ◽  
Protein S ◽  
Protein Protein Interactions ◽  
Virus Surface ◽  
Host Cell Surface

Studies of the molecular mechanisms regarding interaction of different viruses with receptors on the host cell surface have shown that the viral entry depends on the specific relationship between free thiol (SH) groups and disulfides on the virus surface, as well as the thiol disulfide balance on the host cell surface. The presence of oxidizing compounds or alkylating agents, which disturb the thiol-disulfide balance on the surface of the virus, can also affect its infectious potential. Disturbed thiol-disulfide balance may also influence protein-protein interactions between SARS-CoV-2 protein S and ACE2 receptors of the host cell. This review presents the basic mechanisms of maintaining intracellular and extracellular thiol disulfide balance and previous experimental and clinical evidence in favor of impaired balance in SARS-CoV-2 infection. Besides, the results of the clinical application or experimental analysis of compounds that induce changes in the thiol disulfide balance towards reduction of disulfide bridges in proteins of interest in COVID-19 infection are presented.

scholarly journals Using proteomics to identify host cell interaction partners for VgrG and IglJ

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Magdalena Proksova ◽  
Helena Rehulkova ◽  
Pavel Rehulka ◽  
Claire Lays ◽  
Juraj Lenco ◽  
...  
Keyword(s):  
Host Cell ◽  
Cell Interaction ◽  
Interaction Partners ◽  
Host Cell Interaction

scholarly journals The Cell Wall Lipid PDIM Contributes to Phagosomal Escape and Host Cell Exit of Mycobacterium tuberculosis

mBio ◽  
2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Jeff Quigley ◽  
V. Keith Hughitt ◽  
Carlos A. Velikovsky ◽  
Roy A. Mariuzza ◽  
Najib M. El-Sayed ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Tuberculosis ◽  
Host Cell ◽  
Molecular Mechanisms ◽  
Transcriptional Repressor ◽  
Cell Manipulation ◽  
Human Pathogen ◽  
Cell Necrosis ◽  
Unique Cell ◽  
Intracellular Vacuole

ABSTRACT The cell wall of Mycobacterium tuberculosis is composed of unique lipids that are important for pathogenesis. Indeed, the first-ever genetic screen in M. tuberculosis identified genes involved in the biosynthesis and transport of the cell wall lipid PDIM (phthiocerol dimycocerosates) as crucial for the survival of M. tuberculosis in mice. Here we show evidence for a novel molecular mechanism of the PDIM-mediated virulence in M. tuberculosis. We characterized the DNA interaction and the regulon of Rv3167c, a transcriptional repressor that is involved in virulence regulation of M. tuberculosis, and discovered that it controls the PDIM operon. A loss-of-function genetic approach showed that PDIM levels directly correlate with the capacity of M. tuberculosis to escape the phagosome and induce host cell necrosis and macroautophagy. In conclusion, our study attributes a novel role of the cell wall lipid PDIM in intracellular host cell modulation, which is important for host cell exit and dissemination of M. tuberculosis. IMPORTANCE Mycobacterium tuberculosis is a major human pathogen that has coevolved with its host for thousands of years. The complex and unique cell wall of M. tuberculosis contains the lipid PDIM (phthiocerol dimycocerosates), which is crucial for virulence of the bacterium, but its function is not well understood. Here we show that PDIM expression by M. tuberculosis is negatively regulated by a novel transcriptional repressor, Rv3167c. In addition, we discovered that the escape of M. tuberculosis from its intracellular vacuole was greatly augmented by the presence of PDIM. The increased release of M. tuberculosis into the cytosol led to increased host cell necrosis. The discovery of a link between the cell wall lipid PDIM and a major pathogenesis pathway of M. tuberculosis provides important insights into the molecular mechanisms of host cell manipulation by M. tuberculosis. IMPORTANCE Mycobacterium tuberculosis is a major human pathogen that has coevolved with its host for thousands of years. The complex and unique cell wall of M. tuberculosis contains the lipid PDIM (phthiocerol dimycocerosates), which is crucial for virulence of the bacterium, but its function is not well understood. Here we show that PDIM expression by M. tuberculosis is negatively regulated by a novel transcriptional repressor, Rv3167c. In addition, we discovered that the escape of M. tuberculosis from its intracellular vacuole was greatly augmented by the presence of PDIM. The increased release of M. tuberculosis into the cytosol led to increased host cell necrosis. The discovery of a link between the cell wall lipid PDIM and a major pathogenesis pathway of M. tuberculosis provides important insights into the molecular mechanisms of host cell manipulation by M. tuberculosis.

scholarly journals Role of LAMP1 Binding and pH Sensing by the Spike Complex of Lassa Virus

2016 ◽  
Vol 90 (22) ◽  
pp. 10329-10338 ◽  
Author(s):  
Hadas Cohen-Dvashi ◽  
Hadar Israeli ◽  
Orly Shani ◽  
Aliza Katz ◽  
Ron Diskin
Keyword(s):  
Membrane Fusion ◽  
Molecular Mechanisms ◽  
Cell Entry ◽  
Lassa Virus ◽  
Dependent Manner ◽  
Acidic Ph ◽  
Ph Sensing ◽  
Positively Charged

ABSTRACTTo effectively infect cells, Lassa virus needs to switch in an endosomal compartment from its primary receptor, α-dystroglycan, to a protein termed LAMP1. A unique histidine triad on the surface of the receptor-binding domain from the glycoprotein spike complex of Lassa virus is important for LAMP1 binding. Here we investigate mutated spikes that have an impaired ability to interact with LAMP1 and show that although LAMP1 is important for efficient infectivity, it is not required for spike-mediated membrane fusionper se. Our studies reveal important regulatory roles for histidines from the triad in sensing acidic pH and preventing premature spike triggering. We further show that LAMP1 requires a positively charged His230 residue to engage with the spike complex and that LAMP1 binding promotes membrane fusion. These results elucidate the molecular role of LAMP1 binding during Lassa virus cell entry and provide new insights into how pH is sensed by the spike.IMPORTANCELassa virus is a devastating disease-causing agent in West Africa, with a significant yearly death toll and severe long-term complications associated with its infection in survivors. In recent years, we learned that Lassa virus needs to switch receptors in a pH-dependent manner to efficiently infect cells, but neither the molecular mechanisms that allow switching nor the actual effects of switching were known. Here we investigate the activity of the viral spike complex after abrogation of its ability to switch receptors. These studies inform us about the role of switching receptors and provide new insights into how the spike senses acidic pH.

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